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RESUMEN Introducción. El uso inapropiado de antimicrobianos en las unidades de cuidados intensivos (UCI) contribuye a la resistencia bacteriana. Objetivo. El propósito del presente estudio fue medir el uso y tipo de antimicrobianos en los pacientes hospitalizados en la Unidad de Cuidados Intensivos del Hospital Regional de Loreto (HRL). Métodos. Estudio de tipo descriptivo. Revisamos 120 historias clínicas en pacientes de UCI-HRL desde enero a junio 2023. Resultados. La mayoría de los pacientes usaron antimicrobianos (74,2%), indicados por shock séptico (42,7%), de 1 a 3 antimicrobianos (93,2%), con terapia de 1 a 3 días (45%). Del total de antimicrobianos usados, la mayor proporción fueron bactericidas 89 (90,4%), de la familia de cefalosporinas (33,1%) y carbapenémicos (23,5%); los fármacos más empleados fueron ceftriaxona (26,5%) y meropenem (21,1%) por vía intravenosa (90,4%). Conclusión. La mayor proporción de pacientes hospitalizados usan antimicrobianos de la familia de cefalosporinas y carbapenémicos.
ABSTRACT Introduction. Inappropriate use of antimicrobials in the Intensive Care Unit (ICU) contributes to bacterial resistance. Objective. The purpose of the present study was to measure the use and type of antimicrobials in patients hospitalized in the Intensive Care Unit of the Loreto Regional Hospital (HRL). Methods. Descriptive study. We reviewed 120 medical records in ICU-HRL patients from January to June 2023. Results. Most patients used antimicrobials (74.2%), indicated for septic shock (42.7%), 1 to 3 antimicrobials (93.2%), with therapy of 1 to 3 days (45%). Of the total number of antimicrobials used, the greatest proportion were bactericides 89 (90.4%), from the cephalosporin family (33.1%) and carbapenemics (23.5%); the most commonly used drugs were ceftriaxone (26.5%) and meropenem (21.1%) by the intravenous route (90.4%). Conclusion. The highest proportion of hospitalized patients use antimicrobials of the cephalosporin and carbapenemics family.
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Background and Objectives: antimicrobial resistance is one of the main public health concerns worldwide. Intensive Care Units have a high prevalence of resistant microorganisms and infections, and the rational use of antibiotics is one of the main strategies for tackling this problem. This work aimed to describe patterns associated with antimicrobial drugs as well as the resistance profile of microorganisms. Methods: an observational study was carried out using data from patients hospitalized in the Intensive Care Unit who used antimicrobial agents. Results: respiratory and cardiological causes were the most frequent reasons for admission, with cephalosporins (29.02%), with penicillin (25.84%) and macrolides (16.10%) being the most used classes of antibiotics. The predominant microorganisms were Klebsiella pneumoniae (13.98%), Staphylococcus aureus (13.44%) and Acinetobacter baumannii (11.83%). Urine cultures and tracheal aspirate were the culture tests with the highest growth of gram-negative microorganisms. Patients with bacteria isolated in tracheal aspirate had longer hospital stays; 20 patients had positive surveillance cultures; and the mortality rate found was 55.45%. Conclusion: the study combined the institution's epidemiological profile with patient characteristics, isolated microorganisms and outcomes.(AU)
Justificativa e Objetivos: a resistência antimicrobiana é uma das principais preocupações de saúde pública em todo o mundo. As Unidades de Terapia Intensiva têm uma alta prevalência de microorganismos resistentes e infecções, e o uso racional de antibióticos é uma das principais estratégias para lidar com esse problema. Este trabalho teve como objetivo descrever padrões associados a medicamentos antimicrobianos, bem como o perfil de resistência dos microorganismos. Métodos: foi realizado um estudo observacional utilizando dados de pacientes hospitalizados na Unidade de Terapia Intensiva que utilizaram agentes antimicrobianos. Resultados: causas respiratórias e cardiológicas foram os motivos mais frequentes de admissão, com cefalosporinas (29,02%), penicilina (25,84%) e macrolídeos (16,10%) sendo as classes de antibióticos mais utilizadas. Os microorganismos predominantes foram Klebsiella pneumoniae (13,98%), Staphylococcus aureus (13,44%) e Acinetobacter baumannii (11,83%). Culturas de urina e aspirado traqueal foram os testes de cultura com maior crescimento de microorganismos gram-negativos. Pacientes com bactérias isoladas no aspirado traqueal tiveram internações mais longas; 20 pacientes tiveram culturas de vigilância positivas; e a taxa de mortalidade encontrada foi de 55,45%. Conclusão: o estudo combinou o perfil epidemiológico da instituição com características dos pacientes, microorganismos isolados e resultados.(AU)
Antecedentes y Objetivos: la resistencia antimicrobiana es una de las principales preocupaciones de salud pública en todo el mundo. Las Unidades de Cuidados Intensivos tienen una alta prevalencia de microorganismos resistentes e infecciones, y el uso racional de antibióticos es una de las principales estrategias para abordar este problema. Este trabajo tuvo como objetivo describir patrones asociados con medicamentos antimicrobianos, así como el perfil de resistencia de los microorganismos. Métodos: se llevó a cabo un estudio observacional utilizando datos de pacientes hospitalizados en la Unidad de Cuidados Intensivos que utilizaron agentes antimicrobianos. Resultados: las causas respiratorias y cardiológicas fueron las razones más frecuentes de admisión, con cefalosporinas (29,02%), penicilina (25,84%) y macrólidos (16,10%) siendo las clases de antibióticos más utilizadas. Los microorganismos predominantes fueron Klebsiella pneumoniae (13,98%), Staphylococcus aureus (13,44%) y Acinetobacter baumannii (11,83%). Los cultivos de orina y el aspirado traqueal fueron las pruebas de cultivo con mayor crecimiento de microorganismos gramnegativos. Los pacientes con bacterias aisladas en el aspirado traqueal tuvieron estancias hospitalarias más largas; 20 pacientes tuvieron cultivos de vigilancia positivos; y la tasa de mortalidad encontrada fue del 55,45%. Conclusión: el estudio combinó el perfil epidemiológico de la institución con las características de los pacientes, los microorganismos aislados y los resultados.(AU)
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Humanos , Prescripciones de Medicamentos , Brasil , Farmacorresistencia Microbiana , Farmacorresistencia Bacteriana , Prueba de Laboratorio , Unidades de Cuidados Intensivos , Antibacterianos , Utilización de MedicamentosRESUMEN
Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.
