Decellularized Meniscus Scaffolds and Cartilage Progenitor Cells for Total Meniscal Repair

The meniscus comprises two regions: the red zone and the white zone. The white zone has poor healing capacity, leading to poor outcomes for radial meniscal tears. Current treatments, such as partial meniscectomy, increase joint contact forces and risk osteoarthritis. Alternatives, like cadaveric allografts, are limited by donor shortages, mechanical mismatches, and low cell repopulation, resulting in high revision rates. Previously, we developed a decellularized red-zone meniscus scaffold (MEND) by selectively removing elastin to create channels for cell seeding. This study investigates cartilage progenitor cells (CPCs) seeded in MEND to engineer constructs mimicking native white zone meniscus, with comparable mechanics, biochemistry, and phenotype. Cell Source : CPCs and chondrocytes (CCs) were isolated from Yucatan pig ear cartilage and expanded. CPCs were compared to CCs for proliferation, metabolic activity, and pellets chondrogenesis via histology, immunofluorescence(IF), and RT-qPCR. MEND Fabrication : Porcine menisci were decellularized by freeze-thaw cycles and enzymatic digestion with pepsin and elastase. Microchannel formation was confirmed by histology. Recellularization and Differentiation : CPCs were seeded in MEND and cultured in chondrogenic medium for six weeks. Constructs were analyzed by histology, biochemistry, mechanics, and RT-qPCR. Integration : Acellular and CPC-seeded MEND were inserted into incisions in native meniscus and cultured for one week, with integration assessed via histology. CPCs exhibited higher proliferation and lower hypertrophy than CCs, with increased collagen II. Decellularization removed DNA (<50 ng/mg tissue) and created uniform microchannels (average diameter 7µm). CPC-seeded MEND constructs remodeled into lacunae, mimicking white zone meniscus morphology. By six weeks, CPC-MEND constructs exhibited biochemical (collagen and glycosaminoglycan levels) and mechanical properties comparable to native meniscus. Integration studies showed promising preliminary results. CPCs are a promising cell source for meniscal tissue engineering due to high proliferation rates and robust chondrogenic potential. MEND scaffolds with microchannels supported uniform cell seeding without compromising mechanical integrity. CPC-laden MEND constructs recapitulated native meniscus properties, demonstrating potential for white zone meniscus repair. Future work will explore immunogenicity and in vivo performance under physiological loading. CPC-seeded MEND scaffolds offer a versatile solution for meniscal repair, addressing challenges of the white zone's limited healing capacity and advancing options for cartilage regeneration