Hibah Aldawsari

Exosomes as nanocarriers for immunotherapy of cancer and inflammatory diseases.

Cell secreted exosomes (30-100nm vesicles) play a major role in intercellular communication due to their ability to transfer proteins and nucleic acids from one cell to another. Depending on the originating cell type and the cargo, exosomes can have immunosuppressive or immunostimulatory effects, which have potential application as immunotherapies for cancer and autoimmune diseases. Cellular components shed from tumor cells or antigen presenting cells (APCs), such as dendritic cells, macrophages and B cells, have been shown to be efficiently packaged in exosomes. In this review, we focus on the application of exosomes as nanocarriers and immunological agents for cancer and autoimmune immunotherapy. APC-derived exosomes demonstrate effective therapeutic efficacy for the treatment of cancer and experimental autoimmune diseases such as rheumatoid arthritis, inflammatory bowel disease, and multiple sclerosis. In addition to their intrinsic immunomodulating activity, exosomes have many advantages over conventional nanocarriers for drug and gene delivery.

Pancreatic Cancer Cell Exosome-Mediated Macrophage Reprogramming and the Role of MicroRNAs 155 and 125b2 Transfection using Nanoparticle Delivery Systems

Exosomes are nano-sized endosome-derived small intraluminal vesicles, which are important facilitators of intercellular communication by transporting contents, such as protein, mRNA, and microRNAs, between neighboring cells, such as in the tumor microenvironment. The purpose of this study was to understand the mechanisms of exosomes-mediated cellular communication between human pancreatic cancer (Panc-1) cells and macrophages (J771.A1) using a Transwell co-culture system. Following characterization of exosome-mediated cellular communication and pro-tumoral baseline M2 macrophage polarization, the Panc-1 cells were transfected with microRNA-155 (miR-155) and microRNA-125b-2 (miR-125b2) expressing plasmid DNA using hyaluronic acid-poly(ethylene imine)/hyaluronic acid-poly(ethylene glycol) (HA-PEI/HA-PEG) self-assembling nanoparticle-based non-viral vectors. Our results show that upon successful transfection of Panc-1 cells, the exosome content was altered leading to differential communication and reprogramming of the J774.A1 cells to an M1 phenotype. Based on these results, genetic therapies targeted towards selective manipulation of tumor cell-derived exosome content may be very promising for cancer therapy.

Enhanced permeation parameters of optimized nanostructured simvastatin transdermal films: ex vivo and in vivo evaluation.

Abstract Objective: Detailed optimization process was carried out to enhance permeation parameters, and hence bioavailability, of simvastatin (SMV) transdermal films. Methods: SMV solubility was investigated in various oils, surfactants and co-surfactants/co-solvents. Mixtures of the selected components were prepared to identify zone of nanoemulsion formation that was utilized in Extreme Vertices mixture design to develop SMV self-nanoemulsifying drug delivery systems (SNEDDS) with minimum globule size. Optimized SMV-SNEDDS were included in the preparation of transdermal films. A fractional factorial design was implemented to evaluate effects of the factors on the amount of SMV permeated. The optimized film was investigated for ex vivo skin permeation and in vivo pharmacokinetic parameters. Results: The optimum SNEDDS formula was 0.09, 0.8 and 0.11 for Sefsol 218, tween 80 and PEG 200, respectively. Fractional factorial design depicted the optimized SMV transdermal film with 2% HPMC and 2% DMSO as permeation enhancer that showed 1.82-fold improvements in skin flux. The pharmacokinetic data showed higher Cmax and almost doubled AUC compared with raw SMV-loaded films. Conclusion: The two-step optimization implemented to optimize and control the experimental conditions for the preparation of SMV-SNEDDS-transdermal film with improved ex vivo skin permeation and enhanced in vivo parameters.

Design and formulation of a topical hydrogel integrating lemongrass-loaded nanosponges with an enhanced antifungal effect: in vitro/in vivo evaluation.

