Synthetic polymers, regenerative medicine

Electrospinning techniques enable the production of continuous fibers with dimensions on the scale of nanometers from a wide range of natural and synthetic polymers [135]. The number of recent studies regarding electrospun polysaccharides and their derivatives, which are potentially useful for regenerative medicine, is dramatically increasing. 

Due to their availability and controllable degradation rate, synthetic biomaterials are also considered to be potential candidates in tissue engineering and regenerative medicine. Compared to natural polymers, synthetic polymers can easily be tailored into any form snitable for tissue engineering applications. Such materials should provide a three-dimensional (3D) structure that not only plays a supportive role for the tissue but also interacts with cells to control their... 

This chapter reviews major natural and synthetic polymers, based on their diverse apphcations in tissue engineering/regenerative medicine. It also gives an outline of the advantages of biodegradable polymers over conventionally used allografts and autografts. 

SYNTHETIC POLYMERS IN TISSUE ENGINEERING AND REGENERATIVE MEDICINE... 

Polymers used as biomaterials can be natural, synthetic or hybrid. With the growing field of regenerative medicine and medical devices, polymers dominate the soft tissue engineering and drug delivery industry and are gradually replacing metals and ceramics in the hard tissue engineering field as well. 

In regenerative medicine, there are various different materials suitable as implantable scaffolds. These can be fabricated from natural or synthetic materials. Common examples are polysaccharides (eg, chitosan), or polyesters (eg, poly e-caprolactone), for natural and synthetic polymers, respectively. However, they are both capable of degradation (either enzyme mediated, or hydrolysis) in vivo (Bassi et al., 2011 Cunha-Reis et al., 2007). Often, polyesters are used as implantable biodegradable biomaterials, as they have controllable degradation and mechanical properties through formation of block copolymers. Where degradation occurs, the scaffolds... 

One of the major classes of synthetic bioresorbable polymers is that of aliphatic polyesters or poly(a-hydroxy acids). Poly(a-hydroxy acids) such as PGA, poly(lactic acid) (PLA) stereoisomers poly(L-lactic acid) (PLLA) and poly(D-lactic acid), and pol-y(lactic-co-glycolic acid) (PLGA) copolymers are the most widely used and most popular bioresorbable polymers since they received Food and Drug Administration (FDA) approval for clinical use in humans in different forms (eg, fibers for sutures, injectable forms) (Nair and Laurencin, 2007). These polymers are commonly used in regenerative medicine applications. An example is the InQu Bone Graft Extender Substitute (ISTO Technologies), an osteoconductive biosynthetic product used as bone graft substitute in the skeletal system to support new bone formation. The resorption rate of... 

Table 19.1 Natural and synthetic bioresorbable polymers used in the field of cardiovascular regenerative medicine...

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