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Aims@#This study aims to determine the antibacterial potential and identify the bioactive compounds of Hypoxylon monticulosum isolated from marine macroalgae Ulva lactuca.@*Methodology and results @#Ulva lactuca was collected from the Desaru coast, Johor, Malaysia and three endophytes were isolated following surface sterilisation. One fungal isolate was further characterised by the morphology of white, yellowish colonies and fibrous with a waxy structure indicative of a member from the genus Hypoxylon. Molecular identification through internal transcribed spacer (ITS) sequence analysis matches the reference sequence with more than ≥98% homology to Hypoxylon monticulosum AS26-D8. Minimum inhibition concentration (MIC) of the fungal ethyl acetate (EA) extract was determined against five human pathogenic bacteria. Wide spectrum antibacterial activity was noted; with MIC against Escherichia coli was 1.25 ± 0 mg/mL, Bacillus subtilis and Enterobacter faecalis both at 5.00 ± 0 mg/mL, and finally, both Staphylococcus aureus and Klebsiella pneumoniae were 10.00 ± 0 mg/mL, respectively. Bioassay-guided fractionation was performed using solvents of increasing polarities, producing three fractions and analysis by liquid chromatography-mass spectrometry (LC/MS) identified 128 compounds. From these, nine compounds were identified as having biological activities. Dihydrocordoin, D-pantothenoyl-L-cysteine, caffeine and Tumonoic A acid were among the compounds identified as having antibacterial properties.@*Conclusion, significance and impact of study@#Hypoxylon monticulosum from marine source has antibacterial potential owing to the compounds previously reported to display antibacterial and other biological properties. The compounds differ from those previously reported in H. monticulosum from terrestrial sources.
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Aims@#Jambu batu (Psidium guajava Linn.) is a phytotherapic plant used in folk medicine that has active components to treat various diseases. An earlier study has reported on the analysis of its pharmacological properties and was found to possess antibacterial, antifungal, anti-inflammatory and antioxidant activity. The present study aimed to determine the antibacterial activities of P. guajava Linn. leaves extracts on the vegetative cells of Bacillus cereus ATCC33019, Bacillus megaterium ATCC14581, Bacillus pumilus ATCC14884 and Bacillus subtilis ATCC6633 and to evaluate its effects of different temperatures and pHs on antibacterial activity.@*Methodology and results@#The susceptibility test used to determine the bacterial growth inhibition were well diffusion assay (WDA), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill curve assay. The effects of various parameters on temperatures at 10 °C, 28 °C, 30 °C, 50 °C and 80 °C and pH at 3.0, 5.0, 6.7, 7.0 and 11.0 were investigated. WDA assay of the extracts resulted in 13.75 ± 0.95 and 16.25 ± 0.95 mm of inhibition zone on B. subtilis and B. cereus, respectively. The extracts can inhibit the growth with MICs value range of 0.195 to 0.781 mg/mL for B. megaterium and B. pumilus, respectively, and can kill all tested Bacillus spp. with MBCs values of 0.781 mg/mL. The killing time analyses showed that Bacillus spp. can be killed completely within 4 h at 4× MIC (0.781 to 3.124 mg/mL). The extracts remained stable under a wide range of temperatures and pHs, as there was no significant difference in the MIC and MBC values.@*Conclusion, significance and impact of study@#Psidium guajava Linn. ethanolic leaves extract yielded good antibacterial activities, suggesting that the extract can be utilised or explored as a potential anti-Bacillus agent in food applications.
