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Enzymatic Release (enzymatic + release)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Rotaxane-Based Propeptides: Protection and Enzymatic Release of a Bioactive Pentapeptide,

ANGEWANDTE CHEMIE, Issue 35 2009
Anthony Fernandes Dr.
Schützender Ring: Das [2]Rotaxan 1 kann ein bioaktives Pentapeptid schützen und selektiv freisetzen. Der Makrocyclus des Rotaxans stabilisiert das empfindliche Peptid sowohl gegen einzelne Peptidasen als auch gegen eine Enzymmischung aus Humanplasma. Die durch Glycosidase katalysierte Abspaltung einer Kohlenhydrat-Endgruppe, die im Rotaxan als Stopper wirkt, führt zur Freisetzung des Peptids (siehe Bild). [source]

Enzymatic Release of a Surface-Adsorbed RGD Therapeutic from a Cleavable Peptide Anchor

CHEMMEDCHEM, Issue 11 2008
Steven
Implanted medical devices inevitably promote inflammation of the surrounding tissue. A method for enzymatically triggered localized drug delivery would have marked benefits in dealing with this response. Herein we present a rationally designed peptide coating for use with medical devices such as stents, that contains three distinct domains: 1),an implant-adsorptive sequence, 2),an enzymatically cleavable release mechanism, and 3),a therapeutic to be delivered. [source]

Development of spray- and freeze-dried high-concentration sesamol emulsions and antioxidant evaluation in fibroblasts and UV-exposed rat skin slices

DRUG DEVELOPMENT RESEARCH, Issue 5 2008
Juliana Alencar
Abstract Dry sesamol emulsions were synthesized from several combinations of saccharose with hydroxypropylmethylcellulose (HPMC) or sodium caseinate (SC) using spray-drying techniques at 120° to 180°C, or freeze-drying. On the basis of physical characteristics such as droplet size distribution, residual moisture, and microscopic structure, the best material was obtained when spray-drying was applied at either 150° or 180°C with SC or HPMC as excipients, respectively. The extent to which the antioxidant properties of free sesamol towards a set of free radicals (galvinoxyl, diphenylpicrylhydrazyl, superoxide, and hydroxyl) were altered in the starting and reconstituted liquid emulsions submitted to normal storage or pre-exposed to a flux hydroxyl radicals was investigated. Emulsions were further evaluated for their antioxidant properties in cultured 3T3 murine fibroblasts and in an ex vivo model of ultraviolet irradiated rat skin. It was found that, in the material having the best physical properties, encapsulation was decisive in: (1) improving the overall antioxidant behavior of reconstituted versus starting liquid emulsions: (2) sparing sesamol consumption due to free radical attack; and (3) significantly protecting cells and skin against free radical- or irradiation-induced enzymatic release and/or lipid peroxidation. Demonstrating a high activity at high dilutions where interactions of excipient become negligible, the new emulsions could be of great interest in sesamol-based pharmacology or topical applications. Drug Dev Res 69:251,266, 2008. © 2008 Wiley-Liss, Inc. [source]

CXCL12 chemokine up-regulates bone resorption and MMP-9 release by human osteoclasts: CXCL12 levels are increased in synovial and bone tissue of rheumatoid arthritis patients

JOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2004
Francesco Grassi
Chemokines are involved in a number of inflammatory pathologies and some of them show a pivotal role in the modulation of osteoclast development. Therefore, we evaluated the role of CXCL12 chemokine on osteoclast differentiation and function and we analyzed its expression on synovial and bone tissue biopsies from rheumatoid arthritis (RA) patients. Osteoclasts were obtained by 7 days in vitro differentiation with RANKL and M-CSF of CD11b positive cells in the presence or absence of CXCL12. The total number of osteoclast was analyzed by Tartrate-resistant acid phosphatase (TRAP)-staining and bone-resorbing activity was assessed by pit assay. MMP-9 and TIMP-1 release was evaluated by ELISA assay. CXCL12 expression on biopsies from RA patients was analyzed by immunohistochemistry. Osteoclasts obtained in the presence of CXCL12 at 10 nM concentration displayed a highly significant increase in bone-resorbing activity as measured by pit resorption assay, while the total number of mature osteoclasts was not affected. The increased resorption is associated with overexpression of MMP-9. Immunostaining for CXCL12 on synovial and bone tissue biopsies from both rheumatoid arthritis (RA) and osteoarthritis (OA) samples revealed a strong increase in the expression levels under inflammatory conditions. CXCL12 chemokine showed a clear activating role on mature osteoclast by inducing bone-resorbing activity and specific MMP-9 enzymatic release. Moreover, since bone and synovial biopsies from RA patients showed an elevated CXCL12 expression, these findings may provide useful tools for achieving a full elucidation of the complex network that regulates osteoclast function in course of inflammatory diseases. J. Cell. Physiol. 199: 244,251, 2004© 2003 Wiley-Liss, Inc. [source]