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  1. Nuge T, Liu Z, Liu X, Ang BC, Andriyana A, Metselaar HSC, et al.
    Molecules, 2021 Jan 29;26(3).
    PMID: 33572728 DOI: 10.3390/molecules26030699
    Volumetric Muscle Loss (VML) is associated with muscle loss function and often untreated and considered part of the natural sequelae of trauma. Various types of biomaterials with different physical and properties have been developed to treat VML. However, much work remains yet to be done before the scaffolds can pass from the bench to the bedside. The present review aims to provide a comprehensive summary of the latest developments in the construction and application of natural polymers-based tissue scaffolding for volumetric muscle injury. Here, the tissue engineering approaches for treating volumetric muscle loss injury are highlighted and recent advances in cell-based therapies using various sources of stem cells are elaborated in detail. An overview of different strategies of tissue scaffolding and their efficacy on skeletal muscle cells regeneration and migration are presented. Furthermore, the present paper discusses a wide range of natural polymers with a special focus on proteins and polysaccharides that are major components of the extracellular matrices. The natural polymers are biologically active and excellently promote cell adhesion and growth. These bio-characteristics justify natural polymers as one of the most attractive options for developing scaffolds for muscle cell regeneration.
  2. Majumder MAA, Rahman S, Cohall D, Bharatha A, Singh K, Haque M, et al.
    Infect Drug Resist, 2020;13:4713-4738.
    PMID: 33402841 DOI: 10.2147/IDR.S290835
    Antimicrobial resistance (AMR) is a serious threat to global public health. It increases morbidity and mortality, and is associated with high economic costs due to its health care burden. Infections with multidrug-resistant (MDR) bacteria also have substantial implications on clinical and economic outcomes. Moreover, increased indiscriminate use of antibiotics during the COVID-19 pandemic will heighten bacterial resistance and ultimately lead to more deaths. This review highlights AMR's scale and consequences, the importance, and implications of an antimicrobial stewardship program (ASP) to fight resistance and protect global health. Antimicrobial stewardship (AMS), an organizational or system-wide health-care strategy, is designed to promote, improve, monitor, and evaluate the rational use of antimicrobials to preserve their future effectiveness, along with the promotion and protection of public health. ASP has been very successful in promoting antimicrobials' appropriate use by implementing evidence-based interventions. The "One Health" approach, a holistic and multisectoral approach, is also needed to address AMR's rising threat. AMS practices, principles, and interventions are critical steps towards containing and mitigating AMR. Evidence-based policies must guide the "One Health" approach, vaccination protocols, health professionals' education, and the public's awareness about AMR.
  3. Alam S, Rashid MA, Sarker MMR, Emon NU, Arman M, Mohamed IN, et al.
    BMC Complement Med Ther, 2021 Apr 12;21(1):119.
    PMID: 33845836 DOI: 10.1186/s12906-021-03290-6
    BACKGROUND: Colocasia gigantea, locally named as kochu is well-known due to its various healing power. This research is to investigate the antidiarrheal, antimicrobial and antioxidant possibilities of the methanol soluble extract of Colocasia gigantea.

    METHODS: The antidiarrheal investigation was performed by using in vivo castor oil-induced diarrheal method whereas in vitro antimicrobial and antioxidant investigation have been implemented by disc diffusion and DPPH scavenging method respectively. Moreover, in silico studies were followed by molecular docking analysis of several secondary metabolites that were appraised with Schrödinger-Maestro v11.1 and Biovia Discovery Studio.

