In this regard, it should be noted that, depending on the chemical characteristics of the polymer, labeling
the polymer used to prepare the particles with a fluorescent dye can change the surface nature of the nanocarrier. The alternative of labeling a triacylglycerol can allow the obtainment of diverse fluorescent dye-labeled nanocarriers such as nanoemulsions, nanostructured lipid carriers, polymeric nanocapsules, and lipid-core nanocapsules. Additionally, by labeling the lipophilic core, versatile nanocarriers Selleck PRIMA-1MET can be obtained, non-ionic, cationic, or anionic polymeric nanocapsules. Rhodamine B was chosen as the fluorescent dye for use in this study, due to the high find more fluorescence quantum efficiency and low cost. Castor oil (CAO) was chosen as
the reactant since its major component, ricinolein, has three hydroxyl groups VX-661 supplier in its molecule which can react with the carboxyl group of rhodamine B. In order to study whether fluorescent nanoparticles with different surface characteristics could be obtained, the novel fluorescent product was the core material of Eudragit RS100 or Eudragit S100 nanocapsules (NC), which have cationic and anionic surfaces, respectively. To verify if different supramolecular structure could also be obtained, fluorescent lipid-core nanocapsules (LNC) were prepared using sorbitan monostearate and the novel rhodamine B triacylglycerol conjugate as core and poly(ϵ-caprolactone) as interfacial polymer. To investigate if the fluorescent-labeled NC and LNC could be observed by fluorescence microscopy, the nanoparticle uptake was evaluated using a human macrophage cell line. Methods Materials Castor oil was kindly donated by Campestre (São Bernardo do Campo, Brazil). Eudragit S100® and Eudragit RS100® were obtained from Almapal (São
Paulo, Brazil). Rhodamine B, 4-(N,N-dimethyl)aminopyridine (DMAP), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride Erastin cell line (EDCI.HCl), poly(ϵ-caprolactone) with weight average molar mass (Mw) of 14 kg mol-1 (PCL14), sorbitan monostearate (Span® 60), and phorbol 12-myristate 13-acetate (PMA) were purchased from Sigma-Aldrich (Sao Paulo, Brazil). Poly(ϵ-caprolactone) with Mw = 116 kg mol-1 (CapaTM 6500) (PCL116) was kindly donated by Perstorp (Toledo, OH, USA). Capric/caprylic triglyceride (CCT) was acquired from Alpha Quimica (Porto Alegre, Brazil). Polysorbate 80 and sorbitan monooleate (Span 80®) were supplied by Delaware (Porto Alegre, Brazil). RPMI 1640, penicillin/streptomycin, Fungizone®, and 0.5% trypsin/EDTA solution were obtained from Gibco (Gibco BRL, Carlsbad, CA, USA). Fetal bovine serum (FBS) was obtained from Cultilab (Cultilab, Campinas, SP, Brazil). UltraCruz® mounting medium for fluorescence studies with DAPI was supplied by Santa Cruz Biotechnology, Inc. (Santa Cruz, CA, USA). The acetonitrile (ACN) used in the fluorescence measurements was spectroscopic grade.