Synthetic bioresorbable materials

The purpose of our work was to create and evaluate the properties of synthetic bioresorbable calcite based porous material (CBPM) for bone regeneration. 

Note This chapter was previously published as Chapter 3 Synthetic bioresorbable polymers by R. E. Cameron and A. Kamvari-Moghaddam, originally published in Degradation rate of bioresorbable materials predication and evaluation, ed. F. J. Buchanan, Woodhead Publishing Limited, 2008 ISBN 978-1-84569-329-9. 

Cameron, R.E., Kamvari-Moghaddam, A., 2008. Synthetic bioresorbable polymers. Degradation Rate of Bioresorbable Materials. Woodhead Pubishing Limited, Cambridge England, pp. 43 6. 

Although Plaster of Paris was used inl892asabone substitute [Peltier, 1961], the concept of using synthetic resorbable ceramics as bone substitutes was introduced in 1969 [Hentrich et al., 1969 Graves et al., 1972]. Resorbable ceramics, as the name implies, degrade upon implantation in the host. The resorbed material is replaced by endogenous tissues. The rate of degradation varies from material to material. Almost all bioresorbable ceramics except Biocoral and Plaster of Paris (calcium sulfate dihydrate) are variations of calcium phosphate (Table 39.8). Examples of resorbable ceramics are aluminum calcium phosphate, coralline. Plaster of Paris, hydroxyapatite, and tricalcium phosphate (Table 39.8). 

When designing a medical device based on a bioresorbable polymer, the degradation ability of the material during all the phases from the synthesis to the complete resorption in vivo must be carefully considered. In this regard, synthetic polymers are more versatile compared to natural origin polymers, thereby allowing a finer control of the theoretical degradation rate. However, this rate depends from a number of external factors such as production process conditions (eg, humidity, temperature) and site of implantation (eg, pH, mechanical stress) [13—18]. 

Keratoprostheses or artificial corneas have been developed for restoring minimal comeal function [104]. However, most of these devices are manufactured from synthetic materials that are not bioresorbable and are therefore outside the scope of this review. In addition, their use is reserved for end-stage disease. 

In summary, both synthetic and naturally occurring bioresorbable polymers are both very promising materials for ophthalmic application. These materials offer different advantages and are therefore used for different applications varying from drug delivery vehicles to solid implants and in-site geUing injectables. 

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