Biogenic zinc selenide nanoparticles fabricated using Rosmarinus officinalis leaf extract with potential biological activity.

Zinc selenide nanoparticles (ZnSe) are semiconductor metals of zinc and selenium. ZnSe NPs are advantageous for biomedical and bio-imaging applications due to their low toxicity. ZnSe NPs can be used as a therapeutic agent by synthesizing those using biologically safe methods. As a novel facet of these NPs, plant-based ZnSe NPs were fabricated from an aqueous extract of Rosmarinus officinalis L. (RO extract). Physiochemical analyses such as UV-visible and FTIR spectroscopy, SEM-EDX and TEM Imaging, XRD and DLS-Zeta potential analyses confirmed the biological fabrication of RO-ZnSe NPs. Additionally, Ro-ZnSe NPs were investigated for their bioactivity. There was an apparent peak in the UV-visible spectrum at 398 nm to confirm the presence of ZnSe NPs. FTIR analysis confirmed RO-extract participation in ZnSe NPs synthesis by identifying putative functional groups associated with biomolecules. TEM and SEM analyses revealed that RO-ZnSe NPs have spherical shapes in the range of 90-100 nm. According to XRD and EDX analysis, RO-ZnSe NPs had a crystallite size of 42.13 nm and contain Se and Zn (1:2 ratio). These NPs demonstrated approximately 90.6% antioxidant and antibacterial activity against a range of bacterial strains at 100 µg/ml. Antibiofilm activity was greatest against Candida glabrata and Pseudomonas aeruginosa at 100 g/ml. Accordingly, the IC50 values for anticancer activity against HTB-9, SW742, and HF cell lines were 14.16, 8.03, and 35.35 g/ml, respectively. In light of the multiple applications for ZnSe NPs, our research indicates they may be an excellent option for biological and therapeutic purposes in treating cancers and infections. Therefore, additional research is required to determine their efficacy.

Biological Activities of Zinc Oxide Nanoparticles Green Synthesized Using the Aqueous Extract of Dracocephalum kotschyi Boiss.

BACKGROUND: Dracocephalum kotschyi Boiss. is known as a native medicinal plant of Iran. OBJECTIVE: In this study, aqueous extract of D. kotschyi was used to synthesize ZnO-NPs. To produce ZnO-NPs, aerial parts of D. kotschyi were powdered and then macerated for obtaining aqueous extract, after that, aqueous extract was used to reduse zinc nitrate to ZnO-NPs. METHODS: To confirm nanoparticles synthesis, SEM, TEM, UV-Vis, FTIR, and XRD were used. The synthesized ZnO-NPs were studied for antimicrobial activities by microdilution method for calculating MIC and MBC. Analysis of ZnO-NPs confirmed successful synthesis by extract of D. kotschyi. RESULTS: The sizes of ZnO-NPs were estimated 50-200 nm in diameter. Antibacterial and antifungal experiments showed potent activities against Staphylococos aureus, Pseudomonas aeruginosa and Candida albicans. The results of the studies showed that the nanoparticles synthesized with the aqueous extract of D. kotschyi have a much greater antimicrobial effect than the aqueous extract of D. kotschyi and zinc nanoparticles, each alone (MIC values 3.7 to 7.5 mg/ml). CONCLUSION: The noteworthy point is that the inhibitory rate of synthesized zinc oxide nanoparticles is higher compared to broad-spectrum antibiotics, such as chloramphenicol (MIC values 15 mg/ml). Determining the therapeutic and toxic dose of this product for humans requires further investigation and clinical trials.

Synthesis, characterization, and antiparasitic effects of zinc oxide nanoparticles-eugenol nanosuspension against Toxoplasma gondii infection.

