P. Roessler (Bonn, DE)
University Hospital Bonn OrthopaedicsPresenter Of 1 Presentation
16.2.7 - Mechanisms of cell-free cartilage repair using a modified collagen type I matrix and additive fibrin glue
Abstract
Purpose
Cartilage repair using cell-free matrices has become popular as an alternative to matrix-associated autologous chondrocyte transplantation (MACT). Aim of the present investigation was to better understand the mechanisms behind cell-free cartilage regeneration and the impact of various matrix modifications (e.g. perforation, additive fibrin glue) on cell migration and colonization.
Methods and Materials
A cell-free cartilage matrix composed out of rat-tail-derived type I collagen (CaReS-1S, ArthroKinetics GmbH, Krems a.d. Donau, Austria) was used. The effect of additive fibrin glue on the colonization of CaReS-1S was investigated in a special cell culture insert model. Parameters of cell migration of bone marrow-derived mesenchymal stromal cells (BM-MSC) as well as cell counts and proliferation rates were recorded. Secondly, the colonization potential of various periarticular cell niches was tested to identify a preferable cell source. BM-MSC, cartilage MSC (C-MSC) and synovial MSC (S-MSC) were used. Proliferation (MTT) and migration assays were performed, as well as a matrix migration/penetration depth assessment using color coded confocal microscopy. Modification of the matrix with a self-developed micro-needle device was investigated under chondroinductive and standard conditions.
Results
Fibrin glue showed a good attraction potential to BM-MSC, but cell counts over time, as well as subsequent proliferation rates were significantly higher in CaReS-1S. Regarding colonization potential, CaReS-1S did not show a preference for either periarticular cell niche. Micro-perforation of the matrix led to a deeper cell penetration and increased migration of cells under standard culture conditions, but not under chondrogenically induced conditions. Non-induced MSC, regardless of cell niche, showed a deeper migration as compared to induced MSC without significant differences among groups.
Conclusion
Bone marrow, adjacent cartilage and synovium are all suitable sources for colonization of cell-free matrices. Fibrin glue may hinder trans-migration into matrices in vivo due to a high retention of cells. Micro-perforation of the matrix boosted its colonization, especially of deeper layers.