Biodegradable and nonbiodegradable

There are many polymers which have been used as physical matrices for controlled delivery of drugs. In this paper, these polymers are separated into water-soluble, biodegradable, and nonbiodegradable materials. A description of each class of polymers is presented. Examples of polymers from each class that have been used as drug delivery matrices and the criteria for their selection are included in this general review. 

Similar results for biodegradative and nonbiodegradative zones were previously reported by Bopp et al. (4) for the Hudson River. Considering the occurrence of altered residues in the more highly contaminated upper Hudson River sediments, Bopp et al. (4) concluded that reductive dechlorination may not be significant at PCB concentrations less than approximately 150 ig/g. This value is much higher than the maximum concentrations seen in both the Lake Hartwell (16 and 7 xg/g) and Twelve Mile Creek (26 and 40 ig/g) cores. 

As shown in the tables, both biodegradable and nonbiodegradable polymers have been used as matrix for... 

Ven der Giessen W, Lincoff AM, Schwartz RS, et al, Marked inflammatory sequelae to implantation of biodegradable and nonbiodegradable polymers in porcine coronary arteries, Circulation 1996 94 1690-1697. 

Fischell TA, Carter AJ, Laird JR, The beta-particle-emitting radioisotope stent (isostent) animal studies and planned clinical trials. Am J Cardiol I 996 78 45-50, van der Giessen WJ, Lincoff AM, Schwartz RS, et al. Marked inflammatory sequelae to implantation of biodegradable and nonbiodegradable polymers in porcine coronary arteries. Circulation 1996 94 1690-1697. 

Another inverse analytical technique was developed by Ala and Domenico [1] to determine parameters such as the source strength and size, and the advective position of the contaminant front for the instantaneous contaminant plumes at Otis Air Force Base (AFB), Massachusetts. The contaminant plumes contained chloride, biodegradable and nonbiodegradable detergents, trichloro-ethene, and tetrachloroethene. To obtain the uniquely determined parameters, Ala and Domenico structured the analytical technique to solve several equations simultaneously. By assuming a uniform vertical contaminant distribution, the steady state analytical solution becomes... 

What is the difference between biodegradable and nonbiodegradable If you had a choice between using a biodegradable and a nonbiodegradable detergent to clean your clothes, which would you choose ... 

All of these opportunities, such as combination of synthetic and natural polymers, combination of biodegradable and nonbiodegradable materials, with or without incorporation of stem cells, potential functionalization of scaffolding, and tuning of mechanical properties open a complex but awesome medical field in tissue engineering. 

Over the past few years, a wealth of investigation has been performed to enhance the mechanical properties and the impact resistance of PLA. Therefore, PLA now can compete with other low-cost biodegradable/biocompatible or commodity polymers. These efforts have made use of biodegradable and nonbiodegradable fillers, plasticizers, or blending of PLA with other polymers [6]. 

Biocompatibility is the ability of a biomaterial to perform with desired response(s) in a target application. In other words, it cannot be defined in terms of the material properties alone, but it is a combination of the material properties and the function for which it is intended. A variety of materials have been tested as medical devices, which include polymers, metals, ceramics, and their composites. These medical devices can be divided into two groups biodegradable and nonbiodegradable. 

Ester bond-hastd polymers, called polyesters, include several biodegradable and nonbiodegradable polymers such as polyethylene terephthalate (PET), polybutylene terephthalate, polybutylene succinate, polycaprolactone, polylactic acid, polyhydroxyalcanoate and aromatic-aliphatic polyesters. They are derived from starting monomers such as dialcohol, diacid and/or their esters (like methyl esters), and hydroxyl acids that are monomers with both an alcoholic and a carboxylic functional group. All such monomers react to form ester bonds with the release of water (or methanol if the starting monomers are the methylic esters of diacids). 

Figure 11.8 Mechanical properties of selected protein-based films compared with some biodegradable and nonbiodegradable materials. Adapted from S. Guilbert, N. Gontard, M.H. Morel, P. Chalier, V. Micard and A. Redl in Protein-based Films and Coatings, Ed., A. Gennadios, CRG Press, Boca Raton, FL, USA, 2002 [63]. All nonreferenced data are from Saechtling [6] and from commercial data sheets.

D.M. Re5molds. The differentiation of biodegradable and nonbiodegradable dissolved organic matter in wastewaters using fluorescence spectroscopy. /. Chem. Technol. BiotechnoL, 77 965-972, 2002. 

PHAs have been blended with many biodegradable and nonbiodegradable polymers to improve their properties and lower material costs. Miscibility, crysMlization behavior, and biodegradability of the blends are the main topics of the published articles on PHA blending. PHB was found to be miscible with poly(ethylene oxide) (PEO), poly(vinyl acetate) (PVAc), poly(p-vinylphenol), poly(vinylidene... 

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