Exploring the synthesis, properties, and potential of chitosan-functionalized metal-organic frameworks in emerging applications

Chitosan (CS), a natural cationic biopolymer derived from chitin, has emerged as a promising component for synthesizing biological/bioinspired metal-organic frameworks (BioMOFs). CS's biodegradability, low toxicity, mucoadhesive properties, and biocompatibility due to its amino and hydroxyl groups make it ideal for developing BioMOFs with applications in biomedicine, catalysis, sensing, food and environmental remediation. CS-based MOFs combine the structural diversity and tunability of MOFs (metal ions and organic linkers) with CS's inherent advantages, expanding the possibilities for designing functional materials with tailored properties. Incorporating CS into MOF synthesis modulates surface chemistry, pore size, structure, stability, and biocompatibility, making BioMOFs suitable for various biomedical applications (therapeutics, stimuli-responsive drug delivery, antibacterial, anti-inflammatory, wound healing, antidiabetic, and anticancer), food technology (preservation, coating and packaging), and environmental remediation (dye, antibiotic, pesticide removal as sorbents and photocatalysts). This review explores the preparation, properties, and applications of biopolymer CS-based MOFs, which have not been comprehensively summarized in previous reviews. We discuss the potential applications of BioMOFs in biomedicine, environmental remediation, and other fields, highlighting their versatility and potential impact. By comprehensively analyzing recent advancements and challenges in CS-based MOFs, this review aims to provide insights into future directions and opportunities for leveraging CS's unique properties in MOF design and applications.