Background: In this study, zinc oxide nanoparticles-coated with eugenol (ZnO@Eug) were synthesized and evaluated as a nanosuspension (NSus) formulation against Toxoplasma gondii in vitro and in vivo. Methods: An anti-Toxoplasma activity assay for ZnO@Eug NSus was conducted in vitro, ex vivo, and in vivo. FTIR spectroscopy confirmed the formation of ZnO@Eug NSus by detecting several functional groups involved; EDX and SEM demonstrated the grain of ZnO-NPs embedded with Eug and compositional purity. Results: Surface charge (ZP) and size distribution (DLS) of ZnO@Eug NSus were determined to be -22.7 mV and 109.6 nm, respectively. According to the release kinetics, approximately 60% of the ZnO-NPs and Eug were released in the first 45 min. In the cytotoxicity assay, ZnO-NPs, Eug, and ZnO@Eug NSus had IC50 values of 71.85, 22.39, and 2.02 mg/mL, respectively. The therapeutic efficacy of ZnO@Eug against T. gondii was 56.3%, which was not significantly different from that of spiramycin (58.9%) (Positive-control). The tissue tachyzoites in the liver, spleen, and peritoneum were less than 50% in groups treated with Eug, spiramycin, and ZnO@Eug NSus compared to the control. ZnO@Eug-treated groups showed a survival rate of up to 13 days. Conclusions: The ZnO@Eug NSus demonstrated antiparasitic activity against T. gondii with minimal toxic effects and high efficiency in increasing the survival of infected mice. The nanoformulations of ZnO-NPs incorporated with Eug could, in the future, be considered for treating toxoplasmosis in humans and animals if a detailed study was conducted to determine the precise dose and measure side effects.

Nanoparticles as Potent Agents for Treatment of Schistosoma Infections: A Systematic Review.

Background: Schistosomiasis is an acute and chronic parasitic disease caused by blood flukes of the genus Schistosoma. The current drugs for treating schistosomiasis are associated with some side effects. Objective: The aim of this systematic study was an overview of the treatment of diseases caused by Schistosoma based on nanoparticles. Methods: In the present systematic research with keywords "Schistosoma", "parasitism", "anti-Schistosoma activity", "nanoparticles", "metal nanoparticles", "silver nanoparticles", "gold nanoparticles", "polymer nanoparticles", "PLGA nanoparticles", "nanoemulsions", "in vitro", and "in vivo" from five English-language databases, including ScienceDirect, europePMC, PubMed, Scopus, Ovid, and Cochrane were searched from 2000 to 2022 by 2 researchers. Results: In the initial search, 250 studies were selected. Based on the inclusion and exclusion criteria, 27 articles were finally selected after removing duplicate, unrelated, and articles containing full text. In present article, the most nanoparticles used against Schistosoma were gold nanoparticles (22%). Conclusions: The results indicate the high potential of various nanoparticles, including metal nanoparticles, against Schistosoma. Also, the remarkable anti-schistosomal activity of nanoparticles suggests their use in different fields to eliminate this pathogenic microorganism so that it can be used as an effective candidate in the preparation of anti-schistosomal compounds because these compounds have fewer side effects than chemical drugs. Ther Res Clin Exp. 2023; XX:XXX-XXX).

Antibacterial Effects of Nanocomposites on Efflux Pump Expression and Biofilm Production in Pseudomonas aeruginosa: A Systematic Review.

BACKGROUND: Pseudomonas aeruginosa is an opportunistic gram-negative pathogen with multiple mechanisms of resistance to antibiotics. This systematic review aimed to study the antibacterial effects of nanocomposites on efflux pump expression and biofilm production in P. aeruginosa. METHODS: The search was conducted from January 1, 2000, to May 30, 2022, using terms such as (P. aeruginosa) AND (biofilm) AND (antibiofilm activity) AND (anti-Efflux Pump Expression activity) AND (nanoparticles) AND (Efflux Pump Expression) AND (Solid Lipid NPS) AND (Nano Lipid Carriers). Many databases are included in the collection, including ScienceDirect, PubMed, Scopus, Ovid, and Cochrane. RESULTS: A list of selected articles was retrieved by using the relevant keywords. A total of 323 published papers were selected and imported into the Endnote library (version X9). Following the removal of duplicates, 240 were selected for further processing. Based on the titles and abstracts of the articles, 54 irrelevant studies were excluded. Among the remaining 186 articles, 54 were included in the analysis because their full texts were accessible. Ultimately, 74 studies were selected based on inclusion/exclusion criteria. CONCLUSION: Recent studies regarding the impact of NPs on drug resistance in P. aeruginosa found that various nanostructures were developed with different antimicrobial properties. The results of our study suggest that NPs may be a feasible alternative for combating microbial resistance in P. aeruginosa by blocking flux pumps and inhibiting biofilm formation.

