Hybrid polymers as implant material for medical devices

Abstract

Objectives: This study is embedded in the development of a microstent with valve function, which normalizes the intraocular pressure by draining aqueous humor in the suprachoroidal space. The micromechanical approach requires new manufacturing techniques like the 2-photon polymerization and depends on the use of new polymer materials. Materials/Methods: In this study the chemical composition and the mechanical properties of an ORMOCER® were investigated with regard to the influence of a solvent, the storage time and the sterilization process (β, EO). Therefore the infrared spectroscopy (FTIR-ATR) and the 3-point bending test were used. The results were statistically analyzed. Results: The study shows that the used solvent methyl isobutyl ketone is not suitable to remove the inhibited layer and has an influence on mechanical properties with regard to the material strength. The storage time showed no influence on the chemical structure and mechanical properties. Furthermore the FTIR-ATR spectroscopy demonstrates that β-sterilization leads to chain scissions. β-sterilization process leads to material hardening with greater effect than EO-sterilization. Conclusions: The results give an overview over the influence of the different processes to the chemical composition and the mechanical properties. The material is a suitable implant material, however processing parameters must be observed to achieve well determined material properties.