Non-Mulberry Silk Fiber-Based Composite Scaffolds Containing Millichannels for Auricular Cartilage Regeneration

Abstract

Tissue engineering has made significant progress as a cartilage repair alternative. It is crucial to promote cell proliferation and migration within three-dimensional (3D) bulk scaffolds for tissue regeneration through either chemical gradients or physical channels. In this study, by developing optimized silk fiber-based composite scaffolds, millimeter-scaled channels were created in the corresponding scaffolds via facile physical percussive drilling and subsequently utilized for auricular cartilage regeneration. We found that by the introduction of poly-l-lactic acid porous microspheres (PLLA PMs), the channels incorporated into the Antheraea pernyi (Ap) silk fiber-based scaffolds were reinforced, and the mechanical features were well maintained. Moreover, Ap silk fiber-based scaffolds reinforced by PLLA PMs containing channels (CMAF) exhibited excellent chondrocyte proliferation, migration, and synthesis of cartilage-specific extracellular matrix (ECM) in vitro. The biological evaluation in vivo revealed that CMAF had a higher chondrogenic capability for an even deposition of the specific ECM component. This study suggested that multihierarchical CMAF may have potential application for auricular cartilage regeneration.