The Use of Collagen with High Concentration in Cartilage Tissue Engineering by Means of 3D-Bioprinting

Abstract

3D-bioprinting is a promising technology for a tissue scaffold fabrication in the case of damaged tissue/organ replacement. Collagen is one of the most appropriate hydrogel for the purpose, due to its exceptional biocompatibility. However, the use of collagen with conventionally low concentration makes bioprinting process difficult and does not provide its high accuracy. The purpose of the study was evaluation of suitability of collagen with high concentration in case of chondrocyte-laden scaffold fabrication via 3D-bioprinting for cartilage regeneration in vitro and in vivo. The results of the study showed that inherent porosity of 4% collagen was not enough for cell survival in the case of long-term incubation in vitro. With the beginning of the scaffold incubation, cell migration to the surface and out of the scaffold was observed. The residual cells died mostly within 4 weeks. As for in vivo study, in 2 weeks after implantation of the scaffold, a weak granulomatous inflammation was observed. In 6 weeks, a connective tissue was formed in the area of implantation. In the tissue, macrophages and groups of small cells with round nuclei were found. In accordance with morphological criteria, these cells could be considered as young chondrocytes. However, its amount was not enough to initiate the formation of cartilage.

Bioprinting of Cartilage with Bioink Based on High-Concentration Collagen and Chondrocytes

“…The lack of oxygen leads to a decrease rate of cell proliferation, their transition to rest state, and presumable death. The issue has been described consistently in a previous study [ 23 ]. A number of researchers have pointed out that it is possible to avoid cell death by adding to the scaffold cavities and channels (vessels).…”

“…The only way to improve the transport of nutrients and gases is through the use dynamic cultivation systems (e.g., bioreactors) that mimic the vascular system [ 29 ]. The issue has been discussed earlier [ 23 ].…”

Cartilage Formation In Vivo Using High Concentration Collagen-Based Bioink with MSC and Decellularized ECM Granules

“…It is known that muscles are well supplied with blood. Thus, our study again raises the problem of vascularization of tissue-engineered structures [ 57 , 58 ]. Even in the case of cartilage (generally non-vascularized tissue), the issue is urgent.…”

Investigation of Collagen-Incorporated Sodium Alginate Bioprinting Hydrogel for Tissue Engineering

“…Alternatively, researchers tried to reinforce the internal support of bioink by blending different hydrogel solutions or pre-crosslinking. Among these studies, sodium alginate, gelatin, and collagen were the most used materials to produce artificial cartilage tissue, and CaCl 2 was applied for crosslinking [33][34][35]. Yang et al compared the mechanical properties and biological functionality of pure SA, SA/agarose, and SA/COL.…”