Biological Evaluation of Acellular Cartilaginous and Dermal Matrixes as Tissue Engineering Scaffolds for Cartilage Regeneration.

Yong Xu,Yahui Wang,Guangdong Zhou,Yu Liu,Yilin Cao

doi:10.3389/fcell.2020.624337

Abstract

An acellular matrix (AM) as a kind of natural biomaterial is gaining increasing attention in tissue engineering applications. An acellular cartilaginous matrix (ACM) and acellular dermal matrix (ADM) are two kinds of the most widely used AMs in cartilage tissue engineering. However, there is still debate over which of these AMs achieves optimal cartilage regeneration, especially in immunocompetent large animals. In the current study, we fabricated porous ADM and ACM scaffolds by a freeze-drying method and confirmed that ADM had a larger pore size than ACM. By recolonization with goat auricular chondrocytes and in vitro culture, ADM scaffolds exhibited a higher cell adhesion rate, more homogeneous chondrocyte distribution, and neocartilage formation compared with ACM. Additionally, quantitative polymerase chain reaction (qPCR) indicated that expression of cartilage-related genes, including ACAN, COLIIA1, and SOX9, was significantly higher in the ADM group than the ACM group. Furthermore, after subcutaneous implantation in a goat, histological evaluation showed that ADM achieved more stable and matured cartilage compared with ACM, which was confirmed by quantitative data including the wet weight, volume, and contents of DNA, GAG, total collagen, and collagen II. Additionally, immunological assessment suggested that ADM evoked a low immune response compared with ACM as evidenced by qPCR and immunohistochemical analyses of CD3 and CD68, and TUNEL. Collectively, our results indicate that ADM is a more suitable AM for cartilage regeneration, which can be used for cartilage regeneration in immunocompetent large animals.

Highlights

Cartilaginous defect repair is difficult because of the avascular nature and limited regeneration ability of cartilage in situ (Gomoll et al, 2010; Montgomery et al, 2014; Orth et al, 2020)
The results showed that chondrocytes exhibited a round shape within 24 h, gradually stretched, and eventually secreted extracellular matrix (ECM) to cover the pores in both acellular cartilaginous matrix (ACM) (Figures 1C1–C3) and acellular dermal matrix (ADM) (Figures 1D1–D3) scaffolds
Cell viability assays showed that chondrocytes grew well on both ACM and ADM scaffolds with significant proliferation over time and few dead cells were observed at any time point (Figures 2A,B)

Summary

Introduction

Cartilaginous defect repair is difficult because of the avascular nature and limited regeneration ability of cartilage in situ (Gomoll et al, 2010; Montgomery et al, 2014; Orth et al, 2020). Biomaterial scaffolds play an important role in cartilage tissue engineering (Przekora, 2019; Lapomarda et al, 2020) They provide support to maintain the original shape, and guide the regeneration of damaged cartilaginous tissue. Because of the serious inflammatory response in immunocompetent animals, they are not ideal for cartilage regeneration and translation to clinical application (Rotter et al, 2005; Ceonzo et al, 2006; Asawa et al, 2012) Natural scaffolds such as an acellular matrix (AM) are gaining increasing attention for cartilage regeneration, because they provide an ideal extracellular matrix (ECM) and signals that facilitate cell attachment, migration, proliferation, and differentiation (Yang et al, 2008; Lammi et al, 2018)

Methods

Results

Discussion

Conclusion