7 - Chondrocyte Development Flashcards
Delivery systems of cellular engineering
- Cell suspension
- Cell cluster
- Tissue construct
Cell suspension
Single, require homing, local or systemic
Cell cluster
Cell carrier, no matrix production, local, good integration
Tissue construct
Immature but functional matrix, local, poor integration
Cartilage injury
- Irreversible damage that usually leads to OA
- Pharmaceutical, arthroscopy, marrow perforation techniques, and osteochondral allo/ autografting only treat symptoms and/or produce inferior repair tissue
Cartilage support
From subchondral bone
Conventional ACI (Autologous chondrocyte implantation)
- Biopsy of healthy cartilage taken
- Collagenase digestion of cartilage matrix
- Chondrocyte cultivation (10x increase in cell number)
- Injection of cultured chondrocytes under periosteal flap into debrided defect
- Periosteal flap excised from medial tibia and sutured over defect
MACI (Matrix induced autologous chondrocyte implantation)
- Biopsy of healthy cartilage taken
- Collagenase digestion of cartilage matrix
- Chondrocyte cultivation (10x increase in cell number)
- Chondrocytes seeded onto MACI membrane
- Debrided defect filled with fibrin sealant
- Seeded MACI membrane shaped to defect and pressure fit
Autologous chondrocyte implantation using collagen
membrane as scaffold
- Less invasive
- Non periosteal harvesting
- Non suturing
- Better quality control of cell density
MACI cartilage regeneration
- Implantation of chondrocyte seeded type I/III collagen membrane into the fibrin sealant covered base of the defect
- Cell migration of chondrocytes from cambium surface of the membrane into fibrin sealant matrix
- Matrix production by implanted autologous chondrocytes
- Matrix maturation and hyaline-like/hyaline cartilage formation
Successful MACI histology
- Single cell lacunae
- Well integrated with host cartilage
- Chondrocytes in high density scattered in the hyaline-like matrix
Key technique aspects
- Use collagen membrane to replace periosteal membrane;
- Direct integration of chondrocytes onto the collagen membrane by loading;
- Use of fibrin glue to replace suturing.
- Shorten the surgical procedure and over the hypertrophy of graft.
MACI product characterisation
Cells and scaffold –> Cell seeding scaffold –> Cell-scaffold interaction (dose effect) –> Final MACI Product
What does MACI repair
Only cartilage
Future of joint repair
Repair the full osteochondral region with barrier structure or with memory structure
