Three Polymers from the Sea: Unique Structures, Directional Modifications, and Medical Applications.

With the increase of wounds and body damage, the clinical demand for antibacterial, hemostatic, and repairable biomaterials is increasing. Various types of biomedical materials have become research hotspots. Of these, and among materials derived from marine organisms, the research and application of alginate, chitosan, and collagen are the most common. Chitosan is mainly used as a hemostatic material in clinical applications, but due to problems such as the poor mechanical strength of a single component, the general antibacterial ability, and fast degradation speed research into the extraction process and modification mainly focuses on the improvement of the above-mentioned ability. Similarly, the research and modification of sodium alginate, used as a material for hemostasis and the repair of wounds, is mainly focused on the improvement of cell adhesion, hydrophilicity, degradation speed, mechanical properties, etc.; therefore, there are fewer marine biological collagen products. The research mainly focuses on immunogenicity removal and mechanical performance improvement. This article summarizes the source, molecular structure, and characteristics of alginate, chitosan, and collagen from marine organisms; and introduces the biological safety, clinical efficacy, and mechanism of action of these materials, as well as their extraction processes and material properties. Their modification and other issues are also discussed, and their potential clinical applications are examined.