Review of Synthetic and Hybrid Scaffolds in Cartilage Tissue Engineering

Abstract

Cartilage tissue is under extensive investigation in tissue engineering and regenerative medicine studies because of its limited regenerative potential. Currently, many scaffolds are undergoing scientific and clinical research. A key for appropriate scaffolding is the assurance of a temporary cellular environment that allows the cells to function as in native tissue. These scaffolds should meet the relevant requirements, including appropriate architecture and physicochemical and biological properties. This is necessary for proper cell growth, which is associated with the adequate regeneration of cartilage. This paper presents a review of the development of scaffolds from synthetic polymers and hybrid materials employed for the engineering of cartilage tissue and regenerative medicine. Initially, general information on articular cartilage and an overview of the clinical strategies for the treatment of cartilage defects are presented. Then, the requirements for scaffolds in regenerative medicine, materials intended for membranes, and methods for obtaining them are briefly described. We also describe the hybrid materials that combine the advantages of both synthetic and natural polymers, which provide better properties for the scaffold. The last part of the article is focused on scaffolds in cartilage tissue engineering that have been confirmed by undergoing preclinical and clinical tests.

Keywords: articular cartilage; cartilage tissue engineering; chondrocytes; materials for scaffolds; mesenchymal stem cells; regenerative medicine; scaffold obtaining methods; scaffold requirements; scaffolds; synthetic and hybrid scaffolds; tissue engineering.

Figure 1

General schema of the autologous chondrocyte implantation (ACI) method with a 3D scaffold. This schema was modified according to a previous article [44].

Figure 2

Cartilage repair methods via mesenchymal stem cell (MSC)-based therapies: (a) full-thickness cartilage injury; (b–d) therapies using MSCs and appropriate additives. The schema was modified from a previous article [53].

Figure 3

General schematic demonstration of the scaffold properties for the appropriate growth of articular chondrocytes (ACs) and mesenchymal stem cells (MSCs).

Figure 4

Schematic illustration of the main forms of scaffolds for cartilage tissue engineering: (A,B) hydrogels; (C,D) sponges; (E,F) nonwoven (nanofibers). Scale bars: D—300 µm; E—1000 nm; F—300 µm.