Biomedical composites processing

S. Nath, S. Bodhak, B. Basu, HDPE-A1203-Hap composites for biomedical applications processing and characterizations, J. Biomed. Mater. Res. B Appl. Biomater. 88B (2009) 1-11. 

Society is becoming progressively more worried with safety issues while wishing for a sustainable future. Sustainable chemistry represents an area of innovation, which not only preserves resources but also stands for a development process in the chemical industry. The most important goals in fine chemicals, skin care products and pharmaceuticals including biomedical compositions are the development of nontoxic and biodegradable compounds, the advance on new reaction conditions (cleaner solvents, biotechnological processes, etc.) and the use of raw materials from renewable feedstock [1]. 

Ogomi, D., Serizawa, T. and Akashi, M. (2003) Bioinspired organic-inorganic composite materials prepared by an alternate soaking process as a tissue reconstitution matrix. Journal of Biomedical Materials Research, 67A, 1360-1366. 

Zhang, R. and Ma, P.X. (1999) Porous poly(L-lactic acid)/apatite composites created by biomimetic process. Journal of Biomedical Materials Research, 45, 285-293. 

We chose to modify the anhydride monomers with photopolymerizable methacrylate functionalities. Methacrylate-based polymers have a long history in biomedical applications, ranging from photocured dental composites [20] to thermally cured bone cements [21]. Furthermore, photopolymerizations provide many advantages for material handling and processing, including spatial and temporal control of the polymerization and rapid rates at ambient temperatures. Liquid or putty-like monomer/initiator... 

In the field of metallic powder applications, a method of plasma spray coating suitable for biomedical materials has been developed using titanium and calcium phosphate composite powder. By means of the mechanical shock process, the appropriate composite powder was prepared, and plasma sprayed on Ti substrate under a low-pressure argon atmosphere. A porous Ti coating layer was obtained in which the surface and the inside of the pores were covered thinly with hydroxyapatite. This surface coating is expected to show excellent bone ingrowth and fixation with bone (21). 

Applications of polymerization in a supercooled state to the immobilization of various biofunctional components is reviewed. Those applications show advantages because in the low temperature biofunctional components such as proteins, drugs and cells are entrapped or adhered effectively in the polymerized matrix. The immobilized composites are used for biomedical and biochemical systems and processes, such as immuno-diagnosis, artificial organs, drug delivery systems and cell cultures. 

Carbon/carbon composites fabricated by multiple cycles of liquid impregnation and recarbonization are a typical example of modern petroleum derived carbons. In the 1975 ACS Symposium on Petroleum Derived Carbons (JL), papers were presented on carbon/carbon composite materials formed by pyrolytic infiltration processes (2 ) or by liquid impregnation with petroleum pitch (3,4), on fabrication processes for high-modulus carbon fibers based on polyacrylonitrile (PAN) or pitch precursors ( 5 ), and on the use of carbon materials for thermostructural (6 ) as well as biomedical applications (1 ) ... 

Owing to its properties, nanodiamond like the classical diamond is an attractive material for many applications. For the time being, however, just a limited number of industrial scale processes has really been established due to its inhomogeneity and the variable quality available from different suppHers. Pioneers in this area are the countries of the former Soviet Union where by now access has been made to various fields of applicahon. The examples given herein comprise processes developed to an industrial scale already as weU as such stUl operahve on a laboratory scale. They include the preparation of composites and coatings, mechanical apphcations to reduce friction or to modify surfaces, uses in electro-deposition or biomedical apphcahons. 

---