Purpose  

The purpose of this study was to investigate the preparation process of bone morphogenetic protein-2 (BMP-2) containing bovine serum albumin (BSA) nanoparticles (NPs), and to assess the bioactivity of BMP-2 encapsulated in such NPs.

Methods  

The NPs were prepared by a coacervation method, and the effects of process parameters on NP size and polydispersity were examined. Polymer coated NPs were characterized with respect to amount of adsorbed polymer, particle size and zeta potential. Using bone marrow stromal cells (BMSC), biocompatibility of the NPs was investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) Assay, and bioactivity of the encapsulated BMP-2 was investigated by alkaline phosphatase (ALP) induction and calcification.

Results  

The size of NPs could be controlled in the 50–400 nm range by process parameters including BSA concentration, non-solvent:solvent ratio and pH value. After coating with cationic polymers, the particle size and zeta potential were significantly increased. MTT assay indicated no toxicity of both the uncoated and coated NPs on BMSC. Based on ALP induction and calcification, full retention of BMP-2 bioactivity was retained in the polymer-coated NPs.

Conclusions  

This study described a preparation procedure for BSA NPs with controllable particle size, and such polymer-coated BSA NPs are promising delivery agents for local and systemic administration of BMP-2 in bone regeneration.