ABSTRACT
Objective: To explore the effects of three-dimensional (3D) bioprinting gelatin methacrylamide (GelMA) hydrogel loaded with nano silver on full-thickness skin defect wounds in rats. Methods: The experimental research method was adopted. The morphology, particle diameter, and distribution of silver nanoparticles in nano silver solution with different mass concentrations and the pore structure of silver-containing GelMA hydrogel with different final mass fractions of GelMA were observed by scanning electron microscope and the pore size was calculated. On treatment day 1, 3, 7, and 14, the concentration of nano silver released from the hydrogel containing GelMA with final mass fraction of 15% and nano silver with final mass concentration of 10 mg/L was detected by mass spectrometer. At 24 h of culture, the diameters of inhibition zone of GelMA hydrogel containing final mass concentration of 0 (no nano silver), 25, 50, and 100 mg/L nano silver against Staphylococcus aureus and Escherichia coli were detected. Fibroblasts (Fbs) and adipose stem cells (ASCs) were isolated respectively by enzymatic digestion using the discarded prepuce after circumcision from a 5-year-old healthy boy who was treated in the Department of Urology of the Second Affiliated Hospital of Zhejiang University School of Medicine in July 2020, and the discarded fat tissue after liposuction from a 23-year-old healthy woman who was treated in the Department of Plastic Surgery of the Hospital in July 2020. The Fbs were divided into blank control group (culture medium only), 2 mg/L nano sliver group, 5 mg/L nano sliver group, 10 mg/L nano sliver group, 25 mg/L nano sliver group, and 50 mg/L nano sliver group, which were added with the corresponding final mass concentrations of nano sliver solution, respectively. At 48 h of culture, the Fb proliferation viability was detected by cell counting kit 8 method. The Fbs were divided into 0 mg/L silver-containing GelMA hydrogel group, 10 mg/L silver-containing GelMA hydrogel group, 50 mg/L silver-containing GelMA hydrogel group, and 100 mg/L silver-containing GelMA hydrogel group and then were correspondingly treated. On culture day 1, 3, and 7, the Fb proliferation viability was detected as before. The ASCs were mixed into GelMA hydrogel and divided into 3D bioprinting group and non-printing group. On culture day 1, 3, and 7, the ASC proliferation viability was detected as before and cell growth was observed by live/dead cell fluorescence staining. The sample numbers in the above experiments were all 3. Four full-thickness skin defect wounds were produced on the back of 18 male Sprague-Dawley rats aged 4 to 6 weeks. The wounds were divided into hydrogel alone group, hydrogel/nano sliver group, hydrogel scaffold/nano sliver group, and hydrogel scaffold/nano sliver/ASC group, and transplanted with the corresponding scaffolds, respectively. On post injury day (PID) 4, 7, 14, and 21, the wound healing was observed and the wound healing rate was calculated (n=6). On PID 7 and 14, histopathological changes of wounds were observed by hematoxylin eosin staining (n=6). On PID 21, collagen deposition of wounds was observed by Masson staining (n=3). Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, Bonferroni correction, and independent sample t test. Results: The sliver nano particles in nano silver solution with different mass concentrations were all round, in scattered distribution and uniform in size. The silver-containing GelMA hydrogels with different final mass fractions of GelMA all showed pore structures of different sizes and interconnections. The pore size of silver-containing GelMA hydrogel with 10% final mass fraction was significantly larger than that of silver-containing GelMA hydrogels with 15% and 20% final mass fractions (with P values both below 0.05). On treatment day 1, 3, and 7, the concentration of nano silver released from silver-containing GelMA hydrogel in vitro showed a relatively flat trend. On treatment day 14, the concentration of released nano silver in vitro increased rapidly. At 24 h of culture, the diameters of inhibition zone of GelMA hydrogel containing 0, 25, 50, and 100 mg/L nano silver against Staphylococcus aureus and Escherichia coli were 0, 0, 0.7, and 2.1 mm and 0, 1.4, 3.2, and 3.3 mm, respectively. At 48 h of culture, the proliferation activity of Fbs in 2 mg/L nano silver group and 5 mg/L nano silver group was both significantly higher than that in blank control group (P<0.05), and the proliferation activity of Fbs in 10 mg/L nano silver group, 25 mg/L nano silver group, and 50 mg/L nano silver group was all significantly lower than that in blank control group (P<0.05). Compared with the that of Fbs in 0 mg/L silver-containing GelMA hydrogel group, the proliferation activity of Fbs in 50 mg/L silver-containing GelMA hydrogel group and 100 mg/L silver-containing GelMA hydrogel group was all significantly decreased on culture day 1 (P<0.05); the proliferation activity of Fbs in 50 mg/L silver-containing GelMA hydrogel group was significantly increased (P<0.05), while the proliferation activity of Fbs in 100 mg/L silver-containing GelMA hydrogel group was significantly decreased on culture day 3 (P<0.05); the proliferation activity of Fbs in 100 mg/L silver-containing GelMA hydrogel group was significantly decreased on culture day 7 (P<0.05). The proliferation activity of ASCs in 3D bioprinting group show no statistically significant differences to that in non-printing group on culture day 1 (P>0.05). The proliferation activity of ASCs in 3D bioprinting group was significantly higher than that in non-printing group on culture day 3 and 7 (with t values of 21.50 and 12.95, respectively, P<0.05). On culture day 1, the number of dead ASCs in 3D bioprinting group was slightly more than that in non-printing group. On culture day 3 and 5, the majority of ASCs in 3D bioprinting group and non-printing group were living cells. On PID 4, the wounds of rats in hydrogel alone group and hydrogel/nano sliver group had more exudation, and the wounds of rats in hydrogel scaffold/nano sliver group and hydrogel scaffold/nano sliver/ASC group were dry without obvious signs of infection. On PID 7, there was still a small amount of exudation on the wounds of rats in hydrogel alone group and hydrogel/nano sliver group, while the wounds of rats in hydrogel scaffold/nano sliver group and hydrogel scaffold/nano sliver/ASC group were dry and scabbed. On PID 14, the hydrogels on the wound surface of rats in the four groups all fell off. On PID 21, a small area of wounds remained unhealed in hydrogel alone group. On PID 4 and 7, the wound healing rates of rats in hydrogel scaffold/nano sliver/ASC group were significantly higher than those of the other three groups (P<0.05). On PID 14, the wound healing rate of rats in hydrogel scaffold/nano sliver/ASC group was significantly higher than the wound healing rates in hydrogel alone group and hydrogel/nano sliver group (all P<0.05). On PID 21, the wound healing rate of rats in hydrogel alone group was significantly lower than that in hydrogel scaffold/nano sliver/ASC group (P<0.05). On PID 7, the hydrogels on the wound surface of rats in the four groups remained in place; on PID 14, the hydrogel in hydrogel alone group was separated from the wounds of rats, while some hydrogels still existed in the new tissue of the wounds of rats in the other three groups. On PID 21, the collagen arrangement in the wounds of rats in hydrogel alone group was out of order, while the collagen arrangement in the wounds of rats in hydrogel/nano sliver group, and hydrogel scaffold/nano sliver/ASC group was relatively orderly. Conclusions: Silver-containing GelMA hydrogel has good biocompatibility and antibacterial properties. Its three-dimensional bioprinted double-layer structure can better integrate with new formed tissue in the full-thickness skin defect wounds in rats and promote wound healing.
