生物材料概述

Common biopolymers include collagen, a protein polymer from bovine skin and bone with a triple helix structure providing strength; silk, derived from silk moth cocoons with crystalline beta sheets enabling high strength and flexibility; and chitosan, a polysaccharide from crustacean shells with pH-based solubility. Each offers distinct properties for different applications.

Electrospinning applies an electric field between a collector surface and a syringe tip containing biopolymer solution. This induces formation of microscale fibers that create structures mimicking the extracellular matrix in tissue. The resulting fibrous mats are useful for tissue engineering and regenerative medicine applications.

A hydrogel is a solid-like polymer network with high water content and increased biocompatibility. Hydrogels are created by heating biopolymers in aqueous solutions, casting in molds, and cooling until solid. They serve as tissue constructs in artificial tissue and can hold sensitive drug molecules for controlled release applications.

Biomaterials face several challenges: their natural properties are difficult to modify, processing can alter properties adversely, batch-to-batch variability occurs due to differences in organism species and environmental factors, and most are water-soluble limiting stability. Crosslinking can extend lifetime but may cause undesirable mechanical property changes.

Biomaterials are frequently used in drug delivery because they are biodegradable and biocompatible. Hydrogels offer a biocompatible matrix to hold sensitive drug molecules and degrade at predictable rates depending on material properties, enabling controlled release of drugs over time for therapeutic benefit.

DNA origami involves designing DNA strands with specific sequences that induce precise folding into complex structures and patterns. These structures are treated as polymer materials and can create functional assemblies able to sense biological cues, change shape, or release embedded biomolecules for advanced bioengineering applications.

Chitosan is a polysaccharide from crustacean shells with pH-based solubility enabling simple control of fabrication. Chitosan films are biocompatible with regenerating tissue and are used in wound healing applications. Chitosan surgical adhesive films can be fused across cut tissue to close wounds as an alternative to sutures.