Receptor Mediated Targeting of Lectin Conjugated Gliadin Nanoparticles in the Treatment of Helicobacter pylori

The present work describes the potential for using lectin-conjugated gliadin nanoparticles as a means of locating and anchoring a drug delivery system on the carbohydrate receptors of Helicobacter pylori (H. pylori). Gliadin nanoparticles (GNP) bearing acetohydroxamic acid (AHA) were prepared by a desolvation method. Ulex Europaeus Agglutinin I (UEA I) and Conconavalin A (Con A) lectins were bound to GNP formulations by the two-stage carbodiimide coupling technique. Lectin-agglutination assay was performed to evaluate the binding efficacy of lectin formulations to carbohydrate receptors of H. pylori strains. Strong agglutination patterns were observed with mannose-specific Con A-GNP and α(L)-fucose specific UEA–GNP formulations. In situ adherence assay was performed to examine the efficacy of lectin formulations to inhibit the binding of H. pylori strains with human stomach cells. Lectin formulations completely inhibited the H. pylori binding. In addition, the antimicrobial activity of the formulations was evaluated by percent growth inhibition studies (%GI) by using isolated H. pylori strain. The inhibitory efficacy of UEA–GNP and Con A–GNP was approximately two-fold higher compared to GNP. These lectin-conjugated gliadin nanoparticles are found to be potential candidate for targeted drug delivery and are anticipated to be useful in the treatment of H. pylori.     

Cytotoxicity of doxorubicin bound to poly(butyl cyanoacrylate) nanoparticles in rat glioma cell lines using different assays

The cytotoxicity of doxorubicin bound to poly(butyl cyanoacrylate) nanoparticles (Dox-PBCA-NP) was investigated in the rat glioma cell lines GS-9L, F-98 and RG-2. MTT and LDH assays were used as cytotoxic assays. In general, the cytotoxicity of nanoparticle-bound doxorubicin (Dox) was enhanced compared to the free drug in solution. However, responses of the cell lines towards the drug effects were different. In the case of free Dox in solution, this difference correlated with different intracellular concentrations of Dox, which in turn, depended on the level of P-glycoprotein (P-gp) expression in these cell lines. Accordingly, the 9L gliosarcoma (GS-9L) cells, which appeared to be most resistant towards Dox, were characterized by the highest P-gp expression.

Additionally, the influence of surfactants on the cytotoxic effect was investigated at different Dox concentrations. It was shown that the presence of polysorbate 80 (Tween® 80) in the nanoparticle formulation significantly enhanced the cytotoxicity, whereas poloxamer 188 (Pluronic® F68) and poloxamine 908 (Tetronic® 908) had a negligible influence.     

Evaluation of the cytotoxic effect of camptothecin solid lipid nanoparticles on MCF7 cells

Abstract

Camptothecin (CPT) and its analogs exhibit remarkable anti-tumor activity, due to their ability to inhibit DNA topoisomerase I. However, its use is limited by the lack of solubility and stability of the active lactone form. An attractive alternative is the encapsulation of CPT within liposomes. In this study, CPT was incorporated into solid lipid nanoparticles (SLN) based on the triglyceride, Compritol 888 ATO, using supercritical fluid technology without requiring the use of harmful solvents. This drug delivery system was characterized and its cytotoxicity effect was evaluated by measuring MCF7 and MCF10A cell viability as a function of drug loading during a 48-h treatment. Results showed that after 10?h of treatment, MCF7 cells displayed an IC50 of 0.23?±?0.034?μM at a 1:5 (CPT:SLN) loading and 0.22?±?0.027?μM at a 1:10 loading, whereas MCF10A cells displayed an IC50 of 0.40?±?0.036?μM at 1:5 and 0.60?±?0.063?μM at 1:10. On the other hand, the IC50 of free CPT was 0.57?±?0.035?μM and 1.07?±?0.077?μM for MCF7 and MCF10A cells, respectively. Cellular uptake and retention measurements in both cells displayed a two-fold increase when using the SLN formulation. The results from this study showed that the cytotoxic effects of CPT in a SLN formulation improved when compared with those seen with free CPT. The results of this study showed that delivery of CPT as a SLN formulation could be a promising strategy for enhancing its chemotherapeutic effects.     

