Operating an articular cartilage bioreactor requires certain techniques

　　Articular cartilage bioreactoris a device for culturing and maintaining human articular chondrocytes and can be used to study cartilage biology and explore treatments. It generally consists of multiple layers of components, including a cell culture chamber, fluid circulation system, pressure sensor, and temperature controller. Its basic principle is to culture articular cartilage tissue on a permeable, porous, elastic artificial matrix and promote its growth and development through simulated physiological stimuli such as joint movement, pressure, and fluid shear. Its main components include a culture chamber, artificial matrix, pressure sensor, fluid pump, and control system.

　　Articular cartilage bioreactoroperating method mainly includes the following steps:

　　1. Preparation:

　　Cell preparation: obtain seed cells such as chondrocytes or bone marrow stromal stem cells. Stromal stem cells can, for example, be isolated from porcine bone marrow and induced to differentiate toward chondrocytes using a specific medium and induction factors.

　　Scaffold preparation: select a suitable scaffold, such as allogeneic cartilage microparticle decellularized matrix or β-tricalcium phosphate. To prepare allogeneic cartilage microparticle decellularized matrix, first extract microparticles from allogeneic cartilage, then remove cellular components through decellularization while retaining the matrix structure.

　　2. Assembly:

　　Combine the prepared cells and scaffold material. For example, mix induced bone marrow stromal stem cells with allogeneic cartilage microparticle decellularized matrix and mold them into a cylindrical construct with fibrin glue.

　　3. Culture:

　　Place the assembled cell–scaffold construct in the bioreactor. The bioreactor simulates the joint-cavity environment and provides suitable temperature, humidity, nutrients, mechanical stimulation, and other conditions.

　　During culture, adjust and optimize bioreactor parameters as needed, for example by controlling medium composition and flow rate and adjusting the frequency and intensity of mechanical stimulation.

　　4. Monitoring and evaluation:

　　Monitor and evaluate the cultured tissue-engineered cartilage regularly, including cell growth, tissue structure, and mechanical properties. Assessment methods may include microscopy, histological staining, and biomechanical testing.

　　5. Application:

　　After bioreactor culture, remove the mature tissue-engineered cartilage for repair of articular cartilage defects or other related clinical treatment. Cultured cartilage tissue can, for example, be implanted in a patient's knee cartilage defect to restore normal joint function.