New Strategies in the Treatment of Plasmodium berghei Based on Nanoparticles: A Systematic Review.

BACKGROUND: Drug resistance is a current issue affecting parasites caused by Plasmodium. Therefore, researchers have expanded their studies on nanoparticles to find new and effective drugs that can treat drug-resistant strains. The present study systematically investigates the effect of different nanoparticles, including metal, polymer, and lipid nanoparticles, on Plasmodium berghei. METHODS: In this study, English-language online literature was obtained from the databases Science Direct, PubMed, Scopus, Ovid, and Cochrane to conduct a systematic review. In the search, we used the keywords: (Plasmodium Berghei) AND (Malaria) AND (Parasitemia) AND (antimalarial activity) AND (nanoparticles) AND (Solid lipid NPS) AND (Nano lipid carriers) AND (Artemether) AND (Chloroquine) AND (intraperitoneal) AND (in vivo). Initially, a total of 160 studies were retrieved from the search. After removing duplicates, 80 studies remained. After reviewing the title and abstract of each study, 45 unrelated studies were eliminated. RESULTS: The remaining 35 studies were thoroughly reviewed using the full texts. The final result was 21 studies that met the inclusion/exclusion criteria. CONCLUSION: Using these findings, we can conclude that various nanoparticles possess antiparasitic effects that may be applied to emerging and drug-resistant parasites. Together, these findings suggest that nanostructures may be used to design antiparasitic drugs that are effective against Plasmodium berghei.

Evaluation of scolicidal potential of salicylate coated zinc nanoparticles against Echinococcus granulosus protoscoleces.

Echinococcosis is a zoonotic disease caused by larval stages of the Echinococcus genus (metastasis). In this study, salicylate-coated Zinc oxide nanoparticles (SA-ZnO-NPs) were fabricated and characterized by SEM, FTIR and XRD analytical techniques. After that, different doses of SA-ZnO-NPs, SA and ZnO-NPs were taken to assess scolicidal potency. Scanning electron microscopy (SEM) micrographs were also used to evaluate the morphological deformities of treated protoscoleces. Furthermore, Caspase-3&7 inductions were examined in protoscoleces cysts treated with all formulations. Based on SEM and DLS analyses, the size of SA-ZnO-NPs was between 30 and 40 nm, with a spherical shape. The FTIR spectrum verified the presence of SA functional groups on the ZnO coating. At 20 min, SA-ZnO-NPs at 2000 µg/ml exhibited the greatest activity on protoscolices with 100% mortality, followed by ZnO-NPs at 1500 µg/ml at 10 min and SA alone at 2000 µg/ml at 30 min. The activation of Caspase-3&7 apoptotic enzyme was determined for 2000 µg/ml of SA-ZnO-NPs, ZnO-NPs and SA to be 16.4, 31.4, and 35.7%, respectively. The SEM image revealed apoptogenic alterations and the induction of tegument surface wrinkles, as well as abnormalities in rostellum protoscolices. According to the current study, SA-ZnO-NPs have a high mortality rate against hydatid cyst protoscolices. As a result, further studies on the qualitative assessment of these nanoformulations in vivo and preclinical animal trials seem to be required. Furthermore, the adoption of nano-drugs potentially offers alternative therapeutic approaches to combat hydatid cysts.

Preparation of Zinc Oxide Nanoparticles Assisted by Okra Mucilage and Evaluation of its Biological Activities.

