15 mg of product 1/mL of suspension for NC-RS100 and NC-S100 and approximately 1.52 mg of product 1/mL of suspension for LNC-PCL) (check details Figure 6). In the undiluted/unextracted samples of the formulations, it was seen that the bathochromic (7 nm) shift for the λ max – em value in the emission spectrum of the NC-S100-1 formulation was accompanied by a hyperchromic shift (52 a.u.) when compared
to the NC-RS100-1 formulation, selleck products which contains the same quantity of fluorescent product, probably due to protonation of the amino group of rhodamine B, as the pH of this formulation was the lowest among the formulations (3.50 ± 0.09). As previously reported, rhodamine B has an equilibrium of isoforms, lactonic and the zwitterionic isomers . The zwitterion isomer can be protonated more than once due to the presence of two amino groups . A hypochromic shift was observed in the emission spectra of the TSA HDAC concentration undiluted/unextracted samples of the LNC-PCL-1 (114 a.u.),
NC-RS100-1 (230 a.u.), and NC-S100-1 (178 a.u.) formulations compared to the spectrum of the solutions containing the same quantity of the CCT/fluorescent oily product mixture in ACN [solution 1 (1.52 mg/mL) and solution 2 (3.15 mg/mL)] (Figure 6A,B). Unsurprisingly, in the case of the samples containing the CCT/fluorescent oily product mixture (Figure 6C,D), the results for the fluorescence intensity of the diluted/extracted samples of the formulations showed greater similarity when compared to the undiluted/unextracted samples. The previously observed hypochromic shift did not occur and a small hyperchromic shift occurred, especially for NC-RS100-2 (24 a.u.) and NC-S100-2 (27 a.u.). Therefore, these changes in the fluorescence intensity of the undiluted/unextracted samples are probably related to the volume fraction of particles in the dispersed phase of the formulation leading to phenomena such as the inner filter
effect, where the presence of other compounds can partially absorb the emission energy, and they were not sufficiently reduced even with the use of a triangular cuvette [35, 36]. To demonstrate the applicability of the synthesized fluorescent triglyceride (product 1) to the identification of particles containing this compound in image ADP ribosylation factor studies, a cell uptake study was performed. It was possible to observe red fluorescence in the cells treated with the fluorescent nanoparticles (Figure 7). The red fluorescence was very close to the cell nucleus suggesting that the particles are located inside the cells. Martins and co-workers  have reported the uptake of solid lipid nanoparticles (SLN) stabilized with polysorbate 80 by THP1-derived macrophages. The authors loaded the SLN with a green fluorescent dye and evaluated the particle uptake by fluorescence microscopy.