Genetic engineering cell implants

Describe the use of genetically engineered cell implants in drug delivery... 

An alternative approach to obtain pharmacological control is the use of genetically-engineered cell implants which use the endogenous control systems to regulate delivery of a therapeutic protein. 

The same pharmacokinetic limitation is true in principle for the implantation of encapsulated genetically engineered cells, which synthesize and release neurotrophic factors [68]. 

Bjorklund, A. (1993). Better cells for brain repair. Nature 362, 414 415. (Genetically engineered cell for brain implants.)... 

Other treatments remain both experimental and controversial, including stem cell transplants, implantation of fetal nerve cells, and the infrocudtion of genetically engineered cells into neural tissue. 

CNS implants of encapsulated genetically engineered cells producing therapeutic substances Cells for facilitating crossing of the blood-brain barrier Gene transfer... 

None of the currently reported sites employed for islet transplantation, i.e., the liver, the spleen, beneath the renal capsule and the omental porch and the peritoneal cavity, " combine the capacity to bear high numbers of islets and retrievability of the islet graft. However, a site with both features may be a mandatory for large-scale clinical transplantation of encapsirlated islets, because such grafts stiU have their functional limitations and, therefore, may require repeated replacement. Recently, the concept of an intraperitoneally implanted solid support as a transplantation site for genetically-engineered cells has been proposed." Such a solid support may serve as a transplantation site for pancreatic islets as, theoretically, it allows for implantation of high numbers of islets that can be readily retrieved. 

The blastocyst is an early embryonic stage in mammalian development. Murine blastocysts can be harvested at day 3.5 p.c. Their inner cell mass contains embryonic stem cells. Multiple murine embryonic stem cell lines have been established. Embryonic stem cells carrying genetically engineered mutations are injected into blastocysts, which are subsequently implanted into pseudopregnant foster mothers. 

Note Several papers utilize tumor cell implants into knockout or transgenic mice with associated changes in metastatic potential (Araki et al., 1997 Bian-cone et al., 1996 Bourguignon et al., 1998 Davies et al., 1996 De Vries et al., 1995 Driessens et al., 1995 Eitzman et al., 1996 Goldfarb et al., 1998 Hall and Thompson 1997 Kruger et al., 1998 Lloyd et al., 1998 Marvin et al., 1998). The citations listed above are those in which metastases are observed in the genetically engineered mice without inoculation of tumor cells. 

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