Recombinant human gelatin nanoparticles as a protein drug carrier

Considerable attention has been directed to the application of natural gelatin-based nanoparticles. However, there are still critical problems associated with a safety issue of animal-origin gelatins, heterogeneous molecular weight, subsequent nanoparticle size distributions and use of toxic cross-linker. The purpose of this study was to develop a simple, safe and reproducible preparation method of recombinant human gelatin (rHG) nanoparticles via a modified desolvation method using a natural cross-linker for protein drug delivery. The model protein, FITC-BSA, was released from rHG nanoparticles in a biphasic and sustained-release pattern without initial burst. Optimized nanoparticles based on rHG and a natural cross-linker were prepared for the first time and showed great potential for protein drug delivery in terms of sustained release, less initial burst, and safety. In addition, rHG nanoparticles were efficiently internalized in the cell and mainly localized in the cytoplasm without significant cytotoxicity. Overall, these results suggest that rHG nanoparticles are appropriate for a protein drug delivery system with minimal toxicity.