Biocompatibility and biomechanical properties of new polycaprolactone-bioglass based bone implant materials


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü, Türkiye

Tezin Onay Tarihi: 2007

Öğrenci: ÖZGE ERDEMLİ

Eş Danışman: AYŞEN TEZCANER, DİLEK KESKİN

Özet:

Researches on bone defects are focused on the use of composites due to the composite and well-organized hierarchical structure of the bone. In this study, it is aimed to develop Polycaprolactone based implants with different organic DBM, HYA- and/or inorganic bioglass, calcium sulfate- compositions for augmenting bone healing. Bioactivity of the discs was evaluated by scanning electron microscopy and EDS analysis after incubation in SBF for 1, 7 and 14 days. All bioglass containing groups showed apatite molecules at different incubation times. Degradation studies demonstrated that only PCL/BG/HYA discs had fast degradation upon incubations in PBS (4 and 6 weeks). Initial mechanical properties of composites were found to be directly related to the composition. However, decreases in disc mechanical properties were also obtained in the same order with the amount of water uptake at composite groups. According to biocompatibility studies investigated with cytotoxicity tests on Saos-2 cells, all groups, except the HYA involving one were found as biocompatible. After in vivo application of discs to critical size defects on rabbit humeri (for 7 weeks), their efficacy on healing was studied with computerized tomography, SEM and biomechanical tests. The results revealed that bone-implant interface formation has started for all groups with high bone densities at the interface of implant groups compared to empty defect sites of negative controls. Also the healing was suggested to be gradual from bone to implant site as microhardness values increased at regions closer to bone. However, regeneration was found to not reach to healthy bone levels.