Chemically modified water-soluble chitosan derivatives: Modification strategies, biological activities, and applications

ABSTRACTChitosan, a biocompatible and nontoxic heteropolymer derived from chitin, offers various applications. However, its limited solubility above pH 6.5 hinders its broader applications. Chemical, physical, and enzymatic modifications have greatly improved chitosan properties, producing water-soluble chitosan (WSC) and derivatives. WSC and its derivatives possess unique structures, properties, and water solubility, meeting the demands of functional materials. This review highlights native chitosan characteristics, modification strategies for WSC and emphasizes its applications in food production, wastewater treatment, biomedical, and agriculture. Future perspectives for WSC and its derivatives are also discussed at the end of this paper.KEYWORDS: Biological propertiesbiopolymerChitinchitosanmaterial synthesiswater solubility Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThe authors are grateful for the financial support from the Ministry of Higher Education (MOE) Malaysia for supporting this project under the Fundamental Research Grant Scheme (FRGS) (FRGS/1/2018/STG01/USM/02/14). In addition, we also thank The Ministry for Higher Education Malaysia under IPTA Academic Training Scheme (SLAI) and Universiti Malaysia Sarawak that sponsored the first author.Notes on contributorsWan Roslina Wan YusofWan Roslina Wan Yusof received her Bachelor Degree in Biochemistry (2008) at the Universiti Kebangsaan Malaysia (UKM). In 2012, she was awarded with Master of Science Degree in Chemical Pathology at the Universiti Sains Malaysia (USM). Currently, she is a doctorate student and working on chitosan modification and nanoparticles for the control of plant fungal infections under the supervision of Dr. Sumiyyah Sabar and Professor Dr. Awang Ahmad Sallehin Awang Husaini.Nur Yusra Farzana AwangNur Yusra Farzana Awang received her Bachelor Degree in Industrial Chemical Technology (2021) from Universiti Sains Islam Malaysia (USIM). Currently, she is pursuing her Master Degree in Material Chemistry at the Universiti Sains Malaysia (USM), under the supervision of Dr Sumiyyah Sabar and Dr Juzaili Azizi.Muhammad Affuwan Azhar LaileMuhammad Affuwan Azhar Laile received his Bachelor Degree in Applied Chemistry (2021) at the University of Technology MARA (UiTM). At the moment he is pursuing his Master Degree in Chemistry at Universiti Sains Malaysia (USM) under the supervision of Dr Sumiyyah Sabar and Dr Fatehah Omar. He is currently working on the development of water-soluble chitosan as biocoagulant in water treatment.Juzaili AziziJuzaili Azizi serves as a senior lecturer at the Centre for Drug Research, Universiti Sains Malaysia (USM). In 2008, he obtained his Bachelor's degree in Biochemistry from Universiti Malaya (UM) followed by a Master's in Pharmacology from Universiti Sains Malaysia (USM) in 2011. He successfully completed his Ph.D. in Pharmacology at King's College London in 2018. His expertise is in blood-brain barrier (BBB), drug delivery to the brain and neuroprotection in Parkinson's disease.Awang Ahmad Sallehin Awang HusainiDr. Awang Ahmad Sallehin Awang Husaini is currently a Professor in Enzymology and Molecular Biology at the Faculty of Resource Science and Technology, Universiti Malaysia Sarawak. He graduated with the degree of Science majoring in Biochemistry and Microbiology from Universiti Putra Malaysia, and completed his PhD in Biomolecular Sciences from University of Manchester. His research interests focus on the use and application of beneficial microbes and their enzymes in developing green technology such as valorization of agricultural waste to high value added platform chemicals, bioremediation of hazardous pollutants, and development of biofertilizer and biocontrol for sustainable agricultural practices.Azman SeeniDr. Md Azman Seeni Mohamed currently is a Director of Industrial Center of Innovation for Biomedical at SIRIM Berhad. He was Associate Professor at Advanced Medical and Dental Institute, USM for 15 years and also has been secondment to National Institute Biotechnology Malaysia (NIBM) as Acting Executive Director of Malaysian Institute of Pharmaceuticals and Nutraceuticals for 3 years. He has over 20 years' experience in Cancer Research and published numerous paper with High Impact Factor. So far, he has supervised more than 40 postgraduate students in cancer research as well as in biomaterial products. He also won many prestigious awards either in local or international competition e.g. American Association Cancer Research Travel Grant Award 2009, Double Gold Award of British Invention Show 2011 and obtained one patent on chemo preventive agent. Recently, he has focused his research work on Cancer Chemoprevention using nanotechnology.Lee D. WilsonDr. Lee D. Wilson is an Indigenous scholar who obtained a B.Sc. at the University of Winnipeg, followed by a Ph.D. at the University of Saskatchewan, and later obtained PDF training as an NSERC Visiting Fellow at the Steacie Institute for Molecular Sciences (National Research Council of Canada, Ottawa, Canada). Currently, Wilson holds an appointment as professor in the Department of Chemistry at the University of Saskatchewan. His interests are focused on the chemistry of biopolymers and sustainable biomaterials that relate to studies aimed at understanding the structure-function relationships of carbohydrate polymers and their sorption phenomena for diverse processes. His research group is actively involved in studies focused the modification of biomaterials using green chemistry and characterization of their structure and physicochemical properties. The Wilson research group aims to use various research tools and methods address a range of fundamental scientific questions and practical problems relevant to water, food, and energy security and sustainability.Sumiyyah SabarDr. Sumiyyah Sabar is currently a Senior Lecturer in the Chemical Sciences Programme at the School of Distance Education, Universiti Sains Malaysia (USM). Her area of expertise is in the fields of environmental, material, and green chemistry. She completed her Bachelor's degree in Analytical and Environmental Chemistry from Universiti Malaysia Terengganu (UMT) in 2007 and later obtained her PhD in Photocatalysis from USM in 2013. She subsequently joined USM, and in 2018, she pursued a one-year postdoctoral study at the National University of Singapore (NUS), Singapore. Dr. Sumiyyah's current research focuses on visible light active photocatalysts, modification of polysaccharide-based biopolymers, adsorption and regeneration of spent adsorbents, water and wastewater treatment, and green microextraction methods.