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@#The increasing number of drug-resistant pathogens is a global issue and becoming worse because it has reduced the effectiveness of current antibiotics in the management of infectious diseases. Therefore, this situation highlights the urgency of an action plan to identify and develop novel and potent antimicrobials derived from natural resources. Therapeutic compounds from natural resources can offer novel, straightforward approaches against pathogenic bacteria with the least toxic manifestations and a low risk of acquiring resistance. Marine organisms and coastal plants receive much interest among researchers nowadays for developing new pharmaceuticals because they are rich in secondary metabolites that have various pharmacological effects, such as antibacterial, anti-cancer, antiviral, anti-inflammatory and others. This review's goal is to highlight the phytochemical components of marine organisms and coastal plants that might be accountable for their antibacterial properties that have been scientifically confirmed and can be potential aids in treating infectious diseases caused by multidrug resistant (MDR) bacteria in humans.
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@#This paper provides a comprehensive review of the antibacterial properties of three different types of Malaysian honey, namely kelulut, tualang and acacia, in preventing wound infecting bacteria. The antibacterial activity of these honey is mainly attributed to the physicochemical and phytochemical, which have been shown to be effective against a broad range of bacterial pathogens. This review discusses the effectiveness of honey in inhibiting the growth of various wound-infecting bacteria, factors that contributed to the antibacterial properties of the honey, mechanisms of action of honey in inhibiting bacterial growth and their potential for future use in clinical practice. The findings of this review suggest that Malaysian honey has the potential to be used as an alternative and complementary therapy to conventional antibiotics in the prevention and treatment of wound infections.
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Objective@#To investigate the efficacy of antibacterial photodynamic therapy (aPDT) as an adjunct to subgingival scaling and root planning in the treatment of chronic periodontitis.@*Methods@#This study followed medical ethics guidelines, and informed consent was obtained from all patients. Sixteen patients were recruited for this randomized split-mouth controlled trial. The control group underwent subgingival scaling and root planning (SRP), while the experimental group received subgingival scaling and root planing plus aPDT treatment using Perowave® with a toluidine blue O solution photosensitizer. The probing pocket depth (PD), recession, plaque index (PLI), bleeding index (BI) and proportion of positive sites of bleeding on probing (BOP) (BOP%) at all sites were examined at baseline (before treatment) and at 1, 3 and 6 months after treatment.@*Results@#Follow-up was completed for 13 patients. On the control side, 356 teeth were tested at 2 136 sites. A total of 360 teeth on the test side and 2 160 sites were included in the study. Before treatment, there was no significant difference in the baseline indicators between the two groups. After treatment, both groups showed significant improvement in clinical parameters, including PD, PLI, BI, and BOP%,compared with baseline. At 3 months, the BOP% and PLI in the experimental group were significantly lower than those in the control group (P<0.05). The improvement in BOP% and PLI in the experimental group was significantly greater than that in the control group 3 months after treatment (P<0.05).@*Conclusion@#aPDT, as an adjuvant treatment to SRP for chronic periodontitis, can improve gingival bleeding and control periodontal inflammation in the early stage.
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Objective@#To investigate the physicochemical and biological properties of a new calcium sulfate-based root canal sealer for deciduous teeth containing calcium sulfate hemihydrate, barium sulfate, chlorhexidine acetate, and polyethylene glycol 400 (PEG 400).@*Methods@#This study was reviewed and approved by the Ethics Committee. The calcium sulfate hemihydrate and barium sulfate powders with different mass percentages were mixed with liquid PEG 400 at a powder-to-liquid ratio of 3∶1, and chlorhexidine acetate was added to a concentration of 0.2 mg/mL according to the volume of PEG 400. The above materials were mechanically ground at 250 r/min for 24 h to obtain a calcium sulfate-based root canal sealer for deciduous teeth. The sealer was classified into different groups according to mass percentages of components. The mass percentages of components were optimized by performing time, fluidity, and radiopacity experiments, and then the pH, mass loss in vitro, and microscopic morphology of the optimal sealer were evaluated. The antimicrobial properties of the sealer were evaluated by a bacterial-material cocultivation method. The cytocompatibility of the sealer was evaluated by a CCK-8 assay and cytomorphological staining, and its biocompatibility was evaluated by a subcutaneous tissue embedding assay.@*Results@#After optimization, mass percentage of calcium sulfate hemihydrate was 80 wt%, and the mass percentage of barium sulfate was 20 wt%. The flowability and radiopacity of the sealer were in accordance with international standards. The pH stabilized between 6-7. On the 7th and 14th days, the pH in the water group was significantly greater than that in the PBS group (P<0.001), although the pH in both groups gradually increased (P>0.05). In vitro degradation experiments, the mass loss of the sealer was approximately 15.17% during the preimmersion period, and rate of mass loss decreased after 3 weeks, reaching only approximately 8.33%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the main component of the sealer after hydration was calcium sulfate dehydrate. In bacterial growth assays and cytological tests, the sealer showed significant inhibition of the growth of E. faecalis (P<0.001). After 1 and 4 days of culture, the cell viability in the 1∶10 and 1∶20 sealer extract dilution group was lower than that in the control group (P<0.05). On the 7th day, the 1∶20 sealer extract dilution had no significant effect on cell proliferation (P>0.05). Both the sealer group and the control group (Vitapex and zinc oxide eugenol) caused mild inflammatory reactions in tissue sections.@*Conclusion@#In this study, a new type of root canal sealer for deciduous teeth was designed based on calcium sulfate, which has good physicochemical properties and strong antibacterial properties and meets biocompatibility requirements. This study provides an idea for the development of a new type of root canal sealer for deciduous teeth.