BACKGROUND: In this study, zinc oxide nanoparticles (ZnO-NPs) were biologically synthesized from Abelmoschus esculentus L. (Okra) mucilage fraction (OM). METHODS: Analytical techniques were employed to study the formation and properties of OM-ZnO NPs, including their morphology, shape, size distribution, and surface charges. Additionally, OM-ZnO NPs were assessed for their antimicrobial, antioxidant, and cytotoxic properties. RESULTS: UV-visible spectroscopy confirmed the formation of OM-ZnO NPs, evident by the appearance of an SPR peak at 368.8 nm. The FTIR spectroscopy demonstrated that OM functional groups contribute to the formation and stability of the NPs. Micrographs from TEM and SEM showed that OM-ZnO NPs ranged from 15-40 nm in diameter, whereas hydrodynamic diameter and surface charge values obtained from Zeta and DLS were 72.8 nm and 14.6 mv, respectively. XRD analysis indicated the OM-ZnO NPs were crystalline with a wurtzite structure and a crystallite size of 27.3 nm, while EDX revealed a zinc: oxygen ratio of 67.5:34. Further, the OM-ZnO NPs demonstrated significant antimicrobial activity in response to different types of bacteria. In the antioxidant assay, the OM-ZnO NPs scavenged DPPH with 68.6% of the efficiency of ascorbic acid (100%). CONCLUSION: The present study demonstrated the cytotoxic efficacy of MO-ZnO NPs against MCF7 cells with an IC50 of 43.99 µg/ml. Overall, the green synthesis of ZnO NPs by OM was successful for many biological applications, such as antimicrobial, antioxidant, and anticancer. Moreover, OM-ZnO NPs can be applied as a biologically-derived nanotherapeutic agent.

A systematic appraisal of the use of carvacrol-rich plants to treat hydatid cysts.

Hydatid cysts occur in the larval stage of Echinococcus granulosus worms in vital organs such as the liver, lung, brain, kidney, heart and spleen. As a result, the formation of these cysts in humans and animals is considered one of the most catastrophic common infections in humans and animals. So far, there is no definitive effective treatment strategy for this disease in humans. Cyst eradication through surgery is the only treatment, which might be difficult or impossible in some cases. The most difficult aspect of cyst removal surgery is recurrence and anaphylactic shock. As a result, many scolicidal medications are ineffective at inactivating the content of hydatid cysts in vivo. Herbal medicines are now considered a potential treatment for the treatment of hydatid cysts due to their effective anti-cystic activities, minimal side effects, and ability to improve immunity. In the present review study, the anti-cystic role of carvacrol as one of the main constituents of the Lamiaceae family on hydatid cyst has been discussed. The results demonstrate that carvacrol-containing essential oils may be utilized as a hydatid cyst inhibitor. This study has also shown the synergistic activity of carvacrol, thymol and other active plant metabolites.

The Relationship Between HCV-NS5A Gene Mutations and Resistance to Combination Therapy in Patients with HCV- Genotype 1-B.

BACKGROUND: Hepatitis C virus (HCV) is one of the major causes of chronic liver disease, as it holds a significant role in developing liver cirrhosis and hepatocellular carcinoma. Combination therapy with Pegaferon and Ribavirin leads to viral clearance of only 50% of patients. During the host antiviral response, protein kinase R (PKR) interacts with eukaryotic translation initiation factor 2 alpha (eIF2α), that leads to the inhibition of viral protein synthesis. The viral NS5A protein appears to interfere with this antiviral action, evading the host immune response. However, mutations in the NS5A gene have been observed to render HCV more susceptible to treatment. The aim of this study was to determine the mutations present in the IFN Sensitivity Determining Region (ISDR) and NS5A-PKRbinding domain regions in chronic HCV infected patients before and after therapy. METHODS: Viral RNA was isolated from the plasma of 52 chronic HCV infected patients before and after treatment. RT-Nested PCR reaction was used to reverse transcription and amplification of target fragment using the specific primers. RESULTS: Sequence analysis revealed no relationship between NS5A mutations and response to treatment. No significant difference was found between the mutations before and 3 months after treatment among responders and non-responders. CONCLUSION: This study showed that the number of mutations in NS5A did not significantly differ between the patients who responded to treatment and the patients that did not. Therefore, sequencing of these regions does not appear to be a suitable tool for predicting treatment outcomes.

Antimicrobial Activities of Satureja khuzestanica Jamzad; A Review.

