Peking University Third Hospital Unveils New Patent for Meniscus Regeneration and Repair Hydrogel Material

Recently, a “"Preparation Method of Meniscus Hydrogel Material, Meniscus Manufacturing Method, and Meniscus"patent disclosure. The inventors of this patent are the team led by Professor Yu Jiakuo, Director of the Sports Medicine and Knee Surgery Department at Peking University Third Hospital. This research team utilized hydrogel materials to enhance their mechanical properties, thereby improving the repair capability of fabricated menisci.

Meniscal injury is the most common sports-related injury of the knee joint. Its primary symptoms include pain and weakness. In cases of meniscal instability, patients may experience clicking, locking, and associated pain. Regeneration and repair of the meniscus have also become important areas of research.

In the field of meniscal regeneration and repair, the application of hydrogel materials is particularly noteworthy. As biomaterials capable of mimicking the composition of native meniscal tissue, hydrogels are gradually emerging as novel candidate materials for researchers developing biomimetic menisci, owing to their highly tunable chemical properties, excellent biocompatibility, and biodegradability.

Domestic research institutions have also achieved significant results in the study of meniscal regeneration and repair based on hydrogel materials, publishing multiple related articles.

The team led by Yu Yin at the Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, developed an injectable living hydrogel by loading bone marrow-derived mesenchymal stem cells into tissue-specific extracellular matrix (ECM), and established a meniscal injury model in mice through minimally invasive surgery under microscopic guidance.

Liu Wenguang’s team at Tianjin University previously reported a high-strength supramolecular polymer hydrogel-based biomimetic structured meniscal substitute. Implantation of 3D-printed PCL-PNAGA meniscal scaffolds into rabbit knee joints for 12 weeks demonstrated in vivo structural stability, effective prevention of cartilage wear, and mitigation of osteoarthritis progression.

The team led by Professor Guo Quanyi at the 301 Hospital fabricated a scaffold with a wedge-shaped poly(ε-caprolactone) (PCL) framework via 3D printing, injected it with an optimized meniscal extracellular matrix (MECM) hydrogel, and seeded it with meniscal fibrochondrocytes (MFCs). The results demonstrated that this composite scaffold exhibited favorable biomechanical properties comparable to those of the native meniscus.Therefore, as excellent candidates for meniscal repair and regeneration, hydrogel materials, in the form of carrier-based mechanically reinforced constructs, are widely featured in meniscal repair research.

Currently, partial meniscus prostheses available for human use include CMI and Acifit, as well as NUsurface, a permanent total meniscus prosthesis under clinical trials. The primary material for both Acifit and NUsurface is polyurethane. The NUsurface meniscal implant is reinforced with high-strength ultra-high-molecular-weight polyethylene (UHMWPE) fibers.

Regarding hydrogel materials, although various hydrogels have demonstrated promising efficacy in animal models of meniscal injury, few have proven clinically effective, indicating that numerous overlooked issues remain with hydrogels.

In January 2024, Professor Yu Jiakuo’s team published a review on the applications of various implantable medical-grade hydrogels in meniscus repair and regeneration in Advanced Functional Materials (AFM), under the title “Advanced Hydrogel Material for Meniscus Repair.”

The research team highlighted the limitations of currently available hydrogels for meniscal repair.

First, research on 3D-printed hydrogel menisci remains largely confined to animal studies, with a lack of large-scale clinical trial data. Second, composite hydrogel scaffolds have not yet truly achieved the high-performance, comprehensive requirements for biomimetic meniscal scaffolds that integrate drug/cell loading, bioactivity, mechanical strength, and cell adhesion. Third, some 3D-printed hydrogel meniscal scaffolds cannot be implanted into the knee joint cavity via minimally invasive injection. Fourth, due to the presence of synovial fluid in the knee joint cavity, drugs, cells, and cytokines loaded onto hydrogel scaffolds may fail to remain in situ long enough to exert their therapeutic effects.

Looking ahead, the development of hydrogel scaffolds with dynamic controllability and prolonged in situ retention has become a key focus for enterprises and research institutions both in China and abroad.