Biocompatible Phosphorus Containing Photopolymers

Radical photopolymerization is the key technique to prepare films and coatings in an environmentally friendly way within the fraction of a second. During the last decade this technique has found access to many other categories, as for example rapid prototyping, manufacturing of printed circuits boards, dental filling materials and other biomedical applications. Photopolymers display several advantages compared to classical thermally cured materials like polylactic acid (PLA). Their most important features are: easy processability and implantation; it is possible to perform the photopolymerization in vivo and ex vivo, which allows for minimal invasive surgery; preparation of complex shaped polymeric scaffolds; spatial and temporal control of the polymerization process; versatility of the formulations and good storage stability of the formulations under the most appropriate conditions until use. Considering these many advantages, photopolymerized networks have found a broad application spectrum in drug delivery (Liat & Seliktar 2010; Censi et. al. 2009; Clapper et. al. 2007)) tissue engineering (Schuster et. al. 2009; Ma et. al. 2010) cell encapsulation (Nuttelman et. al. 2008; Declerq et. al. 2008), biomimetic coatings (Naik et. al. 2003), contact lenses (Xu et. al. 2010), and dental restorative materials (Anseth et. al. 1996). In current biomedical research, great efforts are undertaken to obtain superior materials for tissue restoration, because the loss of tissue by an accident or disease as well as bone defects are crucial topics for our aging society. The human body as a complex and sensitive biological system provides a great challenge for the development of appropriate materials in the field of tissue engineering. Therefore, the requirements for such biocompatible materials are high: they must display proper mechanical strength, they should be degradable after cells initiate the re-growth of tissue and last but not least these materials, respectively their degradation products, must be safe concerning human health. This chapter will provide a general review on the photopolymerization technology, discuss some biomedical application fields, emphasize still open potentials or challenges and report some of the work that has been carried out so far to further develop this technology, for example the use of monomers based on phosphorus containing vinyl esters.