Cellular Uptake Of Paclitaxel Research Articles

Paclitaxel skin delivery by micelles-embedded Carbopol 940 hydrogel for local therapy of melanoma.

Local application of anticancer drugs provides a potential mode of chemotherapy for cutaneous melanoma with high compliance. However, the efficiency of drug delivery is highly limited by the physiological barrier from the skin to the tumor, which can not achieve the desired therapeutic effect. In the study, we designed ibuprofen-modified methoxy poly (ethylene glycol)-poly (ethylene imine) polymer to prepare paclitaxel-loaded micelles (PTX-M) and Carbopol 940 hydrogel containing PTX-M (PTX-Gel) to improve skin paclitaxel delivery for the local melanoma treatment. The PTX-M performed well both in the skin penetration and retention study. FT-IR analysis showed that PTX-M or PTX-Gel mainly changed the spatial structure of skin lipid and keratin, thus increasing the fluidity of lipid molecules in the stratum corneum, and the polymer was positively charged to enhance the skin permeation and deposition. Moreover, the positive charge also promoted the cellular uptake of PTX-M in B16 melanoma, resulting in better in vitro cytotoxicity of PTX-M to B16 cells Taxol®. As for in vivo against B16 cells solid tumor test, the Taxol® plus PTX-M/Gel group showed preferable anticancer activity than Taxol® alone.

Surface modification of paclitaxel-loaded liposomes using d-α-tocopheryl polyethylene glycol 1000 succinate: Enhanced cellular uptake and cytotoxicity in multidrug resistant breast cancer cells

Liposomes can achieve a controlled release and an improved bioavailability of water- insoluble drug with minimized side effects. Paclitaxel is an efficient anticancer drug for the treatment of various cancers. However, paclitaxel has a solubility of 0.5 mg/L in water and a low bioavailability of 6.5%. Moreover, paclitaxel is a substrate for p-glycoprotein, which shows a decreased accumulation of drug within the cancer cell expressed by a p-glycoprotein. Therefore, the purpose of this study is to prepare a paclitaxel-loaded liposome and evaluate the effect of d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) as an inhibitor of p-glycoprotein on the paclitaxel-loaded liposome. The paclitaxel-loaded liposome and TPGS coated paclitaxel-loaded liposome had spherical vesicles, with mean particle size 184.9 ± 18.45 nm with PDI 0.324 ± 0.018 and 282.6 ± 20.41 nm with PDI 0.269 ± 0.013, respectively. Paclitaxel-loaded liposome and TPGS coated paclitaxel-loaded liposome showed a controlled and sustained release of PTX over 72 h. The cellular uptake of paclitaxel from TPGS coated paclitaxel-loaded liposome was a 3.56-fold increase for 2 h and 5.75-fold increase for 4 h compared to that from paclitaxel-loaded liposome in MCF-7/ADR cells, resulting in improved cytotoxicity against MCF-7/ADR cells. Western blot assay revealed the P-gp inhibitory effect of TPGS-coated PTX-liposome. In conclusion, TPGS coated liposome with a sustained releasing capability and the inhibitory effect of p-glycoprotein may be a promising carrier for future applications in cancer therapy.

Lipid-albumin nanoassemblies co-loaded with borneol and paclitaxel for intracellular drug delivery to C6 glioma cells with P-gp inhibition and its tumor targeting

