Polyglycolide synthetic polymers

Polyglycolide was one of the first synthetic polymers used as a degradable surgical suture [122]. Fig. 8 shows the glycolide monomer and polymer structures. This aliphatic polyester is biodegradable and exhibits negligible toxicity when implanted in tissue. It is also possible to fabricate a strong fiber of this polyester with satisfactory mechanical properties. 

A scientific breakthrough in order to design USCAs on demand can be seen in the third generation (Myomap, Quantison, BiSphere and Sonavist). Compared to the more or less free bubbles of the first and second generations, the novel type of USCAs consist of encapsulated microbubbles with a shell formed by a biopolymer (like human albumin) and/or a biocompatible synthetic polymer (like copolymers of poly-lactide and polyglycolide or derivatives of polycyanoacrylate). In addition to the prolongation of the lifetime in the blood stream, these polymer-stabilized microbubbles can be manufactured to fulfill certain needs, and to interact with diagnostic ultrasound in a defined and optimal manner. 

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... 

Figure 2.1 Basic structures for some groups of synthetic polymers commonly employed as degradable materials in medical applications a) polylactide-co-polyglycolides (also commonly used as their homopolymers (i.e., n/m = 0), b) polycaprolactones, c) polydioxanones, d) polyorthoesters, e) polyanhydrides, f) polyalkylcyanoacrylates, g) poly(organo)phosphazenes and h) polyphosphoesters...

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