Poly(alkylene tartrates) as controlled release agents

Synthesis and Characterization of Saturated and Unsaturated Poly(Alkylene Tartrate)s and Further Cross-Linking

Saturated and unsaturated polyesters based on l-tartaric acid were prepared and characterized. Two kinds of low molecular weight polyesters were synthesized by the reaction of l-tartaric acid and 1-12 dodecandiol and 1-8 octanediol. Three different kinds of low molecular weight unsaturated polyesters were synthesized by the reaction of l-tartaric acid, 1-12 dodecandiol, and maleic anhydride. The saturated and unsaturated polymers were characterized by means of proton nuclear magnetic resonance (H NMR), infrared analysis (IR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). These functionalized polymers were thermally cross-linked in the presence of a radical initiator and with 2-hydroxyethyl methacrylate (HEMA) and/or polyethylene glycol ethyl ether methacrylate) (PEGEEM) to prepare cross-linked polymers for biomedical applications. The films were characterized by means of DSC, TGA, and FTIR. The glass transition temperatures (Tg) of the polymers increase with increasing alkene group length and for the presence of the double bonds. The transition temperatures of the cross-linked films range from about -50°C, for the films contraining PEGEEM, to about 90°C, for the film containing HEMA.

Curable, biodegradable elastomers: emerging biomaterials for drug delivery and tissue engineering

Biodegradable elastomers have a number of potential applications in the biomedical area, especially in the emerging field of soft-tissue engineering where the mechanical properties of the polymer scaffold should match those of the tissue to be grown. An increasing number of synthesis strategies have been employed in order to prepare such elastomers. In this review, these synthesis strategies and the properties of these elastomers are outlined. The factors that influence the characteristics of these elastomers including mechanical properties, degradation rate, and mechanical property change during degradation, are discussed in terms of the design of the elastomer and their advantages and disadvantages for the biomedical applications considered.

Hydrophilic-hydrophobic biodegradable polymers: release characteristics of hydrogen-bonded, ring-containing polymer matrices

Biodegradable hydrogen-bonded, ring-containing polymers were prepared. These included poly(enolketones) by the controlled oxidation of poly(vinyl alcohol), and poly(amide-amines) and poly(amide-enamine-esters) by the reaction of diketene with diamines. These polymers had both hydrophilic and hydrophobic properties and are potentially matrix materials for the controlled release of drugs.