Inhibition of Hypertrophy and Improving Chondrocyte Differentiation by MMP-13 Inhibitor Small Molecule-Encapsulated in Alginate-Chondroitin Sulfate-Platelet Lysate Hydrogel

Abstract

Background Mesenchymal stem cells are a promising cell source for chondrogenic differentiation and have been widely used in several preclinical and clinical studies. However, they are prone to an unwanted differentiation process towards hypertrophy that limits their therapeutic efficacy. Matrix Metallopeptidase 13 (MMP-13) is a well-known factor regulated during this undesirable event. MMP-13 is a collagen degrading enzyme, which is also highly expressed in the hypertrophic zone of the growth plate and in OA cartilage. Accordingly, we investigated the effect of MMP-13 inhibition on MSC hypertrophy.Methods In this study, 5-bromoindole-2-carboxylic acid (BICA) was used as an inhibitory agent for MMP-13 expression. After identifying its optimal concentration, BICA was mixed into a hydrogel and the release rate was studied. To prepare the ideal hydrogel, chondroitin sulfate (CS) and platelet lysate (PL) were mixed with sodium alginate (Alg) at concentrations selected based on synergistic mechanical and rheometric properties. Then, four hydrogels were prepared by combining alginate (1.5%w/v), and/or CS (1%w/v) and/or PL (20%v/v). The chondrogenic potential and progression to hypertrophy of human bone marrow-derived mesenchymal stem cell (hBM-MSC) loaded hydrogels were investigated under free swelling and mechanical loading conditions, in the presence and absence of BICA.Results Viability of hBM-MSCs seeded in the four hydrogels was similar. qRT-PCR revealed that BICA could successfully inhibit MMP-13 expression, which led to an inhibition of Coll X and induction of Coll-II, in both free swelling and loading conditions. The GAG deposition was higher in the group combining BICA and mechanical stimulation.Conclusions It is concluded that BICA inhibition of MMP-13 reduces MSC hypertrophy during chondrogenesis.

Engineering hypertrophic cartilage grafts from lipoaspirate for critical‐sized calvarial bone defect reconstruction: An adipose tissue‐based developmental engineering approach

“…After 2 weeks of hypertrophic induction, the pellets displayed more intense GAG (Figure 3a, right), Col I (Figure 3b, right), and Col II (Figure 3C, right) deposition and were expressed by the hypertrophic markers Col X and BSP (Figure 3d, right and Figure 4a, right), indicating that 6 weeks of endochondral priming converted the Adiscaf pellets from adipose tissue into HyC tissue. Cartilaginous matrix remodeling was further confirmed by staining for MMP‐13 and MMP‐9, which are matrix‐degrading enzymes that specifically degrade Col II and proteoglycans in cartilage 40–42 . The chondrogenic‐primed Adiscaf pellets initially weakly expressed MMP‐13, and the expression levels were enhanced after hypertrophic induction (Figure 4b).…”

“…Cartilaginous matrix remodeling was further confirmed by staining for MMP-13 and MMP-9, which are matrix-degrading enzymes that specifically degrade Col II and proteoglycans in cartilage. [40][41][42] The chondrogenic-primed Adiscaf pellets initially weakly expressed MMP-13, and the expression levels were enhanced after hypertrophic induction (Figure 4b). Similarly, MMP-9 expression was positive in chondrogenically primed Adiscaf pellets and significantly enhanced after hypertrophic induction (Figure 4c).…”