MicroRNA-219 loaded chitosan nanoparticles for treatment of glioblastoma

Recent evidence has implicated microRNA-219 (miR-219) in regulation of gene contributed in glioblastoma (GBM) pathogenesis. This study aimed to prepare miR-219 in chitosan (CS) nanoparticles (NPs), characterize and investigate their efficacy on human GBM cell line (U87 MG). NPs were prepared using ionic gelation method. The influence of process parameters on physicochemical characteristics of NPs was investigated. Apoptotic effect of miR-219 was examined on U87 MG cells. Formulated NPs showed particle size of 109 ± 2.18 nm, with poly dispersity index equal to 0.2 ± 0.05, and zeta potential of +20.5 ± 0.7 mV. Entrapment efficiency of miR-219 in loaded NP has reached 95%. The in vitro release study demonstrated sustained release pattern of miR-219 from CS-NPs. Gel retardation assay has confirmed the integrity of miR-219 after production process. The fabricated NPs reduced the survival of U87 MG cells to 78% after 24 h of post-transfection, and into 67.5% after 48 h. However, fibroblasts were not affected by the NPs, revealing their specificity for GBM cells. Given the tumour suppressing function of miR-219, and advantage of CS-NPs for gene delivery to the central nervous system, the presented NPs have a great potential for treatment of GBM.

Preparation and characterization of Meta-bromo-thiolactone calcium alginate nanoparticles

Recently, the focus has been shifting toward Quorum sensing inhibitors which reduce Pseudomonas aeruginosa virulence factors, alleviating infections. In this work, me-ta-bromo-thiolactone (mBTL), a potent quorum and virulence inhibitor for the Pseudomonas aeruginosa strains, were formulated in calcium alginate nanoparticles (CANPs). Alginate is used as nutrients and as backbone virulence aspect for Pseudomonas and therefore was chosen. mBTL-loaded-CANPs were characterized for particle size, polydispersity index, zeta potential, morphology visualized by Transmission Electron Microscopy (TEM) and drug release profile. Chemical and physical analysis of formulated mBTL-loaded-CANPs were evaluated using Fourier transform infrared Spectroscopy (FTIR) and differential scanning calorimetry (DSC) and Physical stability of mBTL-loaded-CANPs assessed at various temperature 25 ± 1 °C, 4 ± 0.5 °C and −30° ± 1 °C over a period of 4 and 9 months. Synthesized CANPs showed nano-size particles ranging from 140 to 200 nm with spherical particles for plain CANPS and irregular shape for mBTL-loaded-CANPs with a sustainable release profile over 48hrs. FTIR showed stable structure of loaded-mBTL and DSC displayed no interaction between mBTL and polymer. State of released mBTL from CANPs kept at 25 °C, 4 °C and −30 °C over 4 and 9 months showed stable formula at room temperature which kept as a goal of nanoparticles storage. The findings of this study revealed successful preparation of mBTL-loaded-CANPs.

Antibacterial Activity of Chitosan Nanoparticles Against Pathogenic N. gonorrhoea

Purpose

The emergence of Neisseria gonorrhoeae strains that are resistant to the most commonly used antibiotics represents a great concern for global public health. This challenges the effectiveness of clinical treatment regimens and demands the development of alternative antigonococcal agent. In this regard, chitosan nanoparticles (CNPs) are known to have antimicrobial activity against a wide range of pathogens. Thus, they have become a potential candidate for combatting this era of multi-drug resistance. This study aims to formulate CNPs, characterize their physicochemical properties, and examine their antimicrobial activity against gonococcus.

Materials and Methods

The ionic gelation method was used to prepare CNPs of different concentrations. Characterization for their particle size (PZ), polydispersity index (PDI), and zeta potential (ZP) was performed. The anti-microbial activity of CNPs was investigated against 13 WHO N. gonorrhoeae reference strains, using the broth dilution method. Cytotoxicity of CNPs and their effect on bacterial adhesion to HeLa cells were investigated.

Results

The average PZ and ZP of the prepared NPs were increased when the concentration of chitosan was increased from 1 to 5 mg/mL and found to be in the range of 193 nm ± 1.9 to 530 nm ± 13.3, and 14 mV ± 0.5 to 20 mV ± 1, respectively. Transmission electron microscopes (TEM) images revealed spherical NPs, and the NPs had a low PDI value of ≤0.27. The formed CNPs produced antibacterial activity against all tested strains, including those resistant to multiple antibiotics, with a minimum inhibitory concentration (MIC₉₀) of 0.16 to 0.31 mg/mL and a minimum bactericidal concentration (MBC) of 0.31 to 0.61 mg/mL. Of note, at all MIC₉₀ and MBC, the CNPs had no significant cytotoxic effect on HeLa cells and reduced bacterial adhesion to these cells at MBC doses.

Conclusion

The present work findings suggest the potential of the CNPs for the treatment of gonorrhoea.