Satureja khuzestanica Jamzad is a species native to Iran and is highly important in Southwestern regions. It belongs to the Lamiaceae family and grows in different climates. A number of pharmacological properties such as analgesic, anti-inflammatory, anticancer, anti-thyroid, antioxidant, and diuretic have been attributed to this plant. In recent years, a wide range of biological properties, extract, and essential oil of Satureja khuzestanica has been studied by researchers. In the present study, Scopus, SID, ISI, Google Scholar, and PubMed indices were used to extract research articles. No publication time constraint was considered, and the keyword "Satureja khuzestanica" was used to search articles. All extracted articles were examined by two expert researchers and those on the biologic and fundamental science properties of this plan entered the study. Results showed that S. khuzestanica has extensive research and medicinal applications. Considering the economic and medical importance of S. khuzestanica, it is hoped that more extensive studies can be conducted in the future on the use of compounds and derivatives of this plant in order to obtain herbal medications to treat pathogens in human and animal.

Anti-Candida Activity of Curcumin: A Systematic Review.

Curcumin is one of the important natural compounds that is extracted from turmeric. This compound and its derivatives have numerous biological properties, including antioxidant, anticancer, anti-inflammatory, antimicrobial, and healing effects. Extensive research in various fields has been conducted on turmeric as it is widely used as a food additive. The significant antifungal activity is one of the major effects of curcumin. In this paper, recent studies on the effects of different forms of curcumin drug on the candidiasis were systematically examined and discussed. The data in this study were extracted from the articles and reports published in the Web of Science, Google Scholar, PubMed, and Scopus databases. After the preliminary investigation, relevant reports were selected and classified based on the incorporated formulation and purpose of the study. After a systematic discussion of the data, it was found that the use of medicinal forms based on nanoparticles can increase the absorption and target the controlled release of curcumin with a more effective role compared to other formulations. Consequently, it can be concluded that new methods of modern medicine can be employed to increase the efficacy of natural pharmaceutical compounds used in the past. In this regard, the present study analyzed the effect of curcumin against various Candida infections, using the recent data. It was found that applying a combination of drug formulation or the formulation of curcumin and its derivatives can be an effective strategy to overcome the medicine resistance in fungal infections, especially candidiasis.

In vitro potential effect of Pipper longum methanolic extract against protoscolices of hydatid cysts.

This study aimed to evaluate the efficacy of methanolic extract of P. longum (PLM) against protoscolices of hydatid cyst in vitro. Four different concentrations of PLM extract (25, 50, 100 and 150 mg/ml) were used for the experiments. The metabolites in the PLM extract were characterized by Gas chromatography-mass spectrometry (GC-MS). The results showed the highest lethality of PLM extract in 50 mg/ml for 60 min exposure. The IC50 value obtained about 20 mg/ml for 60 min of PLM extract exposure. In this study, valuable findings were obtained for the first time about the scolicidal activity of P. longum, which is expected to conduct further studies in this field in the future.

Bio-inspired silver selenide nano-chalcogens using aqueous extract of Melilotus officinalis with biological activities.

For the first time, an aqueous extract of Melilotus officinalis was used to synthesize bimetallic silver selenide chalcogenide nanostructures (Ag2Se-NCs). The formation of NCs was confirmed and characterized by UV-visible and FTIR spectroscopy, SEM and TEM imaging, XRD and EDX crystallography, zeta potential (ZP) and size distribution (DLS). The bioactivities of biosynthesized Ag2Se-NCs, such as antibacterial, antibiofilm, antioxidant and cytotoxicity potentials, were then examined. Bio-based Ag2Se-NCs were successfully synthesized with mostly spherical shape in the size range of 20-40 nm. Additionally, the MIC and MBC values of Ag2Se-NCs against ß-lactam-resistant Pseudomonas aeruginosa (ATCC 27853) were 3.12 and 50 µg/ml, respectively. The DPPH scavenging potential of Ag2Se-NCs in terms of IC50 was estimated to be 58.52. Green-synthesized Ag2Se-NCs have been shown to have promising benefits and could be used for biomedical applications. Although the findings indicate promising bioactivity of Ag2Se-NCs synthesized by M. officinalis extract (MO), more studies are required to clarify the comprehensive mechanistic biological activities.