    RESULTS: The induction of plant extract (200 and 400 mg/kg, b.w, p.o) has minimized the castor oil mediated diarrhea by 16.96% (p 

  4. Foo SC, Khoo KS, Ooi CW, Show PL, Khong NMH, Yusoff FM
    Front Bioeng Biotechnol, 2020;8:546067.
    PMID: 33553111 DOI: 10.3389/fbioe.2020.546067
    The ever-expanding human population puts tremendous pressure on global food security. With climate change threats lowering crop productivity and food nutritional quality, it is important to search for alternative and sustainable food sources. Microalgae are a promising carbon-neutral biomass with fast growth rate and do not compete with terrestrial crops for land use. More so, microalgae synthesize exclusive marine carotenoids shown to not only exert antioxidant activities but also anti-cancer properties. Unfortunately, the conventional method for fucoxanthin extraction is mainly based on solvent extraction, which is cheap but less environmentally friendly. With the emergence of greener extraction techniques, the extraction of fucoxanthin could adopt these strategies aligned to UN Sustainable Development Goals (SDGs). This is a timely review with a focus on existing fucoxanthin extraction processes, complemented with future outlook on the potential and limitations in alternative fucoxanthin extraction technologies. This review will serve as an important guide to the sustainable and environmentally friendly extraction of fucoxanthin and other carotenoids including but not limited to astaxanthin, lutein or zeaxanthin. This is aligned to the SDGs wherein it is envisaged that this review becomes an antecedent to further research work in extract standardization with the goal of meeting quality control and quality assurance benchmarks for future commercialization purposes.
  5. Kotyla PJ, Engelmann M, Giemza-Stokłosa J, Wnuk B, Islam MA
    Int J Mol Sci, 2021 Feb 28;22(5).
    PMID: 33671049 DOI: 10.3390/ijms22052449
    Recent advances in immunology enabled the characterization of several signal transmitting pathways responsible for proper cytokine and chemokine signaling. Among them, Janus kinases (JAKs) are essential components of receptor activation systems. The discovery of JAK kinases enabled the synthesis of JAK kinase inhibitors (JAKi or Jakinibs), which have proven to be efficacious in the treatment of hematologic malignancies and several rheumatological disorders and continue to be investigated in many clinical indications. Blocking multiple cytokines belonging to several cytokine families with a single small molecule may, however, create a potential risk for the patients. Recently, a higher risk of thromboembolic complications, namely, deep vein thrombosis and pulmonary embolism, has been recognized as the main concern during treatment with Jakinibs. At present, it is not entirely clear whether this increased risk is related to direct cytokine blockade, the presence of concomitant diseases in treated patients or other unknown circumstances that work together to increase the risk of this side effect. In this review, we discuss data on the risk of thromboembolic side effects, with special emphasis on the mechanism that may be responsible for this increased risk. Many indirect data indicate that higher thromboembolic risk may be related to the specificity of JAK inhibitor action, such that preferentially blocking one signaling pathway upsets the balance between pro and anti-thrombotic activities.
  6. Abu Bakar M, McKimm J, Haque SZ, Majumder MAA, Haque M
    J Inflamm Res, 2018;11:329-337.
    PMID: 30233227 DOI: 10.2147/JIR.S162486
    Recurrent tonsillitis is described as when an individual suffers from several attacks of tonsillitis per year. Chronic and recurrent tonsillitis both cause repeated occurrences of inflamed tonsils which have a significant impact on a patient's quality of life. Numerous children suffer from recurrent tonsillitis and sore throats, and these illnesses become part of their life. Antimicrobials can provide temporary relief, but in many cases, tonsillitis recurs. The cause of such recurrent infections have been identified as microorganisms which often create biofilms and a repository of infection in the wet and warm folds of the tonsils. This review discusses different treatment modalities, their advantages and disadvantages, and new treatment options focusing on biofilms. All treatment options should be selected based on evidence and individual need.
  7. Balami AD, Said SM, Zulkefli NAM, Norsa'adah B, Audu B
    Malar J, 2021 Jan 21;20(1):55.
    PMID: 33478529 DOI: 10.1186/s12936-021-03586-5
    BACKGROUND: The prevalence of malaria in pregnancy and its complications, remain very high in Nigeria. This study aimed to determine the effects of a malaria health educational intervention based on the information-motivation-behavioural skills (IMB) model on malaria preventive practices and pregnancy outcomes.

