Topical nano-delivery of 5-fluorouracil: Preparation and characterization of water-in-oil nanoemulsion

Purpose: To prepare and characterize a water-in-oil nanoemulsion of 5-fluorouracil (5FU) for enhanced skin penetration.Methods: Nanoemulsions of 5FU were prepared using Capyrol (propylene glycol monocaprylate). Transcutol (highly purified diethylene glycol monoethyl ether) and polyethylene glycol (PEG) 400 as oil, surfactant and co-surfactant, respectively. The optimized formulations were subjected to heating - cooling cycling, centrifugation and freeze - thaw cycling to assess their stability. Particle size distribution and zeta potential of the nanoemulsions were evaluated. Furthermore, in vitro and in vivo skin permeation studies were carried out on the formulations in a rat model. Skin irritation studies were also performed on rats to assess the irritation potential of the formulations. The 1 % w/v of Carbopol 934 gel loaded with 1 % 5FU was used as control (FU gel).Results: The results showed that the mean droplet size of the nanoemulsions was ~100 nm with a zeta potential of ± 15. Significant increase in permeability was also observed for the nanoemulsion formulations compared with control. The steady-state flux (Jss), enhancement ratio and permeability coefficient (Kp) for optimized nanoemulsion formulation were significantly (p < 0.05) higher than those of the conventional gel (control). Both in vitro and in vivo skin retention results indicate higher drug release from the nanoemulsion (292.45 μg/cm2) than for control (121.42 μg/cm2). Mean irritation index for the nanoemulsion was significantly lower than for control.Conclusion: The results suggest that a water-in-oil nanoemulsion is safe and can potentially be used to promote skin penetration of 5FU following topical application on the skin for the treatment of some skin diseases.Keywords: Nanoemulsion, Controlled release, 5-Fluorouracil, Skin penetration, Skin irritatio

Modulation of glucose transporter proteins by polyphenolic extract of Ichnocarpus frutescens (L.) W. T. Aiton in experimental type 2 diabetic rats

172-180Traditionally, in India, the decoction of Black creeper, Ichnocarpus frutescens (L.) W. T. Aiton leaves is used to treatment diabetes mellitus. However, its molecular mechanisms of antihyperglycemic effects have not been completely studied. Due to the potential antidiabetic effect of I. frutescens, we hypothesized that the polyphonic extract might add to glucose uptake through improvement in the expression of genes of the glucose transporter (GLUT) family messenger RNA (mRNA) in the liver and adipose tissues. Experimentally, diabetes mellitus was induced in Wistar rats through i.p. injection of freshly prepared solution of streptozotocin (45 mg/kg). This was done 15 minutes after the administration of nicotinamide (120 mg/kg, ip). Serum level of insulin and C-peptide were analyzed using standard methods. Glucose metabolism by the hepatocytes and adipocytes were also analyzed by quantitative RT-PCR mRNA expression levels of phosphoenolpyruvate carboxykinase 1 (PCK1), GLUT2 in the hepatocytes, and GLUT4 in the adipocytes. The hemidiaphragm were also isolated and processed to study in-vitro peripheral glucose utilization. Results of the present investigation suggest that STZ-NA induced diabetes is associated with hyperglycemia, altered levels of PCK1 and glucose transporters gene expression as well as decreased levels of insulin and C-peptide. On the other hand, the outcome of the daily oral administration of PPE to STZ-NA induced diabetic rats at different doses (150 and 300 mg/kg bodywt.) for 30 days supports our hypothesis by showing significant improvement of insulin levels, C-peptide level, downregulation of PCK1 and upregulation of GLUT (2, 4) mRNA expression levels when compared to those of diabetic rats. The administration of PPE had also increased the uptake of glucose by rat hemidiaphragm significantly. Findings from this study demonstrate that PPE enhances peripheral glucose uptake through glycogenesis pathway, mediated by upregulation of GLUT2 and GLUT4, and downregulation of PCK1. Our study suggests that the leaf of I. frutescens is a rich source of polyphenolic compounds, including those with an insulin-sensitizing function that may have the potential for treating or managing diabetes or insulin resistance

Electrospun Biomimetic Nanofibrous Scaffolds: A Promising Prospect for Bone Tissue Engineering and Regenerative Medicine

