The Application of 3D Bioprinting with Stem Cells for Cartilage Tissue Engineering: A Systematic Review

Abstract

Introduction: Engineering functional cartilage tissue for joint repair remains a major challenge. 3D bioprinting, a cornerstone of advanced tissue engineering, allows for the precise deposition of stem cells and biomaterials (bio-inks) to create complex, structured tissues. This review assesses the state-of-the-art in 3D bioprinting of stem cell-laden constructs for cartilage repair.

Methods: A systematic search of engineering and medical databases (IEEE Xplore, PubMed, Scopus) was performed for studies that reported on the 3D bioprinting of chondrocytes or mesenchymal stem cells for cartilage constructs. Outcomes of interest included cell viability, chondrogenic differentiation, and mechanical properties of the printed tissue.

Results: Fifty-two in-vitro studies were reviewed. High cell viability (>85%) post-printing was achievable with various printing technologies (extrusion, inkjet, stereolithography). The use of natural hydrogels like alginate and hyaluronic acid as bio-inks promoted robust chondrogenesis, evidenced by the production of collagen type II and aggrecan. The mechanical strength of the constructs, however, remains significantly lower than that of native cartilage.

Discussion: 3D bioprinting is a powerful tool for creating anatomically complex cartilage constructs with high cell viability and differentiation potential. The primary hurdle for clinical translation is achieving the mechanical resilience required for a load-bearing joint surface.

Conclusion: While significant progress has been made in 3D bioprinting of stem cells for cartilage engineering, further innovation in bio-ink development and printing strategies is needed to produce mechanically functional tissue suitable for clinical application.