Subjective sensitivity to noise and non-auditory health effects among adults in Nis, Serbia.

OBJECTIVE: The aim of this study was to examine subjective sensitivity to noise of the citizens of Nis and its impact on their non-auditory health effects. METHODS: This study was designed as a cross-sectional questionnaire survey among 908 adult residents of Nis, Serbia, of whom 387 were men (42.6%) and 521 women (57.4%). Streets with day Leq ≥ 55 dB(A) and night Leq ≥ 45 dB(A) were regarded as noisy and those with day Leq ≤ 55 dB(A) and night Leq ≤ 45 dB(A) were regarded as quiet, in accordance with WHO recommendations. Noise sensitivity was measured with the Weinstein's Noise Sensitivity Scale. Logistic regression analysis was used to assess the impact of noise sensitivity on non-auditory health effects. RESULTS: The study showed that the values of the Weinstein's Noise Sensitivity Scale were significantly higher for those surveyed in the noisy zone. Multiple regression analysis revealed a significant impact of noise sensitivity on night-sleep duration (p = 0.04), subjective assessment of sleep quality (p < 0.01) and daily rest disruption (p < 0.001). CONCLUSION: Based on the study results, it can be confirmed that noise sensitivity has an important role in causing non-auditory health effects among adults.

Energy and nutritional value of the meals in kindergartens in Nis (Serbia).

BACKGROUND: It is well known that high-energy diet, rich in fat and carbohydrates, increases the risk of obesity. Preschool age is an important period to acquire the eating habits continued later in adulthood. Therefore, evaluation of child nutrition in kindergartens is especially important in the prevention of future obesity. OBJECTIVES: To determine the energy value and energy density of meals consumed by children in kindergartens in Nis (Serbia), including the different types of food, in respect to a probable risk of obesity. MATERIAL AND METHODS: The study had been conducted in the years 1998-2012. Three-hundred samples of the meals were gathered and analysed, and the amount of selected food groups used to prepare the meals in kindergartens was calculated (weight, protein, fat and carbohydrate content) in the accredited laboratory of the Public Health Institute in Nis according to the ISO 17025 recommendation. RESULTS: The mean energy value of meals was 978.9 kcal (range: 810 - 1144 kcal). The energy density was low (mean: 1.02 kcal/g, range: 0.92 - 1.42 kcal/g) and decreased over the years, what would imply a reduction in the risk of obesity. The intake of same high-energy food products, such as fats and oils as well as sweets (13.9% and 7.3%, respectively) was higher compared to low-energy foods (fruits - 5.2% and vegetables - 10.8%). CONCLUSIONS: The results of our study indicate that children in kindergarten in Nis, in general, were properly nourished in total energy content. The energy value and energy density of the meals consumed did not pose a risk of developing obesity. However, the distribution of food groups differentiated by the energy density level was unfavourable; the deficit of low-energy foods was observed. Planning the child nutrition in kindergartens, with laboratory control of meals, may be an effective strategy in adequate energy intake and prevention of obesity. Providing the higher amount of low-energy foods (fruits and vegetables) in meals in kindergartens is recommended.

Citric Acid Cross-Linked Gelatin-Based Composites with Improved Microhardness.

The aim of this study is to investigate the influence of cross-linking and reinforcements in gelatin on the physico-mechanical properties of obtained composites. The gelatin-based composites cross-linked with citric acid (CA) were prepared: gelatin type B (GB) and ß-tricalcium phosphate (ß-TCP) and novel hybrid composite GB with ß-TCP and hydroxyapatite (HAp) particles, and their structure, thermal, and mechanical properties were compared with pure gelatin B samples. FTIR analysis revealed that no chemical interaction between the reinforcements and gelatin matrix was established during the processing of hybrid composites by the solution casting method, proving the particles had no influence on GB cross-linking. The morphological investigation of hybrid composites revealed that cross-linking with CA improved the dispersion of particles, which further led to an increase in mechanical performance. The microindentation test showed that the hardness value was increased by up to 449%, which shows the high potential of ß-TCP and HAp particle reinforcement combined with CA as a cross-linking agent. Furthermore, the reduced modulus of elasticity was increased by up to 288%. Results of the MTT assay on L929 cells have revealed that the hybrid composite GB-TCP-HA-CA was not cytotoxic. These results showed that GB cross-linked with CA and reinforced with different calcium phosphates presents a valuable novel material with potential applications in dentistry.

