title: PLGA nanoparticles from nano-emulsion templating as imaging agents: Versatile technology to obtain nanoparticles loaded with fluorescent dyes.
abstract: The interest in polymeric nanoparticles as imaging systems for biomedical applications has increased notably in the last decades. In this work, PLGA nanoparticles, prepared from nano-emulsion templating, have been used to prepare novel fluorescent imaging agents. Two model fluorescent dyes were chosen and dissolved in the oil phase of the nano-emulsions together with PLGA. Nano-emulsions were prepared by the phase inversion composition (PIC) low-energy method. Fluorescent dye-loaded nanoparticles were obtained by solvent evaporation of nano-emulsion templates. PLGA nanoparticles loaded with the fluorescent dyes showed hydrodynamic radii lower than 40nm; markedly lower than those reported in previous studies. The small nanoparticle size was attributed to the nano-emulsification strategy used. PLGA nanoparticles showed negative surface charge and enough stability to be used for biomedical imaging purposes. Encapsulation efficiencies were higher than 99%, which was also attributed to the nano-emulsification approach as well as to the low solubility of the dyes in the aqueous component. Release kinetics of both fluorescent dyes from the nanoparticle dispersions was pH-independent and sustained. These results indicate that the dyes could remain encapsulated enough time to reach any organ and that the decrease of the pH produced during cell internalization by the endocytic route would not affect their release. Therefore, it can be assumed that these nanoparticles are appropriate as systemic imaging agents. In addition, in vitro toxicity tests showed that nanoparticles are non-cytotoxic. Consequently, it can be concluded that the preparation of PLGA nanoparticles from nano-emulsion templating represents a very versatile technology that enables obtaining biocompatible, biodegradable and safe imaging agents suitable for biomedical purposes.
authors: Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), C/Jordi Girona, 18-26, Barcelona, Spain; CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain. Electronic address: cfornaguera@gmail.com.
authors: C
authors: C
authors: Fornaguera
authors: Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), C/Jordi Girona, 18-26, Barcelona, Spain; CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain.
authors: N
authors: N
authors: Feiner-Gracia
authors: Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), C/Jordi Girona, 18-26, Barcelona, Spain; CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain.
authors: G
authors: G
authors: Calderó
authors: Department of Pharmacy and Pharmaceutic Technology, University of Barcelona, Av/Joan XXIII s/n, 08028, Barcelona, Spain; CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain.
authors: M J
authors: MJ
authors: García-Celma
authors: Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), C/Jordi Girona, 18-26, Barcelona, Spain; CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain.
authors: C
authors: C
authors: Solans
mesh_terms: D049109:Cell Proliferation / Q000187:drug effects*; D004337:Drug Carriers / Q000737:chemistry*; D004655:Emulsions; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D009447:Neuroblastoma / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D014407:Tumor Cells, Cultured
chemical_list: D004337:Drug Carriers; D004655:Emulsions; D005456:Fluorescent Dyes; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid
keywords: Bioimaging systems; Fluorescence encapsulation; Imaging nanosystems; Nano-emulsion; Nano-emulsion templating; Polymeric nanoparticles; Versatile technology