Nanoencapsulation of R-phycoerytrin extracted from S. filiformis improves protein stability and enables its biological application as a fluorescent dye.

Aim: We aimed to encapsulate R-PE to improve its stability for use as a fluorescent probe for cancer cells. Methods: Purified R-PE from the algae Solieria filiformis was encapsulated in polymeric nanoparticles using PCL. Nanoparticles were characterized and R-PE release was evaluated. Also, cellular uptake using breast and prostate cancer cells were performed. Results: Nanoparticles presented nanometric particle size (198.8 ± 0.06 nm) with low polydispersity (0.13 ± 0.022), negative zeta potential (-18.7 ± 1.10 mV) and 50.0 ± 7.3% encapsulation. FTIR revealed that R-PE is molecularly dispersed in PCL. DSC peak at 307 °C indicates the presence of R-PE in the nanoparticle. Also, in vitro , it was demonstrated low release for nanoparticles and degradation for the free R-PE. Finally, cellular uptake demonstrated the potential of R-PE/PCL nanoparticles for cancer cell detection. Conclusions: Nanoparticles loaded with R-PE can overcome instability and allow application as a fluorescent probe for cancer cells.