Hygiene training of food handlers in hospital settings: important factor in the prevention of nosocomial infections.

The aim of this study was to evaluate the effects of food hygiene training of food handlers on sanitary-hygienic conditions in hospital kitchens, based on microbiological analysis of smears taken in hospital kitchens. The study was conducted in the 1995-2009 period at the Clinical Centre Nis, Serbia. The food hygiene training was conducted in February 2005, by an infection control officer. 1,076 smears in the central kitchen and 4,025 smears in distributive kitchens were taken from hands and work clothes, work surfaces, equipment, and kitchen utensils. Microbiological analysis of smears was carried out in an accredited laboratory of the Public Health Institute Nis (Serbia). A significantly lower percentage of smears with isolates of bacteria (p < 0.001) taken from hands and work clothes, work surfaces, equipment and kitchen utensils in the central and distributive kitchens was observed in the period following the food safety education programme (2005-2009). The most commonly isolated bacteria was: Enterobacter spp., Acinetobacter spp., Citrobacter spp., and E. coli. Our results confirmed that food hygiene training improved hygiene and is also an important component for the prevention of nosocomial infection.

Electrospun polycaprolactone nanofibers functionalized with Achillea millefolium extract yield biomaterial with antibacterial, antioxidant and improved mechanical properties.

In this study, polycaprolactone (PCL), as a biocompatible polymer was functionalized by addition of medicinal plant extract- Achillea millefolium L. (yarrow). Nanofiber mats were fabricated from PCL solutions containing dry yarrow extract in four concentrations (5%, 10%, 15%, and 20% relative to the weight of the polymer) by using blend electrospinning method. The nanofibers were characterized for their biological, mechanical and drug release behavior. In vitro release of yarrow polyphenols from the electrospun PCL nanofibers over a period of 5 days showed the release of up to 98% of the total loaded polyphenols. The released polyphenols retained its antioxidant activity, which was determined by DPPH assay. Electrospun PCL/yarrow nanofiber mats exhibited the antibacterial effect against Staphylococcus aureus, but had no effect on the growth of Pseudomonas aeruginosa. All PCL/yarrow nanofiber mats had improved mechanical properties compared to the neat PCL nanofibers, as evident by an increase in Young's modulus of elasticity (up to 5.7 times), the tensile strength (up to 5.5 times), and the strain at break (up to 1.45 times). Based on our results, yarrow-loaded PCL nanofiber mats appeared to be multi-functional biomaterials suitable for the production of catheter-coating materials, patches, or gauzes with antibacterial and antioxidant properties.

Biodegradable Cellulose/Polycaprolactone/Keratin/Calcium Carbonate Mulch Films Prepared in Imidazolium-Based Ionic Liquid.

