Polymeric stents

Tanguay JF Santos RM, Kruse KR, et al. Local delivery of a potent GPIIb/llla inhibitor using a composite polymeric stent reduces platelet deposition [abstr], Eur Heart J 1996 ... 

Santos RM, Tanguay JE Crowley JJ, etal, Local administration of L-703,08l using a composite polymeric stent reduces platelet deposition in canine coronary arteries, Am J Cardiol 1998 82(5) 673—675.A8. 

Holmes DR, Camrud AR, Jorgenson MA, Edwards WD, Schwartz RS. Polymeric stenting in the porcine coronary artery model differential outcome of exogenous fibrin sleeves versus polyurethane-coated stents. J Am Coll Cardiol 1994 24(2) 525-531. 

Sharkawi T et al. (2007) Intravascular bioresorbable polymeric stents A potential alternative to current drug eluting metal stents. J Pharm Sci 96 (ll) 2829-2837... 

As noted in Section 12.5.1, a family of polyaxial copolyesters described in Chapter 2 can be used to prepare two or more of the critical components of a femoral sealing device. Other compliant members of this family of polymers, which can be converted to compliant, stretchable membranes and strong, stretchable monofilament fibers, can be used to construct a mantle or cover for metallic endovascular stents. Thus, a composite of thin film, reinforced with a monofilament in cross-coiled configuration, can be assembled into a highly compliant, expandable, tubular mantle or sleeve. This can be placed tightly as a cover outside an expandable metallic or polymeric stent so that under concentric irreversible expansion at the desired site of... 

Fig. 18 Specific thermomechanical characterization of SME for a polymeric stent, (a) Extimple of a free recovery measurement of an SMP stent, (b) Comparison of solid vs perforated stents for a recovery temperature of 37 °C stents made from the 10wt% crosslinked polymer with a 7 of 52 °C (difiinctional crosslinking monomers di(ethylene glycol) dimethacrylate, poly(ethylene glycol)n dimethacrylate). Reprinted from ref [27], Copyright 2007, with permission from Elsevier.

Bioabsorbable polymeric stents can trigger acute or chronic inflammatory responses due to the degradation of the stent. The vascular response to a fully bioabsorbable stent can be more different than that of a metal- or polymer-coated stent. Polymers are listed in Table 7.5. Anti-inflammatory drugs are listed in Table 7.6. 

Chen, M.-C., et al. (2007). Rapidly self-expandable polymeric stents with a shape-memory property. Biomacromolecules, 8(9), 2774-2780. 

Stents are superior to angioplasty because they provide scaffolding of the vessel and prevent elastic recoil and detrimental remodeling following revascularization [140]. However, whether the presence of a permanent stent is favorable, or whether it would be more advantageous that the stent was degraded and absorbed by the body once its task was done, is unclear [140]. Recently, biodegradable polymeric stents have attracted much interest as an alternative to metallic stents [131, 165, 166]. 

Sustained delivery of antiproliferative drugs to prevent in-stent restenosis is crucial for an ideal biodegradable polymeric stent. However, the drugs (sirolimus and paclitaxel) that are most commonly used in currently available DES systems are both lipophilic. The hydrophilic nature of chitosan matrices makes them unable to entrap poorly soluble therapeutic agents and greatly limits their range of applications as drug delivery systems. A consistent limitation of... 

Chen MC, Chang Y, Liu CT et al (2009) The characteristics and in vivo suppression of neointimal formation with sirolimus-eluting polymeric stents. Biomaterials 30 79-88 Mi FL, Shyu SS, Chen CT et al (1999) Porous chitosan microspheie for controlling the antigen release of Newcastle disease vaccine preparation of antigen-adsorbed microsphere and in vitro release. Biomaterials 20 1603-1612... 

Chen MC, Liu CT, Tsai HW et al (2009) Mechanical properties, drug eluting characteristics and in vivo ptaformance of a genipin-crosslinked chitosan polymeric stent. Biomaterials... 

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