ABSTRACT
Clinical applications of siRNA are being hindered by poor intracellular uptake and enzymatic degradation. To address these problems, we devised an oral delivery system for telomerase reverse transcriptase siRNA using N-((2-hydroxy-3-trimethylammonium) propyl) chitosan chloride (HTCC) nanoparticles (HNP). Both the porous structure and the positive charge of HNP facilitated siRNA encapsulation. The outer coating of HTCC not only protected siRNA from enzymatic degradation, but also improved siRNA permeability in intestine tract. In vivo and in vitro experiments proved that HNP could effectively deliver siRNA to lesion site and further into tumor cells. On the basis of confirming the antitumor activity of HNP:siRNA, we continued to encapsulate a hydrophobic chemotherapeutic drug-paclitaxel (PTX) into HNP to form a "two-in-one" nano-complex (HNP:siRNA/PTX). We demonstrated that HNP:siRNA/PTX could simultaneously ferry siRNA and PTX into tumor cells and increase drug concentration, which, in particular, was much more effective in tumor suppression than that of traditional cocktail therapy. These results suggested that the HNP, as a powerful delivery system for both siRNA and chemotherapeutic drug, would have a far-reaching application in human cancer therapy.
Subject(s)
Chitosan/analogs & derivatives , Drug Delivery Systems , Gene Transfer Techniques , Nanoparticles/chemistry , Neoplasms/drug therapy , Paclitaxel/therapeutic use , Quaternary Ammonium Compounds/chemistry , RNA, Small Interfering/administration & dosage , Absorption/drug effects , Animals , Antineoplastic Agents/pharmacology , Caco-2 Cells , Carbocyanines , Carcinoma, Lewis Lung , Cell Death/drug effects , Cell Proliferation/drug effects , Chitosan/chemistry , Endocytosis/drug effects , Flow Cytometry , Gene Silencing/drug effects , Humans , Intracellular Space/drug effects , Intracellular Space/metabolism , Male , Mice , Nanoparticles/ultrastructure , Neoplasms/pathology , Paclitaxel/administration & dosage , Paclitaxel/pharmacology , Permeability/drug effects , RNA, Small Interfering/metabolism , Telomerase/metabolism , Tissue Distribution/drug effects , Xenograft Model Antitumor AssaysABSTRACT
Poor delivery of insoluble anticancer drugs has so far precluded their clinical application. In this study, we developed a tumor-targeting delivery system for insoluble drug (paclitaxel, PTX) by PEGylated O-carboxymethyl-chitosan (CMC) nanoparticles grafted with cyclic Arg-Gly-Asp (RGD) peptide. To improve the loading efficiency (LE), we combined O/W/O double emulsion method with temperature-programmed solidification technique and controlled PTX within the matrix network as in situ nanocrystallite form. Furthermore, these CMC nanoparticles were PEGylated, which could reduce recognition by the reticuloendothelial system (RES) and prolong the circulation time in blood. In addition, further graft of cyclic RGD peptide at the terminal of PEG chain endowed these nanoparticles with higher affinity to in vitro Lewis lung carcinoma (LLC) cells and in vivo tumor tissue. These outstanding properties enabled as-designed nanodevice to exhibit a greater tumor growth inhibition effect and much lower side effects over the commercial formulation Taxol.
Subject(s)
Chitosan/chemistry , Drug Carriers/chemistry , Nanoparticles/chemistry , Oligopeptides/chemistry , Paclitaxel/chemistry , Paclitaxel/therapeutic use , Animals , Cell Line, Tumor , Emulsions/chemistry , Injections, Intravenous , Lung Neoplasms/drug therapy , Male , Mice , Mice, Inbred C57BL , NIH 3T3 CellsABSTRACT
Clinical application of paclitaxel (PTX) is limited because of its poor solubility in aqueous media. To overcome this hurdle, we devised an oral delivery system by encapsulating PTX into N-((2-hydroxy-3-trimethylammonium) propyl) chitosan chloride (HTCC) nanoparticles. These nanoparticles were small (~130 nm), had a narrow size distribution, and displayed high loading efficiency owing to the homogeneous distribution of PTX nanocrystals. The matrix hydrophilicity and porous structure of the obtained nanoparticles accelerated their degradation and improved drug release. In vitro and in vivo transport experiments had proved that the presence of positive charges enhanced the intestinal permeability of these nanoparticles. Further in vitro experiment of cytotoxicity showed that the PTX-loaded HTCC nanoparticle (HTCC-NP:PTX) was more effective than native PTX owing to enhanced cellular uptake. Drug distribution in tissues and in vivo imaging studies confirmed the preferred accumulation of HTCC-NP:PTX in subcutaneous tumor tissue. Subsequent tumor xenograft assays demonstrated the promising therapeutic effect of HTCC-NP:PTX on inhibition of tumor growth and induction of apoptosis in tumor cells. Additional investigation into side effects revealed that HTCC-NP:PTX caused lower Cremophor EL-associated toxicities compared with Taxol. These results strongly supported the notion that HTCC nanoparticle (HTCC-NP) is a promising candidate as an oral carrier of PTX for cancer therapy.
Subject(s)
Carcinoma, Non-Small-Cell Lung/drug therapy , Drug Carriers/chemistry , Nanoparticles/chemistry , Paclitaxel/administration & dosage , Paclitaxel/therapeutic use , Administration, Oral , Animals , Antineoplastic Agents, Phytogenic/administration & dosage , Antineoplastic Agents, Phytogenic/pharmacology , Antineoplastic Agents, Phytogenic/therapeutic use , Biocompatible Materials/chemistry , Cell Line , Chitosan/analogs & derivatives , Chitosan/chemistry , Humans , Lung Neoplasms/drug therapy , Male , Mice , Mice, Inbred C57BL , Nanoparticles/administration & dosage , Nanoparticles/therapeutic use , Paclitaxel/pharmacology , Quaternary Ammonium Compounds/chemistry , Xenograft Model Antitumor AssaysABSTRACT
Chitosan-based nanoparticles (NPs) are widely used in drug delivery, device-based therapy, tissue engineering, and medical imaging. In this aspect, a clear understanding of how physicochemical properties of these NPs affect the cytological response is in high demand. The objective of this study is to evaluate the effect of surface charge on cellular uptake profiles (rate and amount) and intracellular trafficking. We fabricate three kinds of NPs (â¼ 215 nm) with different surface charge via SPG membrane emulsification technique and deposition method. They possess uniform size as well as identical other physicochemical properties, minimizing any differences between the NPs except for surface charge. Moreover, we extend our research to eight cell lines, which could help to obtain a representative conclusion. Results show that the cellular uptake rate and amount are both positively correlated with the surface charge in all cell line. Subsequent intracellular trafficking indicates that some of positively charged NPs could escape from lysosome after being internalized and exhibit perinuclear localization, whereas the negatively and neutrally charged NPs prefer to colocalize with lysosome. These results are critical in building the knowledge base required to design chitosan-based NPs to be used efficiently and specifically.
