POLYMERIC SCAFFOLDS FOR TISSUE ENGINEERING APPLICATIONS

Polymeric materials are commonly used for many purposes in Tissue Engineering Applications. In particular, they are used as scaffolds which are specially prepared in cell growth studies as well as drug loading and release systems. In drug delivery and controlled release systems functional, scaffolds are widely used in order to send the drug to its target region. On the other hand, in cell growth systems patterned polymeric scaffolds are prepared and used to allow the cells to grow at a certain region with a particular form. For this purpose, different techniques are used for the adhesion of cells onto the material surfaces. In this study, patterned scaffolds from various polymers as Polymethylacrylate (PAM), Polystyrene (PS) and polyvinylchloride (PVC) were prepared using micro contact printing with the soft Lithographic Technique. The prepared materials were morphologically analyzed and cell growth was followed by using electron scanning microscope (SEM). Poly (dimethylsiloxane) (PDMS) molds were prepared in different shapes and used as stamp materials to transfer the designed patterns. The cell growth on these patterned surfaces was followed after seeding L929 mouse fibroblasts cells. Neutral Red Uptake Assay was applied to observe cell growth. The cell growth experiments showed that the cells were attached to the patterned surfaces and a significant increase in cell growth on the surfaces were observed

FABRICATION OF TEMPERATURE AND pH SENSITIVE BIOPOLYMER/CLAY BIOCOMPOSITE AS DRUG CARRIER FOR RANITIDINE – HCl

The scientific studies on drug delivery systems that transport drugs to the targeted tissues, at a certain rate and desired time intervals, have gained popularity. The main goal of the drug delivery and release systems is to maintain the drug level in the blood plasma by balancing the amount of active ingredient. In this study, pH and temperature sensitive drug carriers were prepared using chitosan as a biopolymer and clay as a natural material. The characterization of the prepared materials was performed for structural analysis by FT-IR and for morphological analysis by SEM instruments. The swelling properties of the prepared materials were investigated. In this work, Ranitidine-HCl was used as a model drug. The prepared drug carriers were first loaded with Ranitidine-HCl and release properties of the materials were investigated at two different temperatures (25oC, 37oC) and various pH medium. The data obtained from the experiments indicated that the maximum release of Ranitidine–HCl from the prepared sample was observed at pH=7,6 buffer solution at both temperatures by comparing buffer solutions. It has been shown that the materials prepared in this study are suitable carriers for the Ranitidine-HCl drug active ingredient

Strukturiranje i primena materijala na osnovu biopolimera hitozana

Derived from chitin, chitosan is a unique biopolymer that exhibits, beside biocompatibility and biodegradability, outstanding adsorption properties. The layer-by-layer (LBL) deposition technique is based on the alternated adsorption of materials bearing complementary charged or functional groups, in aqueous medium. As a consequence of the polycationic nature of chitosan, chitosan-based films can be used as sensors, drug delivery systems and in tissue engineering. The goal of work was to obtain innovative nano-composites beads based on hitosan, alginate and iron-oxide prepared using LBL deposition method, as magnetic adsorbents used for the separation of dyes from solutions and suspensions.Hitozan je jedinstveni biopolimer koji, pored biokompatibilnosti i biodegradabilnosti, pokazuje i odlična adsorpciona svojstva. Sloj po sloj tehnika (layer-by-layer, (LBL)) se zasniva na naizmeničnoj adsorpciji materijala sa komplementarno naelektrisanim ili funkcionalnim grupama, u vodenoj sredini. Polikatjonska priroda hitozana omogućava njihovu primenu u LBL procesima, i zbog toga se filmovi na osnovu hitozana koriste kao senzori, nosači lekova i u inženjerstvu tkiva. Cilj rada je strukturiranje inovativnih nanokompozitnih granula na osnovu hitozana, alginata i Fe2O3 primenom LBL tehnike radi njihove primene kao magnetnih adsorbenata za uklanjanje boja iz rastvora i iz suspenzija

Supercritical fluids as green solvents

Supercritical fluids(SCFs) offer the possibility for obtaining and designing of new environmentally friendly and sustainable products with special characteristics. Recently, SCFs have been applied for polymer processing,polymer extraction and purification, preparation of optical materials, supercritical blending of additives into polymers,as a foaming agent for microcellular materials, impregnation, fractionation, purification and formation of powdered polymers. This review is focused on some applications of supercritical fluids with special emphasis on their properties of supercritical fluids in water and carbon-dioxide green industrial chemical processes

