Encapsulated cells

For Further Reading C. M. Henry, Special delivery, Chemical and Engineering News (September 18, 2000), pp. 49-64. M. J. Lysaght and P. Aebischei Encapsulated cells as therapy, Scientific American (April 1999), pp. 76-82. S. Morrissey, Nanotech meets medicine, Chemical and Engineering News (May 16, 2005), p. TO. 

Encapsulated cells have been successfully used for the commercial biosynthesis of a number of valuable compounds such as amino acids, and this technique could readily be... 

Keywords Cell encapsulation Cell engineering Cytocompatibility Hydrogel Phospholipid polymers... 

PMBV and PVA can spontaneously form a hydrogel without using any crosslinkers. Even in cell culture conditions, the gelation can be confirmed. Therefore, it was possible to encapsulate cells in the PMBV/PVA hydrogel. The encapsulation method is illustrated in Fig. 6. 

Figure 9 shows the proliferation of cells encapsulated in the PMBV/PVA hydrogel. The encapsulated cells (L929) did not proliferate with the excessive proliferation seen on the TCPS. The encapsulated cells were recovered from the PMBV/PVA... 

Another area where polymers are making a significant difference in nerve regeneration is the use of polymers to encapsulate and release trophic factors, or encapsulate cells that release nerve growth factor or other agents that enhance the regeneration process. This chapter details the advances in the use of polymeric biomaterials that have been explored for nerve regeneration in the peripheral and central nervous systems. 

To date, cellular and gene therapy products submitted to FDA have included clinical studies indicated for bone marrow marking, cancer, cystic fibrosis, AIDS, and inborn errors of metabolism and infectious diseases. Of the current active INDs approximately 78% have been sponsored by individual investigators or academic institutions and 22% have also been industry sponsored. In addition to the variety of clinical indications the cell types have also been varied. Examples include tumor infiltrating lymphocytes (TIL) and lymphocyte activated killer (LAK) cells, selected cells from bone marrow and peripheral blood lymphocytes, for example, stem cells, myoblasts, tumor cells and encapsulated cells (e.g., islet cells and adrenal chromaffin cells). 

Delivery of a putative Parkinson s factor (GDNF) into the rat CNS using a polymer-encapsulated cell line. Baetge, E.E., Emerich, D.F., Winn, S.R., Lee, A., Lindner, M.D., Hammang, J.P. (1993). Mol Biol Cell, 4 Suppl 442A. 

Encapsulation and Suspension. In this case, encapsulated spheroids of hepatocytes are contacted with blood in fluidized-bed, spouted-bed, and/or packed-bed systems. The mass transfer resistance should be high with encapsulated cells. However, the use of a suspension would lead to excessive shear forces being exerted on the cells. 

Garcia-Martin, C., Chuah, M. K., Van Damme, A., Robinson, K. E., Vanzieleghem, B., Saint-Remy, J. M., Gallardo, D., Ofosu, F. A., Vandendriessche, T. and Hortelano, G. (2002). Therapeutic levels of human factor VIII in mice implanted with encapsulated cells Potential for gene therapy of haemophilia A. J. Gene Med. 4, 215-223. 

Very little appears to be known regarding the factors which determine the host specificity of coracidia in copepods. Clearly, the chief factors which may affect development are likely to be the nature of the digestive juices, the structure of the alimentary canal (especially its cellular thickness ) and the nature of the haemocoele, including the reactions of phagocytic or encapsulating cells. 

Reliable stability data of the p-i-n solar cell itself are not easily obtained, especially for non-encapsulated cells or modules. One of these tests e.g. for EN/IEC 61646 certification of modules is the so-called damp-heat test (85°C, 85% humidity, up to lOOOh). Recent studies were performed by Stiebig et al. [50, 51] exposing different types of cells to harsh conditions. One of the most important results was the excellent stability of silicon thin film solar cells. Remarkably, this is also valid for small area modules even without encapsulation [52]. This is of high interest because costs and efforts for module encapsulation strongly depend on the inherent stability of the solar cells. As a more detailed treatment of this subject is beyond the scope of this chapter, the reader is referred to the original papers [50,51]. 

Today, with the exception of bone marrow for hematopoietic reconstitution, therapeutic cellular transplantation is an emerging technology. In recent years novel approaches in the potential restoration of function through cellular transplantation have included the use of fetal human or xenogeneic neural tissue for Parkinson s disease, ectopically implanted pancreatic islets for diabetes, Schwann cells and olfactory ensheathing glia for spinal cord injury, encapsulated chromaffin cells for pain, and various types of stem cells for the treatment of diabetes, cardiac disease, and central nervous system injuries or disease [2], There have also been trials of encapsulated cells to provide enzymes that either remove toxic products or provide activation of prodrugs to therapeutics, usually anticancer derivatives. 

Winn, S. R., Hammang, J. P., Emerich, D. F., Lee, A., Palmiter, R. D., and Baetge, E. E., Polymer-encapsulated cells genetically modified to secrete human nerve growth factor promote the survival of axotomized septal cholinergic neurons, Proc. Natl. Acad. Sci. U.S.A., 91, 2324, 1994. 

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