Successful chemotherapy with paclitaxel (PTX) is impeded by multidrug resistance (MDR) in tumor cells. In this study, lipid-albumin nanoassemblies co-loaded with borneol and paclitaxel (BOR/PTX LANs) were prepared to circumvent MDR in C6 glioma cells. The physiochemical properties including particle size, encapsulation efficiency and morphology were evaluated in vitro. Quantitative and qualitative investigations of cellular uptake were carried out in C6 glioma cells. The cytotoxicity of the BOR/PTX LANs was determined by MTT assay. After that, the tumor targeting was also evaluated in C6 glioma bearing mice by in vivo imaging analysis. BOR/PTX LANs have a higher entrapment efficiency (90.4 ± 1.2%), small particle size (107.5 ± 3.2 nm), narrow distribution (P.I. = 0.171 ± 0.02). The cellular uptake of PTX was significantly increased by BOR/PTX LANs compared with paclitaxel loaded lipid-albumin nanoassemblies (PTX LANs) in quantitative research. The result was further confirmed by confocal laser scanning microscopy qualitatively. The cellular uptake was energy-, time- and concentration-dependent, and clathrin- and endosome/lysosome-associated pathways were involved. The BOR/PTX LANs displayed a higher cytotoxicity agaist C6 glioma cells in comparion with PTX LANs and Taxol. Moreover, the encapsulation of BOR in LANs obviously increased the accumulation of the drug in tumor tissues, demonstrating the tumor targeted ability of BOR/PTX LANs. These results indicated that BOR/PTX LANs could overcome MDR by combination of drug delivery systems and P-gp inhibition, and shown the potential for treatment of gliomas.

Deoxycholic acid-modified chitooligosaccharide/mPEG-PDLLA mixed micelles loaded with paclitaxel for enhanced antitumor efficacy

Poly(ethylene glycol) (PEG) as a block in polymeric micelles can prolong circulation life and reduce systemic clearance but decrease the cellular uptake. To overcome this limitation, a mixed micelle composed of deoxycholic acid-modified chitooligosaccharide (COS-DOCA) and methoxy poly(ethylene glycol)-polylactide copolymer (mPEG-PDLLA) was designed to load paclitaxel (PTX). The PTX-loaded mixed micelles was prepared by nanoprecipitation method with high drug-loading efficiency of 8.03% and encapsulation efficiency of 97.09% as well as small size (∼40nm) and narrow size distribution. COS-DOCA/mPEG-PDLLA mixed micelles exhibited the sustained release property. Due to the positive charge and bioadhesive property of COS-DOCA, the cellular uptake of PTX in mixed micelles was higher in cancer cells but lower in macrophage cells compared to the mPEG-PDLLA micelles. The systemic toxicity of PTX in mixed micelles was much lower than Taxol using zebrafish as a toxicological model. Furthermore, the PTX-loaded COS-DOCA/mPEG-PDLLA mixed micelles can prolong the blood circulation time of PTX and enhance the antitumor efficacy in A549 lung xenograft model. Our findings indicate that COS-DOCA/mPEG-PDLLA mixed micelles could be a potential vehicle for enhanced delivery of anticancer drugs.

Enhanced paracellular and transcellular paclitaxel permeation by chitosan–vitamin E succinate–N-acetyl-l-cysteine copolymer on Caco-2 cell monolayer

The aim of this study was to evaluate the underlying mechanism of enhanced oral absorption of paclitaxel (PTX)-loaded chitosan–vitamin E succinate–N-acetyl-l-cysteine (CS–VES–NAC) nanomicelles from the cellular level. In aqueous solution, CS–VES–NAC copolymer self-assembled into the polymeric nanomicelles, with the size ranging from 190 to 240 nm and the drug loading content as high as 20.5 %. Cytotoxicity results showed that the PTX-loaded nanomicelles exhibited the similar effect to PTX solution (PTX-Sol) on Caco-2 cells, but no toxicity observed for blank CS–VES–NAC nanomicelles. The cellular uptake of PTX was significantly increased by CS–VES–NAC nanomicelles, compared with that of PTX-Sol, due to the possible escapement of P-glycoprotein (P-gp) efflux pumps by endocytosis pathway. Confocal laser scanning microscope (CLSM) images also confirmed CS–VES–NAC nanomicelles could be effectively internalized by Caco-2 cells. More importantly, P app value of PTX-loaded CS–VES–NAC nanomicelles was 2.3-fold higher than that of PTX-Sol, and the efflux ratio decreased by more than 10.8-fold for the nanomicelles. As a consequence of opening of tight junctions and P-gp inhibition induced by free CS–VES–NAC copolymer, the P app value of PTX was almost increased up to 19.5-fold. All the results indicate that CS–VES–NAC copolymer hold great promises as nanocarrier for antitumor drug oral delivery by improving paracellular and transcellular permeation.