Lemongrass oil (LGO) is a volatile oil extracted from the leaves of Cymbopogon citratus that has become one of the most important natural oils in the pharmaceutical industry because of its diverse pharmacologic and clinical effects. However, LGO suffers from low aqueous solubility, which could lead to a reduced effect. Moreover, the instability of its major active constituent, citral, could lead to volatilization, reaction with other formulation ingredients, and consequently, skin irritation. To surmount these problems, this research aims to formulate lemongrass-loaded ethyl cellulose nanosponges with a topical hydrogel with an enhanced antifungal effect and decreased irritation. The minimal inhibitory concentration and minimal fungicidal concentration of LGO against Candida albicans strain ATC 100231, determined using the broth macrodilution method, were found to be 2 and 8 μL/mL, respectively. The emulsion solvent evaporation technique was used for the preparation of the nanosponges. The nanosponge dispersions were then integrated into carbopol hydrogels (0.4%). Nine formulations were prepared based on a 32 full factorial design employing the ethyl cellulose:polyvinyl alcohol ratio and stirring rate as independent variables. The prepared formulations were evaluated for particle size, citral content, and in vitro release. Results revealed that all the nanosponge dispersions were nanosized, with satisfactory citral content and sustained release profiles. Statistical analysis revealed that both ethyl cellulose:polyvinyl alcohol ratio and stirring rate have significant effects on particle size and percentage released after 6 hours; however, the effect of the stirring rate was more prominent on both responses. The selected hydrogel formulation, F9, was subjected to surface morphological investigations, using scanning and transmission electron microscopy, where results showed that the nanosponges possess a spherical uniform shape with a spongy structure, the integrity of which was not affected by integration into the hydrogel. Furthermore, the selected formulation, F9, was tested for skin irritation and antifungal activity against C. albicans, where results confirmed the nonirritancy and the effective antifungal activity of the prepared hydrogel.

Crystallization of a new polymorph of acetohexamide from 2-hydroxybutyl-β-cyclodextrin solution: Form VI with a high aqueous solubility

A new polymorph of acetohexamide (Form VI) was prepared via the formation of a complex with 2-hydoxybutyl-β-cyclodextrin (HB-β-CD) in aqueous solution. An alkaline solution of acetohexamide and HB-β-CD was adjusted to pH 4.0 by titration with hydrochloric acid. The resulting opaque solution was filtered through paper and allowed to stand at 4°C for 24h. The resulting precipitate was isolated on a filter and analyzed for polymorph content by powder X-ray diffractometry and thermal analysis. The diffraction pattern and thermal behavior of the precipitate was different from those of previously reported acetohexamide polymorphs (Forms I, III, IV and V), indicating that a new polymorph of the drug, i.e. Form VI was produced. This new polymorph was fairly stable against conversion to a stable form even at accelerated storage conditions. Crystalline Form VI was highly soluble in water and dissolved more rapidly than the other known polymorphs. This property was reflected in the blood concentrations of the drug after oral administration to rats.

Innovation of natural essential oil-loaded Orabase for local treatment of oral candidiasis

Purpose Oral candidiasis may be manifested in the oral cavity as either mild or severe oral fungal infection. This infection results from the overgrowth of Candida species normally existing in the oral cavity in minute amounts based on many predisposing factors. Several aspects have spurred the search for new strategies in the treatment of oral candidiasis, among which are the limited numbers of new antifungal drugs developed in recent years. Previous studies have shown that thyme and clove oils have antimycotic activities and have suggested their incorporation into pharmaceutical preparations. This study aimed to investigate the possibility of the incorporation and characterization of essential oils or their extracted active ingredients in Orabase formulations. Methods Orabase loaded with clove oil, thyme oil, eugenol, and thymol were prepared and evaluated for their antifungal activities, pH, viscosity, erosion and water uptake characteristics, mechanical properties, in vitro release behavior, and ex vivo mucoadhesion properties. Results All prepared bases showed considerable antifungal activity and acceptable physical characteristics. The release pattern from loaded bases was considerably slow for all oils and active ingredients. All bases showed appreciable adhesion in the in vitro and ex vivo studies. Conclusion The incorporation of essential oils in Orabase could help in future drug delivery design, with promising outcomes on patients’ well-being.

Evaluation of Hepatoprotective Activity of Adansonia digitata Extract on Acetaminophen-Induced Hepatotoxicity in Rats.

The methanol extract of the fruit pulp of Adansonia digitata L. (Malvaceae) was examined for its hepatoprotective activity against liver damage induced by acetaminophen in rats. The principle depends on the fact that administration of acetaminophen will be associated with development of oxidative stress. In addition, hepatospecific serum markers will be disturbed. Treatment of the rats with the methanol extract of the fruit pulp of Adansonia digitata L. prior to administration of acetaminophen significantly reduced the disturbance in liver function. Liver functions were measured by assessment of total protein, total bilirubin, ALP, ALT, and AST. Oxidative stress parameter and antioxidant markers were also evaluated. Moreover, histopathological evaluation was performed in order to assess liver case regarding inflammatory infiltration or necrosis. Animals were observed for any symptoms of toxicity after administration of extract of the fruit pulp of Adansonia digitata L. to ensure safety of the fruit extract.