    METHODS: The study was a randomized controlled parallel-group study, where 372 randomly selected antenatal care attendees were randomly assigned to one of either two groups after collecting baseline data. The intervention group then received a four-hour health education intervention in Hausa language, which was developed based on the IMB model, while the control group received a similarly designed health education on breastfeeding. Follow up data were then collected from the participants at a first (2 months post-intervention) and second (4 months post-intervention) follow up, and at the end of their pregnancies.

    RESULTS: For both groups, reported ITN use had increased from baseline (Intervention: Often-14.0%, Almost always-9.1; Control: Often-12.4%; Almost always 16.1%) to the time of second follow up (Intervention: Often -28.10%, Almost always-24.5; Control: Often-17.2%; Almost always 19.5%). Reported IPTp uptake at second follow up was also higher for the intervention group (Intervention: Two doses-59.0%, Three doses 22.3%; Control group: Two doses-48.4%, Three doses-7.0%). The drop in the haematocrit levels was greater for the control group (32.42% to 30.63%) compared to the intervention group (33.09% to 31.93%). The Generalized Linear Mixed Models (GLMM) analysis revealed that the intervention had significantly improved reported ITN use, reported IPTp uptake, and haematocrit levels, but had no significant effect on the incidence of reported malaria diagnosis or babies' birth weights.

    CONCLUSIONS: The intervention was effective in improving ITN use, IPTp uptake, and haematocrit levels. It is, therefore, recommended for the modules to be adopted and incorporated into the routine antenatal care programmes in health centres with predominantly Hausa speaking clients.

    TRIAL REGISTRATION: Pan African Clinical Trial Registry, PACTR201610001823405. Registered 26 October 2016, www.pactr.org .

  8. Oh WC, Fatema KN, Liu Y, Jung CH, Sagadevan S, Biswas MRUD
    ACS Omega, 2020 Jul 21;5(28):17337-17346.
    PMID: 32715218 DOI: 10.1021/acsomega.0c01699
    In this study, we demonstrate the fabrication and characterization of a new quaternary semiconductor nanocomposite of LiCuMo2O11/graphene oxide/polypyrrole (LCMGP) via a hydrothermal method and testing of an NH3 and H2SO4 sensor operating in gaseous states at room temperature. We used X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy to characterize the properties of LCMGP nanostructures. Our sensor is capable of detecting NH3 and H2SO4 and quantifying their concentration in the gas flow. These results have been confirmed by exposing the sensor to different concentrations of NH3 and H2SO4 (100-1000 ppm). The obtained results confirm the exceptional sensing properties of the graphene-polymer-combined quaternary semiconductor nanocomposite related to the oxidation-reduction process that can be used for detection, identification, and quantification purposes.
  9. Wong LP, Alias H, Farid NDN, Yusop SM, Musa Z, Hu Z, et al.
    Front Public Health, 2023;11:1158698.
    PMID: 37213607 DOI: 10.3389/fpubh.2023.1158698
    INTRODUCTION: This study aims to shed light on parent-child relationships and the psychological health of parents from low-income families after the easing of the COVID-19 pandemic restrictions.

    METHODS: This cross-sectional study recruited 553 parents of children aged 13-24 years in low-income community settings. The Parent-Child Conflict scale of the Parental Environment Questionnaire (PEQ) was used to measure parent-child conflict. Psychological distress was assessed using the Depression, Anxiety, and Stress Scale short form (DASS-21).

    RESULTS: The study revealed a low level of parent-child conflict in the overall study population, with a median PEQ of 48.0 (interquartile range [IQR] 36 to 48). Concerning demographics, married parents reported a likelihood of having a higher level of parent-child conflict over 3 times higher than single parents (OR = 3.18 95%, CI 1.30-7.75). More parent-child conflicts were also found in parents aged 60-72 years old who were unemployed, retired, or housewives and from lower-income groups. In regard to lifestyle factors, a higher level of physical activity and having enough sleep were associated with lower levels of parent-child conflict. Only approximately 1% of the participants reported symptoms of depression, anxiety, or stress.

    DISCUSSION: Low risk exists for parent-child conflict and psychological sequelae following the easing of the COVID-19 pandemic restrictions, which could be due to various support measures implemented by the government. Vulnerable parents identified as being at risk of parent-child conflict warrant attention in future advocacy efforts.

