Formulation and evaluation of silver nanoparticles as antibacterial and antifungal agents with a minimal cytotoxic effect

Preparation of non-biodegradable nonoparticles is a fast growing field,which is vital in both nanomedicine and nanotechnology applications.In this investigation, our attention will be focused on the preparationand evaluation of colloidal silver nanoparticles as antibacterial andantifungal agents. The colloidal silver nanoparticles have beenprepared employing standard chemical reduction methods. Thecolloidal silver nanoparticles were characterized using transmissionelectron microscopy TEM, zeta potential, photo correlationspectroscopy PCS, and in vitro release kinetics. The particles thusobtained were spherical in shape and having an average particles sizeof 5-20 nm , zeta potentials of -25.5 to -38.3 mV, and the releasekinetics was following zero order kinetics with r2>0.96. Thedissolution data indicates that the release of the silver nanoparticles isinversely correlated with the size of the nanoparticles i.e. the releaseincreased with smaller particles. The results suggest that the Ag NPswould be stable in the pharmaceutical preparations and will be easilyto the infection site. The colloidal silver nanoparticles were found tobe very efficient antibacterial agents for different types of bacteria.The bacteria studied were namely: E. coli, S. coccus, Salmonellae, andP. aeruginosa. The associated antifungal effects were also investigatedfor Aspergillus and Pencillium. . Cytotoxicity of the nanoparticle wasstudied using human fibroblast cell line. It was concluded thatcytotoxicity is concentrations dependant. The results provided strongevidence that could warrant the consideration of silver nanoparticles asantibacterial and antifungal agent that could circumvent the side andpassive effects of the conventional antibiotics.Keywords: Silver nanoparticles, antibacterial, antifungal, cytotoxicity, micro-plate assay, release kinetics

Nanosized rods agglomerates as a new approach for formulation of a dry powder inhaler

HF Salem1 ME Abdelrahim2 K Abo Eid3 MA Sharaf3,41Department of Pharmaceutics, 2Department of Clinical Pharmacy, Faculty of Pharmacy, The University of Beni Suef, Beni Suef; 3Department of Chemistry, Helwan University, Ain Helwan, Helwan, Egypt; 4Department of Chemistry, The American University in Cairo, New Cairo, Helwan 11835, EgyptBackground: Nanosized dry powder inhalers provide higher stability for poorly water-soluble drugs as compared with liquid formulations. However, the respirable particles must have a diameter of 1–5 µm in order to deposit in the lungs. Controlled agglomeration of the nanoparticles increases their geometric particle size so they can deposit easily in the lungs. In the lungs, they fall apart to reform nanoparticles, thus enhancing the dissolution rate of the drugs. Theophylline is a bronchodilator with poor solubility in water.Methods: Nanosized theophylline colloids were formed using an amphiphilic surfactant and destabilized using dilute sodium chloride solutions to form the agglomerates.Results: The theophylline nanoparticles thus obtained had an average particle size of 290 nm and a zeta potential of −39.5 mV, whereas the agglomerates were 2.47 µm in size with a zeta potential of −28.9 mV. The release profile was found to follow first-order kinetics (r2 > 0.96). The aerodynamic characteristics of the agglomerated nanoparticles were determined using a cascade impactor. The behavior of the agglomerate was significantly better than unprocessed raw theophylline powder. In addition, the nanoparticles and agglomerates resulted in a significant improvement in the dissolution of theophylline.Conclusion: The results obtained lend support to the hypothesis that controlled agglomeration strategies provide an efficient approach for the delivery of poorly water-soluble drugs into the lungs.Keywords: theophylline, nanoparticles, agglomerates, dry powder inhale

Effects of low dose of aliskiren on isoproterenol-induced acute myocardial infarction in rats

This study examined the effects of aliskiren (Ali) (direct renin inhibitor) on serum cardiac enzymes (LDH and CK-MB), electrocardiography (ECG) changes, myocardial oxidative stress markers (MDA, CAT, and GSH) and the expression of Bcl2, HO-1, and Nrf2 genes in isoproterenol (ISO)-induced myocardial infarction (MI). A total of 40 male albino rats were allocated into four groups, (1) normal control (NC) group, (2) Ali group (rats received Ali at 10 mg/kg/day p.o. for 5 days), (3) ISO group (rats received ISO 150 mg/kg i.p. for two consecutive days at 24 h intervals), and (4) Ali + ISO group (rats received ISO + Ali at 10 mg/kg/day p.o. for 5 days from the 2nd dose of ISO). ISO group showed significant rise in serum cardiac enzymes (CK-MB and LDH), myocardial damage scores, myocardial MDA, HO-1, myocardial Nrf2 expression with significant reduction in myocardial antioxidants (CAT and GSH), and Bcl2 expression compared to the normal group (p < 0.05). ECG showed ST segment elevation, prolonged QT interval and QRS complex, and increased heart rate in ISO group. Co-administration of Ali and ISO caused significant increase in cardiac enzymes and morphology with increase in MDA, serum K, and creatinine with significant decrease in Bcl2, HO-1, and Nrf2 without significant changes in ECG parameters compared to ISO group. We concluded that low dose of Ali seems to exacerbate the myocardial injury in ISO-MI, which might be due to the enhanced oxidative stress and apoptosis

State of the Art Review: Emerging Therapies: The Use of Insulin Sensitizers in the Treatment of Adolescents with Polycystic Ovary Syndrome (PCOS)

PCOS, a heterogeneous disorder characterized by cystic ovarian morphology, androgen excess, and/or irregular periods, emerges during or shortly after puberty. Peri- and post-pubertal obesity, insulin resistance and consequent hyperinsulinemia are highly prevalent co-morbidities of PCOS and promote an ongoing state of excess androgen. Given the relationship of insulin to androgen excess, reduction of insulin secretion and/or improvement of its action at target tissues offer the possibility of improving the physical stigmata of androgen excess by correction of the reproductive dysfunction and preventing metabolic derangements from becoming entrenched. While lifestyle changes that concentrate on behavioral, dietary and exercise regimens should be considered as first line therapy for weight reduction and normalization of insulin levels in adolescents with PCOS, several therapeutic options are available and in wide use, including oral contraceptives, metformin, thiazolidenediones and spironolactone. Overwhelmingly, the data on the safety and efficacy of these medications derive from the adult PCOS literature. Despite the paucity of randomized control trials to adequately evaluate these modalities in adolescents, their use, particularly that of metformin, has gained popularity in the pediatric endocrine community. In this article, we present an overview of the use of insulin sensitizing medications in PCOS and review both the adult and (where available) adolescent literature, focusing specifically on the use of metformin in both mono- and combination therapy