Synthesis and characterization of chitosan quaternary ammonium salt and its application as drug carrier for ribavirin

Abstract

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) is hydro-soluble chitosan (CS) derivative, which can be obtained by the reaction between epoxypropyl trimethyl ammonium chloride (ETA) and CS. The preparation parameters for the synthesis of HTCC were optimized by orthogonal experimental design. ETA was successfully grafted into the free amino group of CS. Grafting of ETA with CS had great effect on the crystal structure of HTCC, which was confirmed by the XRD results. HTCC displayed higher capability to form nanoparticles by crosslinking with negatively charged sodium tripolyphosphate (TPP). Ribavrin- (RIV-) loaded HTCC nanoparticles were positively charged and were spherical in shape with average particle size of 200?nm. More efficient drug encapsulation efficiency and loading capacity were obtained for HTCC in comparison with CS, however, HTCC nanoparticles displayed faster release rate due to its hydro-soluble properties. The results suggest that HTCC is a promising CS derivative for the encapsulation of hydrophilic drugs in obtaining sustained release of drugs.     

Preparation of N,O-carboxymethyl chitosan nanoparticles as an insulin carrier

The aim of this research was to develop pH-sensitive insulin-loaded NOCC (N,O-carboxymethyl chitosan) nanoparticles for the controlled release of insulin via the oral route. Thus, in this study, insulin-loaded NOCC nanoparticles were prepared by ionic gelation of NOCC with TPP (tripolyphosphate). NOCC nanoparticles were formed at conditions of 2?mg/ml of NOCC and 1?mg/ml of TPP. It was found that the encapsulation efficiency and process yield decreased with increasing NOCC to TPP weight ratio. Furthermore, the cumulative release of insulin from insulin-loaded NOCC nanoparticles decreased with decreasing NOCC-to-TPP weight ratio, but it increased with decreasing the initial concentration of insulin. The higher the pH of the phosphate buffered saline, the greater the amount of cumulative release of insulin-loaded NOCC nanoparticles, and thus they could protect insulin from acid.     

Preparation of folate-modified pullulan acetate nanoparticles for tumor-targeted drug delivery

The purpose of this work was to develop a novel nano-carrier with targeting property to tumor. In this study, pullulan acetate (PA) was synthesized by the acetylation of pullulan to simplify the preparation technique of nanoparticles. Folic acid (FA) was conjugated to PA in order to improve the cancer-targeting activity. The products were characterized by proton nuclear magnetic resonance (¹H NMR) spectroscopy. Epirubicin-loaded nanoparticles were prepared by a solvent diffusion method. The loading efficiencies and EPI content increased with the amount of triethylamine (TEA) increasing in some degree. FPA nanoparticles could incorporate more epirubicin than PA nanoparticles. The folate-modified PA nanoparticles (FPA/EPI NPs) exhibited faster drug release than PA nanoparticles (PA/EPI NPs) in vitro. Confocal image analysis and flow cytometry test revealed that FPA/EPI NPs exhibited a greater extent of cellular uptake than PA/EPI NPs against KB cells over-expressing folate receptors on the surface. FPA/EPI NPs also showed higher cytotoxicity than PA/EPI NPs. The cytotoxic effect of FPA/EPI NPs to KB cells was inhibited by an excess amount of folic acid, suggesting that the binding and/or uptake were mediated by the folate receptor.     

Comparative analysis of the methods of drug and protein delivery for the treatment of cancer,genetic diseases and diagnostics

The methods of protein and drug delivery for the treatment of cancer, genetic diseases and diagnostics were summarized. The potential of protein transduction is discussed and the recent developments in the field are reviewed. An overview is provided of the non-viral delivery methods such as liposomes, polymer-based delivery, cell-penetrating peptides, bacterial secretion, cells, virosomes, physical methods including electroporation, microinjection, osmotic lysis, nanoparticles, sonoporation to locally inject therapeutic molecules. The characteristic properties of non-viral vectors and their use for the delivery of therapeutic molecules for the diagnosis and treatment of disorders and to target tumors are also discussed. The potential of the transduced peptides and proteins was used as new therapeutic compounds against infectious diseases, to complement deficiencies in specific genes, to specifically kill tumour cells, for gene therapy. The protein delivery vectors can enhance the transfection at low concentrations and help to develop future gene delivery systems with reduced toxicity. Vitamin B12, folic acid, biotin, and riboflavin are essential in the treatment of cancer. Ultrasound has a potential in the delivery of therapeutic agents. The new developing technologies of drug delivery and targeting offer the possibility to improve the therapeutic possibilities of the existing drugs and to develop novel therapeutics.     