Subject(s)
Male , Rats , Animals , Humans , Hydrogels/pharmacology , Bioprinting , Metal Nanoparticles , Rats, Sprague-Dawley , Silver/pharmacology , Soft Tissue Injuries , Anti-Bacterial AgentsABSTRACT
Silver nanoparticles (AgNPs) is known as one of the most valuable metal nanoparticles in antibacterial and anticancer application. AgNPs-resistant bacteria has been documented, but it is unclear whether cancer cells can also escape the anti-cancer effect of AgNPs. In this study, we aimed to investigate this phenomenon and its underlying mechanism. The antibacterial activity and cytotoxicity of AgNPs were measured in the presence of HeLa cell metabolites. The status of AgNPs in the system associated with metabolites were characterized by UV-Vis, Zetasizer Nano ZS, and transmission electron microscopy. Non-targeted metabolomics was used to reveal the metabolites components that bind with AgNPs. HeLa cells were injected intraperitoneally to establish the tumor-bearing mice model, and the stability of AgNPs in mice serum was analyzed. The results manifested that HeLa cell metabolites inhibited the anticancer and antibacterial effects of AgNPs in a dose-dependent manner by causing AgNPs aggregation. Effective metabolites that inhibited the biological activity of AgNPs were stable in 100 ℃, insoluble in chloroform, containing sulfur elements, and had a molecular weight less than 1 kDa in molecular weight. There were 115 compounds bound with AgNPs. In vitro experiments showed that AgNPs aggregation occurred only when the concentration of α-ketoglutarate (AKG) and glutathione (GSH) together reached a certain threshold. Interestingly, the concentration of AKG and GSH in HeLa cellular metabolites was 10 and 6 times higher than that in normal cervical epithelial cells, respectively, which explained why the threshold was reached. Furthermore, the stability of AgNPs in the serum of tumor-bearing mice decreased by 20% (P < 0.05) compared with the healthy mice. In conclusion, our study demonstrates that HeLa cells escaped the anti-cancer effect of AgNPs through the synergistic effect of AKG and GSH, suggesting the need to develop strategies to overcome this limitation.
Subject(s)
Humans , Animals , Mice , HeLa Cells , Silver/pharmacology , Ketoglutaric Acids/pharmacology , Metal Nanoparticles , Anti-Bacterial Agents/pharmacology , Glutathione , Microbial Sensitivity TestsABSTRACT
The Silver nanoparticle (AgNPs) have received attention for their antiviral potential against SARS-CoV-2. The objective is to conduct a scope review and map the scientific evidence on the use of AgNPs in mouthwashes as an adjunct in decreasing the viral load in the oral cavity of patients with SARS-CoV-2. A search was performed in the PubMed, Medline, Scielo databases, and a manual search in the reference lists, following the standards of the Joanna Briggs Institute for Scoping Review without restriction of year, language or sample size. Thus, 14 articles were included, where they researched the use of AgNPs with antiviral effect against SARS-CoV-2, mouthwashes for SARS-CoV-2 and AgNPs as mouthwashes. We can suggest that AgNPs are likely antiviral therapies for SARS-CoV-2 and its use in mouthwashes associated with other therapies are promising strands for decreasing viral load and infection by the vírus (AU)
As nanopartículas de prata (AgNPs) têm recebido atenção por seu potencial antiviral no SARS-CoV-2. O objetivo deste trabalho é realizar uma revisão de escopo e mapear as evidências científicas sobre o uso de AgNPs em bochechos como adjuvante na diminuição da carga viral na cavidade oral de pacientes com SARS-CoV-2. Foi realizada busca nas bases de dados PubMed, Medline, Scielo e busca manual nas listas de referências, seguindo os padrões do Joanna Briggs Institute for Scoping Review sem restrição de ano, idioma ou tamanho da amostra. Assim, foram incluídos 14 artigos, onde pesquisaram o uso de AgNPs com efeito antiviral contra SARS-CoV-2, enxaguatórios bucais para SARS-CoV-2 e AgNPs como enxaguatórios bucais, vertentes promissoras para diminuição da carga viral e infecção pelo vírus.(AU)
Subject(s)
Silver , Nanoparticles , SARS-CoV-2 , COVID-19 , MouthwashesABSTRACT
Abstract Several species of thymus have therapeutic properties, so they are used in traditional medicine. In this work was carried out to synthesize Thymus vulgalis silver nanoparticles (TSNPS) and evaluate antioxidant and antimicrobial activities of TSNPS and T. vulgalis essential oil extract (TEOE). The essential oils analyzed by GC-MS and were characterized. Major compounds of phenol, 2 methyl 5 (1 methylethyle) (CAS), thymol and 1,2 Benzene dicarboxylic acid, 3 nitro (CAS) (48.75%, 32.42% and 8.12%, respectively) were detected. Results demonstrated that the TSNPS gave a highest DPPH radical scavenging activity, it was obtained 97.2 at 1000 ug/ml. TSNPS, Thymus + Hexane (T+H), Thymus + Ethanol (T+E) gave the greatest antimicrobial activity than amoxicillin (AM) and ciprofloxacin (CIP). In conclusion: The essential oil of thymus (Vulgaris) and thymus (Vulgaris) silver nanoparticles can be a good source of natural preservatives as an antioxidant and antimicrobial agents for increasing the shelf life of foodstuffs.
