The Impact of Compact Layer in Biphasic Scaffold on Osteochondral Tissue Engineering

Abstract

The structure of an osteochondral biphasic scaffold is required to mimic native tissue, which owns a calcified layer associated with mechanical and separation function. The two phases of biphasic scaffold should possess efficient integration to provide chondrocytes and osteocytes with an independent living environment. In this study, a novel biphasic scaffold composed of a bony phase, chondral phase and compact layer was developed. The compact layer-free biphasic scaffold taken as control group was also fabricated. The purpose of current study was to evaluate the impact of the compact layer in the biphasic scaffold. Bony and chondral phases were seeded with autogeneic osteoblast- or chondrocyte-induced bone marrow stromal cells (BMSCs), respectively. The biphasic scaffolds-cells constructs were then implanted into osteochondral defects of rabbits’ knees, and the regenerated osteochondral tissue was evaluated at 3 and 6 months after surgery. Anti-tensile and anti-shear properties of the compact layer-containing biphasic scaffold were significantly higher than those of the compact layer-free biphasic scaffold in vitro. Furthermore, in vivo studies revealed superior macroscopic scores, glycosaminoglycan (GAG) and collagen content, micro tomograph imaging results, and histological properties of regenerated tissue in the compact layer-containing biphasic scaffold compared to the control group. These results indicated that the compact layer could significantly enhance the biomechanical properties of biphasic scaffold in vitro and regeneration of osteochondral tissue in vivo, and thus represented a promising approach to osteochondral tissue engineering.

Current Applications of Mesenchymal Stem Cells for Cartilage Tissue Engineering

“…The biphasic scafolds was cellularized by BMSCs induced with chondrogenic and osteogenic medium and implanted into osteochondral defects in a rabbit knee model. By a histological evaluation, the presence of an uniform neocartilage surface, a clear fusion of neocartilage, a regenerated subchondral bone with a well-deined tidemark, and no evidence of ibrocartilage was demonstrated [41].…”

Composite scaffolds for osteochondral repair obtained by combination of additive manufacturing, leaching processes and hMSC-CM functionalization

“…Typical methods for the manufacture of scaffolds with functional gradients of properties include: the use of embedded (nano ) fibers and textiles within polymeric matrixes [27,28,29], the combination of rigid lattice structures with cell carrying hydrogels [27,28,30], the use of multi layered constructs [31,32] (normally requiring adhesives within layers), and computer aided tissue engineering constructs [33]. Among the most promising approaches, towards stable and effective composite scaffolds, it is important to note the combination of: a) phase separation or leaching processes, normally for obtaining the soft chondral phase, with b) computer aided rapid prototyping technologies based on addi tive manufacturing, usually for manufacturing the rigid bony phase [34]. In spite of the very positive results shown by metallic rapid prototyped prostheses and scaffolds for bone repair [35], most successful composite scaffolds for osteochondral repair are based on polymer ceramic com posites [31,34,36], polymer polymer composites [37], ceramic ceramic composites [38], ceramic metal composites [39] and metal metal composites [40].…”

“…Among the most promising approaches, towards stable and effective composite scaffolds, it is important to note the combination of: a) phase separation or leaching processes, normally for obtaining the soft chondral phase, with b) computer aided rapid prototyping technologies based on addi tive manufacturing, usually for manufacturing the rigid bony phase [34]. In spite of the very positive results shown by metallic rapid prototyped prostheses and scaffolds for bone repair [35], most successful composite scaffolds for osteochondral repair are based on polymer ceramic com posites [31,34,36], polymer polymer composites [37], ceramic ceramic composites [38], ceramic metal composites [39] and metal metal composites [40]. Interestingly, metal polymer composites, which could benefit from the stiffness of metals for the bony phase and from the elasticity of polymers for the chondral phase are not so common.…”

Preparation and Characterization of Integrated Condylar Biomimetic Scaffolds: A Pilot Study

“…The structure of an osteochondral biphasic scaffold is required to mimic native tissue, which owns a calcified layer associated with mechanical and separation function. 4) With the development of tissue engineering, the research on two phase composite materials has provide us new ideas to find new artificial condyle materials. The ideal tissue engineering scaffolds should have good biocompatiblity, surface activity, plasticity and suitable biodegradability and have mechanical strength as well, which is necessary in providing mechanical support at the early stage of new tissue growth.…”