Pharmacokinetics and in vivo biodistribution of optimized PLGA nanoparticulate drug delivery system for controlled release of emtricitabine

Abstract

The objective of this study was to develop systematically optimized (OPT) nanoparticles (NPs) providing a controlled release using PLGA of emtricitabine (FTC) employing Formulation by Design (FbD), and evaluate their in vitro and in vivo performance. FTC generates severe adverse effects with risks of toxicity. Thus, NPs were prepared to reduce these drawbacks in this study. The NPs were prepared by water-in-oil-in-water (w/o/w) emulsion method, followed by high-pressure homogenization. The FTC NPs were systematically OPT using 3² central composite design and the OPT formulation located using overlay plot. The pharmacokinetics and in vivo biodistribution of OPT-FTC NPs were investigated in male Wistar rats via the oral administration. Transmission electron microscopy studies on OPT-FTC NPs demonstrated uniform shape and size of particles. In vitro release was sustained up to 15 days in PBS pH 7.4. Augmentation in the values of C_max (1.63 fold) and AUC_0-∞ (5.39 fold) indicated significant enhancement in the rate and extent of bioavailability by the OPT-FTC NPs compared to pure drug. OPT-FTC NPs showed 2.325 fold increase in the values of FTC concentrations in liver. The OPT-FTC NPs was found to be quite stable during 6 months of study period. Hence, the developed OPT-FTC NPs can be used as drug carrier for sustained/prolonged drug release and/or to reduce toxic effects.     

Preparation of honokiol-loaded chitosan microparticles via spray-drying method intended for pulmonary delivery

It has been demonstrated that spray-drying is a powerful method to prepare dry powders for pulmonary delivery. This paper prepared dispersible dry powders based on chitosan and mannitol containing honokiol nanoparticles as model drug. The results showed that the prepared microparticles are almost spherical and have appropriate aerodynamic properties for pulmonary delivery (aerodynamic diameters was between 2.8–3.3 μm and tapped density ranging from 0.14–0.?18?g/cm³). Moreover, surface morphology and aerodynamic properties of the powders were strongly affected by the content of mannitol. Fourier transform infra-red (FTIR) spectrum of powders indicated that the honokiol nanoparticles were successfully incorporated into microparticles. In vitro drug release profile was also observed. The content of mannitol in powders significantly influenced the release rate of honokiol from matrices.     

In vivo controlled release and prolonged antitumor effects of 2-methoxyestradiol solid lipid nanoparticles incorporated into a thermosensitive hydrogel

A two-phase delivery system involving local injections of solid lipid nanoparticles (SLNs) -loaded hydrogel was developed using 2-methoxyestradiol as a model anticancer drug. This approach improves the effectiveness of conventional treatments for subcutaneous tumors and avoids that solid lipid nanoparticles are rapidly cleared from the circulation following systemic administration. The specific aim of the study presented in this article was to investigate the in vivo release, delivery and antitumor effects of 2-ME SLNs entrapped in a hydrogel. The results indicated that the hydrogel could deliver fluorescence-marked SLNs to tumor masses and cancer cells, exhibiting a controlled release of 2-ME SLNs over 46 days following a zero-order model. After treatment with the 2-ME SLN-loaded hydrogel, BALB/c mice that had been inoculated with syngeneic 4T1 breast cancer cells displayed significantly more tumor growth suppression for at least 21 days than those treated with a hydrogel containing the free drug, which was consistent with the in vitro cytotoxicity of 2-ME SLNs. This experiment demonstrated the efficacy of the hydrogel as a depot of 2-ME SLNs. Additionally, the mice treated with the hydrogel did not exhibit a loss of body weight or abnormal levels of white blood cells compared to the control group. These experiments demonstrated the potential value of 2-ME SLN hydrogel local injections as a safer and more effective method for the chemotherapy of subcutaneous tumors.