Resumo Diversas espécies de timo possuem propriedades terapêuticas, por isso são utilizadas na medicina tradicional. Neste trabalho foi realizado para sintetizar nanopartículas de prata Thymus vulgalis (TSNPS) e avaliar as atividades antioxidante e antimicrobiana de TSNPS e extrato de óleo essencial de T. vulgalis (TEOE). Os óleos essenciais analisados por GC-MS e foram caracterizados. Os principais compostos de fenol, 2 metil 5 (1 metiletilo) (CAS), timol e ácido 1,2 Benzenodicarboxílico, 3 nitro (CAS) (48,75%, 32,42% e 8,12%, respectivamente) foram detectados. Os resultados demonstraram que o TSNPS deu uma maior atividade de eliminação do radical DPPH , foi obtido 97,2 a 1000 ug / ml. TSNPS, Timo + Hexano (T + H), Timo + Etanol (T + E) deu a maior atividade antimicrobiana do que amoxicilina (AM) e ciprofloxacina (CIP). Em conclusão: O óleo essencial de nanopartículas de prata do timo (Vulgaris) e do timo (Vulgaris) pode ser uma boa fonte de conservantes naturais como agentes antioxidantes e antimicrobianos para aumentar a vida útil de alimentos.
Subject(s)
Oils, Volatile/pharmacology , Thymus Plant , Metal Nanoparticles , Anti-Infective Agents/pharmacology , Silver , Antioxidants/pharmacologyABSTRACT
Several species of thymus have therapeutic properties, so they are used in traditional medicine. In this work was carried out to synthesize Thymus vulgalis silver nanoparticles (TSNPS) and evaluate antioxidant and antimicrobial activities of TSNPS and T. vulgalis essential oil extract (TEOE). The essential oils analyzed by GC-MS and were characterized. Major compounds of phenol, 2 methyl 5 (1 methylethyle) (CAS), thymol and 1,2 Benzene dicarboxylic acid, 3 nitro (CAS) (48.75%, 32.42% and 8.12%, respectively) were detected. Results demonstrated that the TSNPS gave a highest DPPH radical scavenging activity, it was obtained 97.2 at 1000 ug/ml. TSNPS, Thymus + Hexane (T+H), Thymus + Ethanol (T+E) gave the greatest antimicrobial activity than amoxicillin (AM) and ciprofloxacin (CIP). In conclusion: The essential oil of thymus (Vulgaris) and thymus (Vulgaris) silver nanoparticles can be a good source of natural preservatives as an antioxidant and antimicrobial agents for increasing the shelf life of foodstuffs.
Diversas espécies de timo possuem propriedades terapêuticas, por isso são utilizadas na medicina tradicional. Neste trabalho foi realizado para sintetizar nanopartículas de prata Thymus vulgalis (TSNPS) e avaliar as atividades antioxidante e antimicrobiana de TSNPS e extrato de óleo essencial de T. vulgalis (TEOE). Os óleos essenciais analisados por GC-MS e foram caracterizados. Os principais compostos de fenol, 2 metil 5 (1 metiletilo) (CAS), timol e ácido 1,2 Benzenodicarboxílico, 3 nitro (CAS) (48,75%, 32,42% e 8,12%, respectivamente) foram detectados. Os resultados demonstraram que o TSNPS deu uma maior atividade de eliminação do radical DPPH , foi obtido 97,2 a 1000 ug / ml. TSNPS, Timo + Hexano (T + H), Timo + Etanol (T + E) deu a maior atividade antimicrobiana do que amoxicilina (AM) e ciprofloxacina (CIP). Em conclusão: O óleo essencial de nanopartículas de prata do timo (Vulgaris) e do timo (Vulgaris) pode ser uma boa fonte de conservantes naturais como agentes antioxidantes e antimicrobianos para aumentar a vida útil de alimentos.
Subject(s)
Anti-Infective Agents/analysis , Antioxidants/analysis , Thymus Extracts/chemistry , Nanoparticles , Silver , Oils, Volatile/analysis , Food PreservationABSTRACT
OBJECTIVE@#This study tests the efficacy of Bletilla striata polysaccharide (BSP), carboxymethyl chitosan (CMC), baicalin (BA) and silver titanate (ST) in a wound dressings to fight infection, promote healing and provide superior biocompatibility.@*METHODS@#The antibacterial activity of BA and ST was evaluated in vitro using the inhibition zone method. BA/ST/BSP/CMC porous sponge dressings were prepared and characterized. The biocompatibility of BA/ST/BSP/CMC was assessed using the cell counting kit-8 assay. The therapeutic effect of BA/ST/BSP/CMC was further investigated using the dorsal skin burn model in Sprague-Dawley rats.@*RESULTS@#The wound dressing had good antibacterial activity against Escherichia coli and Staphylococcus aureus through BA and ST, while the combination of BSP and CMC played an important role in promoting wound healing. The BA/ST/BSP/CMC porous sponge dressings were prepared using a freeze-drying method with the concentrations of BA and ST at 20 and 0.83 mg/mL, respectively, and the optimal ratio of 5% BSP to 4% CMC was 1:3. The average porosity, water absorption and air permeability of BA/ST/BSP/CMC porous sponge dressings were measured to be 90.43%, 746.1% and 66.60%, respectively. After treatment for 3 and 7 days, the healing rates of the BA/ST/BSP/CMC group and BA/BSP/CMC group were significantly higher than those of the normal saline (NS) group and silver sulfadiazine (SSD) group (P < 0.05). Interleukin-1β expression in the BA/ST/BSP/CMC group at 1 and 3 days was significantly lower than that in the other three groups (P < 0.05). After being treated for 3 days, vascular endothelial growth factor expression in the BA/BSP/CMC group and BA/ST/BSP/CMC group was significantly higher than that in the NS group and SSD group (P < 0.05). Inspection of histological sections showed that the BA/ST/BSP/CMC group and BA/BSP/CMC group began to develop scabbing and peeling of damaged skin after 3 days of treatment, indicating accelerated healing relative to the NS group and SSD group.@*CONCLUSION@#The optimized concentration of BA/ST/BSP/CMC dressing was as follows: 6 mg BSP, 14.4 mg CMC, 0.5 mg ST and 12 mg BA. The BA/ST/BSP/CMC dressing, containing antibacterial constituents, was non-cytotoxic and effective in accelerating the healing of burn wounds, making it a promising candidate for wound healing. Please cite this article as: Gong YR, Zhang C, Xiang X, Wang ZB, Wang YQ, Su YH, Zhang HQ. Baicalin, silver titanate, Bletilla striata polysaccharide and carboxymethyl chitosan in a porous sponge dressing for burn wound healing. J Integr Med. 2023; 21(5): 487-495.
