Efficacy of thermoresponsive, photocrosslinkable hydrogels derived from decellularized tendon and cartilage extracellular matrix for cartilage tissue engineering

Abstract

Tissue engineering using adult mesenchymal stem cells (MSCs), a promising approach for cartilage repair, is highly dependent on the nature of the matrix scaffold. Thermoresponsive, photocrosslinkable hydrogels were fabricated by functionalizing pepsin-soluble decellularized tendon and cartilage extracellular matrices (ECM) with methacrylate groups. Methacrylated gelatin hydrogels served as controls. When seeded with human bone marrow mesenchymal stem cells (MSCs) and cultured in chondrogenic medium, methacrylated ECM hydrogels experienced less cell-mediated contraction, as compared against non-methacrylated ECM hydrogels. However, methacrylation slowed or diminished chondrogenic differentiation of seeded MSCs, as determined through analyses of gene expression, biochemical composition, and histology. In particular, methacrylated cartilage hydrogels supported minimal chondrogenesis over 42 weeks, as hydrogel disintegration beginning at day 14 presumably compromised cell-matrix interactions. As compared against methacrylated gelatin hydrogels, MSCs cultured in non-methacrylated ECM hydrogels exhibited comparable expression of chondrogenic genes (Sox9, Aggrecan, and collagen type II) but increased collagen type I expression. Non-methacrylated cartilage hydrogels did not promote chondrogenesis to a greater extent than either non-methacrylated or methacrylated tendon hydrogels. Whereas methacrylated gelatin hydrogels supported relatively homogenous increases in proteoglycan and collagen type II deposition throughout the construct over 42 days, ECM hydrogels possessed greater heterogeneity of staining intensity and construct morphology. These results do not support the utility of pepsin-solubilized cartilage and tendon hydrogels for cartilage tissue engineering over methacrylated gelatin hydrogels. Methacrylation of tendon and cartilage ECM hydrogels permits thermal- and light-induced polymerization but compromises chondrogenic differentiation of seeded MSCs.

Functionality of decellularized matrix in cartilage regeneration: A comparison of tissue versus cell sources

“…However, contrary studies found that cartilage T-dECMs had a limited or failed capacity to induce chondrogenic differentiation [88,89]. For example, only a small portion of cartilaginous and fibrous tissue was formed when decellularized pig ears seeded with porcine BMSCs without chondrogenic induction were implanted into nude mice.…”

Applications of decellularized extracellular matrix in bone and cartilage tissue engineering

“…Like solubilized bone dECM, cartilage solubilized dECM can be used to deliver cells, drugs, and other bioactive molecules for cartilage regeneration.The most common limitation of hydrogels formed from solubilized dECM is poor mechanical properties. For this reason, different approaches to enhance the mechanical properties of solubilized dECM have been implemented, including mixing with biological polymers, such as alginate,78,79 and crosslinking using physical, UV photochemical,26,62,82 or chemical83,84 methods. Although such treatments create hydrogels that are physically stable, they can also limit the chondrogenic capacity of the hydrogel.…”

Regulation of Decellularized Tissue Remodeling via Scaffold-Mediated Lentiviral Delivery in Anatomically-Shaped Osteochondral Constructs

“…While these studies demonstrated that PLL treatment was well tolerated by cells [55,62,63,67], a critical objective of the current investigation was to verify that lentivirus immobilization did not negatively impact the native structure or composition of CDM, which in turn influence cell attachment and viability. Minimizing alterations to CDM is of the utmost importance as processing techniques including excessive chemical crosslinking [47,68], pepsin digestion [34,69], encapsulation in PLGA microspheres [23,70], incorporation with carbon nanotubes [71], or functionalization with methacrylate groups [17,72] can inhibit cell attachment [47,68,71] and compromise the ability of CDM to support chondrogenesis [47,[68][69][70] or endochondral ossification [17]. In the current study, there was no difference in the baseline biochemical composition between NT and eGFP-transduced constructs (reported in the caption of Fig.…”