A Novel Biodegradable Polyurethane Matrix for Auricular Cartilage Repair

Abstract

Auricular reconstruction poses a challenge for reconstructive and burns surgeons. Techniques involving cartilage tissue engineering have shown potential in recent years. A biodegradable polyurethane matrix developed for dermal reconstruction offers an alternative to autologous, allogeneic, or xenogeneic biologicals for cartilage reconstruction. This study assesses such a polyurethane matrix for this indication in vivo and in vitro. To evaluate intrinsic cartilage repair, three pigs underwent auricular surgery to create excisional cartilage ± perichondrial defects, measuring 2 × 3 cm in each ear, into which acellular polyurethane matrices were implanted. Biopsies were taken at day 28 for histological assessment. Porcine chondrocytes ± perichondrocytes were cultured and seeded in vitro onto 1 × 1 cm polyurethane scaffolds. The total culture period was 42 days; confocal, histological, and immunohistochemical analyses of scaffold cultures were performed on days 14, 28, and 42. In vivo, the polyurethane matrices integrated with granulation tissue filling all biopsy samples. Minimal neocartilage invasion was observed marginally on some samples. Tissue composition was identical between ears whether perichondrium was left intact, or not. In vitro, the polyurethane matrix was biocompatible with chondrocytes ± perichondrocytes and supported production of extracellular matrix and Type II collagen. No difference was observed between chondrocyte culture alone and chondrocyte/perichondrocyte scaffold coculture. The polyurethane matrix successfully integrated into the auricular defect and was a suitable scaffold in vitro for cartilage tissue engineering, demonstrating its potential application in auricular reconstruction.

Effects of collagen matrix and bioreactor cultivation on cartilage regeneration of a full-thickness critical-size knee joint cartilage defects with subchondral bone damage in a rabbit model

“…The need for improved treatment options for cartilage injuries has encouraged scientists to focus on in vitro implants from isolated chondrocytes [ 17 – 19 ]. Generally, chondrocyte proliferation in vitro with carrier matrices has included collagen gels [ 20 – 23 ], fibrin and hyaluronan [ 7 , 24 , 25 ], polyglycolic acid [ 26 , 27 ], polyurethane microstructures [ 28 , 29 ], and self-assembly in agarose gel [ 30 ].…”

Improved Chondrogenic Differentiation of rAAV SOX9-Modified Human MSCs Seeded in Fibrin-Polyurethane Scaffolds in a Hydrodynamic Environment

“…An analysis is currently being performed to assess the impact of higher cell-seeding densities on the levels and significance of chondrogenic differentiation in the current system in order to further increase articular cartilage resurfacing and restore the integrity of damaged articular cartilage. Work is also ongoing to evaluate the potential of the approach in vivo by implanting similar constructs in experimental models of articular cartilage defects [ 15 , 20 , 33 , 35 , 38 ] in light of the performance of PU scaffolds in vivo [ 39 ]. Taken together, the present study demonstrates preliminary benefits of the propagation of constructs made of rAAV SOX9-transduced hMSCs in PU scaffolds in hydrodynamic culture conditions as a possible tool to generate adapted treatments for articular cartilage lesions.…”

Rational design of biodegradable thermoplastic polyurethanes for tissue repair

“…Furthermore, acellular biodegradable PU foam matrixes (Novosorb™, Polynovo Biomaterials Pty Ltd, Port Melbourne, Victoria, Australia) were implanted into pig ears. After 28 days, the matrix showed great integration with the auricular defect [ 282 ]. However, the PU itself was not bioactive and did not facilitate cell growth.…”