Tissue engineering of human knee meniscus using functionalized and reinforced silk-polyvinyl alcohol composite three-dimensional scaffolds: Understanding the in vitro and in vivo behavior.

Tissue engineered constructs with rapid restoration of mechanical and biological properties remain a challenge, emphasizing the need to develop novel scaffolds. Here, we present a multicomponent composite three-dimensional scaffold structure with biomimetic reinforcement and biomolecule functionalization for meniscus tissue engineering. The scaffold structure was developed using 3:1 silk fibroin (SF) and polyvinyl alcohol (PVA). Autoclaved eggshell membrane (AESM) powder (1-3%w/v) was used as reinforcement to enhance biomechanical properties. Further to improve cell attachment and proliferation, these scaffolds were functionalized using an optimized unique combination of biomolecules. Comprehensive analysis of scaffolds was carried out on morphological, structural, mechanical and biological functionalities. Their mechanical properties were compared with different native human menisci. The results indicated that, functionalized SF-PVA with 3%AESM has shown similar order of magnitude of compressive and dynamic mechanical properties as in human meniscus. Moreover, 3% AESM based scaffolds were found to support better primary human meniscal cellular proliferation and extracellular matrix secretion. Immunohistochemical analysis revealed angiogenesis and biocompatibility with minimal inflammatory response for subcutaneously implanted scaffolds in New Zealand white rabbits. The developed reinforced and functionalized SF-PVA scaffolds can uniquely combine the potential for load-bearing properties with improved in vitro and in vivo support for meniscus tissue regeneration.