Design of a multiphase osteochondral scaffold III: Fabrication of layered scaffolds with continuous interfaces

Abstract

There is a need to improve current treatments for articular cartilage injuries. This article is the third in a series describing the design and development of an osteochondral scaffold based on collagen-glycosaminoglycan and calcium phosphate technologies for regenerative repair of articular cartilage defects. The previous articles in this series described methods for producing porous, three-dimensional mineralized collagen-GAG (CGCaP) scaffolds whose composition can be reproducibly varied to mimic the composition of subchondral bone, and pore microstructure and mineral phase can be modified. This article describes a method, "liquid-phase cosynthesis," that enables the production of porous, layered scaffolds that mimic the composition and structure of articular cartilage on one side, subchondral bone on the other side, and the continuous, gradual or "soft" interface between these tissues: the tidemark of articular joints. This design enables the layered scaffolds to be inserted into the subchondral bone at an osteochondral defect site without the need for sutures, glue, or screws, with a highly interconnected porous network throughout the entire osteochondral defect. Moreover, the differential moduli of the osseous and cartilaginous compartments enable these layered scaffolds to exhibit compressive deformation behavior that mimics the behavior observed in natural articular joints.

A biomimetic multi-layered collagen-based scaffold for osteochondral repair

“…Due to the complex zonal organisation of osteochondral tissue, development of a single implantable biomaterial with a gradient structure is of great interest in the field of osteochondral tissue engineering [36,37]. This study built on the existing collagenbased scaffold expertise within our research group to develop a novel multi-layered material for osteochondral repair.…”

Bioactive Stratified Polymer Ceramic-Hydrogel Scaffold for Integrative Osteochondral Repair

“…Several groups have reported on the development of tissue engineered osteochondral grafts [3][4][5][6]17,21,[23][24][25]27,33,34,39,57,59,[70][71][72][73][74][75]78,79,83 that have demonstrated significant potential. Most of these osteochondral grafts use a stratified scaffold design that facilitates the development of both cartilaginous and bony regions.…”

Composite Growth Factor Supplementation Strategies to Enhance Tenocyte Bioactivity in Aligned Collagen-GAG Scaffolds

“…[13][14][15][16][17] CG scaffolds have also been adapted for a variety of orthopedic applications covering osteochondral, bone, and tendon tissue engineering. [18][19][20][21] We have recently demonstrated a directional freeze-drying method to create geometrically anisotropic CG scaffolds with aligned tracks of ellipsoidal pores that mimic elements of native tendon anisotropy. 21 While we showed that the platelet-derived growth factor BB (PDGF-BB) and the insulin-like growth factor 1 (IGF-1) promoted increased tenocyte proliferation and migration within these anisotropic scaffolds, 21 a major concern remains the trade-off between increased proliferation and retention of the tenocyte-associated phenotype.…”