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

Abstract

We aimed to encapsulate R-PE to improve its stability for use as a fluorescent probe for cancer cells. Purified R-PE from the algae Solieria filiformis was encapsulated in polymeric nanoparticles using PCL. Nanoparticles were characterised and R-PE release was evaluated. Also, cellular uptake using breast and prostate cancer cells were performed. 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. Nanoparticles loaded with R-PE can overcome instability and allow application as a fluorescent probe for cancer cells.

Keywords:

• Nanocapsules
• polycaprolactone
• R-phycoerythrin
• fluorescent probe
• protein

Author contributions

Jéssica Roberta Pereira Martins: investigation and writing—original draft. Antonia Livânia Linhares de Aguiar: investigation. Karina Alexandre Barros Nogueira: investigation and writing—original draft. Acrisio José Uchôa Bastos Filho: investigation. Thais da Silva Moreira: investigation, statistics, and writing—review and editing. Márjory Lima Holanda Araújo: methodology and writing—review and editing. Claudia Pessoa: conceptualisation. Josimar O. Eloy: conceptualisation and writing—review and editing. Ivanildo José da Silva Junior and Raquel Petrilli Eloy: conceptualisation, writing—review and editing, supervision, and funding acquisition.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the FUNCAP (MLC-0191-00296.01.00/22; PS1-0186-00043.01.00/21 and scholarship BMD-0008-01445.01.01/18) and by the National Council for Scientific and Technological Development (CNPq) (grant # 409352/2018-7). The authors would like to thank the Central Analítica-UFC (funded by Finep-CT-INFRA, CAPES-Pró-Equipamentos, and MCTI-CNPq-SisNano2.0) for microscopy measurements and Maria Karolina de Araújo Barroso for technical support.