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

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

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

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

Investigation of adsorption of the dyestuff astrazon red violet 3rn (basic violet 16) on montmorillonite clay

In this study, color removal by absorption from synthetically prepared wastewater was investigated using montmorillonite clay by adsorption. As dyestuff Astrazon Red Violet 3RN (Basic Violet 16) was used. Experimental parameters selected were pH, temperature, agitation speed, initial dyestuff concentration, adsorbent dosage and ionic strength. It was established that adsorption rate increased with increasing pH, temperature, dye concentration and agitation speed, but decreased with increased ionic strength and adsorbent dosage. Adsorption equilibrium data obtained by a series of experiments carried out in a water bath were employed with common isotherm equations such as Langmuir, Freundlich, Temkin, Elovich and Dubinin-Radushkevich. It was found that the Langmuir equation appears to fit the equilibrium data better than the other models. Furthermore, the fit of the kinetic data to common kinetic models such as the pseudo-first-order, second-order, Elovich and intraparticle diffusion models was tested to elucidate the adsorption mechanism. Kinetic data conformed to the pseudo-second-order model, indicating chemisorptions. In addition, the thermodynamic parameters activation energy, Ea, enthalpy ΔH*, entropy, ΔS*, and free energy change, ΔG*, were calculated. The values of the calculated parameters indicated that physical adsorption of ARV on the clay was dominant and that the adsorption process was endothermic

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.</jats:p

A SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF CMC FOR ALKYL PHENOL POLYGLYCOL-ETHER AND LAURYL ALCOHOL POLYGLYCOL-ETHER

A differential spectrophotometric method has been used for determination of critical micelle concentration (CMC) of alkyl phenol polyglycol ether and lauryl alcohol polyglycol ether. The CMC values so determined are in agreement with the values obtained by other techniques which were used by the same author in previous study.1 The variation with temperature of CMC for these surfactans has been measured. For these solutions, the changes of micellization enthalpies were calculated by using Clasius-Clapeyron equation