Subject(s)
Rats , Animals , Chitosan/pharmacology , Silver/pharmacology , Porosity , Vascular Endothelial Growth Factor A/pharmacology , Rats, Sprague-Dawley , Wound Healing , Polysaccharides/pharmacology , Bandages , Burns/drug therapy , Anti-Bacterial Agents/pharmacology , Silver Sulfadiazine/pharmacologyABSTRACT
Aims@#This study was aimed to screen and isolate soil and endophytic fungi with the ability to biosynthesize stable silver nanoparticles (SNPs) with antimicrobial and antiproliferative activities.@*Methodology and results@#A total of 60 fungal isolates isolated from soil and plant samples were screened for their ability to biosynthesize SNPs. Among which, 21 isolates have supported the biosynthesis of SNPs. Furthermore, the endophytic isolate PRR2.1 synthesized highly thermostable SNPs with long shelf life. The PRR2.1 isolate was identified as Albifimbria verrucaria by morphological and molecular means. The synthesis of SNPs was initially monitored by UV-Vis spectroscopy. Further characterization by transmission electron microscopy, X-ray diffraction and dynamic light scattering revealed well-dispersed spherical crystalline in nature SNPs with a mean size of 14 nm and zeta potential of –24.47 mV. Fourier transform infrared spectroscopy showed the presence of biomolecules adsorbed on the surface of biosynthesized SNPs responsible for their synthesis and stability. The mycosynthesized SNPs exhibited stronger antifungal activity against pathogenic strains of Aspergillus niger, A. flavus, A. fumigatus and Candida albicans with respect to its antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacillus cereus and Klebsiella pneumoniae compared to standard antifungal itraconazole and antibiotic cefadroxil with mostly consistent minimum inhibitory concentration of 5.31 μg/mL. The biosynthesized SNPs demonstrated dose-dependent in vitro antiproliferative activity against cancerous HeLa cell line with IC50 value of 2.52 μg/mL and less cytotoxic activity against WI-38 (normal human lung fibroblasts) cell line with CC50 value of 10.2 μg/mL.@*Conclusion, significance and impact of study@#These results show the potential of endophytic fungi biosynthesized SNPs as possible biofriendly, safe and efficient antimicrobial agents with promising antiproliferative activity and low cytotoxicity, which can be furtherly implemented in various biomedical and biotechnological applications.
Subject(s)
Silver , Nanoparticles , Soil Microbiology , Endophytes , Anti-Infective AgentsABSTRACT
Abstract Objective: To evaluate the efficacy of silver diamine fluoride (SDF) in arresting dentin caries lesions when applied under different concentrations and times. Material and Methods: Forty-two bovine blocks were selected and fixed in 24-well plates. Each well received a mixed bacterial inoculum added to the culture medium with 5% sucrose. The plates were incubated in microaerophilia (7 days) for caries formation, confirmed by micro-CT (M1). SDF was applied over the carious lesions for different times and concentrations (n=6): SDF 30% - immediate removal, 1 minute and 3 minutes; SDF 38%, - immediate removal, 1 minute and 3 minutes. The group without treatment was the control. Then, the samples were again scanned by micro-CT (M2) and submitted to a second cariogenic challenge for 21 days. Then, a final scan was performed (M3). Results: Mean pH at the culture medium and lesion depth were compared using Kruskal-Wallis and Wilcoxon tests. 38% SDF showed the lowest metabolic activity of the biofilm. All 38% groups and 30% 1 and 3 minutes did not show an increase in mean lesion depth comparing M3 with M1. However, only 30% 3 minutes and 38% 1 and 3 minutes showed a significant reduction of lesion depth. Conclusion: The minimum application time of 30% SDF to arrest dentin caries lesion was 1 minute, while 38% SDF arrested with application and immediate removal.
Subject(s)
Animals , Cattle , Tooth Remineralization , Cariostatic Agents/therapeutic use , Dental Caries/epidemiology , Dentin , Diamines/chemistry , Fluorides/chemistry , Silver/therapeutic use , In Vitro Techniques/methods , Longitudinal Studies , Statistics, Nonparametric , Biofilms , X-Ray Microtomography/instrumentationABSTRACT
Abstract Nanotechnology has been used in the field of medicine and pharmacology for its greater efficacy of drug delivery than crude molecules of drugs. In the present study medicinal mushroom Ganoderma applanatum extract mediated silver nanoparticles (AgNPs) were synthesized, characterized by Ultraviolet-visible (UV-Vis.) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction, Dynamic light scattering (DLS) and Furior transform-infrared (FTIR) spectroscopy. Maximum absorbance was recorded at 435nm by UV-Vis. The synthesized nanoparticles of 13.54nm-255nm in size with an average particle size of 58.77nm were analyzed by DLS. FTIR-Spectroscopy provided high transmission at 3606cm-1 corresponds for phenolic capping biochemical. Thus G. applanatum extract can be used for synthesis of silver nanoparticles and the synthesized nanoparticles may be used for development of future therapeutic agent for treatment of diseases.
