Decellularized Porcine Cartilage Scaffold; Validation of Decellularization and Evaluation of Biomarkers of Chondrogenesis

Osteoarthritis is a major concern in the United States and worldwide. Current non-surgical and surgical approaches alleviate pain but show little evidence of cartilage restoration. Cell-based treatments may hold promise for the regeneration of hyaline cartilage-like tissue at the site of injury or wear. Cell–cell and cell–matrix interactions have been shown to drive cell differentiation pathways. Biomaterials for clinically relevant applications can be generated from decellularized porcine auricular cartilage. This material may represent a suitable scaffold on which to seed and grow chondrocytes to create new cartilage. In this study, we used decellularization techniques to create an extracellular matrix scaffold that supports chondrocyte cell attachment and growth in tissue culture conditions. Results presented here evaluate the decellularization process histologically and molecularly. We identified new and novel biomarker profiles that may aid future cartilage decellularization efforts. Additionally, the resulting scaffold was characterized using scanning electron microscopy, fluorescence microscopy, and proteomics. Cellular response to the decellularized scaffold was evaluated by quantitative real-time PCR for gene expression analysis.

Developing a Pro-Angiogenic Amniochorionic-Derived Decellularized Scaffold with Two Exposed Basement Membranes for Cultivating Endothelial Cells

Decellularized placental membrane has widely been used as scaffold and graft in tissue engineering and regenerative medicine. Exceptional pro-angiogenic and biomechanical properties and low immunogenicity have made the amniochorionic membrane a unique scaffold which provides enriched niche for cellular growth. Herein, an optimized combination of enzymatic solutions (based on Streptokinase) with mechanical scrapping is used to remove the amniotic epithelium and chorion trophoblastic layer, which results in exposing the basement membranes of both sides without their separation and subsequent damages to the in-between spongy layer. Biomechanical and biodegradability properties, endothelial proliferation capacity, and in-vivo pro-angiogenic capabilities of the scaffold were also evaluated. Histological staining and scanning electron microscope (SEM) demonstrated that the underlying amniotic and chorionic basement membranes remained intact while the epithelial and trophoblastic layers were entirely removed without considerable damage to basement membranes. The biomechanical evaluation showed that the scaffold is suturable. Proliferation assay and immunohistochemistry demonstrated that both side basement membranes could support growth of endothelial cells without altering endothelial characteristics. The dorsal skinfold chamber animal model indicated that both side basement membranes could promote angiogenesis. This bi-sided decellularized scaffold with two exposed surfaces for cultivating various cells would have potential applications in skin, cardiac, vascularized composite allografts, and microvascular tissue engineering.

Decellularized scaffold and its elicited immune response towards the host: the underlying mechanism and means of immunomodulatory modification

The immune response between decellularied scaffold and the implanted host is complex. Not only a number of immune cells can influence this process, but also the characteristics, preparation and modification...

Re-endothelization of human saphenous vein scaffold surfaces for bioprosthesis fabrication

Various in vitro methods have been used for biological and synthetic scaffold fabrication. Some use polymers such as expanded polytetrafluoroethylene (ePTFE), polytetrafluoroethylene (PTFE), and polyethylene terephthalate (PET), while others use allogeneic or xenogeneic biological materials (e.g. blood vessels). While fabricating a biological scaffold, the first step is complete decellularization by enzymes (e.g. trypsin, collagenase, etc.) or chemicals (e.g. SDS, Triton-X, etc.), and the scaffolds should maintain its extracellular matrix (ECM). The second step involves re-endothelization so as to get fully biomimetic graft. In this study, we focused (concentrated) on the fabrication of a human saphenous vein scaffold by using various chemicals. We observed that cationic 1% SDS solution (Group B) performed excellent decellularization without altering the extracellular matrix as compared to the other chemicals like 0.25% trypsin and 70% ethanol (Groups C and D). Decellularization percentage and intactness of ECM (in all tunicae – intima, media, and adventitia) were confirmed based on histology. The PicoGreen assay showed that Group B (1% SDS decellularized scaffold, n = 3) had no detectable residual DNA. Re-endothelization on the complete decellularized scaffold (Group B) was done in both ways, without initial fibrin glue application (Group E) and with prior fibrin glue application (Group F). The vWF and lectin expressions suggested that endothelial cells did not alter their phenotype on human saphenous vein scaffolds. Uniaxial tensile testing revealed no significant differences in strain characteristics and modulus between native tissue and decellularized scaffolds. The live-dead (FDA/PI) and MTT assays confirmed the endothelial cell proliferation and viability, and the scanning electron microscope (SEM) data showed that the cells adhered to the scaffold matrix (Group F). We concluded that an allogeneic human saphenous vein scaffold with desirable properties can be fabricated and re-endothelialized to form a non-thrombogenic intimal surface in vitro using this protocol.

A decellularized scaffold derived from squid cranial cartilage for use in cartilage tissue engineering

Decellularized cartilage scaffold (DCS) is an emerging substitute for cartilage defect application.