The hydrolytic degradation behaviour of self-reinforced bioabsorbable poly-L,D-lactide with an initial LL/DD dimer ratio of 96/4 (PLA96) and a composite containing 20 wt% of osteoconductive beta-tricalcium phosphate (beta-TCP) and 80 wt % of PLA96 was studied in-vitro. The initial mechanical properties of the composites were lower than that of self-reinforced PLA96 but their degradation was slower in terms of mechanical properties, mass loss and molecular weight of the samples and the pH of the buffer solution. The acidic degradation products of the matrix polymer were also neutralised by the alkaline degradation products of the beta-TCP particles and so the autocatalytic effect of the matrix polymer was eliminated. The potential use of the composites as implant materials for bone fracture fixations was suggested. 23 refs.

The evolution of drug-eluting coronary stent technology is outlined and the role of parylene coatings in this technology is discussed. The characteristics, which make parylene suitable for in-vivo medical devices, and the process for depositing parylene are described and the benefits of using parylene for stent manufacture are discussed. Possible future uses for combined drug delivery/medical devices are also considered and several examples of devices, which might benefit from drug eluting technologies are listed. 8 refs.

A look is taken at the market for medical plastics, recent developments in polymers and packaging films for the medical industry and some award-winning designs of medical devices. Some of the polymers and devices mentioned include PEEK for implants and coatings, medical-grade PU elastomers, thermoplastic elastomers, thermoformed PU medical balloons, antibacterial polymers, engineering plastics, a portable, automated blood collection system and an electrocardiogram monitoring system. A list of contacts is included

The synthesis of 2,4,6-trimethylphenyl 2-(4-(dihydroxyphosphoryl)-2-oxa- butyl)acrylate and its free radical polymerisation under various reaction conditions were investigated. Copolymerisation with methyl methacrylate, ethyl 2-(4-(dihydroxyphosphoryl)-2-oxabutyl)acrylate and N,N'-diethyl-1,3-bis(acrylamido)propane were also studied, and the products, with dental adhesive applications, were characterised by proton and carbon-13 NMR, FTIR, GPC and DSC. 20 refs.

The synthesis of polyurethanes based on polyols derived from triglyceride oil and hexamethylene diisocyanate or diphenylmethane diisocyanate, and their characterisation by FTIR, GPC, TGA and DSC, is described. The gas permeability, film and mechanical properties of solution-cast membranes were investigated and the results are discussed in terms of potential applications as wound dressings. 12 refs.

Factors affecting the development of tissue engineering from laboratory to clinic and its emergence as a cost-effective treatment in regenerative medicine are reviewed. Examples discussed include the fabrication of electrospun polymer scaffolds, the design of in vitro bioreactor systems for the growth of tissue-engineered constructs, and the marketing of tissue-engineered devices. 46 refs.

It is briefly reported that scientists are developing new plastics to produce thinner intraocular lenses to improve the minimally invasive operating techniques. Folding intraocular lenses made of high-performance polymers permit a type of micro-invasive surgery that can be performed on outpatients. The refractive index of intraocular lenses is currently about 1.5. The greater the refraction index, the thinner the lenses can be made. Researchers at the Fraunhofer Institute for Applied Polymer Research have already attained a greater index using highly refractive acrylates with molecular crosslinkers and polymers containing nano-size particles of titanium oxide.

China's areas of innovation align strongly with those offering the highest global growth: automotive; domestic appliances and personal computers; medical; and telecommunications. This makes it an attractive proposition for an ambitious foreign plastics producer wanting to tap into the new age of Chinese consumerism. To what extent China's innovation expertise will benefit foreign companies largely depends on their ability to work with Chinese players in joint ventures, to overcome the problems associated with intellectual property rights and issues of business culture.

The aim of this review is to give an overview and some insight into different radiopaque polymeric materials that are currently used as medical implants or inserts. Making the polymers radio logically visible is by increasing the average electron density and the specific gravity of the polymers by incorporating heavy elements into these systems. In dentistry, polymeric resins find extensive application in removable dentures, temporary crown and bridge materials, restorative fillings and impression compounds. Applications of this nature require non-destructive diagnostic procedures like X-ray and ultrasound imaging techniques. Synthetic, degradable polymers are currently being evaluated as medical implants in a wide range of applications such as orthopaedic bone fixation devices, drug delivery systems and cardiovascular implants. A radiopaque polymer would offer the unique advantage of being traceable via routine X-ray imaging. 8 refs.