Nano-scale Adhesion between Polymers and Hydroxyapatite
Sina Youssefian (Worcester Polytechnic Institu ), Jie Song (), Pingsheng Liu (), Nima Rahbar (Worcester Polytechnic Institute)
Advances in Nanocomposites for Thermal and Structural Applications
Tue 4:20 - 5:40
Barus-Holley 165
Current clinically used synthetic orthopedic materials tend to consist of a single bio-inert material, such as metals, ceramics or polymers. Although these materials provide an immediate solution for many patients, their long term outcomes are not satisfactory. Of particular interest is the design of biocompatible hydrogel-hydroxyapatite (HA) composite bone substitutes with outstanding interfacial adhesion that would warranty the ability for the composite to withstand functional (physiological) loadings without exhibiting brittle fractures. For this purpose, the cross-linked biocompatible synthetic hydrogel polymer, can be surface mineralized by nanocrystalline HA (nHA) with robust interfacial adhesion. In this study, the interfacial adhesion of different pHEMA derivatives which are functionalized with potent HA-binding motifs have been investigated to reveal which polymer has better adhesion with nHA. Molecular dynamic simulation has been used to obtain the fracture energies between each polymer and HA, numerically. The Atomic Force Microscopic (AFM) experiments were used to quantify the energies between single crystalline HA mineral surface and functional derivatives of pHEMA hydrogel that are coated on the AFM tips. Both experimental and numerical results show that modified pHEMA has a stronger adhesion forces with HA and can be used as high-affinity polymer-HA composite