Characteristics of electrospun chitosan/carbon nanotube coatings deposited on AZ31 magnesium alloy

Abstract Mg-based biomaterials are commonly used as biodegradable orthopedic implants (e.g., bone regeneration applications). However, achieving high biocompatibility and corrosion resistance has remained a challenge to be tackled. In this work, to investigate various fabricated coatings (with and without pre- anodizing), five categories of samples are considered: (a) bare Mg alloy (Mg), (b) Anodized Mg alloy (Mg-A), (c) CS-coated Mg alloy (Mg-C), (d) CS-coated anodized Mg alloy (Mg-AC), and (e) CS-CNT-coated anodized Mg alloy (Mg-ACC). These samples were characterized by using Field Emission Scanning Electron Microscopes (FE-SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FT-IR), and Raman Spectroscopy. The adhesion within the coated samples was compared. Then, the effects of the coatings were evaluated by comparing wettability, corrosion behavior, and biocompatibility for bare and coated samples. The adhesion test showed that the coatings exhibited higher adhesion for Mg-AC and Mg-ACC compared to Mg-C. Desired wettability was achieved as the contact angles of coated samples were in the range of 55°– 65°. Electrochemical impedance and polarization as well as immersion tests showed higher corrosion resistance for coated samples. The composite coated sample showed improved cell adhesion since the osteoblast cells covered almost the entire surface of the sample. Moreover, osteoblast cell viability for the sample was around 40% higher than that of the bare sample. Graphical abstrac

Evaluation of antibiotic resistance changes in Acinetobacter baumannii in the era of COVID-19 in Northern Iran

Background and Objectives: During the coronavirus pandemic, the overuse of antibiotics to reduce coinfections and mortality may be contributing to the rise of antimicrobial resistance. In this study, we aim to investigate the antibiotic resistance changes of Acinetobacter baumannii post-COVID-19 pandemic in Northern Iran. Materials and Methods: The current study is a cross-sectional study. Between 2022 and 2023, 2190 clinical samples were collected from patients with healthcare-associated infections (HAIs) at four hospitals in Sari, which served as corona centers after the COVID-19 pandemic. Antimicrobial sensitivity was determined using standard broth macro-dilution, and resistance genes were detected using multiplex PCR. Results: Based on the results co-amoxiclav had a resistance rate of 100%, while piperacillin/tazobactam showed the least resistance rate of 29.82%. In terms of GM MIC values, colistin was the most potent against multi-drug resistant isolates. The frequency of blaOXA-51, ampC, aphA6, and blaNDM genes were 100%, 99.12%, 90.35%, and 69.30% respectively. Conclusion: Our study revealed high multi-drug resistance rates. Piperacillin/tazobactam recommended for treating multidrug resistant Acinetobacter baumannii infections in Northern Iran

Vaccines for COVID-19: A Review of Feasibility and Effectiveness

International audienceIntroduction: Many potential vaccines for COVID-19 are being studied, and several studies have reported the results of these vaccines. We aimed to review the current evidence of the feasibility and effectiveness of Vaccines for COVID-19. Methods: A search was carried out utilizing the keywords in the online databases, including Scopus,Web of Science, PubMed, Embase, and Cochrane. We included both human and non-human studies because of the vaccine novelty, which could limit our ability to include sufficient human studies. Results: The review of studies showed that several SARS-CoV-2 vaccines are under development; different platforms are being used, including eight vaccines are adenovirus-based vectors, six vaccines are RNA-based formulations, one vaccine is DNA-based formulations, and other vaccines are using other platforms, including lipid nano particles. Conclusion: It is crucial to gather as much clinically relevant evidence as possible regarding the immunogenicity, efficacy, and safety profiles of these vaccines and adhere wisely to CDC protocols and guidelines of vaccine production