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@#Electrolyzed water (EW) has been introduced as a surface disinfectant due to its antimicrobial properties without cytotoxic effects to oral tissues contrary to sodium hypochlorite (NaOCl), which is cytotoxic and can be detrimental if extruded beyond the root canal. This scoping review aimed to compare antimicrobial efficacy of EW with NaOCl on root canal pathogens and to assess effect of concentration and exposure time on antimicrobial efficacy. The review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews protocol guidelines. Electronic databases were searched for eligible articles published between 2011-2021 in PubMed, PLOS, Science Direct, and Google Scholar. Joanna Briggs Institute Critical Appraisal Tool was used for quality assessment. Of the 784 articles recovered, only 8 were eligible based on inclusion criteria. The included studies assessed several types of EW, which showed antimicrobial potential against E. faecalis in vitro in suspension and biofilm forms. EW demonstrated antimicrobial efficacy comparable with NaOCl in 5 of 8 studies. Only one study found that higher concentration and exposure time increased antimicrobial efficacy of EW; other studies showed otherwise. It can be concluded that EW can be a potential alternative solution for NaOCl as an endodontic irrigant.
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objective:To prepare a composite photocrosslinked hydrogel containing zeolite imidazole framework-8(ZIF-8),and to evaluate its in vitro cytotoxicity,drug release capability,and antimicrobial propertie.Methods:The ZIF-8 particles were synthesized by hydrothermal method,and the microstructure characteristic was observed under scanning electron microscope(SEM).The particles were mixed with the gelatin methacryloyl(GelMA)with the mass fraction of 0.2%to obtain the composite hydrogel GelMA-Z.The atomic absorption spectroscope was used to detect the cumulative zinc ion(Zn2+)release amounts in GelMA-Z at different time points.The NIH-3T3 cells were co-cultured with GelMA-Z for 1,3,and 7 d;the viabilities of the cells in various groups were detected by CCK-8 assay;the GelMA-Z was co-cultured with Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)for 6,12,and 24 h and divided into control group,GelMA group,and GelMA-Z group.The bacterial activities of the cells in various groups at different time points were detected by microplate reader;the bacterial formation and the presence of live/dead becterial staining condition were detected by plate antibacterial experiment and live/dead bacterial staining method.Results:The SEM observation results showed that the hydrothermally synthesized ZIF-8 particles had the uniform particle sizes.The atomic absorption spectroscope results showed that Zn2+ in GelMA-Z showed an initial burst phase within 1 d,followed by a slow release,and reached the equilibrium around 7 d.Compared with control group,the viabilities the cells in GelMA group and GelMA-Z group were above 90%on the 1st,3rd,and 7th days,but there was no significant difference(P>0.05).The bacterial activity detection results showed that when co-cultured with bacteria for 6,12,and 24 h,compared with control group and GelMA group,the bacterial activities of the E.coli and S.aureus in GelMA-Z group were decreased(P<0.05).The plate antibacterial experiment results showed that the number of bacterial formation in GelMA-Z group was fewer than those in control group and GelMA group.The live/dead bacterial staining results showed that in GelMA-Z group,there was a large number of red fluorescence stained dead bacteria;in control group and GelMA group,there was a large number of green fluorescence stained live bacteria.Conclusion:The GelMA hydrogel loaded with ZIF-8 particles can achieve the in situ photocrosslinking and possesses good Zn2+ release capability and antimicrobial activity,and it is a novel hydrogel dressing for treatment of the infected wounds.
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Bacterial biofilms(BF)are complex microbial communities formed by bacteria on living or abiotic surfaces.Their formation significantly enhances bacterial virulence and drug resistance and is associated with a high proportion of chronic bacterial infections,posing a serious threat to human health.The ability of traditional antibiotics and commonly used disinfectants to clear biofilms is limited,and an effective new strategy to treat BF is urgently needed.Bacteriophage,as a kind of virus that can infect and lyse bacteria,has high safety and specificity,and is considered as a promising alternative method for the treatment of BF.In this paper,the mechanism of bacteriophage anti-bacterial biofilm and the application strategies based on bacteriophage and its derivatives in the prevention and control of bacteriophage biofilm formation were reviewed,which provided new ideas for the development of efficient bacteriophage anti-bacterial biofilm methods.
