Chondrocyte-based intraoperative processing strategies for the biological augmentation of a polyurethane meniscus replacement

Abstract

Purpose/Aim of Study: Menisectomies account for over 1.5 million surgical interventions in Europe annually and there is a growing interest in regenerative strategies to improve outcomes in meniscal replacement. The overall objective of this study was to evaluate the role of intraoperatively applied fresh chondrocyte isolates compared to minced cartilage fragments, used without cell isolation, to improve bioactivity and tissue integration when combined with a polyurethane replacement. Materials and Methods:Firstly, to optimise the intraoperative cell isolation protocol, caprine articular cartilage biopsies were digested with 750 U/ml or 3000 U/ml collagenase type II (ratio of 10 ml per g of tissue) for 30 min, 1 h or 12 hrs with constant agitation and compared to culture expanded chondrocytes in terms of matrix deposition when cultured on polyurethane scaffolds. Finally, fresh chondrocytes and minced cartilage augmented polyurethane scaffolds were evaluated in a caprine meniscal explant model to assess the potential enhancements on tissue integration strength.Results: Adequate numbers of fresh chondrocytes were harvested using a 30 min chondrocyte isolation protocol and demonstrated improved matrix deposition compared to standard culture expanded cells in vitro. Upon evaluation in a meniscus explant defect model, both fresh chondrocytes and minced cartilage showed improved matrix deposition at the tissue scaffold interface and enhanced push-out strength, 4 fold and 2.5 fold respectively compared with the acellular implant. Conclusions:Herein, we have demonstrated a novel approach that could be applied intraoperatively using fresh chondrocytes or minced cartilage for improved tissue integration with a polyurethane meniscal replacement.

Meniscal Regenerative Scaffolds Based on Biopolymers and Polymers: Recent Status and Applications

“…Polyurethane (PU) possesses elasticity, thermoplasticity and excellent biocompatibility and has already been applied in meniscal tissue engineering ( Venkatesan and Kim, 2014 ; Koch et al, 2018 ; Vedicherla et al, 2018 ; Bharadwaz and Jayasuriya, 2020 ). For example, Actifit ® implants have been studied as a cellular component delivery vehicle.…”

“…For example, Actifit ® implants have been studied as a cellular component delivery vehicle. Vedicherla et al (2018) developed a cell-seeded PU scaffold. Fresh chondrocytes (FCs) and minced cartilage (MC) were cultured on the scaffold, and the tissue integration effect was evaluated in a caprine meniscal explant model.…”

“…Fresh chondrocytes (FCs) and minced cartilage (MC) were cultured on the scaffold, and the tissue integration effect was evaluated in a caprine meniscal explant model. The results exhibited better matrix deposition and tissue integration in both the FC and MC groups than in the acellular scaffold group ( Vedicherla et al, 2018 ). MSCs are also promising for meniscal repair due to their potential for fibrochondrogenesis and their ability to secrete reparative growth factors ( Koch et al, 2018 ).…”