Delivery of soluble tumor necrosis factor receptor from in-situ forming PLGA implants:: In-vivo
Delivery of soluble tumor necrosis factor receptor from in-situ forming PLGA implants:: In-vivo
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DOI:
10.1023/a:1007621512647
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发表时间:
2000-12-01
影响因子:
3.7
通讯作者:
Kost, J
中科院分区:
文献类型:
--
作者:
Eliaz, RE;Wallach, D;Kost, J
Many harmful effects of tumor necrosis factor (TNF) result from chronic formation of this cytokine at certain distinct loci in the body. The soluble forms of the TNF receptors p55 and p75, which have the ability to block TNF action by competing for it with the cell surface TNF receptors (1–4), can protect against harmful pathological effects of TNF in chronic inflammatory diseases. Chronic inflammatory diseases are associated with increased endogenous formation of the soluble TNF receptors, in part resulting from stimulation of their synthesis by TNF (5–12). These receptors are formed by proteolytic processing of the cell surface TNF receptors and correspond to the cysteine-rich ligand-binding regions in their extracellular domains.Since sp55-R are cleared rather rapidly from the blood, repeated injections may not maintain them at the required site, at high enough concentrations. Due to the short half-life (6 hours) of this protein in-vivo, a controlled delivery system based on implants of ethylene vinyl-acetate (EVAc) or injections of microspheres of poly (lactic-co-glycolic) acid (PLGA) copolymers containing human soluble p55 TNF receptors (13), could enhance the therapeutic potential of the natural soluble TNF receptors in chronic diseases. The objective of this study was to develop a drug delivery system with the benefits of an implant but the ease of administration of an injection to the site of need. This delivery system involves simple preparation procedures and avoids an invasive technique such as surgery in its implantation or removal. We have developed an in-situ forming implant system that can be administered as a liquid using standard syringes and needles. A biodegradable injectable delivery system was described recently by Dunn et al.(14). Upon contact with