Amphotericin B liposomal formulation: applicable preparation methods, challenges, and tips.

OBJECTIVE: This study was intended to explore and evaluate the appropriate methods for preparation of Amphotericin B (AmB) liposomes with acceptable characteristics. SIGNIFICANCE: This project provides pre-formulations for industrial manufacturing of liposomal AmB which confers improved properties, besides reduced toxicity compared with the plain drug. METHODS: At first, Solubility screening tests were performed, and in the following, three liposome preparation methods including ethanol injection, solvent evaporation, and solvent-free method were examined. In the following, the physicochemical characteristics of the prepared liposomes as well as size, size distribution, zeta potential (ZP), morphology, drug loading, loading capacity, physicochemical stability, and drug-lipid interaction studies were investigated. HPLC was applied for analyzing AmB. RESULTS: In all three methods, liposomes with acceptable characteristics were obtained. The size range of liposomes was 150.3 to 263.9 nm and polydispersity index ≤0.32. In morphologic evaluations, the liposomes have appeared as spherical and separate vesicles. A physical loading of AmB without specific interaction between components was achieved. The lyophilized powder in the solvent-free method was physicochemically stable for 6 months without changes in appearance; the remaining drug after 6-month storage at 25 °C and 60% RH, accounts for 91.5 ± 0.5% compared with the initial drug loaded in liposomes, and degradation pattern follows a linear order. CONCLUSION: As a result, AmB-loaded liposomes were prepared in three applicable methods. The solvent-free method can be considered the most economical and environmental-friendly.

Advances in Aptamers-Based Applications in Breast Cancer: Drug Delivery, Therapeutics, and Diagnostics.

Aptamers are synthetic single-stranded oligonucleotides (such as RNA and DNA) evolved in vitro using Systematic Evolution of Ligands through Exponential enrichment (SELEX) techniques. Aptamers are evolved to have high affinity and specificity to targets; hence, they have a great potential for use in therapeutics as delivery agents and/or in treatment strategies. Aptamers can be chemically synthesized and modified in a cost-effective manner and are easy to hybridize to a variety of nano-particles and other agents which has paved a way for targeted therapy and diagnostics applications such as in breast tumors. In this review, we systematically explain different aptamer adoption approaches to therapeutic or diagnostic uses when addressing breast tumors. We summarize the current therapeutic techniques to address breast tumors including aptamer-base approaches. We discuss the next aptamer-based therapeutic and diagnostic approaches targeting breast tumors. Finally, we provide a perspective on the future of aptamer-based sensors for breast therapeutics and diagnostics. In this section, the therapeutic applications of aptamers will be discussed for the targeting therapy of breast cancer.

Bortezomib-loaded lipidic-nano drug delivery systems; formulation, therapeutic efficacy, and pharmacokinetics.

AIM: Nano drug delivery systems can provide the opportunity to reduce side effects and improve the therapeutic aspect of a variety of drugs. Bortezomib (BTZ) is a proteasome inhibitor approved for the treatment of multiple myeloma and mantle cell lymphoma. Severe side effects of BTZ are the major dose-limiting factor. Particulate drug delivery systems for BTZ are polymeric and lipidic drug delivery systems. This review focussed on lipidic-nano drug delivery systems (LNDDSs) for the delivery of BTZ. RESULTS: LNDDSs including liposomes, solid lipid nanoparticles, and self-nanoemulsifying drug delivery systems showed reduce systemic side effects, improved therapeutic efficacy, and increased intestinal absorption. Besides LNDDSs were used to target-delivery of BTZ to cancer. CONCLUSION: Overall, LNDDSs can be considered as a novel delivery system for BTZ to resolve the treatment-associated restrictions.

Self-assembled peptide nanoparticles for efficient delivery of methotrexate into cancer cells.

