Prediction of mechanical properties of multilayer gradient hydroxyapatite reinforced poly(vinyl alcohol) gel biomaterial

Functional graded materials provided us one new concept for artificial articular cartilage design with graded component and graded structure. In this article, a novel functional material design was proposed by functionalizing hydroxyapatite (HA) particles in poly(vinyl alcohol) (PVA) hydrogel. The goal of the present study was to fabricate a multilayer gradient HA/PVA gel biocomposites through layer-by-layer casting method combining with freeze/thaw cycle technology and establish a mechanical model to predict the compressive mechanical properties of multilayer gradient gel biocomposites. The results showed that the compressive strength of the multilayer gradient gel biocomposites increased with the rise of HA content, but it presented decreasing trend with the rise of interlayer gradient concentration of HA particles. Furthermore, the compressive strength of multilayer gradient biocomposites would be approximately predicted by the established mechanical model. The maximum error between theoretical compressive strength predicted by the model and the experimental strength is less than 7%. On the other hand, the compressive mechanical properties of multilayer gradient composites could be designed and controlled by the mechanical model as established in this study. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.