Skeletal-related disorders such as arthritis, bone cancer, osteosarcoma, and osteoarthritis are among the most common reasons for mortality in humans at present. Nanostructured scaffolds have been discovered to be more efficient for bone regeneration than macro/micro-sized scaffolds because they sufficiently permit cell adhesion, proliferation, and chemical transformation. Nanofibrous scaffolds mimicking artificial extracellular matrices provide a natural environment for tissue regeneration owing to their large surface area, high porosity, and appreciable drug loading capacity. Here, we review recent progress and possible future prospective electrospun nanofibrous scaffolds for bone tissue engineering. Electrospun nanofibrous scaffolds have demonstrated promising potential in bone tissue regeneration using a variety of nanomaterials. This review focused on the crucial role of electrospun nanofibrous scaffolds in biological applications, including drug/growth factor delivery to bone tissue regeneration. Natural and synthetic polymeric nanofibrous scaffolds are extensively inspected to regenerate bone tissue. We focused mainly on the significant impact of nanofibrous composite scaffolds on cell adhesion and function, and different composites of organic/inorganic nanoparticles with nanofiber scaffolds. This analysis provides an overview of nanofibrous scaffold-based bone regeneration strategies; however, the same concepts can be applied to other organ and tissue regeneration tactics

Multifunctional Biomimetic Nanofibrous Scaffold Loaded with Asiaticoside for Rapid Diabetic Wound Healing

Diabetes mellitus is a chronic disease with a high mortality rate and many complications. A non-healing diabetic foot ulcer (DFU) is one the most serious complications, leading to lower-extremity amputation in 15% of diabetic patients. Nanofibers are emerging as versatile wound dressing due to their unique wound healing properties, such as a high surface area to volume ratio, porosity, and ability to maintain a moist wound environment capable of delivering sustained drug release and oxygen supply to a wound. The present study was aimed to prepare and evaluate a polyvinyl alcohol (PVA)–sodium alginate (SA)–silk fibroin (SF)-based multifunctional nanofibrous scaffold loaded with asiaticoside (AT) in diabetic rats. The SEM findings showed that fibers’ diameters ranged from 100–200 nm, and tensile strengths ranged from 12.41–16.80 MPa. The crosslinked nanofibers were sustained AT over an extended period. The MTT and scratch assay on HaCat cells confirmed low cytotoxicity and significant cell migration, respectively. Antimicrobial tests revealed an excellent anti-microbial efficacy against P. aeruginosa and S. aureus bacteria. In-vivo study demonstrated better wound healing efficacy in diabetic rats. In addition, the histopathological studies showed its ability to restore the normal structure of the skin. The present study concluded that developed multifunctional nanofibers have a great potential for diabetic wound healing applications

Correction: Chitosan-propolis nanoparticle formulation demonstrates anti-bacterial activity against Enterococcus faecalis biofilms.

[This corrects the article DOI: 10.1371/journal.pone.0174888.]

Chitosan-propolis nanoparticle formulation demonstrates anti-bacterial activity against Enterococcus faecalis biofilms.

Propolis obtained from bee hives is a natural substance with antimicrobial properties. It is limited by its insolubility in aqueous solutions; hence ethanol and ethyl acetate extracts of Malaysian propolis were prepared. Both the extracts displayed antimicrobial and anti-biofilm properties against Enterococcus faecalis, a common bacterium associated with hospital-acquired infections. High performance liquid chromatography (HPLC) analysis of propolis revealed the presence of flavonoids like kaempferol and pinocembrin. This study investigated the role of propolis developed into nanoparticles with chitosan for its antimicrobial and anti-biofilm properties against E. faecalis. Bacteria that grow in a slimy layer of biofilm are resistant to penetration by antibacterial agents. The use of nanoparticles in medicine has received attention recently due to better bioavailability, enhanced penetrative capacity and improved efficacy. A chitosan-propolis nanoformulation was chosen based on ideal physicochemical properties such as particle size, zeta potential, polydispersity index, encapsulation efficiency and the rate of release of the active ingredients. This formulation inhibited E. faecalis biofilm formation and reduced the number of bacteria in the biofilm by ~90% at 200 μg/ml concentration. When tested on pre-formed biofilms, the formulation reduced bacterial number in the biofilm by ~40% and ~75% at 200 and 300 μg/ml, respectively. The formulation not only reduced bacterial numbers, but also physically disrupted the biofilm structure as observed by scanning electron microscopy. Treatment of biofilms with chitosan-propolis nanoparticles altered the expression of biofilm-associated genes in E. faecalis. The results of this study revealed that chitosan-propolis nanoformulation can be deemed as a potential anti-biofilm agent in resisting infections involving biofilm formation like chronic wounds and surgical site infections

Percentage survival of bacteria in biofilm and planktonic form.

<p>Graphs describing the percentage survival of bacteria present in the biofilms (A and C) or in planktonic form (B and D) either co-treated (A and B) or pre-formed biofilm treated (C and D) with propolis Eth extract, EA extract or chitosan-propolis nanoparticle formulation F1. Graph depicting percentage survival of biofilm bacteria treated with pure pinocembrin or propolis Eth extract containing equivalent amount of pinocembrin (E).</p

Rate of release of propolis from the formulation.

<p>Graph depicting the rate of release of propolis from the ethanol extract versus chitosan-propolis nanoparticles measured over 48 hours. Abbreviations: Propolis Eth: Propolis ethanol extract.</p