Cartilage Injury Repair by Human Umbilical Cord Wharton's Jelly/Hydrogel Combined with Chondrocyte

Therapeutic Performance of Hydrogel-Derived Extracellular Wharton's Jelly Matrix and Wharton's Jelly Mesenchymal Stem Cells in Repairing Infarcted Myocardium of Ischemic Rats: a Preclinical Study

Following myocardial infarction (MI), progressive death of cardiomyocytes and subsequent loss of the extracellular matrix leads to drastic alterations in the structure and mechanical performance of the heart, thereby leading to infarct expansion and cardiac dysfunction. To compensate for the lack of reparative potency in infarcted hearts and to inhibit negative remodeling in the myocardium after MI, stem cell-based therapy in combination with hydrogels has emerged as a promising strategy to improve cardiac function recovery. In this study, a novel injectable hydrogel derived from decellularized Wharton's jelly extracellular matrix (DWJM) is prepared and examined the therapeutic performance of a combination of bioactive DWJM hydrogels and Wharton's jelly mesenchymal stem cells (WJMSCs) for myocardial repair in ischemic rats. In vitro examinations indicated that the DWJM hydrogel exhibited appropriate rheological performance and is capable of undergoing sol-gel transition at 37 °C. After intramyocardial injection in MI rats, DWJM-trapped WJMSCs significantly improved cardiac function recovery, reduced scar formation, and promoted cardiomyogenesis and microvascular renewal compared to WJMSCs or DWJM hydrogels alone. The results demonstrated that the DWJM hydrogel and WJMSCs synergistically promoted myocardial repair, which further confirmed the promising stem cell therapy using the bioactive ECM hydrogel.

The mitochondrial protectant SS31 optimized decellularized Wharton's jelly scaffold improves allogeneic chondrocyte implantation-mediated articular cartilage repair

Background

The process of allogeneic chondrocyte implantation entails obtaining donor chondrocytes, culturing them in a medium enriched with growth factors, and then introducing them-either individually or in conjunction with biocompatible scaffolds-into areas of cartilage damage. While promising, this approach is hindered by mitochondrial dysfunction in the implanted chondrocytes.

Methods

This research introduced an innovative approach by creating a new type of scaffold derived from Decellularized Umbilical Cord Wharton's Jelly (DUCWJ) extracted from human umbilical cords. The scaffold was manufactured using procedures involving decellularization and lyophilization. The resulting scaffold demonstrated superior characteristics, including high porosity, hydrophilic properties, and excellent biocompatibility. To enhance its function, SS31 peptides, known for their mitochondrial-protective properties, were chemically bonded to the scaffold surface, creating an SS31@DUCWJ system. This system aims to protect chondrocytes and regulate the mitochondrial respiratory chain (MRC), thereby improving cartilage repair mediated by allogeneic chondrocyte implantation.

Results

In vitro studies have shown that SS31 effectively attenuates metabolic dysfunction, extracellular matrix degradation, oxidative stress, inflammation, and mitochondrial damage induced by serial cell passages. Complementary in vivo experiments showed that the SS31@DUCWJ scaffold promoted regeneration of healthy articular cartilage in femoral condylar defects in rabbits.

Conclusions

This SS31-modified porous decellularized scaffold represents an innovative biomaterial with anti-inflammatory properties and targeted mitochondrial regulation. It offers a promising new approach for treating articular cartilage injuries.

The translational potential of this article

Our study was the first to successfully load the mitochondrial protectant SS31 onto a DUCWJ hydrogel scaffold for localized drug delivery. This method is highly efficacious in repairing cartilage defects and offers a promising new avenue for the treatment of such conditions.

Hydrogel-Enhanced Autologous Chondrocyte Implantation for Cartilage Regeneration-An Update on Preclinical Studies

Autologous chondrocyte implantation (ACI) and matrix-induced ACI (MACI) have demonstrated improved clinical outcomes and reduced revision rates for treating osteochondral and chondral defects. However, their ability to achieve lasting, fully functional repair remains limited. To overcome these challenges, scaffold-enhanced ACI, particularly utilizing hydrogel-based biomaterials, has emerged as an innovative strategy. These biomaterials are intended to mimic the biological composition, structural organization, and biomechanical properties of native articular cartilage. This review aims to provide comprehensive and up-to-date information on advancements in hydrogel-enhanced ACI from the past decade. We begin with a brief introduction to cartilage biology, mechanisms of cartilage injury, and the evolution of surgical techniques, particularly looking at ACI. Subsequently, we review the diversity of hydrogel scaffolds currently undergoing development and evaluation in preclinical studies for articular cartilage regeneration, emphasizing chondrocyte-laden hydrogels applicable to ACI. Finally, we address the key challenges impeding effective clinical translation, with particular attention to issues surrounding fixation and integration, aiming to inform and guide the future progression of tissue engineering strategies.

Advancements and Challenges in Hydrogel Engineering for Regenerative Medicine

This manuscript covers the latest advancements and persisting challenges in the domain of tissue engineering, with a focus on the development and engineering of hydrogel scaffolds. It highlights the critical role of these scaffolds in emulating the native tissue environment, thereby providing a supportive matrix for cell growth, tissue integration, and reducing adverse reactions. Despite significant progress, this manuscript emphasizes the ongoing struggle to achieve an optimal balance between biocompatibility, biodegradability, and mechanical stability, crucial for clinical success. It also explores the integration of cutting-edge technologies like 3D bioprinting and biofabrication in constructing complex tissue structures, alongside innovative materials and techniques aimed at enhancing tissue growth and functionality. Through a detailed examination of these efforts, the manuscript sheds light on the potential of hydrogels in advancing regenerative medicine and the necessity for multidisciplinary collaboration to navigate the challenges ahead.

Advancements in tissue engineering for articular cartilage regeneration

Articular cartilage injury is a prevalent clinical condition resulting from trauma, tumors, infection, osteoarthritis, and other factors. The intrinsic lack of blood vessels, nerves, and lymphatic vessels within cartilage tissue severely limits its self-regenerative capacity after injury. Current treatment options, such as conservative drug therapy and joint replacement, have inherent limitations. Achieving perfect regeneration and repair of articular cartilage remains an ongoing challenge in the field of regenerative medicine. Tissue engineering has emerged as a key focus in articular cartilage injury research, aiming to utilize cultured and expanded tissue cells combined with suitable scaffold materials to create viable, functional tissues. This review article encompasses the latest advancements in seed cells, scaffolds, and cytokines. Additionally, the role of stimulatory factors including cytokines and growth factors, genetic engineering techniques, biophysical stimulation, and bioreactor systems, as well as the role of scaffolding materials including natural scaffolds, synthetic scaffolds, and nanostructured scaffolds in the regeneration of cartilage tissues are discussed. Finally, we also outline the signaling pathways involved in cartilage regeneration. Our review provides valuable insights for scholars to address the complex problem of cartilage regeneration and repair.