Trastuzumab Targeted Neratinib Loaded Poly-Amidoamine Dendrimer Nanocapsules for Breast Cancer Therapy

Background

Human epidermal growth factor receptor2 (Her2) positive breast cancer represents 25% of breast cancer cases. Targeted therapy with Her2 monoclonal antibody, trastuzumab (TZ), represents the first-line treatment for this type of breast cancer. In addition, neratinib, an irreversible inhibitor of the HER-2 receptor tyrosine kinase, has recently been approved as adjuvant therapy to TZ. This study aims to formulate (TZ)-grafted dendrimers loaded with neratinib, allowing a dual treatment alongside reducing the associated resistance as well as targeted therapy.

Methods

TZ was conjugated on the surface of dendrimer using hetero-cross linker, MAL-PEG-NHS, and the zeta potential, and in vitro release of neratinib from dendrimers was characterized. Formulated dendrimers were also fluorescently conjugated with fluorescein isothiocyanate to visualize and quantify their SKBR-3 cellular uptake.

Results

The G4 PAMAM dendrimer showed successful encapsulation of neratinib and a sustained release profile. Comparative in vitro studies revealed that these TZ-targeted dendrimers loaded with neratinib were more selective and have higher antiproliferation activity against SKBR-3 cells compared to neratinib alone and neratinib loaded dendrimer.

Conclusion

In the current study, neratinib loaded in plain and trastuzumab-grafted dendrimer were successfully prepared. Enhanced cellular uptake of trastuzumab conjugated dendrimers was shown, together with a higher cytotoxic effect than plain neratinib dendrimers. These findings suggest the potential of TZ-conjugated dendrimers as targeting carrier for cytotoxic drugs, including neratinib.

Nanotechnology as a tool to overcome the bariatric surgery malabsorption

Obesity is a metabolic disease that affects all ages; it is considered life-threatening condition as it leads to fatal complications such as; cardiovascular diseases and diabetes. The therapeutic options include; life-style modifications, pharmacotherapy intervention, and surgical intervention. Bariatric surgery (BS) is considered as the most effective option among the others for its rapid weight loss, maintaining the lost mass, and improving the quality of life of the patients. Nevertheless, BS leads to severe changes in the bioavailability of medications, especially for chronic diseases, which may reach to limit where the patient's life endangers. Recently, pharmaceutical formulations had developed several methods to improve the drug bioavailability of drugs though the implying of nanotechnology. Nonotechnology is responsible for reducing the size of the drugs to the nano range (<1000 nm), which increase the drug surface area, dissolution, absorption, and, most importantly, the bioavailability of these drugs. It is believed that BS malabsorption and drugs bioavailability problems can be solved using nanotechnology for its advantages in overcoming BS complications.

Voltammetric determination of montelukast sodium in dosage forms and human plasma

The voltammetric behaviour of montelukast (MKST) was studied using cyclic voltammetry, direct current (DCt), differential pulse polarography (DPP) and alternating current (ACt) polarography. MKST exhibited well-defined cathodic waves over the range pH range 1-5. No anodic waves were produced over the same pH range. At pH 1, the analytical pH; the diffusion current constant (Id) was 2.2+/-0.01 microA l mmol-1. The current concentration plot was rectilinear over the range 2-20 microg ml-1 with correlation coefficient (n=10) of 0.9943. The lower limit of detection (S/N=2) was 0.2 microg ml-1 (3.41x10(-7) M). The wave has been characterised as being diffusion-controlled, although adsorption phenomenon played a limited role in the electrode reaction. The proposed method was successfully applied to the determination of MKST in commercial tablets, and results were in agreement with those given with a reference HPLC method. The method was further extended to the in vitro determination of the drug in spiked human plasma. The mean % recovery (n=5) was 101.38+/-3.85. The number of electrons transferred in the reduction process could be accomplished and a proposal of the electrode reaction was proposed.

Spectrofluorometric determination of montelukast in dosage forms and spiked human plasma

The native fluorescence of montelukast has been studied under different experimental conditions. The highest fluorescence intensity was obtained in methanol at 390 nm using 340 nm for excitation. Surfactants and sensitizers had either a negative or a slightly positive effect on its fluorescence intensity. The fluorescence intensity-concentration plot was rectilinear over the range 0.125 to 5 microg/ml with a lower detection limit of 0.02 microg/ml (3.4 x 10(-8) M). Interference likely to be introduced from co-formulated drugs (such as loratadine) or co-administered drugs (such as verapamil, carbazepam, propranolol) or other common drugs, was studied. The method was successfully applied to the determination of the drug in tablets (pediatric tablets, chewable tablets and adult tablets). The mean % recoveries were in agreement with those provided by the manufacturer. The method was further applied to the in vitro determination of montelukast in spiked human plasma, the mean % recovery (n = 5) was 100.08 +/- 1.40.