  10. Sani NM, McAuslane N, Kasbon SH, Ahmad R, Yusof FAM, Patel P
    Ther Innov Regul Sci, 2020 Sep;54(5):1215-1224.
    PMID: 32865804 DOI: 10.1007/s43441-020-00140-4
    INTRODUCTION: The National Pharmaceutical Regulatory Agency (NPRA) embarked on a regulatory-strengthening program and is evaluating its processes. Optimising Efficiencies in Regulatory Agencies (OpERA) is a regulatory-strengthening program that provides benchmarking data that can define performance targets and focus performance improvement. The objective of this study was to use OpERA methodology to determine where time is spent in the NPRA approval process and to form a baseline to measure the performance improvements.

    METHODS: The OpERA tool was used to collect specific milestone data that identify time periods, review stages, and data points for new active substances and biosimilars approved by NPRA in 2017.

    RESULTS: In 2017, 25 new active substances and 1 biosimilar were approved by NPRA in a median of 515 days, representing both agency and applicant time. The median time between dossier receipt and the initiation of NPRA scientific assessment was 135 days, but there was a wide variation in queuing time. The median total assessment time was 279 days (agency and applicant timing). NPRA took a median of 166 days; applicants took a median of 131 days to respond to deficiency questions, with up to 6 cycles of review required for approval and 65% of applications requiring 4-5 cycles to provide satisfactory responses.

    CONCLUSIONS: As a result of these data, NPRA proposes three improvements: target start for scientific assessment 100 days after file acceptance, a maximum of 5 review cycles, and applicant response time limited to 6 months. These results will serve as a baseline for further assessment.

