Eco-friendly synthesis of chitosan and its medical application: from chitin extraction to nanoparticle preparation.

Background and Purpose: Chitosan, a chitin deacetylation product, has been applied in nanoparticle or nano-chitosan for medical applications. However, the chitin extraction from crustacean shells and other natural resources, chitin deacetylation, and crosslinking of the chitosan forming the nano-chitosan mostly involve hazardous chemical and physical processes. The risks of these processes to human health and the environment attract the attention of scientists to develop safer and greener techniques. This review aims to describe the progress of harmless chitosan synthesis. Experimental Approach: All strongly related publications to each section, which were found on scientific search engines (Google Scholar, Scopus, and Pubmed), were studied, selected, and then used as references in writing this review. No limitation for the publication year was applied. The publications were searched from April 2022 - June 2023. Key Results: Nano-chitosan could be synthesized in harmless techniques, including the preparation of the chitosan raw materials and crosslinking the chitosan polymer. Enzymatic processes in shell deproteination in the chitin extraction and deacetylation are preferable to reduce the negative effects of conventional chemical-physical processes. Mild alkalines and deep eutectic solvents also provide similar benefits. In the nano-chitosan synthesis, naturally derived compounds (carrageenan, genipin, and valinin) show potency as safer crosslinkers, besides tripolyphosphate, the most common safe crosslinker. Conclusion: A list of eco-friendly and safer processes in the synthesis of nano-chitosan has been reported in recent years. These findings are suggested for the nano-chitosan synthesis on an industrial scale in the near future.

Dissection of Capsid Protein HPV 52 to Rationalize Vaccine Designs Using Computational Approaches Immunoinformatics and Molecular Docking.

BACKGROUND: Human Papillomavirus type 52 (HPV 52) is considered one of the threatening HPV types inducing cervical cancer worldwide. This study was conducted to address strategies of an effective vaccine against cervical cancer using computational approaches immuno-informatics and molecular docking. METHODS: Major capsid protein L1 and L2 HPV 52 (L1 and L2 HPV 52) sequences were investigated by multiple analyses including B and T cell epitope, toxicity, allergenicity, Immunogenicity, epitope conservancy, population coverage, and molecular docking. RESULTS: L1 and L2 HPV 52 showed a conserved sequence among amino acid levels. Q307K, S383D/N, and D473E are found as major mutations in L1, while mutations in L2 are S122T, Q247H, L247S, and E365D. Multiple epitopes were identified and elicited strong immune responses against cross types of HPV in various HLA populations. To enhance vaccine effectiveness that allows having cross-protection over HPV types, N terminus HPV L2 was analyzed suggesting multi-candidates chimeric L1/L2 vaccine design. CONCLUSION: This study shed a light on a useful pipeline with robust analysis for effective vaccine production.

Genome Profiling of SARS-CoV-2 in Indonesia, ASEAN and the Neighbouring East Asian Countries: Features, Challenges and Achievements.

Whole-genome sequencing (WGS) has played a significant role in understanding the epidemiology and biology of SARS-CoV-2 virus. Here, we investigate the use of SARS-CoV-2 WGS in Southeast and East Asian countries as a genomic surveillance during the COVID-19 pandemic. Nottingham-Indonesia Collaboration for Clinical Research and Training (NICCRAT) initiative has facilitated collaboration between the University of Nottingham and a team in the Research Center for Biotechnology, National Research and Innovation Agency (BRIN), to carry out a small number of SARS-CoV-2 WGS in Indonesia using Oxford Nanopore Technology (ONT). Analyses of SARS- CoV-2 genomes deposited on GISAID reveal the importance of clinical and demographic metadata collection and the importance of open access and data sharing. Lineage and phylogenetic analyses of two periods defined by the Delta variant outbreak reveal that: (1) B.1.466.2 variants were the most predominant in Indonesia before the Delta variant outbreak, having a unique spike gene mutation N439K at more than 98% frequency, (2) Delta variants AY.23 sub-lineage took over after June 2021, and (3) the highest rate of virus transmissions between Indonesia and other countries was through interactions with Singapore and Japan, two neighbouring countries with a high degree of access and travels to and from Indonesia.