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BACKGROUND:Micro-arc oxidation can effectively add bioactive elements to the metal surface and improve the anti-bacterial and anti-inflammatory properties of biomedical metal materials,so this technology has become one of the hotspots of biomedical materials. OBJECTIVE:To summarize the anti-bacterial and anti-inflammatory properties of surface coatings prepared by the combination of micro-arc oxidation and other surface modification technologies. METHODS:Articles from January 1996 to December 2022 were searched on CNKI,WanFang and PubMed databases using Chinese and English search terms"micro-arc oxidation,antibacterial properties,anti-inflammatory properties,metal implants".After preliminary screening according to inclusion and exclusion criteria,89 articles were retained and summarized. RESULTS AND CONCLUSION:The ceramic layer prepared by micro-arc oxidation can improve the anti-bacterial and anti-inflammatory properties of titanium,magnesium and other alloys.Combination with other surface modification technologies can effectively solve the effect of pores on the surface properties of the alloy,and further improve the biological properties of the oxide film.It has a wide application prospect in orthopedics and dentistry.At present,most studies are limited to metal coatings,and most of them focus on metal elements with good antibacterial properties such as silver and copper,while only a few studies mention non-metallic coatings such as graphene oxide,hydroxyapatite and chitosan.In the future,extensive studies can be conducted on inorganic coatings and polymer coatings,and more combinations of different bioactive elements can also be adopted to improve antibacterial properties.Currently,studies on the inflammation of implant coatings prepared by micro-arc oxidation are mostly limited to the immune system and focused on macrophages,while studies on neutrophils and platelets are scarce.In the future,a variety of advanced technologies should be combined to explore the specific effects of micro-arc oxidation coating on other immune cells and inflammatory cells.
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BACKGROUND:The repair process of skin trauma is complex and susceptible to infection,easy to lead to poor healing,is the current difficulty and hot spot in wound repair research,and has received extensive attention in the fields of traditional Chinese medicine and tissue engineering. OBJECTIVE:To investigate the effect of moxibustion and reduced graphene oxide/cerium oxide nanocomposite on promoting the healing of infectious wounds. METHODS:(1)Reduced graphene oxide/cerium dioxide nanocomposites with mass ratios of 2:1,1:1 and 1:2 were synthesized by hydrothermal method.The resulting composites were recorded as G2C1,G1C1 and G1C2,respectively.The photothermal properties,cytotoxicity and antibacterial properties of the three kinds of materials were tested.After taking moxa sticks,three kinds of moxibustion distances were set(3.0-3.5 cm,recorded as moxibustion 1;2.5-3.0 cm,recorded as moxibustion 2;2.0-2.5 cm,recorded as moxibustion 3).Moxibustion was applied to the surface of human skin for 10 minutes to detect the photothermal properties.The antibacterial properties of moxibustion were tested at three different distance intervals.Simultaneously,the back body surface infrared imaging of rats with different mass concentrations of G1C1 material,moxibustion(three kinds of moxibustion distances)and moxibustion 2+G1C1 material was detected.(2)Sixty male Sprague-Dawley rats were selected to model the wound of Staphylococcus aureus infection.48 hours later,they were randomly divided into 10 groups with 6 rats in each group:control group(did not receive any treatment),mupirocin group,moxibustion 2+G1C1 group,moxibustion 1 group,moxibustion 2 group,moxibustion 3 group and 60,80,100,and 120 μg/mL G1C1 groups(The G1C1 group was given 808 nm near-infrared laser irradiation for 10 min/time,and the G1C1 suspension was loaded on the wound surface before each treatment.Each group of moxibustion underwent in-situ suspension moxibustion,and the intervention time was 10 min/time.Moxibustion 2+G1C1 group was loaded with G1C1 suspension on the wound surface before each treatment,and moxibustion was suspended in situ with moxa strips,and the intervention time was 10 min/time).The frequency of treatment was 2 days once.Wound healing,wound colony count and repair were detected after 7 days of intervention. RESULTS AND CONCLUSION:(1)The three kinds of reduced graphene oxide/cerium dioxide nanocomposites had good photothermal properties,and the higher the mass concentration of the composites,the better the photothermal properties.The temperature of the moxibustion 2 group reached 47.6 ℃for 10 minutes without causing thermal damage,which was more suitable for animal experiments.The results of co-culture with NIH-3T3 cells exhibited that 60,80,and 100 μg/mL G1C1 had good biocompatibility.The results of a co-culture experiment with Staphylococcus aureus suspension displayed that G2C1,G1C1 and G1C2 had good antibacterial activity,among which G1C1 group demonstrated excellent antibacterial performance,and the antibacterial rate reached 100％when its mass concentration was 80 μg/mL.60-120 μg/mL G1C1 could effectively remove Staphylococcus aureus biofilm,and the higher the material mass concentration,the better the removal effect.Moxibustion could also effectively remove Staphylococcus aureus biofilm,and the closer the moxibustion was,the better the removal effect.(2)Compared with the control group,the wound area of the mupirocin group,moxibustion 2 group,moxibustion 2+G1C1 group and 80,100 μg/mL G1C1 groups was significantly reduced on day 7 of treatment,and the quality of wound repair was better.Mupirocin,G1C1,moxibustion and moxibustion 2+G1C1 could effectively remove the residual bacteria on the wound surface,and the higher the mass concentration of G1C1,the lower the residual bacteria.Among them,the wound repair efficiency and bacterial residue of 80 μg/mL G1C1 group and moxibustion 2 group were very similar,and the wound repair efficiency of both was better than that of mupirocin group.In addition,it was also observed that the combination of materials and moxibustion had a better ability to clear wound bacteria than that used alone.(3)The results confirm that moxibustion,reduced graphene oxide/cerium dioxide nanocomposites and their combination have good anti-infection and wound healing effects.
