Modified acrylic hydrogels as controlled release systems

Pınardağ, Fatma Esra
In this study, pH-sensitive poly(acrylamide-co-acrylic acid) hydrogels were synthesized as controlled release systems in the presence of N,N-methylene bisacrylamide as crosslinker and ammonium persulfate as initiator. A set of hydrogels were used in the form they were prepared. One set of hydrogels were prepared as porous networks by incorporating sodium chloride into the reaction medium and then leaching of it after the completion of polymerization reaction. Two sets of hydrogels were modified by argon-plasma at different discharge powers. Hydrogels were characterized by 13C-NMR, XPS, SEM, ATR-FTIR, ESR as well as equilibrium degree of swelling (EDS) and contact angle measurements. Prepared hydrogels were loaded with a model antibiotic, ciprofloxacin-HCl (CPFX), and in-vitro release of CPFX from hydrogel matrices were examined in buffer solutions of varying pH values. There are two factors determining the release rates of CPFX; one is the pH-dependent solubility of CPFX and the other is EDS of the hydrogel samples. For porous samples drug loading and release rates were higher when compared to the control samples and CPFX solubility dominated over release kinetics. Plasma treatment resulted in prolonged release rates in acidic medium.


Synthesis, characterization and electrochromic properties of conducting copolymers of terephthalic acid bis-(thiophen-3-ylmethyl)thioester with thiophene and pyrrole and conducting polymer of 1-(4-fluorophenyl)-2,5-di(thiophen-2-yl)-1h-pyrrole
Türkarslan, Özlem; Toppare, Levent Kamil; Department of Chemistry (2006)
Terephthalic acid bis-(thiophen-3-ylmethyl)thioester (TTMT) was synthesized via the reaction of thiophen-3-ylmethanethiol with terephthaloyl dichloride. Nuclear magnetic resonance (1H-NMR) and Fourier transform infrared (FTIR) spectroscopies were utilized for the characterization of the monomer. This 3-functionalized thiophene monomer was polymerized in the presence of thiophene (Th) and pyrrole (Py) upon constant potential application in acetonitrile/tetrabutylammonium tetrafluoroborate (TBAFB). The result...
Immobilization of invertase, polyphenol oxidase and glucose oxidase n conducting copolymers of thiophene-capped polytetrahydrofuran and pyrrole
Böyükbayram, Ayşe Elif; Toppare, Levent Kamil; Department of Chemistry (2005)
Immobilization of invertase, polyphenol oxidase (PPO) and glucose oxidase (GOD) enzymes were performed in electrochemically synthesized two types of conducting copolymers. One end and two end thiophene-capped polytetrahydrofuran (TPTHF-1 and TPTHF-2) were copolymerized with pyrrole under conditions of constant potential electrolysis. The copolymers were characterized by thermal, spectroscopic and scanning electron microscopy analyses. Immobilization was carried out via entrapment of enzymes in two types of ...
Covalent immobilization of glucose isomerase on poly(2-hydoxyethyl methacrylate) particles
Yıldız, Ümit Hakan; Hasırcı, Nesrin; Department of Chemistry (2004)
In this study, poly (2-hydroxyethyl methacrylate), P(HEMA), particles were prepared by suspension polymerization of the monomer 2-hydroxyethyl methacrylate with addition of ethylene glycol dimethyacrylate, EGDMA, as cross linker. Glucose isomerase, GI, enzyme was covalently immobilized on the prepared P(HEMA) particles after activation of the particles with cyanuric chloride. The activities of the free and immobilized enzymes were measured with Ethanol-Carbazole method. The immobilization of GI on P(HEMA) p...
Synthesis and characterization of a new soluble polythiophene derivative and its electrochromic application
Tarkuç, Simge; Toppare, Levent Kamil; Department of Chemistry (2006)
The Knorr-Paal reaction of 1,4-di(2-thienyl)-1,4-butanedione with aniline to yield 1-phenyl-2,5-di(2-thienyl)-1H-pyrrole (PTP) was performed in the presence of catalytical amounts of p-toluenesulfonic acid (PTSA). Chemical polymerization of the monomer yielded a soluble polymer. Structures of both the monomer and the polymer were investigated by Nuclear Magnetic Resonance (1H and 13C NMR) and Fourier Transform Infrared (FTIR) Spectroscopy. The average molecular weight of the chemically synthesized polymer w...
Characterization of conducting polymers of ester linkage containing thiophene derivatives via mass spectroscopy
Aslan, Evren; Toppare, Levent Kamil; Department of Chemistry (2004)
In order to investigate the thermal and structural characteristics of terepthalic acid bis-(2-thiophen-3-yl-ethyl)ester (TATE), decanedioic acid bis-(2-thiophen-3-yl- ethyl) ester (DATE) and octanoic acid 2-thiophen-3-yl-ethyl ester (OTE), their corresponding homopolymers, copolymers with thiophene and polythiophene, pyrolysis mass spectrometry technique was utilized. The results were discussed in detail considering the effects of spacer group in between ester linkages. Thermal Gravimetry Analysis was used ...
Citation Formats
F. E. Pınardağ, “Modified acrylic hydrogels as controlled release systems,” M.S. - Master of Science, Middle East Technical University, 2006.