The low cellular uptake of Methotrexate (MTX), a commonly used anticancer drug, is a big challenge for efficient cancer therapy. Self-assembled peptide nanoparticles (SAPNs) are one of the major classes of peptide vectors that have gained much attention toward novel drug delivery systems. In the present study, different sequences of cell-penetrating peptides including R2W4R2 and W3R4W3 and their SAPNs (R2W4R2-E12 and W3R4W3-E12) were designed for efficient delivery of MTX into MCF7 breast cancer cells. Based on electron microscopy results, the obtained SAPNs were in nano scale with spherical shape. There was a positive relationship between the free energy of water to octanol transferring and cellular penetration of designed nanostructures. The R2W4R2 possessed proper free energy and ability to form a spherical structure and hydrophobic-hydrophobic interactions, therefore, exhibited more cellular penetration than W3R4W3. The cellular uptake of obtained nanoparticles was examined by flow cytometry and fluorescence microscopy, in which, R2W4R2 and R2W4R2-E12 showed more appropriate penetration into MCF7 cells than W3R4W3 and W3R4W3-E12. The cytotoxicity of MTX-loaded peptides and SAPNs was examined by MTT assay. As a result, at higher concentrations, the R2W4R2 and R2W4R2-E12 showed higher cytotoxic behavior than their counterparts. Despite their enhanced cellular internalization, the cytotoxic behavior of MTX-loaded SAPNs at lower concentrations was relatively less than free MTX, which could be ascribed to the gradual nature of drug detachment from these conjugates. Therefore, R2W4R2 could be considered as an efficient choice to enhance the therapeutic efficiency of MTX in cancer treatments.

Enhancement of the intestinal absorption of bortezomib by self-nanoemulsifying drug delivery system.

Purpose: Intestinal drug absorption is one of the main factors that govern the fraction of oral dose absorbed (Fa) of drugs. It is reported that oral absorption of bortezomib (BTZ) can be restricted by its low intestinal permeability. In this study, we aimed to evaluate the impact of self-nanoemulsifying drug delivery systems (SNEDDS) on the intestinal absorption and Fa of BTZ.Methods: Intestinal permeability studies were conducted using in situ single-pass intestinal perfusion (SPIP) technique in rats. Human intestinal absorption (Peff (Human)) and Fa values of BTZ and BTZ-SNEDDS were predicted based on SPIP data.Results: Based on the obtained data, Peff (rat) values of (3.36 ± 0.5) × 10-5 and (8.9 ± 3) × 10-5 cm/s (mean ± SEM) were calculated for BTZ and BTZ-SNEDDS, respectively. Meanwhile, Peff (human) values of (7 × 10-5) and (68 × 10-5) cm/sec were predicted for BTZ and BTZ-SNEDDS, respectively. Besides, Fa (human) values of 72.5 and 97% were estimated for BTZ and BTZ-SNEDDS, respectively.Conclusions: According to the obtained data, it is concluded that SNEDDS can be considered as a promising drug delivery system to improve the intestinal absorption and Fa values of BTZ.

PLA-PCL-PEG-PCL-PLA based micelles for improving the ocular permeability of dexamethasone: development, characterization, and in vitro evaluation.

The aim of the present research was to investigate the feasibility of developing polylactide-polycaprolactone-polyethylene glycol-polycaprolactone-polylactide (PLA-PCL-PEG-PCL-PLA) based micelles to improve ocular permeability of dexamethasone (DEX). PLA-PCL-PEG-PCL-PLA copolymers were synthesized by a ring-opening polymerization method. DEX was loaded into the developed copolymers. The DEX-loaded micelles were characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS) methods. Cytotoxicity of the micelles obtained was investigated on L929 cell line. Cellular uptake was followed by fluorescence microscopy and flow cytometry analyses. The release behavior of DEX from the micelles as well as the drug release kinetics was studied. Corneal permeability was also evaluated using an ex vivo bovine model. The pentablock copolymers were successfully synthesized. The TEM results verified the formation of spherical micelles, the sizes of which was approximately 65 nm. The micelles exhibited suitable compatibility on L929 cells. The release profile showed an initial burst release phase followed by a sustained release phase, the kinetic of which was close to the Weibull's distribution model. The micelles showed higher corneal permeability in comparison to a marketed DEX eye drop. Taken together, the results indicated that the PLA-PCL-PEG-PCL-PLA micelles could be appropriate candidates for the ocular delivery of DEX, and probably other hydrophobic drugs.

Effects of Heracleum persicum Hydroalcoholic Extract on Insulin, Serum Anti-Oxidant Enzymes, Glucose, and Lipid Profiles in Alloxan-Induced Diabetic Rats.