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BACKGROUND:Frog active peptides have rich activities,such as antibacterial and anti-tumor,and are expected to solve the problem of antibiotic resistance. OBJECTIVE:The active peptide QUB2984 was discovered in the skin secretions of Agalychnis callidryas.Its structure and properties were simulated by bioinformatics.The peptide was synthesized,purified,and identified and its biological functions were investigated. METHODS:Agalychnis callidryas skin secretions were collected by electrostimulation.The sequence of QUB2984 was obtained through constructing a cDNA library with isolated mRNA.BLAST was used for peptide sequence alignment.Besides that,Iterative Threading ASSEmbly Refinement(I-TASSER)and HeliQuest tools were used for protein secondary structure simulation.It was synthesized by solid-phase peptide synthesis,purified by reverse-phase high-performance liquid chromatography,and structurally confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.The purified peptide was used to evaluate its biological activity.Its antibacterial effect was evaluated by the minimum inhibitory concentration method.Its cytotoxic effect was detected by MTT assay.Its safety was investigated by a hemolysis test. RESULTS AND CONCLUSION:(1)Peptide QUB2984 had basically α-spiral structure,with a relatively intact hydrophobic surface,and a certain destructive ability to biofilm.The third amino acid position of QUB2984 was composed of W and had a G-X-G structure.(2)The minimum inhibitory concentration of QUB2984 against gram-positive Staphylococcus aureus was 2 μmol/L,the minimum inhibitory concentration against gram-negative Escherichia coli was 2 μmol/L,and the minimum inhibitory concentration against the fungus Candida albicans was 8 μmol/L.(3)The active peptide QUB2984 had obvious inhibitory effect on human non-small cell lung cancer cells NCI-H838 at 10-5 mol/L concentration,and the hemolytic effect on horse red cells at 64 μmol/L concentration was 50%.(4)The results showed that QUB2984 had anti-bacterial and anti-cancer activity,and it had a positive charge of +3,which was conducive to contact with bacteria or cells.
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BACKGROUND:Shikonin contributes to the promotion of bone defect repair and the treatment of osteoporosis. OBJECTIVE:To summarize the application potential of shikonin and its derivatives in oral soft and hard tissue regeneration. METHODS:A literature review was conducted in databases such as PubMed,Web of Science,Wanfang,China National Knowledge Infrastructure(CNKI),and VIP,spanning articles from 2002 to 2023.The search terms were"shikonin,oral cavity,periodontitis,antibacterial,bone formation,osteoclast,osteoporosis,toxicology"in Chinese and English. RESULTS AND CONCLUSION:Shikonin and its derivatives possess anti-inflammatory effects,inhibit periodontal pathogens such as Porphyromonas gingivalis,promote periodontal wound healing,and regenerate alveolar bone tissue.Shikonin formulations can be used to treat oral diseases such as aphthous ulcers and oral candidiasis.These findings suggest a promising future for shikonin and its derivatives in treating periodontal diseases,preventing oral ailments,and promoting the regeneration of both soft and hard periodontal tissues.Further research is needed to explore how to combine shikonin with tissue engineering to achieve quicker healing of oral soft and hard tissues.
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BACKGROUND:The increase in multi-drug resistant bacterial infections has become a major problem in modern healthcare due to the development of bacterial resistance to antibiotics and the development of new antibacterial alternative drug materials is of great importance. OBJECTIVE:To synthesize and perform a series of characterization of a CeO2 nanoenzyme to investigate its biocompatibility and antibacterial properties against Escherichia coli. METHODS:CeO2 nanoenzymes were synthesized using a hydrothermal method.The morphology,product composition,and chemical composition were analyzed using characterization methods such as X-ray diffraction,X-ray photoelectron spectroscopy,Fourier infrared analysis,Raman spectroscopy,scanning electron microscopy,and transmission electron microscopy.The peroxide-mimetic enzyme activity of CeO2 nanoenzymes was characterized using TMB color development assay.The toxic effect of CeO2 nanoenzymes at different concentrations(10,25,and 50 μg/mL)on mouse fibroblast L929 cells was evaluated using the CCK-8 assay.The antibacterial properties of CeO2 nanoenzymes against Escherichia coli under different conditions were evaluated using the plate coating method.Changes in intra-bacterial reactive oxygen species after treatment with different conditions were detected using a reactive oxygen species detection kit. RESULTS AND CONCLUSION:(1)The morphology of the synthesized CeO2 nanoparticles was rod-shaped,with Ce3+ accounting for 29.87%of the total Ce3+/Ce4+ and an average grain size of 7.4 nm.In a slightly acidic environment containing TMB and pH=5.5,CeO2 nanoenzymes mixed with H2O2 showed excellent peroxidase activity,but did not show peroxidase simulated activity at pH=7.4.(2)There was no statistically significant difference in the toxic effects of CeO2 nanoparticles at various mass concentrations on mouse fibroblast L929 cells.(3)In a slightly acidic environment at pH 5.5,Escherichia coli was inhibited to a certain extent in the presence of CeO2 nanoenzyme alone at a concentration of 10 μg/mL,with a decrease in CFU results of about 0.5 log(P＜0.01);in a slightly acidic environment containing 50 μmol/L H2O2,CeO2 nanoenzyme showed excellent antibacterial effects against Escherichia coli,with a decrease in Escherichia coli CFU results of by about 1.5 log(P＜0.001).After CeO2 nanoenzymes interacted with Escherichia coli,the level of reactive oxygen species in Escherichia coli increased(P＜0.05);after CeO2 nanoenzymes interacted with Escherichia coli together with H2O2,the level of reactive oxygen species in Escherichia coli increased significantly(P＜0.001).(4)The results show that the CeO2 nanoenzymes have good biocompatibility,are inherently antibacterial,and can exhibit peroxidase activity in a slightly acidic environment containing low concentrations of H2O2,and generate reactive oxygen species to kill bacteria,thus showing excellent antibacterial effects.
