Synthesis of pristine chitosan foams with enhanced pore structure, surface area, and mechanical strength for tissue engineering applications

Abstract With its excellent biocompatibility, biodegradability, and antimicrobial activity, chitosan is a promising scaffold material for hard-tissue engineering. Yet, pristine chitosan foams typically lack the strength and porosity required for such use. Here we present a simple emulsion-templating approach to fabricate pristine chitosan foams with optimized strength and porosity. Sodium dodecyl sulfate (SDS), a widely used biocompatible anionic surfactant, was employed at trace levels to aid polymerization. The foams display a dual-scale pore morphology. Cavities of 150–300 μm are separated by around 50 μm thick chitosan walls containing large interconnecting openings. The walls are further populated with meso- and macropores of 50–500 nm. This architecture should support cell attachment and growth, facilitate proliferation, and enhance nutrient transport and metabolic exchange. The structure yields high surface area (up to 10 m 2 g −1 ). Mechanically, the thick-walled cavities impart both elastic recovery and high compressive resistance (255 kPa at 40% strain from foams polymerized with 4% chitosan). A preliminary drug-release study using vancomycin confirmed excellent loading and sustained release.