OBJECTIVEThis study aims to construct a long-term, osteogenesis-targeting HU-308 drug delivery implant by the layer-by-layer electrostatic self-assembly (LBL) technique, and observe the features of its delayed release in vitro.

METHODSA heparin (Hep) and chitosan (Chi) multilayer was coated on pure titanium using the LBL technique, and the titanium implants were dipped into the solution to load HU-308. The amount of loaded drug and release rates were measured using a UV-Vis spectrophotometer. The relationships between the loading efficiency, release time, and multilayer films were evaluated. The morphology of all the multilayers was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM).

RESULTSThe results showed that the Hep/Chi self-assembly multilayer was gradually fabricated on the titanium surface. HU-308 was successfully loaded on the titanium implants. The amount of loaded drug increased with the amount of multilayer films, except in the T20 group. In vitro drug release study showed that drug release was more difficult in the system with thicker films, and large amounts of multilayer films decreased the release speed. Both SEM and AFM measurements showed typical LBL deposition of Hep and Chi.

CONCLUSIONThe HU-308 drug delivery implant is successfully fabricated via LBL technology. It could provide sustained release of HU-308 over 30 d. This type of implant may provide a new possi- bility of promoting implant-bone osseointegration for osteoporotic patients.