  11. Charoenkwan P, Chiangjong W, Lee VS, Nantasenamat C, Hasan MM, Shoombuatong W
    Sci Rep, 2021 Feb 04;11(1):3017.
    PMID: 33542286 DOI: 10.1038/s41598-021-82513-9
    As anticancer peptides (ACPs) have attracted great interest for cancer treatment, several approaches based on machine learning have been proposed for ACP identification. Although existing methods have afforded high prediction accuracies, however such models are using a large number of descriptors together with complex ensemble approaches that consequently leads to low interpretability and thus poses a challenge for biologists and biochemists. Therefore, it is desirable to develop a simple, interpretable and efficient predictor for accurate ACP identification as well as providing the means for the rational design of new anticancer peptides with promising potential for clinical application. Herein, we propose a novel flexible scoring card method (FSCM) making use of propensity scores of local and global sequential information for the development of a sequence-based ACP predictor (named iACP-FSCM) for improving the prediction accuracy and model interpretability. To the best of our knowledge, iACP-FSCM represents the first sequence-based ACP predictor for rationalizing an in-depth understanding into the molecular basis for the enhancement of anticancer activities of peptides via the use of FSCM-derived propensity scores. The independent testing results showed that the iACP-FSCM provided accuracies of 0.825 and 0.910 as evaluated on the main and alternative datasets, respectively. Results from comparative benchmarking demonstrated that iACP-FSCM could outperform seven other existing ACP predictors with marked improvements of 7% and 17% for accuracy and MCC, respectively, on the main dataset. Furthermore, the iACP-FSCM (0.910) achieved very comparable results to that of the state-of-the-art ensemble model AntiCP2.0 (0.920) as evaluated on the alternative dataset. Comparative results demonstrated that iACP-FSCM was the most suitable choice for ACP identification and characterization considering its simplicity, interpretability and generalizability. It is highly anticipated that the iACP-FSCM may be a robust tool for the rapid screening and identification of promising ACPs for clinical use.
  12. Agina OA, Shaari MR, Isa NMM, Ajat M, Zamri-Saad M, Hamzah H
    Pathogens, 2020 Aug 25;9(9).
    PMID: 32854179 DOI: 10.3390/pathogens9090697
    Theileriosis is a blood piroplasmic disease that adversely affects the livestock industry, especially in tropical and sub-tropical countries. It is caused by haemoprotozoan of the Theileria genus, transmitted by hard ticks and which possesses a complex life cycle. The clinical course of the disease ranges from benign to lethal, but subclinical infections can occur depending on the infecting Theileria species. The main clinical and clinicopathological manifestations of acute disease include fever, lymphadenopathy, anorexia and severe loss of condition, conjunctivitis, and pale mucous membranes that are associated with Theileria-induced immune-mediated haemolytic anaemia and/or non-regenerative anaemia. Additionally, jaundice, increases in hepatic enzymes, and variable leukocyte count changes are seen. Theileria annulata and Theileria parva induce an incomplete transformation of lymphoid and myeloid cell lineages, and these cells possess certain phenotypes of cancer cells. Pathogenic genotypes of Theileria orientalis have been recently associated with severe production losses in Southeast Asia and some parts of Europe. The infection and treatment method (ITM) is currently used in the control and prevention of T. parva infection, and recombinant vaccines are still under evaluation. The use of gene gun immunization against T. parva infection has been recently evaluated. This review, therefore, provides an overview of the clinicopathological and immunopathological profiles of Theileria-infected cattle and focus on DNA vaccines consisting of plasmid DNA with genes of interest, molecular adjuvants, and chitosan as the most promising next-generation vaccine against bovine theileriosis.
  13. Aunkor MTH, Raihan T, Prodhan SH, Metselaar HSC, Malik SUF, Azad AK
    R Soc Open Sci, 2020 Jul;7(7):200640.
    PMID: 32874659 DOI: 10.1098/rsos.200640
    Graphene oxide (GO) is a derivative of graphene nanosheet which is the most promising material of the decade in biomedical research. In particular, it has been known as an antimicrobial nanomaterial with good biocompatibility. In this study, we have synthesized and characterize GO and checked its antimicrobial property against different Gram-negative and Gram-positive multidrug drug resistant (MDR) hospital superbugs grown in solid agar-based nutrient plates with and without human serum through the utilization of agar well diffusion method, live/dead fluorescent staining and genotoxicity analysis. No significant changes in antibacterial activity were found in these two different conditions. We also compare the bactericidal capability of GO with some commonly administered antibiotics and in all cases the degree of inhibition is found to be higher. The data presented here are novel and show that GO is an effective bactericidal agent against different superbugs and can be used as a future antibacterial agent.
  14. Selvanathan V, Ruslan MH, Aminuzzaman M, Muhammad G, Amin N, Sopian K, et al.
    Polymers (Basel), 2020 Sep 22;12(9).
    PMID: 32972016 DOI: 10.3390/polym12092170
    A starch-resorcinol-formaldehyde (RF)-lithium triflate (LiTf) based biodegradable polymer electrolyte membrane was synthesized via the solution casting technique. The formation of RF crosslinks in the starch matrix was found to repress the starch's crystallinity as indicated by the XRD data. Incorporation of the RF plasticizer improved the conductivity greatly, with the highest room-temperature conductivity recorded being 4.29 × 10-4 S cm-1 achieved by the starch:LiTf:RF (20 wt.%:20 wt.%:60 wt.%) composition. The enhancement in ionic conductivity was an implication of the increase in the polymeric amorphous region concurrent with the suppression of the starch's crystallinity. Chemical complexation between the plasticizer, starch, and lithium salt components in the electrolyte was confirmed by FTIR spectra.
  15. Premkumar M, Sinha G, Ramasamy MD, Sahu S, Subramanyam CB, Sowmya R, et al.
    Sci Rep, 2024 Mar 05;14(1):5434.
    PMID: 38443569 DOI: 10.1038/s41598-024-55619-z
    This study presents the K-means clustering-based grey wolf optimizer, a new algorithm intended to improve the optimization capabilities of the conventional grey wolf optimizer in order to address the problem of data clustering. The process that groups similar items within a dataset into non-overlapping groups. Grey wolf hunting behaviour served as the model for grey wolf optimizer, however, it frequently lacks the exploration and exploitation capabilities that are essential for efficient data clustering. This work mainly focuses on enhancing the grey wolf optimizer using a new weight factor and the K-means algorithm concepts in order to increase variety and avoid premature convergence. Using a partitional clustering-inspired fitness function, the K-means clustering-based grey wolf optimizer was extensively evaluated on ten numerical functions and multiple real-world datasets with varying levels of complexity and dimensionality. The methodology is based on incorporating the K-means algorithm concept for the purpose of refining initial solutions and adding a weight factor to increase the diversity of solutions during the optimization phase. The results show that the K-means clustering-based grey wolf optimizer performs much better than the standard grey wolf optimizer in discovering optimal clustering solutions, indicating a higher capacity for effective exploration and exploitation of the solution space. The study found that the K-means clustering-based grey wolf optimizer was able to produce high-quality cluster centres in fewer iterations, demonstrating its efficacy and efficiency on various datasets. Finally, the study demonstrates the robustness and dependability of the K-means clustering-based grey wolf optimizer in resolving data clustering issues, which represents a significant advancement over conventional techniques. In addition to addressing the shortcomings of the initial algorithm, the incorporation of K-means and the innovative weight factor into the grey wolf optimizer establishes a new standard for further study in metaheuristic clustering algorithms. The performance of the K-means clustering-based grey wolf optimizer is around 34% better than the original grey wolf optimizer algorithm for both numerical test problems and data clustering problems.
  16. Ting ASY, Zoqratt MZHM, Tan HS, Hermawan AA, Talei A, Khu ST
    3 Biotech, 2021 Feb;11(2):40.
    PMID: 33479595 DOI: 10.1007/s13205-020-02617-3
    Microbial communities from a lake and river flowing through a highly dense urbanized township in Malaysia were profiled by sequencing amplicons of the 16S V3-V4 and 18S V9 hypervariable rRNA gene regions via Illumina MiSeq. Results revealed that Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes were the dominant prokaryotic phyla; whereas, eukaryotic communities were predominantly of the SAR clade and Opisthokonta. The abundance of Pseudomonas and Flavobacterium in all sites suggested the possible presence of pathogens in the urban water systems, supported by the most probable number (MPN) values of more than 1600 per 100 mL. Urbanization could have impacted the microbial communities as transient communities (clinical, water-borne and opportunistic pathogens) coexisted with common indigenous aquatic communities (Cyanobacteria). It was concluded that in urban water systems, microbial communities vary in their abundance of microbial phyla detected along the water systems. The influences of urban land use and anthropogenic activities influenced the physicochemical properties and the microbial dynamics in the water systems.

    Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-020-02617-3.

  17. Ang ZY, Balqis-Ali NZ, Jailani AS, Kong YL, Sharif SM, Fun WH
    PMID: 38230253 DOI: 10.5365/wpsar.2023.14.4.1058
    OBJECTIVE: Effective prevention and control measures are essential to contain outbreaks of infectious diseases, such as coronavirus disease (COVID-19). Understanding the characteristics of case clusters can contribute to determining which prevention and control measures are needed. This study describes the characteristics of COVID-19 case clusters in Malaysia, the method used to detect a cluster's index case and the mode of early transmission, using the seven cluster categories applied in Malaysia.

    METHODS: This cross-sectional study collected publicly available data on COVID-19 clusters occurring in Malaysia from 1 March 2020 to 31 May 2021. The characteristics of cases were described by category, and their associations with several outcomes were analysed. Descriptive analyses were performed to explore the method used to detect the index case and the mode of early transmission, according to cluster category.

    RESULTS: A total of 2188 clusters were identified. The workplace cluster category had the largest proportion of clusters (51.5%, 1126/2188 clusters), while the custodial settings category had the largest median cluster size (178 cases per cluster) and longest median duration of cluster (51 days). The high-risk groups category had the highest mortality. There were significant differences in cluster size, duration and rate of detection across the categories. Targeted screening was most commonly used to detect index cases, especially in custodial settings, and in imported and workplace clusters. Household-social and social-workplace contacts were the most common modes of early transmission across most categories.

