Model study of biostability of DPPC layersrndeposited by LB/LS on Ti–6Al–4V alloy

摘要

This paper reports surface property research on bare Ti–6Al–4V alloy covered with 1,2-dipalmitoyl-sn-glycero-3-rnphosphocholine (DPPC), which is the main component of cell membranes. The monolayer and bilayer of thernphospholipid were deposited by the Langmuir–Blodgett (LB)/Langmuir–Schaefer (LS) technique, and their biostabilityrnwas investigated in water, phosphate-buffered saline (PBS), simulated body fluid (SBF) and 1% Triton X-100 aqueousrnsolution at 37°C. Moreover, their biostability is compared with that of films prepared by spreading method. Thernsurface free energy changes calculated by Lifshitz–van der Waals/acid–base and contact angle hysteresis measurementrnare consistent with the changes in surface roughness obtained by optical profilometry. The films prepared by bothrnmethods were relatively stable in water. PBS and SBF solutions caused large effects in the change in the layers’ polarrncomponent – that is, the electron donor parameter. Also, significant changes took place when Triton X-100 solutionrnwas applied, probably because of the DPPC film removal by the surfactant. Finally, it appeared that no drasticrndifferences in the energy changes were observed between the DPPC layers dried overnight in a vacuum desiccatorrnand those dipped into the SBF solution immediately after their deposition on Ti–6Al–4V alloy by the LB/LS method.