Tissue Engineering Part 3 Table 69-2 Tissue-Engineering Products in Clinical Trials TRC Aastrom Autologous adult bone marrow cells for bone grafting LiverX2000 Algenix Extracorporeal l
Trang 1Chapter 069 Tissue Engineering
(Part 3)
Table 69-2 Tissue-Engineering Products in Clinical Trials
TRC (Aastrom) Autologous adult bone marrow cells for
bone grafting LiverX2000 (Algenix) Extracorporeal liver assist device
Encapsulated proliferated
islet (Amcyte)
Encapsulated islet cells Myocell (Bioheart) Encapsulated cells for myocardial
infarction
Trang 2BioSeed-C, BioSeed-Oral
Bone (Biotissue Technologies)
Autologous tissue repair for bone and cartilage
E-matrix (Encelle) Repair or regeneration of diseased or
damaged tissue MarkII (Excorp) Extracorporeal liver assist device
ICX-PRO, ICX-TRC
(Intercytex)
Wound repair and hair regeneration
HuCNS-SC (Stem Cell
Inc)
Human central nervous system stem cells
NT-501 (Neurotech SA) Encapsulated cell technology for
long-term delivery of therapeutic factors to retina
Procord (Proneuron) Autologous activated macrophage
therapy for patients with acute complete spinal cord injury
Trang 3ChondroCelect (Tigenix) Autologous chondrocyte implantation
Spheramine (Titan
Pharmaceutical)
Retinal pigment epithelial cells in microcarriers to provide continuous source of dopamine in the brain
ELAD (Vigagen) Extracorporeal liver assist device
Challenges to Tissue Engineering
The greatest success in tissue engineering to date has been in tissues such
as skin and cartilage where the requirements for nutrients and oxygen are relatively low Due to oxygen diffusion limitations, the maximal thickness of an engineered tissue is 150–200 µm if there is not an intrinsic capillary network Strategies used to overcome this limitation include transplantation of the tissue directly into the patient's vasculature or trying to induce angiogenesis by incorporating growth factors such as vascular endothelial cell growth factor into the scaffold A more recent approach involves the creation of an intrinsic network
of vascular channels immediately adjacent to the engineered tissue A combination
of microelectro mechanical systems (MEMS) fabrication technology and computational models of fractal branching allows the construction of an intrinsic microvascular network scaffold within a biocompatible polymer This preformed
Trang 4capillary-like network can be seeded with cells and ultimately sustains the growth and function of complex three-dimensional tissues
Immune rejection of allogenic cells is another major obstacle The use of immunosuppressive drugs is not considered an optimal solution to this problem One potential solution is to develop "universal donor" cells by masking the histocompatibility proteins on the cell surface
Off-the-shelf availability will need to be addressed for tissue engineering products to be used widely Ideally, products should be reproducible and available
at a wide variety of hospitals, including those without sophisticated facilities for cell culture and cell proliferation
Further Readings
Ahsan T, Nerem RM: Bioengineered tissues: The science, the technology, and the industry Orthod Craniofacial Res 8:134, 2005 [PMID: 16022714]
Lavik E, Langer R: Tissue engineering: Current state and perspectives Appl Microbiol Biotechnol 65:1, 2004 [PMID: 15221227]
Lysaght MJ, Hazlehurst AL: Tissue engineering: The end of the beginning
Trang 5Tissue Engineering 10:12, 2004
Sheih SJ, Vacanti JP: State-of-the-art tissue engineering: From tissue engineering to organ building Surgery 137:1, 2005
Yow KH et al: Tissue engineering of vascular conduits Br J Surg 93(6):652, 2006 [PMID: 16703652]