Popular Science: Chitosan is widely used in clinical treatment

Chitosan is a product of the natural polysaccharide chitin with some acetyl groups removed, and is also an important derivative of chitin. Chitosan has a wide range of sources, and about 100 billion tons of chitosan are produced from different sources each year. So far, the main commercial source of chitosan is crab and shrimp shells. Due to its unique cationic properties and its multiple physiological functions such as biodegradability, biocompatibility, non-toxicity, antibacterial, anti-cancer, lipid-lowering, and immune-enhancing, it has important applications in the biomedical field and many other fields.

Chitosan as a biopolymer has been extensively studied in wound healing. Uncontrolled bleeding may endanger the patient's life. Chitosan is a popular hemostatic agent. The positively charged chitosan forms a clot with the negatively charged red blood cells (RBCs), producing a cell clot or hemostatic plug that produces rapid hemostasis. Due to its important antifungal and antibacterial properties, it has superior hemostatic properties than traditional gauze.

Chitosan is widely used to treat dental infections due to its antimicrobial properties. Chitosan is primarily used in dentistry to deliver medications to treat oral infections such as periodontitis, endodontic infections, pulpotomies, stomatitis, and candidal infections. It is also used as an excipient in toothpastes), mouthwashes, toothbrushes, and dental implant coatings.

Chitosan has excellent mucoadhesive properties, which are attributed to the interaction of positively charged amino functional groups with negatively charged sialic acid in mucus. Because mucus turnover is slower than tear turnover, this mucoadhesive property increases the residence time of drugs in the eye. In addition, the long-term retention of drugs also enhances the bioavailability of drugs in the eye.

Osteoarthritis is a degenerative inflammatory disease characterized by damaged articular cartilage with minimal self-repair capabilities. Transplanting stem cells into defective cartilage is one of the promising approaches to repair cartilage. Chitosan’s biodegradability, non-toxicity, and biocompatibility make it an ideal biomaterial for cartilage regeneration. Recently, Medovent GmbH has developed a chitosan-based nerve guide, Reaxon®, that can treat nerve defects in the fingers by repairing peripheral nerve discontinuities.

Chitosan has a certain lipid-lowering effect because the positively charged tertiary amino functional groups of chitosan can form bonds with the carboxyl groups of fatty acids and bile acids in the gastrointestinal tract, interfering with the emulsification of neutral lipids (such as cholesterol) and reducing fat absorption.

Studies have shown that saccharified chitosan is a non-toxic immune adjuvant that can be used for cancer treatment. Chitosan can reduce the motility and invasiveness of mammalian breast cancer cells in vitro and in vivo. The combination of laser irradiation and saccharified chitosan can effectively treat human breast cancer and melanoma.

In addition to the above clinical treatments, chitosan is also widely used in the treatment of diabetic foot ulcers, relief of chronic pain, and anti-adhesion barriers.