A Three-Layered Osteochondral Plug: Structural, Mechanical, and in vitro Biocompatibility Analysis

This study aims to produce an osteochondral plug with three distinct layers resembling the naturally occurring cartilage, tidemark, and subchondral zones, for the regeneration of defects of articular cartilage. The bone layer is constructed from a PLLA/PCL polymeric blend using a dual-porogen approach. The pore surfaces are coated with type-I collagen and hydroxyapatite. The upper layer, made of PGA nonwoven felt, is combined with the lower using a polymeric blend with a pigment for better visualization during implantation. Vertical channels are formed from the bottom layer to the upper border of the tidemark to facilitate the delivery of stem cells and blood from the bone marrow when implanted. The Young's modulus of the osteochondral plugs is 94.5 +/- 9.42 kPa. Cell-culture studies confirm the biocompatibility.