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BACKGROUND:Polylactic acid has good biocompatibility and biodegradability,and has become a new orthopedic fixation material.However,the lack of cell recognition signal of this material is not conducive to cell adhesion and osteogenic differentiation,which limits its application in biomaterials. OBJECTIVE:3D-printed polylactic acid-nano-hydroxyapatite(nHA)/chitosan(CS)scaffold to evaluate its drug sustained-release and biological properties. METHODS:The porous polylactic acid scaffold(recorded as PLA scaffold)with interporous pores was printed by fused deposition modeling technique,and the scaffold was soaked in dopamine solution to prepare polylactic acid-dopamine scaffold(recorded as PLA-DA scaffold).Nano-hydroxyapatite was immersed in chitosan solution,and then the PLA-DA scaffold was immersed in it to prepare polylactic acid-nano-hydroxyapatite/chitosan scaffold(recorded as PLA-nHA/CS scaffold).The micro-morphology,porosity,water contact angle,and compressive strength of the three scaffolds were characterized.PLA-nHA/CS scaffold loaded with doxycycline(recorded as PLA-nHA/CS-DOX scaffold)was prepared by freeze-drying method,and its drug release was characterized.PLA,PLA-DA,PLA-nHA/CS,and PLA-nHA/CS-DOX scaffolds were co-cultured with MC3T3-E1 cells,separately,to detect cell proliferation and osteogenic differentiation.Staphylococcus aureus suspensions of different concentrations were co-cultured with four groups of scaffolds.The antibacterial performance of scaffolds was detected by inhibition zone test. RESULTS AND CONCLUSION:(1)Under scanning electron microscopy,the surfaces of PLA and PLA-DA scaffolders were dense and smooth,and nHA particles were observed on PLA-nHA/CS scaffolders.The porosity of PLA,PLA-DA and PLA-nHA/CS scaffolds decreased gradually,and the compressive strength increased gradually.The elastic modulus of PLA-nHA/CS scaffolds met the requirements of cancelous bone.The water contact angle of PLA-DA and PLA-nHA/CS brackets was smaller than that of PLA scaffolds.The PLA-nHA/CS scaffold sustainably released drugs in vitro for 8 days.(2)CCK-8 assay showed that the proliferation of MC3T3-E1 cells was not significantly affected by the four groups of scaffolds.The activity of alkaline phosphatase in PLA-DA group,PLA-nHA/CS group,and PLA-nHA/CS-DOX group was higher than that in PLA group.Alizarin red staining showed that compared with PLA group,the cells in PLA-nHA/CS group and PLA-nHA/CS-DOX group showed higher mineralized water level.(3)Inhibition zone test exhibited that PLA and PLA-DA scaffolds had no antibacterial properties.PLA-nHA/CS scaffolds had certain antibacterial properties.PLA-nHA/CS-DOX scaffolds had super antibacterial properties.(4)The results showed that the PLA-nHA/CS-DOX scaffold had good drug release performance,cell compatibility,osteogenic properties,and antibacterial properties.
