Nanofiber scaffolds based on extracellular matrix for articular cartilage engineering: A perspective

Abstract

Articular cartilage has a low self-repair capacity due to the lack of vessels and nerves. In recent times, nanofiber scaffolds have been widely used for this purpose. The optimum nanofiber scaffold should stimulate new tissue's growth and mimic the articular cartilage nature. Furthermore, the characteristics of the scaffold should match those of the cellular matrix components of the native tissue to best merge with the target tissue. Therefore, selective modification of prefabricated scaffolds based on the structure of the repaired tissues is commonly conducted to promote restoring the tissue. A thorough analysis is required to find out the architectural features of scaffolds that are essential to make the treatment successful. The current review aims to target this challenge. The article highlights different optimization approaches of nanofibrous scaffolds for improved cartilage tissue engineering. In this context, the influence of the architecture of nanoscaffolds on performance is discussed in detail. Finally, based on the gathered information, a future outlook is provided to catalyze development in this promising field.

Keywords: Articular cartilage; Articular cartilage defect; Collagen type II; Scaffolds.

Figure 1

Extracellular matrix of articular cartilage. Two major load-bearing macromolecules are present in articular cartilage: Collagens (mainly type II) and proteoglycans (notably, aggrecan). Smaller classes of molecules, such as non-collagenous proteins and smaller proteoglycans, are present in lower amounts. The interaction between the highly negatively charged cartilage proteoglycans and type II collagen provides the compressive and tensile strength of the tissue. Reproduced with permission . Copyrighted by the Authors (2019).

Figure 2

Structure of the articular cartilage layer. Reproduced with permission . Copyrighted by the Authors (2021).

Figure 3

Schematic representation of osteochondral autograft transplantation. Reproduced with permission . Copyrighted by the Authors (2021).

Figure 4

Electrospinning of fibrous (A) isotropic and (B) anisotropic nanoscaffolds. Reproduced with permission from . Copyrighted by Wiley (2012).

Figure 5

Schematic illustration of a mixed material of a nanofiber scaffold along with scaffold-free tissue-engineered construct (TEC) consisting of cells and extracellular matrix (ECM). A: The parallel structure of the scaffold. B: TEC structure. C: H&E staining of the combined material consisting of an electrospun nanofibrous scaffold (A) and a TEC (B). D: Schematic depiction of combined material comprising an electrospun nanofibrous scaffold (A) and a TEC (B). Reproduced with permission . Copyrighted by the Authors.

Figure 6

Most important factors, which should be the matter of further research to increase the technology readiness level of nanofiber-bases scaffolds for cartilage engineering.