Hybrid photo-crosslinked decellularized extracellular matrix scaffold from porcine Achilles tendon: a biocompatible and non-immunogenic matrix for tissue engineering

A considerable number of xenogeneic tissues are still underutilised due to concerns about immunogenicity, biocompatibility, and structural integrity. Decellularized extracellular matrix (dECM) hydrogels are gaining popularity due to their ability to mimic natural biochemical cues and structural integrity required for tissue regeneration. In this study, we used pig tendon tissues, which are commonly discarded, to create photo-crosslinked dECM hydrogels. We created and comprehensively examined tendon-derived dECM hydrogels processed with three different decellularization techniques, assessing their physicochemical properties, biocompatibility, and immunogenicity. SEM, XRD, and FTIR were used to characterize the dECM hydrogel's structural and biochemical integrity. SEM demonstrated an intact collagenous architecture, while XRD proved the presence of a natural collagen fibrillar structure. The FTIR study revealed intact amide I and II bands, indicating minimal ECM disruption. Rheological experiments revealed good shear-thinning behaviour, which improves injectability. Furthermore, TGA verified thermal stability in the groups, and swelling experiments revealed consistent hydrogel stability, with CD exhibiting the largest equilibrium swelling due to improved water-polymer interaction without compromising flexibility. THP-1 cells were grown on dECM hydrogels to test biocompatibility and immunogenicity. Cellular morphology examination demonstrated that THP-1 cells cultivated on dECM hydrogels had good cell viability and structural integrity. Notably, the constant expression of CD14, a major monocyte surface marker, without any pro-inflammatory activation demonstrated the hydrogels' non-immunogenic character, implying a broader applicability. Our research confirms that dECM hydrogels generated from tendon are durable biomaterials that do not elicit an immune response. A biocompatible and non-immunogenic matrix is produced by the optimised decellularization approach, which has great potential for use in tissue engineering and regenerative medicine.