Subject(s)
Silver , Nanoparticles , X-Ray Diffraction/methods , Microscopy, Electron, Scanning/methods , GanodermaABSTRACT
As atividades industriais e de agronegócio, embora necessárias para o desenvolvimento da sociedade, tem causado sérios problemas ambientais devido à eliminação inadequada de seus efluentes, sendo o tratamento destes um dos assuntos mais importantes em relação ao controle de poluição. Os microrganismos podem ser utilizados como biomarcadores de contaminação, portanto, o conhecimento de mecanismos associados à resistência e a capacidade de imobilização e biotransformação de poluentes é um fator importante para a identificação de linhagens adaptadas, que podem ser eficientes no tratamento e na recuperação de áreas contaminadas. O objetivo do presente projeto foi avaliar o perfil de tolerância de patógenos bacterianos de alto risco em saúde única, aos metais pesados (mercúrio, prata, telúrio e arsênio) e ao agrotóxico glifosato; identificando o resistoma associado. A correlação fenótipo-genótipo foi avaliada em isolados de Klebsiella pneumoniae (n= 35), Escherichia coli (n=46), e Salmonella spp. (n=19), determinando a CIM pelo método de microdiluição, e analisando as respectivas sequências genômicas. Entre os isolados de K. pneumoniae, 32 cepas apresentaram CIM elevadas (64- 512µg/mL) para o metal prata, dos quais 20 carregam o operon silPABCRSE responsável por conferir resistência. Uma cepa de K. pneumoniae carregando genes terABCE apresentou uma CIM de 64 µg/mL para telúrio. Seis cepas de E. coli apresentaram uma CIM >32 µg/mL para telúrio, sendo que 3 cepas carregam os genes tehA/B. Outras 6 cepas de E. coli apresentaram CIM para prata de 256-512 µg/mL, mas só duas carregaram genes silPFCE. Duas cepas de Salmonella apresentaram CIM 64-128 µg/mL para telúrio, e carregam genes tehA/B e terABCDEF. Em relação ao arsênio, 24 cepas de E. coli apresentaram uma CIM ≥ 512 µg/mL, e destas, 12 cepas carregam os genes arsRBC. Salmonella spp., que carregam o gene merR apresentaram CIMs de 8-16 µg/mL para mercúrio. Não foi possível correlacionar a presença do operon phnC-P (sugerido como responsável pela tolerância ao glifosato) com CIMs elevadas para este composto. Os resultados obtidos suportam a hipóteses que a exposição de bactérias de origem humana, animal e ambiental, aos metais pesados pode estar contribuindo para a seleção de linhagens tolerantes, sendo que a tolerância à prata mediada pelo operon silPABCRSE em K. pneumoniae foi predominante no grupo clonal CG258, característica com potencial de biomarcador que pode ser utilizado para monitorar o impacto do uso deste metal nas diferentes atividades humanas. Neste trabalho foi possível padronizar a técnica de PCR com os genes do operon sil de interesse
Industrial and agribusiness activities have caused serious environmental problems due to the inadequate disposal of their effluents, the treatment of which being one of the most important issues in relation to pollution control. Microorganisms can be used as biomarkers of contamination, therefore the knowledge of mechanisms associated with resistance and the immobilization and biotransformation capacity of pollutants can be an important factor for the identification of adapted strains, efficient in the treatment and recovery of contaminated areas. The aim of this study was to evaluate the tolerance profile of critical priority bacterial pathogens relevant in One Health, to heavy metals (mercury, silver, tellurium, and arsenic) and to the pesticide glyphosate, identifying the associated resistome. The phenotype-genotype correlation was evaluated in antibiotic-resistant isolates of Klebsiella pneumoniae (n= 35), Escherichia coli (n= 46), and Salmonella spp. (n= 19), by MIC determination using the microdilution method, and by analysis of their respective genomic sequences. Among the isolates of K. pneumoniae, 32 strains showed elevated MIC (64-512 µg/mL) for silver metal, of which 20 carried the silPABCRSE operon responsible for conferring resistance. A strain of K. pneumoniae carrying terrace genes showed a MIC of 64 µg/mL for tellurium. Six strains of E. coli showed an MIC> 32 µg/mL for tellurium, with 3 strains carrying the Thea/B genes. Other 6 strainsof E. coli showed MIC for silver of 256-512 µg/mL, but only two carried silPFCE genes. Two strains of Salmonella showed MIC 64-128 µg/mL for tellurium and carried the/B and terABCDEF genes. In relation to arsenic, 24 strains of E. coli had a MIC 512 µg/mL, and of these, 12 strains carried the arsRBC genes. Salmonella spp., which carriedthe mer gene, had MICs of 8-16 µg/mL for mercury. It was not possible to correlate thepresence of the phonic-P operon (suggested as responsible for glyphosate tolerance) with elevated MICs for this compound. The silver tolerance mediated by the operon sil was a predominant feature in K. pneumoniae strains belonging to the clonal group CG258, suggesting a intrinsic property that has contributed to the persistence and wide dissemination of CG258 within a One Health context, which could be as a biomarkerto monitor the impact of the use of silver compounds and silver-based biomaterial on different human activities. In this work it was possible to standardize the PCR technique with the genes of the sil operon of interest
Subject(s)
Phenotype , Agrochemicals/adverse effects , Metals, Heavy/adverse effects , One Health , Genotype , Silver , Silver Compounds/toxicity , Environmental Pollution/analysis , Agribusiness/classification , Environmental Restoration and Remediation , Anti-Bacterial Agents/pharmacologyABSTRACT
Abstract Traditionally dates is consumed as a rich source of iron supplement and the current research discuss the synthesis of silver nanoparticles (AgNPs) using methanolic seed extract of Rothan date and its application over in vitro anti-arthritic, anti-inflammatory and antiproliferative activity against lung cancer cell line (A549). FTIR result of synthesised AgNPs reveals the presence of functional group OH as capping agent. XRD pattern confirms the crystalline nature of the AgNPs with peaks at 38º, 44º, 64º and 81º, indexed by (111), (200), (220) and (222) in the 2θ range of 10-90, indicating the face centered cubic (fcc) structure of metallic Ag. HR- TEM results confirm the morphology of AgNPs as almost spherical with high surface areas and average size of 42 ± 9nm. EDX spectra confirmed that Ag is only the major element present and the Dynamic light scattering (DLS) assisted that the Z-average size was 203nm and 1.0 of PdI value. Zeta potential showed − 26.5mv with a single peak. The results of the biological activities of AgNPs exhibited dose dependent activity with 68.44% for arthritic, antiinflammatory with 63.32% inhibition and anti-proliferative activity illustrated IC50 value of 59.66 µg/mL expressing the potential of AgNPs to combat cancer
Subject(s)
Silver , In Vitro Techniques/methods , Chronology as Topic , Nanoparticles , Phoeniceae/adverse effects , Lung Neoplasms/classification , Seeds , zeta Potential , Spectroscopy, Fourier Transform Infrared , Inhibitory Concentration 50 , Dosage/methodsABSTRACT
Abstract A study was carried out to synthesize silver nanoparticles (Ag-NPs) using plant extracts and to explore their pharmaceutical application as antibacterial agents. Dried leaves of Mentha arvensis Linn. were powdered and extracts were prepared using three different organic solvents. Preliminary screening on antibacterial activity by agar well diffusion method indicated that the methanolic extract possessed higher potential than the other two. Phytochemical analysis of the leaf extract revealed that it possesses tannins, steroids, terpenoids and flavonoids. Ag-NPs prepared using this extract were of spherical to cuboidal shape ranging in size from 40 to 70 nm. It retained essential chemical groups and had the required surface plasmon resonance. Further to the antimicrobial assay, the Ag-NPs, in contrast to the whole methanolic leaf extract, showed better (100% vs. 80%) bactericidal activity against the indicator organisms. The zones of growth inhibition for gram positive bacteria ranged between 14±0.6 and 23±0.3, while it was between 12±0.6 and 22±0.2 for gram negative bacteria. The Ag-NPs presented the minimum inhibitory concentration values of 250 µg/mL for gram positive bacteria and 250 - 500 µg/mL for gram negative bacteria. These findings suggest that the natural compounds present in M. arvensis L. possess the potency to facilitate the synthesis and antibacterial action of Ag-NPs.
