Cell encapsulation technology as a therapeutic strategy for CNS malignancies

Abstract

Gene therapy using viral vectors has to date failed to reveal its definitive clinical usefulness. Cell encapsulation technology represents an alternative, nonviral approach for the delivery of biologically active compounds to tumors. This strategy involves the use of genetically engineered producer cells that secrete a protein with therapeutic potential. The cells are encapsulated in an immunoisolating material that makes them suitable for transplantation. The capsules, or bioreactors, permit the release of recombinant proteins that may assert their effects in the tumor microenvironment. During the last decades, there has been significant progress in the development of encapsulation technologies that comprise devices for both macro- and microencapsulation. The polysaccharide alginate is the most commonly used material for cell encapsulation and is well tolerated by various tissues. A wide spectrum of cells and tissues has been encapsulated and implanted, both in animals and humans, indicating the general applicability of this approach for both research and medical purposes, including CNS malignancies. Gliomas most frequently recur at the resection site. To provide local and sustained drug delivery, the bioreactors can be implanted in the brain parenchyma or in the ventricular system. The development of comprehensive analyses of geno- and phenotypic profiles of a tumor (genomics and proteomics) may provide new and important guidelines for choosing the optimal combination of bioreactors and recombinant proteins for therapeutic use.

Prospects for Delivery of Recombinant Angiostatin by Cell-Encapsulation Therapy

“…5, A1-A3). The viable cells mainly comprised the larger spheroids, whereas dead cells appeared in small clusters as previously described (Visted et al, 2001). The VVF was 22% after 3 weeks and 12% after 11 weeks of encapsulation (beads C; Table 1 and Fig.…”

Central Nervous System

“…Cell survival and immunogenicity are significant challenges. An approach that has been the focus of intensive research is cell encapsulation [227]. Cells are placed in a biomaterial in order to prevent immunological rejection, which is especially important when xenogeneic sources or cell lines are used.…”

Hydrogels for Tissue Engineering and Delivery of Tissue-Inducing Substances

“…[217][218][219][220][221] Implants include intraocular lenses, 222,223 artificial corneas, [224][225][226][227][228] coating for drainage tubes and stents, [229][230][231][232] vitreous humor replacements, 233 soft tissue substitutes/replacements, 126,234,235 burn dressing, [236][237][238][239][240][241] bone ingrowth sponges, 242 plastic surgery, [243][244][245] scleral buckling implants for retinal surgery. [246][247][248][249] Finally, as pure TE products, temporal artificial skin substitutes, membranes used to prevent postoperation adhesion and to promote healing, 250 HGs produced in vivo by using in situ photopolymerization, 9,10,35,37,202,262,263,275,276,279 HGs for cell encapsulation 28,29,45,52,…”