Ionic liquid 1-butyl-3-methylimidazolium chloride [BMIM][Cl] was used to prepare cellulose (CELL), cellulose/polycaprolactone (CELL/PCL), cellulose/polycaprolactone/keratin (CELL/PCL/KER), and cellulose/polycaprolactone/keratin/ground calcium carbonate (CELL/PCL/KER/GCC) biodegradable mulch films. Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) spectroscopy, optical microscopy, and Field-Emission Scanning Electron Microscopy (FE-SEM) were used to verify the films' surface chemistry and morphology. Mulch film made of only cellulose regenerated from ionic liquid solution exhibited the highest tensile strength (75.3 ± 2.1 MPa) and modulus of elasticity of 944.4 ± 2.0 MPa. Among samples containing PCL, CELL/PCL/KER/GCC is characterized by the highest tensile strength (15.8 ± 0.4 MPa) and modulus of elasticity (687.5 ± 16.6 MPa). The film's breaking strain decreased for all samples containing PCL upon the addition of KER and KER/GCC. The melting temperature of pure PCL is 62.3 °C, whereas that of CELL/PCL film has a slight tendency for melting point depression (61.0 °C), which is a characteristic of partially miscible polymer blends. Furthermore, Differential Scanning Calorimetry (DSC) analysis revealed that the addition of KER or KER/GCC to CELL/PCL films resulted in an increment in melting temperature from 61.0 to 62.6 and 68.9 °C and an improvement in sample crystallinity by 2.2 and 3.0 times, respectively. The light transmittance of all studied samples was greater than 60%. The reported method for mulch film preparation is green and recyclable ([BMIM][Cl] can be recovered), and the inclusion of KER derived by extraction from waste chicken feathers enables conversion to organic biofertilizer. The findings of this study contribute to sustainable agriculture by providing nutrients that enhance the growth rate of plants, and hence food production, while reducing environmental pressure. The addition of GCC furthermore provides a source of Ca2+ for plant micronutrition and a supplementary control of soil pH.

The Structuring of Sage (Salvia officinalis L.) Extract-Incorporating Edible Zein-Based Materials with Antioxidant and Antibacterial Functionality by Solvent Casting versus Electrospinning.

In this study, in order to develop zein-based, edible, functional food-contact materials in different forms incorporating sage extract (10, 20, and 30%), solvent casting and electrospinning were employed. The study aimed to assess the effects of the applied techniques and the extract's incorporation on the materials' properties. The solvent casting generated continuous and compact films, where the extract's incorporation provided more homogenous surfaces. The electrospinning resulted in non-woven mats composed of ribbon-like fibers in the range of 1.275-1.829 µm, while the extract's incorporation provided thinner and branched fibers. The results indicated the compatibility between the materials' constituents, and efficient and homogenous extract incorporation within the zein matrices, with more probable interactions occurring during the solvent casting. All of the formulations had a high dry matter content, whereas the mats and the formulations incorporating the extract had higher solubility and swelling in water. The films and mats presented similar DPPH• and ABTS•+ radical scavenging abilities, while the influence on Staphylococcus aureus and Salmonella enterica subsp. enterica serovar Typhimurium bacteria, and the growth inhibition, were complex. The antioxidant and antibacterial activity of the materials were more potent after the extract's incorporation. Overall, the results highlight the potential of the developed edible materials for use as food-contact materials with active/bioactive functionality.

Modification of CaCO3 and CaCO3 pin-coated cellulose paper under supercritical carbon dioxide-ethanol mixture for enhanced NO2 capture.

In this work, we examine two modifications of fine-ground calcium carbonate material (GCC) in order to enhanced sorption of NO2 and subsequent reaction properties toward NO2-/NO3- formation by firstly exposing the GCC to supercritical (sc) CO2 in order to increase particle surface area, a choice specifically made to avoid altering the surface chemistry, and secondly considering the potential advantage of using a surface coupling agent toward NO2. The modification by the coupling agent amino silane (AMEO silane) was applied in a supercritical CO2-ethanol mixture. The samples were characterised before and after modification by field emission scanning electron microscopy (FESEM), specific surface area determination (BET nitrogen adsorption), ATR-FTIR spectroscopy and ion chromatography to reveal the effects of the surface modification(s) on the morphology, surface textural properties and sorption versus reaction properties with NO2. The performance of the treated sorbents for NO2 capture was evaluated at room temperature. Results show that reactivity of NO2 with GCC was observed to increase as a function of increased surface area resulting from scCO2 exposure, but that the presence of AMEO silane on the surface, while enhancing initial adsorption of NO2 was seen subsequently to act to block reactivity. Thus, judicious use of coupling agent can provide desired rapid initial adsorption of the gas, but the goal of long-term CaCO3-consuming reactivity, so as to prolong the uptake of NO2 beyond surface saturation alone, is achieved by increasing surface area while retaining chemical-free exposed CaCO3 surface.

