The aim of this study was to develop a fetal cartilage-derived progenitor cell (FCPC) based cartilage gel through self-assembly for cartilage repair surgery, with clinically useful properties including adhesiveness, plasticity, and continued chondrogenic remodeling after transplantation. Characterization of the gels according to in vitro self-assembly period resulted in increased chondrogenic features over time. Adhesion strength of the cartilage gels were significantly higher compared to alginate gel, with the 2-wk group showing a near 20-fold higher strength (1.8 ± 0.15 kPa vs. 0.09 ± 0.01 kPa, p < 0.001). The in vivo remodeling process analysis of the 2 wk cultured gels showed increased cartilage repair characteristics and stiffness over time, with higher integration-failure stress compared to osteochondral autograft controls at 4 weeks (p < 0.01). In the nonhuman primate investigation, cartilage repair scores were significantly better in the gel group compared to defects alone after 24 weeks (p < 0.001). Cell distribution analysis at 24 weeks showed that human cells remained within the transplanted defects only. A self-assembled, FCPC-based cartilage gel showed chondrogenic repair potential as well as adhesive properties, beneficial for cartilage repair.

The aim of this study was to develop a porcine epiphyseal plate-derived extracellular matrix powder (PEPEP) for epiphyseal plate regeneration. PEPEP was characterized by chemical assay to determine the contents of DNA and epiphyseal plate complex chemical components (glycosaminoglycan and hydroxyproline). The effects of PEPEP on the viability, proliferation, and differentiation of human bone marrow mesenchymal stem cells (hBMSCs) were also evaluated. hBMSCs cultured in PEPEP exhibited a good distribution with excellent viability after 72 h, demonstrating the ability of PEPEP to support hBMSC proliferation. At week 4 and 6 in vitro, the PEPEP + hBMSCs structure showed chondrogenic ability and an increase in expression of collagen type I, type II, and type X. PEPEP showed a promising ability to enhance cartilage formation and promote chondrocyte differentiation, maturation, and hypertrophy. The results provide insights into the feasibility of PEPEP as a potential material for tissue engineering applications.

(1) Autologous chondrocyte implantation (ACI) is a prominent method for treating cartilage damage, but periosteal patches can cause chondrocyte leakage. This study evaluates the potential of a decellularized membrane derived from the cell-produced extracellular matrix of 1-day-old porcine cartilage (pcECM-DM) to act as a substitute for periosteal patches. (2) The interaction between young rabbit chondrocyte cells and pcECM-DM was assessed through cytotoxicity, differentiation, cell viability, cell migration, and adhesive ability. Rabbit chondrocyte cells, cultivated until passage two, were seeded onto a 6 mm diameter membrane. Assessments included DAPI-PKH26 staining, histological staining, live/dead assay, WST-1 assay, and proteomics analysis. (3) Results: DAPI-PKH26 staining showed successful adhesion and the uniform distribution of cells on the membrane. Safranin-O and H&E staining confirmed that the membrane supports chondrocyte adhesion and extracellular matrix production with high cell density and typical chondrocyte morphology. The live/dead assay demonstrated a high proportion of viable cells at 24 and 48 h, with increased cell proliferation over time. The WST-1 assay showed a significant increase in OD450 values, confirming cell proliferation and biocompatibility. Proteomic analysis revealed the significant enrichment of genes associated with extracellular matrix organization, cell adhesion, and cartilage development. (4) Conclusions: This novel biomaterial holds the potential to enhance cartilage regeneration and offer a viable alternative to periosteal patches.

(1) Background: Knee cartilage injury is at the top of the rising concerns among bone and joint disorder patients. Autologous chondrocyte implantation (ACI) is widely used to approach knee cartilage deterioration. Integrating autologous chondrocytes and periosteal patches aids in forming new cartilage-like tissue at the lesion area. This study uses a novel cell source from one-day-old porcine cartilage to fabricate a biomembrane as a substitute for periosteal membranes in cell implantation techniques for treating knee cartilage injuries. (2) Methods: Cells isolated from one-day-old porcine cartilage tissue were identified and assessed for their proliferation capability, differentiation ability, and membrane formation potential. The protein component of the biomembrane was also defined by proteomics. The cartilage repair ability was also confirmed using an in vitro transplantation model. (3) Results: Negative results for porcine infectious diseases are pivotal in selecting suitable piglets to provide cartilage tissue. The cells successfully obtained from one-day-old porcine cartilage exhibited stem-cell-like characteristics (CD34-, CD45-, CD90+, CD105+), including a high proliferation to 20 passages (doubling time: 1–2 days) and a capacity to differentiate into various cell types (osteogenesis, adipogenesis, and chondrogenesis). The stem cells were successfully applied in the fabrication of the biomembranes. The protein components of the biomembrane included an extracellular matrix and growth factors. The in vitro transplantation model showed that the biomembrane induced the repair ability of cartilage defects. (4) Conclusions: This study is the first to successfully harvest stem cells from one-day-old porcine cartilage for biomembrane fabrication for a knee cartilage injury therapeutic application.

Osteoarthritis is a common knee joint disease that significantly affects pet health, especially among domestic dogs. Bone marrow mesenchymal stem cells (BMSCs) are multipotent cells capable of differentiating into multiple lineages and self-renewing. However, their limited quantity and proliferative capacity during laboratory cultivation present challenges. In this study, BMSCs were isolated from the bone marrow of immature dogs and evaluated for various biological characteristics. Researchers assessed their ability to form colonies (Colony Forming Unit—CFU), stability of cellular morphology, proliferative capacity, expression of stem cell markers, and potential for differentiation into other cell types. The results indicated that the isolated cells exhibited colony-forming ability with a CFU-f of 5 ± 1 colonies per million mononuclear cells. The cells maintained stable morphology through the 8th passage and showed a doubling time of less than 42 hours. Additionally, these BMSCs expressed surface markers CD90 and CD105 while lacking CD34 and CD45, and they successfully differentiated into bone, cartilage, and fat cells. These findings encourage continued research into the clinical use of canine BMSCs for joint repair. In conclusion, this study presents a successful method for isolating and culturing canine BMSCs, highlighting their potential application in treating degenerative knee diseases.