    DISCUSSION: Targeted screening might effectively reduce the size and duration of COVID-19 clusters. Measures to prevent and control COVID-19 outbreaks should be continually adjusted based on ongoing assessments of the unique context of each cluster.

  18. Shameli K, Ahmad MB, Yunus WM, Rustaiyan A, Ibrahim NA, Zargar M, et al.
    Int J Nanomedicine, 2010 Oct 22;5:875-87.
    PMID: 21116328 DOI: 10.2147/IJN.S13632
    In this study, silver nanoparticles (Ag-NPs) were synthesized using a green physical synthetic route into the lamellar space of montmorillonite (MMT)/chitosan (Cts) utilizing the ultraviolet (UV) irradiation reduction method in the absence of any reducing agent or heat treatment. Cts, MMT, and AgNO(3) were used as the natural polymeric stabilizer, solid support, and silver precursor, respectively. The properties of Ag/MMT/Cts bionanocomposites (BNCs) were studied as the function of UV irradiation times. UV irradiation disintegrated the Ag-NPs into smaller sizes until a relatively stable size and size distribution were achieved. Meanwhile, the crystalline structure and d-spacing of the MMT interlayer, average size and size distribution, surface morphology, elemental signal peaks, functional groups, and surface plasmon resonance of Ag/MMT/Cts BNCs were determined by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence, Fourier transform infrared, and UV-visible spectroscopy. The antibacterial activity of Ag-NPs in MMT/Cts was investigated against Gram-positive bacteria, ie, Staphylococcus aureus and methicillin-resistant S. aureus and Gram-negative bacteria (ie, Escherichia coli) by the disk diffusion method on Muller-Hinton Agar at different sizes of Ag-NPs. All of the synthesized Ag/MMT/Cts BNCs were found to have high antibacterial activity. These results show that Ag/MMT/Cts BNCs can be useful in different biologic research and biomedical applications, such as surgical devices and drug delivery vehicles.
  19. Shameli K, Ahmad MB, Yunus WM, Ibrahim NA, Gharayebi Y, Sedaghat S
    Int J Nanomedicine, 2010 Dec 01;5:1067-77.
    PMID: 21170354 DOI: 10.2147/IJN.S15033
    Silver nanoparticles (Ag-NPs) were synthesized into the interlamellar space of montmorillonite (MMT) by using the γ-irradiation technique in the absence of any reducing agent or heat treatment. Silver nitrate and γ-irradiation were used as the silver precursor and physical reducing agent in MMT as a solid support. The MMT was suspended in the aqueous AgNO(3) solution, and after the absorption of silver ions, Ag(+) was reduced using the γ-irradiation technique. The properties of Ag/MMT nanocomposites and the diameters of Ag-NPs were studied as a function of γ-irradiation doses. The interlamellar space limited particle growth (d-spacing [d(s)] = 1.24-1.42 nm); powder X-ray diffraction and transmission electron microscopy (TEM) measurements showed the production of face-centered cubic Ag-NPs with a mean diameter of about 21.57-30.63 nm. Scanning electron microscopy images indicated that there were structure changes between the initial MMT and Ag/MMT nanocomposites under the increased doses of γ-irradiation. Furthermore, energy dispersive X-ray fluorescence spectra for the MMT and Ag/ MMT nanocomposites confirmed the presence of elemental compounds in MMT and Ag-NPs. The results from ultraviolet-visible spectroscopy and TEM demonstrated that increasing the γ-irradiation dose enhanced the concentration of Ag-NPs. In addition, the particle size of the Ag-NPs gradually increased from 1 to 20 kGy. When the γ-irradiation dose increased from 20 to 40 kGy, the particle diameters decreased suddenly as a result of the induced fragmentation of Ag-NPs. Thus, Fourier transform infrared spectroscopy suggested that the interactions between Ag-NPs with the surface of MMT were weak due to the presence of van der Waals interactions. The synthesized Ag/MMT suspension was found to be stable over a long period of time (ie, more than 3 months) without any sign of precipitation.
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