Phosphonate-Modified Cellulose Nanocrystals Potentiate the Th1 Polarising Capacity of Monocyte-Derived Dendritic Cells via GABA-B Receptor.

Purpose: Phosphonates, like 3-AminoPropylphosphonic Acid (ApA), possess a great potential for the therapy of bone tumours, and their delivery via cellulose nanocrystals (CNCs) seems a promising approach for their increased efficacy in target tissues. However, the immunological effects of CNC-phosphonates have not been investigated thoroughly. The main aim was to examine how the modification of CNCs with phosphonate affects their immunomodulatory properties in human cells. Methods: Wood-based native (n) CNCs were modified via oxidation (ox-CNCs) and subsequent conjugation with ApA (ApA-CNCs). CNCs were characterised by atomic force microscopy (AFM) and nanoindentation. Cytotoxicity and immunomodulatory potential of CNCs were investigated in cultures of human peripheral blood mononuclear cells (PBMCs) and monocyte-derived dendritic cells (MoDCs)/T cells co-cultures by monitoring phenotype, cytokines production, allostimulatory and Th/Treg polarisation capacity. Results: AFM showed an increase in CNCs' thickens, elasticity modulus and hardness during the modification with ApA. When applied at non-toxic doses, nCNCs showed a tolerogenic potential upon internalisation by MoDCs, as judged by their increased capacity to up-regulate tolerogenic markers and induce regulatory T cells (Treg), especially when present during the differentiation of MoDCs. In contrast, ox- and ApA-CNCs induced oxidative stress and autophagy in MoDCs, which correlated with their stimulatory effect on the maturation of MoDCs, but also inhibition of MoDCs differentiation. ApA-CNC-treated MoDCs displayed the highest allostimulatory and Th1/CTL polarising activity in co-cultures with T cells. These effects of ApA-CNCs were mediated via GABA-B receptor-induced lowering of cAMP levels in MoDCs, and they could be blocked by GABA-B receptor inhibitor. Moreover, the Th1 polarising and allostimulatory capacity of MoDCs differentiated with ApA-CNC were largely preserved upon the maturation of MoDCs, whereas nCNC- and ox-CNC-differentiated MoDCs displayed an increased tolerogenic potential. Conclusion: The delivery of ApA via CNCs induces potent DC-mediated Th1 polarisation, which could be beneficial in their potential application in tumour therapy.

Estimated daily intake of benzoic acid through food additives in adult population of South East Serbia.

The aim of this study is to estimate dietary intake of benzoic acid and its salts through food additives in adult population of South East Serbia. Information on dietary intake among 620 adults (aged 18-65) was collected using a food frequency questionnaire, and 748 food samples were analyzed. The mean estimated intake of benzoic acid -0.32 mg/kg of body weight (bw) per day was below acceptable daily intake (ADI). Dietary exposure to benzoic acid (0.36 mg/kg of bw/day; 7.2% ADI) (consumer only), also did not exceed ADI. The main contributors of benzoic acid to dietary intake were non alcoholic beverages (43.1%), ketchup and tomato products (36.1%), and domestic pickled vegetables (19.4%). The results of this study indicate that dietary exposure to benzoic acid and its salts through food preservatives does not represent a public health risk for the adult population of South East Serbia.

3D Printed Buccal Films for Prolonged-Release of Propranolol Hydrochloride: Development, Characterization and Bioavailability Prediction.

