Antiproliferative Activity and VEGF Expression Reduction in MCF7 and PC-3 Cancer Cells by Paclitaxel and Imatinib Co-encapsulation in Folate-Targeted Liposomes.

Co-encapsulation of anticancer drugs paclitaxel and imatinib in nanocarriers is a promising strategy to optimize cancer treatment. Aiming to combine the cytotoxic and antiangiogenic properties of the drugs, a liposome formulation targeted to folate receptor co-encapsulating paclitaxel and imatinib was designed in this work. An efficient method was optimized for the synthesis of the lipid anchor DSPE-PEG(2000)-folic acid (FA). The structure of the obtained product was confirmed by RMN, FT-IR, and ESI-MS techniques. A new analytical method was developed and validated for simultaneous quantification of the drugs by liquid chromatography. Liposomes, composed of phosphatidylcholine, cholesterol, and DSPE-mPEG(2000), were prepared by extrusion. Their surface was modified by post-insertion of DSPE-PEG(2000)-FA. Reaction yield for DSPE-PEG(2000)-FA synthesis was 87%. Liposomes had a mean diameter of 122.85 ± 1.48 nm and polydispersity index of 0.19 ± 0.01. Lyophilized formulations remained stable for 60 days in terms of size and drug loading. FA-targeted liposomes had a higher effect on MCF7 cell viability reduction (p < 0.05) when compared with non-targeted liposomes and free paclitaxel. On PC-3 cells, viability reduction was greater (p < 0.01) when cells were exposed to targeted vesicles co-encapsulating both drugs, compared with the non-targeted formulation. VEGF gene expression was reduced in MCF7 and PC-3 cells (p < 0.0001), with targeted vesicles exhibiting better performance than non-targeted liposomes. Our results demonstrate that multifunctional liposomes associating molecular targeting and multidrug co-encapsulation are an interesting strategy to achieve enhanced internalization and accumulation of drugs in targeted cells, combining multiple antitumor strategies.

Biodegradable polymeric nanocapsules based on poly(DL-lactide) for genistein topical delivery: obtention, characterization and skin permeation studies.

The isoflavone genistein (GEN) is a natural product with potential applications for skin cancer treatment and chemoprevention; however its high lipophilicity and chemical instability limits its clinical use. Therefore, attempts towards protecting GEN against degradation and increasing its penetration in the skin might be a valid approach. In this work, GEN loaded-PLA nanocapsules (GEN-NC) were prepared by interfacial deposition of preformed polymer (nanoprecipitation); physicochemical characterization and stability studies for 90 days were conducted. GEN-NC were incorporated into semi-solid formulations and permeation experiments were carried out using porcine ear skin. GEN-NC optimized formulation presented a mean diameter of 139 +/- 7.31 nm, polydispersity index of 0.128 +/- 0.08, encapsulation efficiency of 89.63 +/- 2.27% and drug loading from 0.6 to 1.4 w/w%. Stability studies demonstrated that nanocapsules did not exhibit aggregation during the 90 days of the assay, however, a drop in encapsulation efficiency was observed in the first 10 days. Permeation experiments demonstrated that a higher amount of GEN reaches deeper layers of the skin and increased penetration was achieved when GEN-NC were incorporated in a semi-solid gel formulation, indicating that GEN-NC might be a promising nanocarrier system for skin delivery of GEN.