In vitro evaluation on novel modified chitosan for targeted antitumor drug delivery

In this study, a novel amphiphilic copolymer designed as N-octyl-N-phthalyl-3,6-O-(2-hydroxypropyl) chitosan (OPHPC) were synthesized and then conjugated with folic acid (FA-OPHPC) to produce a targeted drug carrier for tumor-specific drug delivery. OPHPC and FA-OPHPC were characterized by FT-IR, 1H NMR, 13C NMR and elemental analysis. Paclitaxel (PTX) loaded OPHPC micelles (PTX-OPHPC) with well-defined spherical shape and homogeneous distribution exhibited drug-loading rate ranging from 33.6% to 45.3% and entrapment efficiency from 50.5% to 82.8%. In the cellular uptake studies, PTX-OPHPC brought about a significantly higher amount of PTX accumulated in human breast adenocarcinoma cell line (MCF-7 cells) compared with Taxol®. Moreover, the cellular uptake of PTX in PTX loaded FA-OPHPC micelles (PTX-FA-OPHPC) was 3.2-fold improved in comparison with that of PTX-OPHPC. The results revealed that OPHPC micelle might be a promising drug carrier for promoting PTX cellular uptake and FA-OPHPC micelle could be used as a potential tumor-targeted drug vector.

Solid lipid nanoparticles of paclitaxel strengthened by hydroxypropyl-β-cyclodextrin as an oral delivery system

The objective of this study was to evaluate the potential of surface-modified paclitaxel (PTX)-incorporated solid lipid nanoparticles with hydroxypropyl-β-cyclodextrin (smPSH). The smPSH released 89.70 ± 3.99% of its entrapped PTX within 24 h when placed in dissolution medium containing sodium lauryl sulfate. The cellular uptake of PTX from smPSH in Caco-2 cells was 5.3-fold increased compared to a PTX solution based on a Taxol formulation. Moreover, smPSH showed an increased cytotoxicity compared to PTX solution. In addition, AUC (5.43 µg•h/ml) and Cmax (1.44 µg/ml) of smPSH were higher than those (1.81 µg•h/ml and 0.73 µg/ml) of PTX solution. The drug concentration of smPSH (11.12 ± 4.45 ng/mg of lymph tissue) in lymph nodes was higher than that of the PTX solution (0.89 ± 0.75 ng/mg of lymph tissue), suggesting that more PTX was transported to the lymphatic vessels in the form of smPSH. In conclusion, smPSH have a potential as an alternative delivery system for oral administration of PTX.

Abstract 1924: The aurora kinase inhibitor CYC3 synergizes with low concentrations of paclitaxel in pancreatic cancer cells in vitro

Abstract CYC3, an Aurora Kinase A specific inhibitor, suppresses the pancreatic cancer cell growth (72h GI50 2.4μM in MiaPaCa-2 cells and 1.95μM in Panc-1 cells), arrest the cells at M phase and induces apoptosis. In order to evaluate CYC3's clinical potential, we employed mathematical models and simulations to look for possible synergistic combinations of CYC3 with paclitaxel in MiaPaCa-2 and Panc-1 cells. We have identified low concentrations of paclitaxel (3nM) and CYC3 is synergistic in inhibiting pancreatic cell growth, achieving similar effects as high concentrations of paclitaxel (30nM). Liquid Chromatography-Mass Spectrometry (LC-MS) analysis shows that CYC3 does not alter the cellular uptake of paclitaxel, supporting a synergistic mechanism at molecular level. In addition, the combination of CYC3 with low concentration of paclitaxel (3nM) displays less myelotoxicity compared to high concentrations of paclitaxel (30nM) in colony formation assay using Colony Forming Unit of Granulocyte and Macrophage (CFU-GM) (60-70% vs 100% inhibition), suggesting a potentially safer but equally efficient application of paclitaxel in patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1924. doi:1538-7445.AM2012-1924

Enhanced cellular uptake of paclitaxel in the presence of macelignan, a phytoestrogen and its implication in cancer chemotherapy

Enhanced cellular uptake of paclitaxel in the presence of macelignan, a phytoestrogen and its implication in cancer chemotherapy