Subject(s)
Silver , Plant Extracts/pharmacology , Mentha/chemistry , Nanoparticles , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Anti-Bacterial Agents/pharmacology , Microbial Sensitivity TestsABSTRACT
Green synthesis of silver nanoparticles (AgNPs) is an ecofriendly, cost-effective and promising approach for discovery of novel therapeutics. The aim of the current work was to biogenic synthesize, characterize AgNPs using seed extracts of three economically important varieties of date palm (Iklas, Irziz and Shishi), and assess their anti-pathogenic bacterial activities. AgNPs were synthesised then characterised using electron microscopy and Fourier transform infrared analyses. The bactericidal activities of AgNPs against five different bacterial pathogens, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae, were determined in vitro. In particular, changes in membrane integrity of virulent bacterial strains in response to AgNPs were investigated. Results of lactate dehydrogenase, alkaline phosphatase activity assays, and measurement of membrane potential revealed that the cytotoxic effects of the AgNPs were mainly centred on the plasma membrane of bacterial cells, leading to loss of its integrity and eventually cell death. In conclusion, green synthesis of AgNPs is an efficient, cost-effective and promising strategy to combat virulent antibiotic-resistant strains.
A síntese verde de nanopartículas de prata (AgNPs) é uma abordagem ecologicamente correta, econômica e promissora para a descoberta de novas terapêuticas. O objetivo do presente trabalho foi sintetizar biogênica, caracterizar AgNPs usando extratos de sementes de três variedades economicamente importantes de tamareira (Iklas, Irziz e Shishi) e avaliar suas atividades bacterianas antipatogênicas. AgNPs foram sintetizados e caracterizados usando microscopia eletrônica e análise de infravermelho por transformada de Fourier. As atividades bactericidas de AgNPs contra cinco diferentes patógenos bacterianos, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus aureus resistente à meticilina e Streptococcus pneumoniae, foram determinadas in vitro. Em particular, foram investigadas alterações na integridade da membrana de cepas bacterianas virulentas em resposta a AgNPs. Os resultados da lactato desidrogenase, dos ensaios da atividade da fosfatase alcalina e da medição do potencial de membrana revelaram que os efeitos citotóxicos dos AgNPs estavam principalmente centrados na membrana plasmática das células bacterianas, levando à perda de sua integridade e, eventualmente, à morte celular. A síntese verde de AgNPs é uma estratégia eficiente, econômica e promissora para combater cepas virulentas resistentes a antibióticos.
Subject(s)
Metal Nanoparticles , Methicillin-Resistant Staphylococcus aureus , Phoeniceae , Silver , Plant Extracts/pharmacology , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacologyABSTRACT
Abstract Silver nanoparticles (AgNPs) are among the most known nanomaterials being used for several purposes, including medical applications. In this study, Calendula officinalis L. flower extract and silver nitrate were used for green synthesis of silver nanoparticles under red, green and blue light-emitting diodes. AgNPs were characterized by Ultraviolet-Visible Spectrophotometry, Field Emission Scanning Electron Microscopy, Dynamic Light Scattering, Electrophoretic Mobility, Fourier Transform Infrared Spectroscopy and X-ray Diffraction. Isotropic and anisotropic silver nanoparticles were obtained, presenting hydrodinamic diameters ranging 90 - 180 nm, polydispersity (PdI > 0.2) and moderate stability (zeta potential values around - 20 mV)
Subject(s)
Silver , Silver Nitrate/agonists , Calendula/adverse effects , Flowers/genetics , Nanoparticles/analysis , Spectrophotometry/methods , X-Ray Diffraction/methods , Microscopy, Electron, Scanning/methods , Spectroscopy, Fourier Transform Infrared , LightABSTRACT
Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in "De Man, Rogasa, and Sharp" broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cellfree supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.
Muitas cepas patogênicas adquiriram padrões multirresistentes nos últimos anos, o que representa um grande problema de saúde pública. A crescente necessidade de agentes antimicrobianos eficazes como novas terapias contra patógenos multirresistentes atraiu a atenção dos cientistas para a nanotecnologia. As nanopartículas de prata são consideradas capazes de matar isolados multirresistentes por causa de seu efeito oligodinâmico em microrganismos. Neste estudo de pesquisa, as NPs foram sintetizadas usando a bactéria Gram-positiva Lactobacillus bulgaricus e sua atividade contra cepas patogênicas selecionadas. Culturas puras de Lactobacillus bulgaricus foram isoladas do leite cru e cultivadas em caldo "De Man, Rogasa e Sharp" para síntese de nanopartículas. A cultura de Lactobacillus bulgaricus foi centrifugada, e o sobrenadante livre de células foi empregado com íons prateados aquosos, avaliando-se suas atividades antibacterianas contra cepas bacterianas, isto é, Staphylococcus aureus, Staphylococcus epidermidis e Salmonella typhi usando ensaio de difusão em poço de ágar. O perfil de antibióticos contra cepas patogênicas selecionadas também foi conduzido usando o método de difusão em disco. A síntese e a caracterização das nanopartículas de prata foram monitoradas principalmente pela conversão da cor amarelo-pálida da mistura em uma cor marrom-escura e por espectroscopia de absorção visível e ultravioleta e por microscopia eletrônica de varredura, respectivamente. O resultado mostrou que AgNPs com tamanho de 30,65-100 nm, obtidas de Lactobacillus bulgaricus, exibiram atividades antibacterianas contra cepas bacterianas selecionadas. Tomados em conjunto, esses achados sugerem que o Lactobacillus bulgaricus tem um grande potencial para a produção de AgNPs com atividades antibacterianas e altamente eficazes em comparação aos antibióticos testados.
Subject(s)
Lactobacillus delbrueckii , Metal Nanoparticles , Anti-Infective Agents , Silver/pharmacology , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacologyABSTRACT
Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in "De Man, Rogasa, and Sharp" broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cell free supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.