Potential Use of /2-Hydroxypropyl-β-cyclodextrin Nanoparticles as a New Photosensitizer in the Treatment of Cancer

The photosensitizing ability of C60/2-hydroxypropyl-β-cyclodextrin (HP-β-CyD) nanoparticles under visible light irradiation was studied by electron spin resonance (ESR) and phototoxicity on cancer cells. In addition, the photoinduced antitumor effect to the tumor-bearing mice was evaluated. C60 nanoparticles were prepared by grinding a mixture of HP-β-CyD. The resulting C60/HP-β-CyD nanoparticles were highly-sensitive to visible light and generated higher levels of 1O2 than protoporphyrin IX (PpIX). C60/HP-β-CyD reduced the viability of cancer cells (HeLa cells and A549 cells) in response to irradiation by visible light in a dose-dependent manner. The IC50 values of the C60/HP-β-CyD nanoparticles was 10 μM for HeLa cells and 60 μM for A549 cells at an irradiation level of 35 mW/cm2. The photodynamic effect of C60/HP-β-CyD nanoparticles on the in vivo growth of mouse sarcoma S-180 cells was evaluated after intratumor injection. The outcome of PDT by C60/HP-β-CyD was directly dependent on the dose of irradiated light. Treatment with C60/HP-β-CyD nanoparticles at a C60 dose of 2.0 mg/kg under visible light irradiation at 350 mW/cm2 (63 J/cm2) markedly suppressed tumor growth, whereas that at 30 J/cm2 was less effective. These findings suggest that C60/HP-β-CyD nanoparticles represent a promising candidate for use in cancer treatment by PDT.

Metronidazole and Pentoxifylline films for the local treatment of chronic periodontal pockets: preparation, in vitro evaluation and clinical assessment

Objective: Periodontitis is one of the most important chronic inflammatory dental diseases arising from the destructive actions caused by a variety of pathogenic organisms presented in the oral cavity. The aim of this study is the preparation and in vitro evaluation of films for the local treatment of periodontal pockets. Methods: The prepared films contained either metronidazole (Mtr), for its antimicrobial effect in periodontal diseases, using a mixture of polymers namely hydroxypropyl methyl cellulose, Carbopol 934 or locally applied Pentoxifylline (PTX), for its anti-inflammatory activity, using chitosan. All films were prepared using solvent casting technique and were evaluated for their physical characteristics, drug content uniformity, surface pH, swelling behavior, mechanical properties and in vitro release. Further characterization was done on the selected formulations using differential scanning calorimetry and scanning electron microscopy for surface structure. Clinical evaluation tests were also performed. Result: Appropriate physical characteristics and mechanical properties for most formulations and their suitability for periodontal application were observed. In vitro drug release from most films showed a burst release rate for both Mtr and PTX during the first 2 h after which the release rate was markedly decreased. Clinical trials on patients revealed the advantageous use of Mtr and PTX as an adjunct treatment with traditionally used dental techniques. Conclusion: The effectiveness of the co-therapy of either drug could add benefit in the eradication of chronic periodontal hazards.

Combined use of cyclodextrins and hydroxypropylmethylcellulose stearoxy ether (Sangelose®) for the preparation of orally disintegrating tablets of type-2 antidiabetes agent glimepiride

Despite recent advances in the formulation of orally disintegrating tablets (ODTs), the efforts to enhance the swallowing of the drug after disintegration have been limited. In this study, the feasibility of the combined use of cyclodextrins (CyDs) and a functional drug carrier, hydroxypropylmethylcellulose stearoxy ether (Sangelose®) was investigated to improve usability of ODTs. Glimepiride, a potent third generation hypoglycemic agent for type 2 diabetes was used as a model drug, because it is poorly water-soluble and elimination half life is fairly short. The direct compression method was employed for the preparation of glimepiride tablets, containing CyDs and Sangelose®, and various characteristics of the tablets were examined. In the cases of α-CyD and β-CyD, a short disintegration time with an appropriate hardness was obtained, complying with ODT criteria. On the other hand, γ-CyD, HP-β-CyD and HB-β-CyD increased in the hardness and disintegration time of the tablets. The rheological evaluation revealed that CyDs, except γ-CyD, significantly reduced the viscosity of the fluids after disintegration of the tablets, suggesting an ease of swallowing. This was ascribable to the complexation of the hydrophobic stearoyl moiety of Sangelose® with CyDs after dissolution, leading to the inhibition of the polymer–polymer interaction of Sangelose® and to the decrease in viscosity of the solution. The interaction of glimepiride with α- and β-CyDs was studied by the solubility method, demonstrating that glimepiride formed water-soluble complexes with these CyDs. Results obtained here suggested that α-CyD and β-CyD can be particularly useful for the Sangelose®-based ODT formulation, compared to γ-CyD, HP-β-CyD and HB-β-CyD, because of the short disintegration time of the tablets containing α-CyD and β-CyD, their shear-thinning effect on Sangelose® solutions and their solubility enhancing effect on the drug.