BACKGROUND: Heracleum persicum (H. persicum) is a medicinal herb used in Iranian traditional medicine for its anti-toxic property. It is commonly consumed in the form of food additives and as a medicinal herbal tonic to treat liver and kidney diseases. The present study aimed to investigate the anti-oxidant, anti-diabetic, and anti-hyperlipidemic effects of H. persicum hydroalcoholic extract in alloxan-induced diabetic rats. METHODS: Adult male Wistar rats (n=30) were assigned to five groups: a normal group, a diabetic control group, and three diabetic groups treated orally with 200 and 400 mg/kg of the extract and 5 mg/kg of glibenclamide, respectively, for two weeks. Blood glucose and bodyweight were measured at the end of each week. On day 15, blood samples were collected to measure the levels of insulin, insulin growth factor-I (IGF-I), antioxidant markers for malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), total antioxidant activity (TAS), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) using commercial kits. The data were analyzed using SPSS Software (version 22.0). RESULTS: Daily treatment with 400 mg/kg of the extract significantly reduced the blood glucose level (P<0.001) and improved bodyweight (P=0.002), insulin (P<0.001), IGF-I (P=0.024), SOD (P=0.001), GPx (P=0.009), MDA (P<0.001), TAS (P=0.006), TG (P<0.001), HDL (P=0.023), LDL (P=0.005), and VLDL (P<0.001) compared with the diabetic control group. CONCLUSION: Beneficial effects of H. persicum for the treatment of diabetes were confirmed.

Drug Targeting Strategies Based on Charge Dependent Uptake of Nanoparticles into Cancer Cells.

The aim of this review was to describe the preferred charged nano-particles (CNPs) for targeted delivery in tumor cells. Zeta Potential (ZP), which represents the surface charge of NPs was highlighted in cell entrance and interactions. In this regard, various types of endocytosis pathways which are involved in NPs' uptake were first introduced. Then, significance of positively charged NPs (PCNPs) in proton sponge effect corresponding to lysosomal escape was discussed. Cells prefer to endocyte the NPs with positive charge in passive targeting and gene delivery, while in active targeting; the charge of receptors' ligand binding site determines the NPs cellular uptake. Moreover, pH-sensitive NPs represent charge reversible behavior depending on pH changes which leads to longer blood circulation residence and higher uptake at acidic microenvironment of the cancer media. Role of the CNPs in overcoming multidrug resistance (MDR) and bypassing p-glycoprotein was further investigated.

Evaluation of anti-inflammatory impact of dexamethasone-loaded PCL-PEG-PCL micelles on endotoxin-induced uveitis in rabbits.

The aim of this study was to investigate the capability of polycaprolactone-polyethylene glycol-polycaprolactone (PCL-PEG-PCL) micelles in improving the anti-inflammatory effects of dexamethasone (DEX). A film hydration method was used for the preparation of the DEX-loaded PCL-PEG-PCL micelles. In vitro cytotoxicity of the micelles obtained was investigated on L929 cells. Cellular uptake was studied by using flow cytometry and fluorescence microscopy. Anterior uveitis was induced in a group of rabbits by intravitreal injection of endotoxin from Salmonella typhimurium. The severity of inflammation-induced was clinically graded by using Hogan's classification method. Protein concentration in the aqueous humor was also measured. The micelles exhibited suitable compatibility on L929 cells and were taken up by the cells in a concentration- and time-dependent manner. The DEX-loaded micelles could reduce the clinical symptoms of uveitis after a lag-time. At 24 and 36 h after the LPS injection, the PCL-PEG-PCL micelles showed a better inhibitory effect on uveitis than the marketed eye drop, the differences did not reach significant levels though. This study demonstrated the potential of the PCL-PEG-PCL micelles as carriers for DEX in treating anterior uveitis. However, this concept is still to be further investigated.

Bortezomib-loaded solid lipid nanoparticles: preparation, characterization, and intestinal permeability investigation.

Bortezomib (BTZ), a proteasome inhibitor, is clinically used for the treatment of multiple myeloma and mantle cell lymphoma via intravenous or subcutaneous administration. Since BTZ has limited intestinal permeability, in this study, solid lipid nanoparticles (SLNs) were selected as lipid carrier to improve the intestinal permeability of BTZ. The nanoparticles were prepared by hot oil-in-water emulsification method and characterized for physicochemical properties. Moreover, in situ single-pass intestinal perfusion technique was used for intestinal permeability studies. Mean particle size of the BTZ-loaded solid lipid nanoparticles (BTZ-SLNs) was 94.6 ± 0.66 nm with a negative surface charge of -18 ± 11 mV. The entrapment efficiency of the BTZ-SLNs was 68.3 ± 3.7% with a drug loading value of 0.8 ± 0.05%. Cumulative drug release (%) over 48 h, indicated a slow release pattern for nanoparticles. Moreover, the SEM image showed a spherical shape and uniform size distribution for nanoparticles. Also, FTIR analysis indicated that BTZ was successfully loaded in the SLNs. The results of the intestinal perfusion studies revealed an improved effective permeability for BTZ-SLNs with a Peff value of about threefold higher than plain BTZ solution.