Biocompatibility and biodegradability of multilayered polymeric materials for tissue regeneration

The tissue regeneration, especially the tympanic membrane regeneration, remains a significant challenge in otorhinolaryngology, necessitating the development of the advanced biomaterials. This study evaluates the biocompatibility and biodegradation of three novel multi-layer polymer scaffolds: KPC (carboxymethyl cellulose/polyethylene oxide/polyvinylpyrrolidone/chitosan), PHC (pullulan/hyaluronic acid/chitosan), and HCA (hyaluronic acid/chitosan/alginate), that designed as biomimetic matrices for tissue repair. The materials were subcutaneously implanted into Wistar rats for 21st and 45th days, with histological evaluation of the peri-implant fibrous capsule. All polymeric matrices underwent biodegradation, with a chronic aseptic inflammatory response characterized by macrophage and lymphocyte infiltration within the fibrous capsule. However, the severity and dynamics of the inflammation were highly dependent on material content. The KPC matrix induced the mildest cellular reaction, which significantly subsided by the day 45th, accompanied by the formation of mature collagen layers and an absence of giant multinucleated foreign body giant cells. In contrast, PHC and HCA matrices provoked more pronounced and sustained inflammation, with PHC showing intensification at the later point linked to accelerated bioresorption and the presence of numerous spherical degradation products. Mast cell involvement was minimal for KPC but notable within the capsule for PHC and HCA at the 45th day. In conclusion, while all tested composites are biodegradable, the KPC formulation demonstrates superior biocompatibility with a self-limiting inflammatory response, making it the most promising candidate for further development of regenerative implant for middle ear reconstruction.