Gelatin-polyvinylpyrrolidone (PVP) and gelatin-poly(vinyl alcohol) (PVA) mucoadhesive buccal films loaded with propranolol hydrochloride (PRH) were prepared by semi-solid extrusion 3D printing. The aim of this study was to evaluate the effects of the synthetic polymers PVP and PVA on thermal and mechanical properties and drug release profiles of gelatin-based films. The Fourier-transform infrared spectroscopy showed that hydrogen bonding between gelatin and PVP formed during printing. In the other blend, neither the esterification of PVA nor gelatin occurred. Differential scanning calorimetry revealed the presence of partial helical structures. In line with these results, the mechanical properties and drug release profiles were different for each blend. Formulation with gelatin-PVP and PRH showed higher tensile strength, hardness, and adhesive strength but slower drug release than formulation with gelatin-PVA and PRH. The in silico population simulations indicated increased drug bioavailability and decreased inter-individual variations in the resulting pharmacokinetic profiles compared to immediate-release tablets. Moreover, the simulation results suggested that reduced PRH daily dosing can be achieved with prolonged-release buccal films, which improves patient compliance.

Mucoadhesive Gelatin Buccal Films with Propranolol Hydrochloride: Evaluation of Mechanical, Mucoadhesive, and Biopharmaceutical Properties.

This study processes and characterizes propranolol hydrochloride/gelatin mucoadhesive buccal films. Two types of gelatin are used: Gelatin from porcine skin, type A (GA), and gelatin from bovine skin (GB). The influence of gelatin type on mechanical, mucoadhesive, and biopharmaceutical characteristics of buccal films is evaluated. Fourier-Transfer infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) analysis show that GA with propranolol hydrochloride (PRH) in the film (GAP) formed a physical mixture, whereas GB with PRH (GBP) form a compound-complex. Results of mechanical testing (tensile test, hardness) revealed that GAP films exhibit higher elastic modulus, tensile strength, and hardness. A mucoahesion test shows that GBP has higher adhesion strength, while GAP shows higher work of adhesion. Both in vitro release study and in silico simulation indicated that processed films can provide effective drug transport through the buccal mucosa. In silico simulation shows improved bioavailability from buccal films, in comparison to the immediate-release tablets-indicating that the therapeutic drug dose can be markedly reduced.

Tetragonal CoMn2O4 nanocrystals on electrospun carbon fibers as high-performance battery-type supercapacitor electrode materials.

We herein report a simple two-step procedure for fabricating tetragonal CoMn2O4 spinel nanocrystals on carbon fibers. The battery-type behavior of these composite fibers arises from the redox activity of CoMn2O4 in an alkaline aqueous solution, which, in combination with the carbon fibers, endows good electrochemical performance and long-term stability. The C@CoMn2O4 electrode exhibited high specific capacity, up to 62 mA h g-1 at 1 A g-1 with a capacity retention of around 90% after 4000 cycles. A symmetrical coin-cell device assembled with the composite electrodes delivered a high energy density of 7.3 W h kg-1 at a power density of 0.1 kW kg-1, which is around 13 times higher than that of bare carbon electrodes. The coin cell was cycled for 5000 cycles with 96.3% capacitance retention, at a voltage of up to 0.8 V, demonstrating excellent cycling stability.

Arginase activity in human milk during the first month of lactation.

Arginase (L-arginine amidinohydrolase, EC 3.5.3.1) is the key enzyme in urea synthesis, hydrolyzing L-arginine into L-ornithine and urea. Arginase modulates levels of nitric oxide, creatine, and creatinine, likely by regulating intracellular L-arginine availability. The objective of the present study was to determine the arginase activity and concentration of urea and creatinine in colostrum and mature human milk obtained from nursing mothers. Our longitudinal biochemical analyses show that arginase activities and urea concentrations were the highest at the first day of lactation (colostrum). The decreasing enzyme activity and urea start at the second day, remaining at this level until the end of the first month of lactation (30th day). The concentration of creatinine in human colostrum and mature milk did not significantly change. The alteration of arginase activity between colostrum and mature milk may be a consequence of the transfer of arginase from the blood of the breast mother mammary glands into the colostrum and mature milk. The concentration of nutrients in colostrum and mature milk undergo alterations, probably to satisfy the requirements of the nursing infant for arginine, essential amino acids for human body growth, and normal physiology.

Preparation and modeling of three-layered PCL/PLGA/PCL fibrous scaffolds for prolonged drug release.

