Preparation of Rhodamine B Fluorescent Poly(methacrylic acid) Coated Gelatin Nanoparticles

Poly(methacrylic acid) (PMAA)-coated gelatin nanoparticles encapsulated with fluorescent dye rhodamine B were prepared by the coacervation method with the aim to retard the release of rhodamine B from the gelatin matrix. With sodium sulfate as coacervation reagent for gelatin, a kind of biopolymer with excellent biocompatibility, the formed gelatin nanoparticles were crosslinked by formaldehyde followed by the polymerization of methacrylic acid coating. The fluorescent poly(methacrylic acid) coated gelatin (FPMAAG) nanoparticles had a uniform spherical shape and a size distribution of 60 +/- 5 nm. Infrared spectral analysis confirmed the formation of PMAA coating on the gelatin nanoparticles. Based on UV-Vis spectra, the loading efficiency of rhodamine B for the FPMAAG nanoparticles was 0.26 mu g per mg nanoparticles. The encapsulated rhodamine B could sustain for two weeks. Favorable fluorescence property and fluorescence imaging of cells confirmed that the FPMAAG nanoparticles have promising biochemical, bioanalytical, and biomedical applications.