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BACKGROUND:Calcium phosphate(CaP)coatings are widely used to improve the integration of titanium implants into bone but these coatings are associated with risks of infection.It is thus desirable to confer antibacterial properties to CaP coatings. OBJECTIVE:To prepare CaP-MgO composite coatings by impregnating magnesium oxide(MgO)sol into CaP coatings and assess the in vitro antibacterial activities and cytocompatibility. METHODS:An electrolyte was determined by titration and used for CaP coating electrodeposition on titanium(referred to as Ti-CaP).MgO was impregnated into the coating by immersing in an MgO sol with different mass fractions(15%,30%,50%)and subsequently calcined to form MgO-CaP composite coatings,which were recorded as Ti-CaP-15Mg,Ti-CaP-30Mg and Ti-CaP-50Mg,respectively.Microstructure,tensile properties,critical load,and Mg2+ release of coatings in vitro were characterized.Antibacterial activity was assayed using spread plate method by culturing S.aureus on the pure titanium sheet surface and Ti-CaP,Ti-Cap-15mg,Ti-Cap-30mg and Ti-Cap-50mg surfaces for 24 and 48 hours.Mouse osteoblast suspension was inoculated on pure titanium sheets and Ti-CaP,Ti-CaP-15Mg,Ti-CaP-30Mg and Ti-CaP-50Mg coated titanium sheets,respectively.Cell proliferation was detected by CCK-8 assay,and cell survival rate was calculated.The morphology of composite coating soaked in DMEM was also observed. RESULTS AND CONCLUSION:(1)Homogeneous,microporous CaP coatings consisting of octacaclium phosphate crystal flakes were prepared on titanium by electrodeposition.After sol impregnation-calcination,MgO aggregates were filled into the inter-flake voids.The extent of MgO filling and Mg concentration in the coating increased with the number of sol impregnation procedures.When immersed in phosphate buffered saline,all composite coatings actively released Mg2+ within 1 day;subsequently,the Mg2+ release slowed down on day 3.A small amount of Mg2+ release was still detected on day 7.The yield strength,tensile strength and fracture growth rate of Ti-CaP-30Mg coated titanium were not significantly different from those of pure titanium(P>0.05).There was no significant difference in the critical load of Ti-CaP,Ti-CaP-15Mg,Ti-CaP-30Mg and Ti-CaP-50Mg groups(P>0.05).(2)Except that pure titanium sheet and Ti-CaP had no antibacterial properties,the other samples had good antibacterial properties,and the antibacterial rate increased with the increase of MgO content in the coating.(3)After 1 and 3 days of co-culture,the cell survival rate of Ti-CaP-15Mg,Ti-CaP-30Mg and Ti-CaP-50Mg groups was lower than that of pure titanium group and Ti-CaP group(P<0.05).After 5 and 7 days of culture,there was no significant difference in cell survival rate among five groups(P>0.05).The content of MgO in the coating decreased gradually with the time of immersion in the medium.(4)The MgO sol impregnation added antibacterial properties to the CaP coatings while retained their biocompatibility.
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BACKGROUND:At present,the treatment of infected bone defects has the problems of long course of disease,poor treatment effect and high cost.The osteogenic effect of personalized bone replacement materials in clinical treatment is limited.Therefore,a 3D-printed bone graft material with both good osteogenic effect and antibacterial effect is urgently needed for clinical treatment. OBJECTIVE:To summarize the research status of 3D-printed scaffolds loaded with antimicrobial agents for the treatment of infected bone defects. METHODS:PubMed,Web of Science,Elsevier,and CNKI databases from January 2010 to June 2022 were searched for related articles.The Chinese search terms were"bone defect,3D printing,scaffold material,antibacterial,animal experiments,in vitro experiments".English search terms were"bone defect,3D printing,scaffold,antibiosis,animal experiment,in vitro".Finally,60 articles were included for review and analysis. RESULTS AND CONCLUSION:The 3D scaffolds made of titanium,magnesium,tantalum and other metals and their alloys have certain osteogenic properties,but do not have antibacterial function.Hydroxyapatite and other bioceramic materials have good biocompatibility and are prone to be degraded,whereas due to the lack of strength,they are usually combined with artificial polymer materials to form composite materials,which respectively mimic the inorganic and organic components in natural bone,and play their respective excellent functions.Antibiotics,silver/copper nanoparticles,antimicrobial peptides,gallium and other antibacterial agents play an antibacterial role by destroying bacterial cell membrane,producing reactive oxygen species to interfere with bacterial DNA replication,inhibiting iron absorption and other mechanisms.As a result,the 3D-printed scaffold has both antibacterial and osteogenic effects.However,there are still some problems such as drug resistance and difficult to control effective concentrations.3D-printed scaffolds are often loaded with antibacterial agents by loading drug-loaded microspheres on scaffolds,preparing antibacterial coating on the scaffold surface,and participating in joint 3D printing with drugs.The loading mode of antibacterial coating prepared on the scaffold surface is the most widely used,and its antibacterial effect is more stable.Nonetheless,the selection of the most suitable loading mode for antibacterial agents needs to be further discussed and summarized.It is a future research prospect to optimize the mechanical properties of composite scaffolds and prepare biomimetic bone scaffolds so that the degradation rate is consistent with the bone reconstruction rate in infected bone defects.The ideal antibacterial agents may play a role through a variety of antibacterial mechanisms,thus being expected to play a good antibacterial effect through low antibacterial concentration,which should be a hot spot of anti-bone infection research.After loading antibacterial agents on the surface of the scaffold,antibacterial agents can"intelligently"react to the local microenvironment,achieving controlled release,and regulating the osteogenesis,vascularization and immune response of the microenvironment,which is the focus of current research.