Muitas cepas patogênicas adquiriram padrões multirresistentes nos últimos anos, o que representa um grande problema de saúde pública. A crescente necessidade de agentes antimicrobianos eficazes como novas terapias contra patógenos multirresistentes atraiu a atenção dos cientistas para a nanotecnologia. As nanopartículas de prata são consideradas capazes de matar isolados multirresistentes por causa de seu efeito oligodinâmico em microrganismos. Neste estudo de pesquisa, as NPs foram sintetizadas usando a bactéria Gram-positiva Lactobacillus bulgaricus e sua atividade contra cepas patogênicas selecionadas. Culturas puras de Lactobacillus bulgaricus foram isoladas do leite cru e cultivadas em caldo "De Man, Rogasa e Sharp" para síntese de nanopartículas. A cultura de Lactobacillus bulgaricus foi centrifugada, e o sobrenadante livre de células foi empregado com íons prateados aquosos, avaliando-se suas atividades antibacterianas contra cepas bacterianas, isto é, Staphylococcus aureus, Staphylococcus epidermidis e Salmonella typhi usando ensaio de difusão em poço de ágar. O perfil de antibióticos contra cepas patogênicas selecionadas também foi conduzido usando o método de difusão em disco. A síntese e a caracterização das nanopartículas de prata foram monitoradas principalmente pela conversão da cor amarelo-pálida da mistura em uma cor marrom-escura e por espectroscopia de absorção visível e ultravioleta e por microscopia eletrônica de varredura, respectivamente. O resultado mostrou que AgNPs com tamanho de 30,65-100 nm, obtidas de Lactobacillus bulgaricus, exibiram atividades antibacterianas contra cepas bacterianas selecionadas. Tomados em conjunto, esses achados sugerem que o Lactobacillus bulgaricus tem um grande potencial para a produção de AgNPs com atividades antibacterianas e altamente eficazes em comparação aos antibióticos testados.
Subject(s)
Lactobacillus delbrueckii , Nanostructures , Silver/pharmacologyABSTRACT
This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-¹, Pb = 180 mg. Kg-¹), double (Ag = 50 mg. Kg-¹, Pb = 360 mg. Kg-¹) and triple (Ag = 75 mg. Kg-¹, Pb = 540 mg. Kg-¹) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.
Este estudo teve como objetivo avaliar os efeitos de diferentes concentrações de chumbo (Pb) e prata (Ag) na germinação, crescimento inicial e alterações anatômicas de Lactuca sativa L. As plantas utilizam vários mecanismos para reduzir os impactos causados pela ação antrópica, como elementos xenobióticos de solos e água contaminada por metais pesados. Esses metais foram fornecidos como nitrato de chumbo e nitrato de prata e foram estabelecidos os seguintes tratamentos:controle para ambos os metais, dose máxima de metais pesados, para solos cultiváveis, permitida pelo Conselho Nacional do Meio Ambiente (Ag = 25mg.Kg-¹, Pb = 180mg.Kg-¹), dobro (Ag = 50mg.Kg-¹, Pb = 360mg.Kg-¹) e triplo (Ag = 75mg.Kg-¹, Pb = 540 mg.Kg-¹) desta dosagem. Foram realizados testes de vigor e germinação das sementes e possíveis alterações anatômicas nas folhas e raízes das plantas de alface. A espécie apresentou alta capacidade de germinar sob estresse de Ag e Pb, e a germinação nunca foi completamente inibida; entretanto, a germinação diminuiu com o aumento das concentrações de Pb, mas não sob estresse de Ag. O uso de doses crescentes dos metais, reduziu o vigor das sementes e aumentou o teor de clorofila. Também foi observado aumento da biomassa nas plantas a partir dos tratamentos submetidos ao Pb. Os efeitos fitotóxicos dos metais foram mais acentuados aos 15 dias após a semeadura. Anatomicamente, L. sativa foi influenciada pelas concentrações de metais, e teve uma redução de até 79,9% na espessura da epiderme radicular na maior concentração de Pb, embora algumas estruturas não tenham sofrido alterações significativas. Os resultados sugerem que L. sativa apresenta tolerância a altas concentrações de metais pesados, mostrando possíveis mecanismos para superar o estresse causado por esses metais. Nesta pesquisa a alface possivelmente utilizou o mecanismo de exclusão de metais retendo Pb e Ag nas raízes preservando o aparato [...].
Subject(s)
Lactuca/growth & development , Lactuca/physiology , Lead/administration & dosage , Lead/toxicity , Silver/administration & dosage , Silver/toxicityABSTRACT
Green synthesis of silver nanoparticles (AgNPs) is an ecofriendly, cost-effective and promising approach for discovery of novel therapeutics. The aim of the current work was to biogenic synthesize, characterize AgNPs using seed extracts of three economically important varieties of date palm (Iklas, Irziz and Shishi), and assess their anti-pathogenic bacterial activities. AgNPs were synthesised then characterised using electron microscopy and Fourier transform infrared analyses. The bactericidal activities of AgNPs against five different bacterial pathogens, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae, were determined in vitro. In particular, changes in membrane integrity of virulent bacterial strains in response to AgNPs were investigated. Results of lactate dehydrogenase, alkaline phosphatase activity assays, and measurement of membrane potential revealed that the cytotoxic effects of the AgNPs were mainly centred on the plasma membrane of bacterial cells, leading to loss of its integrity and eventually cell death. In conclusion, green synthesis of AgNPs is an efficient, cost-effective and promising strategy to combat virulent antibiotic-resistant strains.
A síntese verde de nanopartículas de prata (AgNPs) é uma abordagem ecologicamente correta, econômica e promissora para a descoberta de novas terapêuticas. O objetivo do presente trabalho foi sintetizar biogênica, caracterizar AgNPs usando extratos de sementes de três variedades economicamente importantes de tamareira (Iklas, Irziz e Shishi) e avaliar suas atividades bacterianas antipatogênicas. AgNPs foram sintetizados e caracterizados usando microscopia eletrônica e análise de infravermelho por transformada de Fourier. As atividades bactericidas de AgNPs contra cinco diferentes patógenos bacterianos, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus aureus resistente à meticilina e Streptococcus pneumoniae, foram determinadas in vitro. Em particular, foram investigadas alterações na integridade da membrana de cepas bacterianas virulentas em resposta a AgNPs. Os resultados da lactato desidrogenase, dos ensaios da atividade da fosfatase alcalina e da medição do potencial de membrana revelaram que os efeitos citotóxicos dos AgNPs estavam principalmente centrados na membrana plasmática das células bacterianas, levando à perda de sua integridade e, eventualmente, à morte celular. A síntese verde de AgNPs é uma estratégia eficiente, econômica e promissora para combater cepas virulentas resistentes a antibióticos.