The authors present the preparation procedure and a computational model of a three-layered fibrous scaffold for prolonged drug release. The scaffold, produced by emulsion/sequential electrospinning, consists of a poly(D,L-lactic-co-glycolic acid) (PLGA) fiber layer sandwiched between two poly(ε-caprolactone) (PCL) layers. Experimental results of drug release rates from the scaffold are compared with the results of the recently introduced computational finite element (FE) models for diffusive drug release from nanofibers to the three-dimensional (3D) surrounding medium. Two different FE models are used: (1) a 3D discretized continuum and fibers represented by a simple radial one-dimensional (1D) finite elements, and (2) a 3D continuum discretized by composite smeared finite elements (CSFEs) containing the fiber smeared and surrounding domains. Both models include the effects of polymer degradation and hydrophobicity (as partitioning) of the drug at the fiber/surrounding interface. The CSFE model includes a volumetric fraction of fibers and diameter distribution, and is additionally enhanced by using correction function to improve the accuracy of the model. The computational results are validated on Rhodamine B (fluorescent drug l) and other hydrophilic drugs. Agreement with experimental results proves that numerical models can serve as efficient tools for drug release to the surrounding porous medium or biological tissue. It is demonstrated that the introduced three-layered scaffold delays the drug release process and can be used for the time-controlled release of drugs in postoperative therapy.

The impact of malnutrition on mortality in patients on maintenance hemodialysis in Serbia.

Numerous studies suggest a strong association between nutrition and clinical outcome in chronic hemodialysis (HD) patients. While determination of malnutrition is often based on objective measurements, such as biochemical parameters and anthropometric data, there is no single measurement that can reliably predict the risk for malnutrition or poor outcome. The aim of the present investigation was to determine the prevalence and severity of malnutrition among HD patients in a large university-affiliated HD center in Serbia, and to examine the relationship between various nutritional and nonnutritional factors, and the clinical outcome in the period of 20 months follow-up. The prospective observational cohort study included patients (n = 197) with more than 3 months on HD treatment before entering the study. Global nutritional status was evaluated by the dialysis malnutrition score (DMS). Body mass index (BMI), triceps skinfold thickness (TSF), mid-arm circumference (MAC), and mid-arm muscle circumference (MAMC), as well as several laboratory parameters and clinical examination, were recorded. Dose of HD and protein equivalence of nitrogen appearance normalized to ideal body weight (nPNA) were evaluated by the urea kinetic model. Mortality data were collected prospectively during the 20 months of follow-up. A moderate/severe degree of malnutrition was presented in 39.2% of female and 22.8% of male patients, while signs of mild malnutrition existed in 45.5% and 66.9% of patients, respectively. Kaplan-Meier survival analysis showed that in the entire group of patients with DMS score >10, the mortality rate was higher (log rank 5.61; P < 0.05) than in those with DMS score

Body Mass Index and the Literacy on Obesity in Relation to Media Following.

BACKGROUND: The aim of this study was to investigate the effects of TV, magazines, radio, and internet following on body mass index (BMI) and obesity-related literacy among adults. METHODS: In this cross-sectional study, the subjects were recruited from an outpatient center in the city of Sombor, Serbia during Mar-Apr 2013. We collected data by a questionnaire from 657 (397 women; 59%) subjects, aged from 18 to 87 yr (Mean = 45; SD =14). The questionnaire consisted of personal data, body height and weight, frequency of television, radio, magazines and internet following and personal opinion on the impact of smoking, alcohol consumption, stress and physical inactivity on obesity. RESULTS: Spearman's rank correlation analysis showed that BMI increased with longer TV viewing with a very weak strength of the correlation (r=0.104; P=0.009) and decreased with more internet following with a weak strength of the correlation (r=-0.200: P<0.001). Multiple linear regression analysis revealed that only internet use had a significant independent effect on BMI. The frequency rise of internet following from "rare" to "often" and "every day" decreased BMI by 0.5 per each grade. Internet followers showed a significantly better knowledge of the importance of smoking (P = 0.003), alcohol consumption (P<0.001) and physical inactivity (P=0.004) for obesity in comparison to non-followers. CONCLUSION: Internet is the only media that independently and positively influence weight control and the literacy on obesity among adults.

