The activity of unloaded gelatin nanoparticles on murine melanoma B16-F0 growth in vivo.

BACKGROUND

Bacillus Calmette-Guérin (BCG) vaccine is a non-specific immunostimulant which has been used clinically in the treatment of melanoma. In this communication, the antimelanoma activity of BCG was related to its fibronectin-binding properties and mimicked using gelatin nanoparticles.

MATERIALS AND METHODS

The fibronectin-binding properties of aqueous gelatin solutions, gelatin nanoparticles, BCG vaccine, and PS1 (a glucan extracted from Tice BCG) were compared by an enzyme-linked immunosorbent assay and their ability to suppress murine B16-F0 melanoma in vivo investigated.

RESULTS

Aqueous gelatin solutions, gelatin nanoparticles and BCG all bound to fibronectin in vitro. The immunostimulant PS1 did not. In vivo, BCG and gelatin nanoparticles suppressed melanoma growth while PS1 and aqueous gelatin solutions had no effect.

CONCLUSIONS

The antimelanoma activity of BCG is not due to the associated immunostimulatory glucan but can be correlated to its fibronectin-binding properties. Since solutions of gelatin have no effect whereas nanoparticles produce total suppression, this suggests a relationship between the volume of the fibronectin-binding entities and their antitumour activity. Thus, gelatin nanoparticles may represent an attractive alternative to the use of BCG vaccine in melanoma treatment.