Subject(s)
Antibiosis , Bacillus subtilis/drug effects , Escherichia coli/drug effects , Nanoparticles/analysis , Phoeniceae , Silver/analysis , Staphylococcus aureus/drug effects , Streptococcus pneumoniae/drug effects , Microscopy , In Vitro TechniquesABSTRACT
As doenças peri-implantares apresentam-se como o novo desafio da Implantodontia. Devido sua alta prevalência e grandes dificuldades no tratamento, estudos sobre alternativas preventivas poderiam trazer grande contribuição. Desta forma estudamos a aplicação de um filme antimicrobiano contendo prata em componentes protéticos dos implantes dentários. Para encontrar um equilíbrio entre efeito antimicrobiano e toxicidade, propusemos a avaliação da citotoxidade deste filme com diferentes concentrações do agente antimicrobiano, aplicados a discos de titânio, diante de cultura primária de fibroblastos. Portanto, no presente estudo investigamos a citotoxicidade de filmes nanoestruturados em discos de titânio diante de cultura primária de fibroblastos, visando desenvolver um material antimicrobiano e biocompatível capaz de impedir a colonização bacteriana em áreas reabilitadas por implantes. As culturas foram divididas nos seguintes grupos: Grupo A (controle): discos de titânio sem deposição de prata; Grupo B (teste): discos de titânio com uma camada de deposição de solução coloidal de prata e sílica, Grupo C (teste): discos de titânio com o dobro de deposição de solução coloidal de prata em relação ao grupo B, e Grupo D (teste): discos de titânio extra polidos com deposição de uma camada de solução coloidal de prata. Para a análise de citotoxicidade, os materiais foram cultivados com fibroblastos e analisados através de ensaios de citotoxicidade direta (MTT) com período de 24h, 48h e 72h de incubação buscando determinar a taxa de proliferação e viabilidade celular. Para o controle estrutural foi realizada microscopia eletrônica de varredura (MEV) após 24h de incubação. As amostras não se apresentaram como citotóxicas e novos estudos deverão ser realizados visando resultados in vivo para uma possível aplicação do revestimento em componentes protéticos de implantes.
Subject(s)
Silver , FibroblastsABSTRACT
Resumen: Una proporción importante de infecciones en el pie diabético consisten en onicomicosis y tinea pedis, problema común en el pie, amenazante de la viabilidad del tejido que puede provocar infecciones bacterianas secundarias. Requieren períodos prolongados de tratamiento antimicótico con alta tasas de recaídas y reinfección. Diversos estudios han mostrado la seguridad y eficacia de las nanopartículas de plata (NP Ag) como agente antimicrobiano. Realizamos un estudio donde se evaluó el tratamiento con NP Ag en dermatomicosis del pie de pacientes diabéticos. Método: estudio piloto, abierto, prospectivo, randomizado y controlado en pacientes que asisten a una policlínica de pie diabético. Dieciocho pacientes cumplieron con los criterios de inclusión conformándose dos grupos homogéneos. Ambos grupos recibieron tratamiento estándar que consistió en antimicótico tópico y desbastado mecánico. El grupo intervención utilizó un textil (medias) confeccionadas con hilos con NP Ag. Se realizó control clínico y microbiológico hasta las 12 semanas. Se evaluó el porcentaje de remisión y el tiempo hasta alcanzar el mismo. Resultados: predominó la onicomicosis y el germen Trichophyton rubrum. En el grupo intervención se logró un mayor porcentaje de remisión de lesiones y en un tiempo menor que el grupo control. Conclusiones: el uso de medias confeccionadas con hilos de NP Ag se asoció con una mayor probabilidad de curación completa en un período de 12 semanas a pesar de que el número de pacientes no permitió llegar al nivel de significación estadística, pudiendo contribuir a la prevención de infecciones o úlceras suplementarias en el pie diabético.
Summary: Onychomycosis and tinea pedis represent a significant proportion of infections in the diabetic foot, a common foot problem, and they constitute a threat to the viability of tissues that may provoke secondary bacterial infections. To combat them, antifungal treatments are required for long periods of time, the rates of relapse and reinfection being high. Several studies have proved the safety and effectiveness of silver nano particles (NP Ag) as an antimicrobial agent. A study was conducted to assess nanoparticle agents for foot dermatomycosis in diabetic patients. Method: pilot, open, prospective randomized and controlled study in patients who are assisted in a diabetic foot policlinic. 18 patients complied with the inclusion criteria and two homogeneous groups were formed. Both groups received standard treatment consisting in topic antifungal and mechanical roughing. The intervention groups used a textile (stockings) made with silver nanoparticle threads. Clinical and microbiological control was made during 12 weeks, also assessing the remission percentage and the time it took to achieve it. Resultados: onychomycosis and trichophyton rubrum prevailed. The intervention group showed a greater percentage of remission of lesions in a period of time that was shorter than that of the control group. Conclusions: the use of stockings made with NP Ag threads was associated with a greater probability of complete healing, in a 12-week period, despite the fact that the number of patients was not statistically significant. This could contribute to the prevention of supplementary infections or ulcers in the diabetic foot.
Resumo: Uma proporção significativa de infecções do pé diabético consiste em onicomicose e Tinea pedis, um problema comum nos pés que ameaça a viabilidade do tecido e pode causar infecções bacterianas secundárias. Requerem períodos prolongados de tratamento antifúngico com altas taxas de recidiva e reinfecção. Vários estudos têm demonstrado a segurança e a eficácia das nanopartículas de prata (NP Ag) como agente antimicrobiano. Realizamos um estudo onde o tratamento com NP Ag foi avaliado na dermatomicose do pé de pacientes diabéticos. Método: estudo piloto, aberto, prospectivo, randomizado e controlado em pacientes atendidos em uma policlínica de pé diabético. Dezoito pacientes preencheram os critérios de inclusão, formando dois grupos homogêneos. Ambos os grupos receberam tratamento padrão que consiste em antifúngico tópico e moagem mecânica. O grupo intervenção utilizou um tecido (meias) confeccionado com fios NP Ag. O controle clínico e microbiológico foi realizado até 12 semanas. A porcentagem de remissão e o tempo para alcançá-la foram avaliados. Resultados: predominaram a onicomicose e o germe Trichophyton rubrum. No grupo intervenção, obteve-se maior percentual de remissão das lesões e em menor tempo que o grupo controle. Conclusões: o uso de meias confeccionadas com fios NP Ag esteve associado a uma maior probabilidade de cura completa, no período de 12 semanas, apesar do número de pacientes não permitir atingir o nível de significância estatística, podendo contribuir para a prevenção de infecções ou úlceras adicionais no pé diabético.