A Computational Model for Drug Release from PLGA Implant.

Due to the relative ease of producing nanofibers with a core⁻shell structure, emulsion electrospinning has been investigated intensively in making nanofibrous drug delivery systems for controlled and sustained release. Predictions of drug release rates from the poly (d,l-lactic-co-glycolic acid) (PLGA) produced via emulsion electrospinning can be a very difficult task due to the complexity of the system. A computational finite element methodology was used to calculate the diffusion mass transport of Rhodamine B (fluorescent drug model). Degradation effects and hydrophobicity (partitioning phenomenon) at the fiber/surrounding interface were included in the models. The results are validated by experiments where electrospun PLGA nanofiber mats with different contents were used. A new approach to three-dimensional (3D) modeling of nanofibers is presented in this work. The authors have introduced two original models for diffusive drug release from nanofibers to the 3D surrounding medium discretized by continuum 3D finite elements: (1) A model with simple radial one-dimensional (1D) finite elements, and (2) a model consisting of composite smeared finite elements (CSFEs). Numerical solutions, compared to experiments, demonstrate that both computational models provide accurate predictions of the diffusion process and can therefore serve as efficient tools for describing transport inside a polymer fiber network and drug release to the surrounding porous medium.

Cefazolin-loaded polycaprolactone fibers produced via different electrospinning methods: Characterization, drug release and antibacterial effect.

Antibiotic containing polycaprolactone (PCL) fibers were produced by using three electrospinning methods: blend, emulsion and co-axial electrospinning (labeled as S1, S2 and S3, respectively). The profiles of drug release from three different systems were studied and antimicrobial properties of produced materials were evaluated. Morphology of the produced fibers was characterized and revealed that cefazolin-loaded PCL fibers had smaller diameter compared to neat PCL fibers, while the chemical interaction between the antibiotic and PCL showed that cefazolin neither had reacted with PCL phase, nor had degraded during the electrospinning process. The crystallinity and thermal characterization of fabricated fibers showed that the addition of cefazolin decreased the crystallinity of PCL. The results of the drug release behavior of the blend and co-axial electrospun fibers was on a higher level (~68% and ~43%, respectively) compared to the emulsion electrospun fibers (~5%), after a period of 30 days. The obtained data had the best fitting with the first order model and the Higuchi model, while the Korsmeyer-Peppas model showed a Pseudo-Fickian diffusion of the drug. Antibacterial evaluations showed that cefazolin-loaded PCL fibers had better effects on Staphylococcus aureus compared to Escherichia coli during the treatment period and that the effect of the emulsion fibers was notably weaker than the other two studied systems. The aim of the study was to test different systems for control drug release of different dynamics, which will be applied for prevent bacterial accumulation when indwelling urinary catheters, applied for different periods of time.

Formulation and characterization of nanofibers and films with carvedilol prepared by electrospinning and solution casting method.

The preparation and characterization of films and nanofibers with carvedilol as a poorly water-soluble drug in poly (ethylene oxide) (PEO) polymer were investigated. Films are prepared by solution casting method, and nanofibers by electrospinning from a polymer solution. Water and mixture of ethanol and water were used as solvents. FT-IR analysis of the samples showed that there was no interaction between the polymer and the drug substance. DSC analysis revealed that carvedilol was dissolved in the polymer and influenced the degree of crystallinity of PEO. Carvedilol release rate for all of the formulations was increased in comparison with pure carvedilol. Significant differences in the rate of release of carvedilol from the films and nanofibers were observed. Field Emission Scanning Electron Microscope (FESEM) images of the obtained fiber was revealed the dependence of the fiber diameter of formulation and electrospinning process parameters, and consequently influence the amount and distribution of carvedilol in the encapsulated fibers.