Emerging Involvement of long non-coding RNAs in gastrointestinal associated inflammatory disorders.

Gastrointestinal (GI) disorders including a wide range of infectious, inflammatory, autoimmune, etc. disorders. Inflammatory bowel and celiac disease are non-fatal but overwhelming GI associated disorders. IBD and celiac's complications, besides the great suffering, disturb the normal life of the patients and make them involved in mental and physical problems. The emerging role of genetic content is deniable for GI inflammatory disorders incidence, and long non-coding RNAs (lncRNAs) function is the recent topic for its association. Analyzing of absolute lncRNAs interference in GI inflammatory appearance remains in infancy, and more studies are requested. Here, we concisely performed a systematic review in the last knowledge up to 2020 to identify all of the significant lncRNAs associated with the initiation and progression of GI inflammatory diseases. Accordingly, this assay attempted to refer to the expression of lncRNAs changing from the normal state, discovery of genetic mechanisms, and main effectors that would trigger associated IBD and celiac expression and immune responses would be effective for therapeutic approaches. It could be useful for prognostic and diagnostic purposes of GI associated inflammatory disorders.

Designation of chitosan nano-vaccine based on MxiH antigen of Shigella flexneri with increased immunization capacity.

Shigella flexneri is a gram-negative pathogen that causes shigellosis in humans and primates. MxiH antigen is known as one of the invasive factors in most Gram-negative bacteria consisting of a needle-like structure in the main backbone of the type 3 secretory system. Recombinant MxiH antigen was produced by E. coli BL21 and purified antigen was loaded into chitosan nanoparticles (CS-MxiH). After 20thand 55th of intranasal vaccinations, the titers of IgG, IgA, IL-4, and IFN-γ were evaluated. The results indicated the successful synthesis of CS nanoparticles followed by the effective loading of MxiH antigen. The results of animal experiments showed that the intranasal administration of CS-MxiH increased IgG and IgA compared to control groups. Increased levels of IL-4 and IFN-γ in groups immunized with CS-MxiH are probably due to the activation of plasmacytoid and myeloid cells presenting antigen in nasal epithelial mucosa and stimulating B cells.

Oncogenesis and Tumor Inhibition by MicroRNAs and its Potential Therapeutic Applications: A Systematic Review.

MicroRNAs appear as small molecule modifiers, which improve many new findings and mechanical illustrations for critically important biological phenomena and pathologic events. The best-characterized non-coding RNA family consists of about 2600 human microRNAs. Rich evidence has revealed their crucial importance in maintaining normal development, differentiation, growth control, aging, modulation of cell survival or apoptosis, as well as migration and metastasis as microRNAs dysregulation leads to cancer incidence and progression. By far, microRNAs have recently emerged as attractive targets for therapeutic intervention. The rationale for developing microRNA therapeutics is based on the premise that aberrantly expressed microRNAs play a significant role in the emergence of a variety of human diseases ranging from cardiovascular defects to cancer, and that repairing these microRNA deficiencies by either antagonizing or restoring microRNA function may yield a therapeutic benefit. Although microRNA antagonists are conceptually similar to other inhibitory therapies, improving the performance of microRNAs by microRNA replacement or inhibition that is a less well- described attitude. In this assay, we have condensed the last global knowledge and concepts regarding the involvement of microRNAs in cancer emergence, which has been achieved from the previous studies, consisting of the regulation of key cancer-related pathways, such as cell cycle control and the DNA damage response and the disruption of profile expression in human cancer. Here, we have reviewed the special characteristics of microRNA replacement and inhibition therapies and discussed explorations linked with the delivery of microRNA mimics in turmeric cells. Besides, the achievement of biomarkers based on microRNAs in clinics is considered as novel non-invasive biomarkers in diagnostic and prognostic assessments.

Cancer stem cells and nanotechnological approaches for eradication.

