Polylactide and

Health Safety. PET fibers pose no health risk to humans or animals. Eibers have been used extensively iu textiles with no adverse physiological effects from prolonged skin contact. PET has been approved by the U.S. Eood and Dmg Administration for food packagiug and botties. PET is considered biologically iuert and has been widely used iu medical iaserts such as vascular implants and artificial blood vessels, artificial bone, and eye sutures (19). Other polyester homopolymers including polylactide and polyglycoHde are used iu resorbable sutures (19,47). 

Polyesters, specifically polylactides and poly(lactide-co-glycolide)s have played a critical role in the development of polymer-based CR technologies. The biocompatibility and the well-established safety profiles of PLA and PLGA polymers have made them the polymer of choice for CR applications. However the off-patent status of these polymers makes them freely available for research in industry as well as academia. This has led to a vast number of patents covering various applications of these polymers within the drug delivery sector. Due to these issues, very limited scope remains to utilize these polymers to reformulate generic, off-patent drugs. 

Arshady, R. Preparation of biodegradable microspheres and microcapsules 2. Polylactides and related polyesters. J. Contr. Rel. 17 1—22, 1991. 

Hietala EM, Maasilta R Valimaa T et al. Platelet responses and coagulation activation on polylactide and heparin-polycaprolactone-L-lactide-coated polylactide stent struts. J Biomed Mater Res A2003 67(3) 785—791. 

Table 1. Monomers and resulting repeating units of polylactide and some of its copolymers...

Gas chromatography-mass spectrometry (GC-MS), liquid chromatography (LC), enzymatic assays, and capillary zone electrophoresis (CZE) have been used to monitor abiotic and biotic degradation products of polylactide and its copolymers [35,37,115,126-128]. In abiotic aqueous environments the degra-... 

The hydrophobic core of nanoparticles is mostly made of solid glassy polymers such as polycaprolactone, polylactide, and their random copolymers. Drags are physically trapped and dispersed in the core. Except for the initial burst release period, the drug release from the solid nanoparticle cores tends to be a slow diffusion-controlled process [126]. Thus, nanoparticles responding to the acidic environments of tumor intercellular fluid or intracellular acidic compartments have been developed for fast drug release. 

Plackett D, Andersen TL, Pedersen WB, Nielsen L (2003) Biodegradable composites based on L-polylactide and jute fibres. Compos Sci Technol 63(9) 1287-1296 Sebastien F, Stephane G, Copinet A, Coma V (2006) Novel biodegradable films made from chitosan and poly(lactic acid) with antifungal properties against mycotoxinogen strains. Carbohydr Polym 65(2) 185-193... 

At the time of writing, the applications of biodegradable polymers are confined mostly to the field of agriculture, where they are used in products with limited lifetimes, such as mulch films and pellets for the controlled release of herbicides. The synthetic polyesters used in medical applications, principally polylactide and poly(lactide-co-glycolide), while claimed to be biodegradable, are degraded in the body mainly, if not entirely, by chemical hydrolysis. There is little evidence that the hydrolysis of these polyesters of a-hydroxyacids can be catalyzed by hydrolase or depolymerase enzymes. 

The sensitivity of this method was demonstrated by Jordan and Wilkes [1989] who showed, after aging, that blends of racemic polylactide and... 

Selection of a tissue engineering substrate includes a choice between absorbable and nonabsorbable material, as well as a choice between synthetic and naturally derived materials. The most common synthetic polymers used for fibrous meshes and porous scaffolds include polyesters such as polylactide and polyglycolide and their copolymers, polycaprolactone, and polyethylene glycol. Synthetic polymers have advantages over natural polymers in select instances, such as the following i... 

Bonartsev, A. R et al. Hydrolytic degradation of poly(3-hydroxybutyrate),polylactide and their derivatives kinetics, crystallinity, and surface morphology. Mole. Cryst. Liquid Cryst 2012, 556(1), 288-300. 

The use of lipids, including lipid-protein membranes, concentric lipid manbranes, and submicron ultrathin lipid membranes is another common approach. Biodegradable synthetic polymers offer another approach. The first one used was polylactide. Many types of polylactides and poly-glycolic acids are now used for artificial cells. Other synthetic biodegradable polymers, such as polyanhydride, also are used. The use of biodegradable artificial cells has become an active field. 

Dunne M, Bibby DC, Jones JC, Cndmore S. Encapsulation of protamine sulphate compacted DNA in polylactide and polylactide-co-glycolide microparticles. Journal of Controlled Release. September 19, 2003 92(l-2) 209-219. PnbMed PMID 14499198. 

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