Biomedical polymers copolymers

Several excellent reviews have recently been published that describe the broad field of degradable biomedical polymers [9,10]. Well-known hydrolytically degradable polymers developed or being developed for biomedical used include homo- and copolymers of polyamides (usually derived from amino adds), polyesters, polyanhydrides, poly(ortho ester)s, poly(anfido amines), and poly(P-amino esters). This chapter is focused on polyacetals, which... 

Ratner BD (1985) Graft copolymer and block copolymer surfaces. In Andrade JD (ed) Surface and interfacial aspects of biomedical polymers, Vol Surface chemistry and physics. Plenum Press, New York, p 373... 

The most widely investigated temperature-responsive biomedical polymer is poly(A-isopropyl acrylamide) (pNIPAM). This polymer is the focus of Chapter 1 in this book, and therefore it will not be discussed in depth here. However, pNIPAM has been paired with polyampholyte copolymers and applied to nanoparticle separations (Das et al., 2008), drug delivery (Bradley, Liu, Keddie, Vincent, Burnett, 2009 Bradley, Vincent, Burnett, 2009), and tissue engineering applications (Xu et al., 2008). In a related system, latridi et al. (2011) also used the LCST-responsive properties of polyethylene glycol methacrylate (PEGMA) copolymerized with methac-rylic acid and 2-(diethylamino) ethyl methacrylate in a temperature- and pH-sensitive doxorubicin drug delivery system. However, the primary focus of this study was to demonstrate the pH-dependent release properties as discussed earlier. 

MPC can be dissolved in alcohol and easily polymerized with other vinyl monomers by conventional radical copolymerization using a radical initiator. Moreover, the MPC copolymers obtained are soluble in alcohol but insoluble in water, depending on the MPC composition. This is one of the good characteristics required for biomedical polymers for surface modification of medical devices. Among these copolymers, poly(MPC-c0-n-butyl methacrylate (BMA))s exhibit excellent blood compatibility as shown by reduction of platelet adhesion and aggregation and suppression of protein adsorption (7-10). 

Vert, M. (1986) Biomedical polymers from chiral lactides and functional lactone -properties and applications, Macromol. Chem., Macromol. Symp., 6,109-22. Fischer, E. W., Sterzel, H. J. and Wegner, G. (1973) Investigation of the structure of solution grown crystals of lactide copolymers by means of chemical reactions, Kolloid Z. u. Z. Polymere, 251,980-90. 

It is worth mentioning here that PEG is a biomedical polymer with excellent biocompatibility and resistance to platelet and protein adsorption due to its mobility in aqueous environments [30]. Indeed, PEG allows biomaterials to retain their excellent water swelling properties, whereas PDMS modifies its surface to inhibit protein adsorption [17]. Hence, PDMS-PEG copolymers are considered to be ideal candidates as biomaterials... 

Krogman, N.R., Weikel, A.L., Nguyen, N.Q., Nair, L.S., Laurencin, C.T., AUcock, H.R. Synthesis and characterization of new biomedical polymers serine- and threonine-containing polyphosphazenes and poly(L-lactic add) grafted copolymers. Macromolecules 41(21), 7824-7828 (2008). doi 10.1021/ma801961m... 

Recently, many studies have focused on self-assembled biodegradable nanoparticles for biomedical and pharmaceutical applications. Nanoparticles fabricated by the self-assembly of amphiphilic block copolymers or hydrophobically modified polymers have been explored as drug carrier systems. In general, these amphiphilic copolymers consisting of hydrophilic and hydrophobic segments are capable of forming polymeric structures in aqueous solutions via hydrophobic interactions. These self-assembled nanoparticles are composed of an inner core of hydrophobic moieties and an outer shell of hydrophilic groups [35, 36]. 

Bioerodible polymers offer a unique combination of properties that can be tailored to suit nearly any controlled drug delivery application. By far the most common bioerodible polymers employed for biomedical applications are polyesters and polyethers (e.g., polyethylene glycol), polylactide, polyglycolide and their copolymers). These polymers are biocompatible, have good mechanical properties, and have been used in... 

The PPDX-fr-PCL diblock copolymers were recently synthesized [111] and apart from the references already mentioned, only the contribution of Lendlein and Langer [112] deals with chemically similar materials, although structurally quite different since they employed multiblock copolymers of PPDX and PCL with very low molecular weights to prepare shape memory polymers for biomedical applications. 

HPMA copolymers are water-soluble biocompatible polymers, widely used in anticancer drug delivery (reviewed in Reference [22]). HPMA copolymers containing reactive groups at side-chain termini were previously used for the modification of trypsin [23], chymotrypsin [23,24], and acetylcholinesterase [25]. The modification dramatically increased the acetylcholinesterase survival in the blood stream of mice and the thermostability of modified enzymes when compared to the native proteins. However, the modification involved multipoint attachment of the copolymers to the substrates, which may cause crosslinking. To modify proteins or biomedical surfaces by one point attachment, semitelechelic polymers should be used. 

Bizzari R, Chiellini F, Solaro R, Chiellini E, Cammas-Marion S, Guerin P (2002) Synthesis and characterization of new malolactonate polymers and copolymers for biomedical applications. Macromolecules 35 1215-1223... 

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