Cancer stem cells (CSCs) are currently known as the main cause of tumor recurrence. After chemotherapy is completed, CSCs proliferate and then differentiate to generate new tumor tissues. Similar to normal stem cells, this non-uniformly distributed cell population in the tumor tissue has self-renewal capacity and is responsible for survival of the tumor and difference in its genetic and metabolic characteristics. Followed by gene instability in CSCs, new phenotypic markers are aberrantly expressed in CSCs subpopulation. Hence, some of the surface markers and metabolic pathways that are upregulated in CSCs may be applied as specific targets for development of diagnostic and therapeutic approaches. In this review article, the distinctive properties of CSCs including signal pathways implicated in self-renewal and surface markers were discussed. Moreover, targeting CSCs based on their specific properties using nanodrugs was reviewed.

Mentha piperita essential oils loaded in a chitosan nanogel with inhibitory effect on biofilm formation against S. mutans on the dental surface.

Mentha piperita essential oils (MPEO) were loaded into chitosan nanogel to use as antibiofilm agent against Streptococcus mutans and to protect its dental plaque. Chitosan nanoparticles (CsNPs) were prepared by sol-gel method using linking bridge of tripolyphosphate (TPP). Physiological properties of MPEO-CNs were assessed by FTIR, SEM/EDX, DLS and zeta potential. Release kinetics, MIC and MBC were determined for MPEO-CNs. Expression of biofilm-associated genes including 8 genes: grfB, C and D, brpA, spaP, gbpB, relA and vicR was investigated at the presence of sub-MIC of MPEO-CNs. Most abundant bioactive compounds of MPEO were l-menthol (45.05%) and l-menthal (17.53%). SEM/EDX exhibited successful entrapment of MPEO into CsNPs followed by the changes in abundance of elemental peaks. A signal at 1737 cm-1 on chitosan spectrum was attributed to the carboxylic (CO) groups overlapped by MPEO incorporation. A new signal at 2361 cm-1 was assigned to electrostatic interactions of amine groups in chitosan with phosphoric units of TPP within the MPEO-chitosan. MPEO incorporation into porous nanogel decreased monodispersity of the nanoparticles and then raises z-average. Maximum release of MPEO was about 50% during 360 h in a hydroalcoholic solvent at ambient temperature. The adherence of bacterial cells showed high sensitivity to the nanoformulation of MPEO compared with unloaded chitosan-nanogel. Antibiofilm inhibition of S. mutans occurred in 50 and 400 µg/mL for MPEO-CNs and unloaded-nanogel, respectively. Among biofilm synthesis genes, gtfB, gtfC, gtfD were slightly affected by MPEO-CNs treatment, while gbpB, spaP, brpA, relA, and vicR genes underwent significant down-regulation in the presence of both unloaded-nanogel and MPEO-loaded-nanogel. This study demonstrated that the MPEO-CNs promised an efficient nanoformulation with the greatest inhibitory action against some glycosyltransferase genes (gtfB, C and D) as important enzymes involved in extracellular polymers. Finally, the results concluded that MPEO-CNs have a potential use as antibiofilm agent in toothpaste or mouth washing formulations.

Evaluation of antimicrobial activity of synthesised silver nanoparticles using Thymus kotschyanus aqueous extract.

Development of a green chemistry process for the synthesis of silver nanoparticles (AgNPs) has become a focus of interest. Characteristics of AgNPs were determined using techniques, such as ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The synthesised AgNPs using Thymus kotschyanus had the most growth inhibition against gram-positive bacteria such as Staphylococcus aureus and Bacillus subtilise, while the growth inhibition of AgNPs at 1000-500 µg/ml occurred against Klebsiella pneumonia and at 1000-250 µg/ml of AgNPs was observed against E. coli. The UV-vis absorption spectra confirmed the formation of the AgNPs with the characteristic peak at 415 nm and SEM micrograph acknowledged spherical particles in a nanosize range. FTIR measured the possible biomolecules that are responsible for stabilisation of AgNPs. XRD analysis exhibited the crystalline nature of AgNPs and showed face-centred cubic structure. The synthesised AgNPs revealed significant antibacterial activity against gram-positive bacteria.