Gamma irradiation ageing study of elastomers based on ethylene/propylene/5-ethylidene-2-norbornene rubber

V International Conference on Radiation in Various Fields of Research : RAD 2017 : book of abstracts; June 12-16, 2017; Budva, Montenegr

Hitozan/bentonit granule za tretman otpadnih voda

Aim of this research was synthesis of chitosan/bentonite nanocomposite beads for colored wastewater treatment by adsorption. Influence of preparation procedure on the morphology, adsorption and thermal properties has been studied. It was proved that procedure method affects morphology, as well as enthalpy of absorbed water evaporation, which depends on the molarity of NaOH, and does not affect glass transition temperature. Chitosan adsorption capacity was improved by addition of modified bentonite, which is desirable in colored wastewater treatment.Cilj ovog istraživanja je bila sinteza hitozan/bentonit nanokompozitnih granula za prečišćavanje obojenih otpadnih voda metodom adsorpcije. Proučavan je uticaj postupka pripreme na morfologiju, kao i na adsorpciona i toplotna svojstva nanokompozitnih biopolimera. Dokazano je da način pripreme hibridnih granula utiče na morfologiju, kao i na entalpiju isparavanja adsorbovane vode čija vrednost zavisi od molarnosti NaOH, a ne utiče na temperaturu prelaska u staklasto stanje. Sposobnost adsorpcije hitozana je poboljšana dodavanjem modifikovanog bentonita, koji je poželjan u tretmanu obojenih otpadnih voda

Determination of glass transition temperature and irradiation resistance of elastomeric materials based on chlorinated natural rubber

VI International Conference on Radiation in Various Fields of Research : RAD 2018 : book of abstracts; June 18-22, 2018; Ohrid, Macedoni

Magnetic field responsive methylcellulosepolycaprolactonenanocomposite gels for targeted and controlled release of 5-Fluorouracil

5-Fluorouracil loaded magnetic field sensitive methylcellulose and polycaprolactone gels were prepared and characterized by FTIR, XRD, TGA, SEM, and VSM. Swelling analysis supplied important information on drug diffusion properties. The release profile of gels was investigated in different buffer solutions and the highest release values were observed at pH = 7.2. Release kinetic was analyzed using an empirical equation to clarify the transport properties of drug. The effects of nanoparticle concentration and applying external magnetic field were investigated on release profile. The results indicated that the drug release decreased by both, applying external magnetic field and increasing the concentration of Fe3O4 nanoparticles

The synthesis of silica-coated magnetic nanoparticles and using as adsorbent

In this work, the silica-coated magnetic field-sensitive iron nanoparticles (Si-gamma Fe2O3) were successfully prepared by sol-gel method and used as the adsorbent in the adsorption of methylene blue. The adsorption capacity was evaluated. Batch adsorption experiments were performed as a function of contact time, initial dye concentration (5-20 mg/L), solution pH (4.0-9.6) and temperature (298-328 K). The structure and the morphology of this material were characterized by the Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The adsorption kinetic studies were achieved using pseudo-first order, and pseudo-second order kinetic models. The adsorption kinetic of methylene blue on Si-gamma Fe2O3 is consistent with the pseudo-second order kinetic model. Thermodynamic parameters such as Gibbs free energy (Delta GA degrees), enthalpy (Delta HA degrees) and entropy (Delta SA degrees) changes were evaluated and the results indicated that adsorption process was endothermic and spontaneous. The equilibrium isotherms for the adsorption of methylene blue on the adsorbent were described by the Freundlich and Langmuir isotherm models

Viscometric Analysis of Miscibility and Interactions for Binary, Ternary Polycarbonate/Brominated Polystyrene plus Chloroform Systems at Different Temperatures

Viscosities of ternary systems consist of polycarbonate (PC)/brominated polystyrene (PBrS) in chloroform and their corresponding binary systems were measured at different temperatures (20, 25, and 30 degrees C). All the measurements were carried out at the concentration ranges of 0.1-0.6gdL(-1). The mass ratio of PC to PBrS was selected as 75:25, 50:50, and 25:75 in the ternary solutions. Two empirical expressions of Huggins and Kraemer equations with three-parameters were used for reproducing of the experimental viscosity data. The fitting parameters were obtained for the corresponding temperatures. The miscibility criteria on the basis of the sign of [](m) based on the difference between experimental and ideal values of [](m), was calculated by applying the Garcia etal., theoretical equation. The effect of temperature on the viscosity data was also studied. The results from this method were correlated with the miscibility data obtained for the same system by differential scanning calorimeter (DSC) findings