Water Interactions in Hydrated Aliphatic Polyester Composite Scaffolds

The organ bone consists of mineralized and non-mineralized tissues. The mineralized tissues can be defined from a material science point of view as composites of inorganic and organic matter. Hydration of the composites is vital for mechanical and physico-chemical properties, supporting macromolecular networks in optimizing structure and function. In the field of scaffold-guided bone regeneration (SGBR), researchers have sought to mimic these naturally derived composites by combining ceramic particles with polymeric biodegradable biomaterials, mainly aliphatic polyesters, aiming to enhance the physicochemical properties of the polymeric matrix. However, the behavior of these resulting composites under physiological conditions remains underexplored. A complex interplay exists among the polymeric chains, ceramic particles, and water molecules, influencing various characteristics, including crystallinity, thermal properties, and mechanical strength, of the composite. Future advancements in scaffold design and manufacturing in SGBR cannot be separated from a comprehensive understanding of the diverse, multiscale physicochemical mechanisms at work in hydrated ceramic particle-polymer composites (CPPCs). This review analyzes literature on the molecular origins of hyperelasticity in polymers, focusing on hydration and structural rearrangements. It also discusses interfacial mechanisms in hydrated CPPCs, which allows future research to refine manufacturing, design, and strategies for next-generation CPPCs.