RESUMO
Doxorubicin (Dox) clinical use is limited by dose-related cardiomyopathy, becoming more prevalent with increasing cumulative doses. Previously, we developed Dox-loaded lipid-core nanocapsules (Dox-LNC) and, in this study, we hypothesized that self-assembling and interfacial reactions could be used to obtain arginylglycylaspartic acid (RGD)-surface-functionalized-Dox-LNC, which could target tumoral cells overexpressing αvß3 integrin. Human breast adenocarcinoma cell line (MCF-7) and human glioblastoma astrocytoma (U87MG) expressing different levels of αvß3 integrin were studied. RGD-functionalized Dox-LNC were prepared with Dox at 100 and 500 mg·mL-1 (RGD-MCMN (Dox100) and RGD-MCMN (Dox500)). Blank formulation (RGD-MCMN) had z-average diameter of 162 ± 6 nm, polydispersity index of 0.11 ± 0.04, zeta potential of +13.2 ± 1.9 mV and (6.2 ± 1.1) × 1011 particles mL-1, while RGD-MCMN (Dox100) and RGD-MCMN (Dox500) showed respectively 146 ± 20 and 215 ± 25 nm, 0.10 ± 0.01 and 0.09 ± 0.03, +13.8 ± 2.3 and +16.4 ± 1.5 mV and (6.9 ± 0.6) × 1011 and (6.1 ± 1.0) × 1011 particles mL-1. RGD complexation was 7.73 × 104 molecules per nanocapsule and Dox loading were 1.51 × 104 and 7.64 × 104 molecules per nanocapsule, respectively. RGD-functionalized nanocapsules had an improved uptake capacity by U87MG cells. Pareto chart showed that the cell viability was mainly affected by the Dox concentration and the period of treatment in both MCF-7 and U87MG. The influence of RGD-functionalization on cell viability was a determinant factor exclusively to U87MG.
RESUMO
Cancer is a major public health problem in the world, being breast cancer the most frequent cancer affecting women. Despite advances in detection and treatment, mortality rates remain high. Therefore, new approaches for breast cancer treatments are necessary. In this study, our objective was to develop a liquid formulation containing doxorubicin-loaded lipid-core nanocapsules (DOX-LNC), to evaluate the in vitro antiproliferative activity and to determine the nanocapsules uptake by MCF-7 cells. Lipid-core nanocapsules (LNC), blank formulation, and DOX-LNC, proposed treatment, were prepared by self-assembling using the solvent displacement method. Hydrodynamic mean diameters (z-average) were respectively 191±31nm and 230±23nm presenting narrow size distributions. Drug content was 0.102±0.029mgmL-1 with an encapsulation efficiency higher than 90%. Formulations were applied to semiconfluent MCF-7 cells. After 24h, LNC showed no cytotoxicity, while DOX-LNC showed an IC50 of 4.49 micromolar. After 72h of incubation, DOX-LNC showed an IC50 of 1.60 micromolar demonstrating a sustained effect. The nanocapsules were internalized by endocytosis mediated by caveolin and by fluid phase endocytosis, which are active transport mechanisms. In conclusion, the liquid formulation containing DOX-LNC showed to be a promising product for the breast cancer treatment opening new avenues for further in vivo studies.
Assuntos
Neoplasias da Mama , Linhagem Celular Tumoral , Doxorrubicina , Humanos , Lipídeos , Células MCF-7 , NanocápsulasRESUMO
Lipid nanoparticles are drug delivery systems able to increase bioavailability of poorly soluble drugs. They can be prepared with different lipid materials, especially natural lipids. Shea butter is a natural lipid obtained from the Butyrospermum parkii seed and rich in oleic and stearic acids. Nimesulide is a COX 2 selective anti-inflammatory that is poorly soluble in water. The purpose of this study was to develop and characterize shea butter lipid nanoparticles using a new technique and evaluate the in vivo activity of these nanoparticles. Lipid nanoparticles were prepared by melting shea butter and mixing with an aqueous phase using a high shear mixer. The nanoparticles presented pH of 6.9 +/- 0.1, mean particle size of 90 nm and a narrow polydispersity (0.21). Zeta potential was around -20 mV and the encapsulation efficiency was 97.5%. Drug release was evaluated using dialysis bags and presented monoexponential profile with t50% of 4.80 h (free drug t50% was only 2.86 h). Antinociceptive activity was performed by the acetic acid model. Both nimesulide and nimesulide-loaded nanoparticles presented significant activity compared to the control. The in vivo anti-inflammatory activity was evaluated by paw edema and was statistically different for the nanoparticles containing nimesulide compared to free nimesulide, blank nanoparticles and saline. In conclusion, the use of shea butter as encapsulating lipid was very successful and allowed nanoparticles to be prepared with a very simple technique. The nanoparticles presented significant pharmacological effects that were not seen for free drug administration.