7 - Chondrocyte Development

Question 1

Delivery systems of cellular engineering

Answer 1

• Cell suspension
• Cell cluster
• Tissue construct

Question 2

Cell suspension

Answer 2

Single, require homing, local or systemic

Question 3

Cell cluster

Answer 3

Cell carrier, no matrix production, local, good integration

Question 4

Tissue construct

Answer 4

Immature but functional matrix, local, poor integration

Question 5

Cartilage injury

Answer 5

• 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

Question 6

Cartilage support

Answer 6

From subchondral bone

Question 7

Conventional ACI (Autologous chondrocyte implantation)

Answer 7

• 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

Question 8

MACI (Matrix induced autologous chondrocyte implantation)

Answer 8

• 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

Question 9

Autologous chondrocyte implantation using collagen
membrane as scaffold

Answer 9

• Less invasive
• Non periosteal harvesting
• Non suturing
• Better quality control of cell density

Question 10

MACI cartilage regeneration

Answer 10

• 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

Question 11

Successful MACI histology

Answer 11

• Single cell lacunae
• Well integrated with host cartilage
• Chondrocytes in high density scattered in the hyaline-like matrix

Question 12

Key technique aspects

Answer 12

• 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.

Question 13

MACI product characterisation

Answer 13

Cells and scaffold –> Cell seeding scaffold –> Cell-scaffold interaction (dose effect) –> Final MACI Product

Question 14

What does MACI repair

Answer 14

Only cartilage

Question 15

Future of joint repair

Answer 15

Repair the full osteochondral region with barrier structure or with memory structure

Question 16

Cells in regenerative therapies

Answer 16

• Chondrocytes
• MSCs

Question 17

Bioactive scaffold in regenerative therapies

Answer 17

• Fibrin
• Collagen
• Cell guided