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Due to lack of self-repair mechanism in neuronal tissue, biomaterials have been widely studied to regenerate damaged nerve tissue. Despite having advantages, nano materials may cause oxidative stress and this could affect the treatment. In the present study, whether PHBV [poly (3-hydroxybutyrate-co-3-hydroxyvalerate)] used for axonal regeneration could lead to lipid peroxidation, protein oxidation in rats or not and also its effects on antioxidant molecules was explored. In the study, PHBV nanofiber membranes were formed by electrospinning and conduits were formed by using the nanofiber membrane. After the formation of a 1 cm gap in the rat peritoneal nerves, PHBV conduits were placed. Animals were sacrificed at 17th week after the operations. Malondialdehyde (MDA), advanced oxidation protein products (AOPP), glutathione (GSH) levels and superoxide dismutase (SOD) activities of livers, as well as surrounding tissues of conduits (muscles) and serums were measured. Compared to control groups, MDA, AOPP and GSH levels and SOD activites in all graft group serums showed a significant increase, while only MDA and AOPP levels in tissues were statistically higher. Therefore, these findings suggest that PHBV nerve graft used for sciatic nerve defects may lead to oxidative stress in rats.

Background: It was previously reported that vitamin B 12 (Vit B 12 ) has the regulatory effects on epidermal growth factor (EGF) and tumor necrosis factor alpha (TNF-α). The role of Vit B 12 , EGF and TNF-α in the pathogenesis of alzheimer dementia has not been elucidated yet. In this study the plasma Vit B 12 , EGF and TNF-α level were examined in individuals, between 65-99 years old with and without alzheimer dementia (AD). Methods: The study group comprised 47 patients with AD and 38 cases without dementia. EGF and TNF-α were analyzed by ELISA, and Vit B 12 was analyzed by chemiluminescence method. Results: Vit B 12 and EGF levels were significantly lower (p

The role of increased oxidative stress in the development of oxidative protein damage in aging have been reported. There is an important role of oxidative stress on development of dementia. Advanced oxidation protein products (AOPPs) are novel markers of oxidative stress. The aim of this study was to compare AOPP levels in healthy aged person and aged person with dementia. AOPP levels were in the control group 83.36 ± 35.51 I¼mol/L, and 178.78 ± 110.50 I¼mol/L in the group with dementia. This elevation in the group with dementia was statistically significant (p

Objective: In this study, the changes in the levels of the epidermal growth factor (EGF), tumor necrosis factor alpha (TNF-α), and thioredoxine (TRX) in the cerebral tissue of rats following the cerebral ischemia model were investigated.Methods: The left middle cerebral artery occlusion (MCAO) was done in 27 out of 48 rats recruited into the study for obtaining focal cerebral ischemia model (MCAO group). Twenty-one rats underwent a sham operation; the middle cerebral artery was exposed but not occluded (Sham group). EGF, TNF-α, and TRX levels were studied in the operated left and contralateral hemispheres at the 16Results: EGF levels at 96Conclusion: The results suggested that cerebral ischemia following MCAO might affect EGF, TNF-α and TRX levels in both ischemic and contralateral hemispheres in cerebral tissue; and this effect may change by the time passed after MCAO.

WOS: 000314927200069, The design and the development of novel scaffold materials for tissue engineering have attracted much interest in recent years. Especially, the prepared nanofibrillar scaffold materials from biocompatible and biodegradable polymers by electrospinning are promising materials to be used in biomedical applications. In this study, we propose to produce low-cost and cell-friendly bacterial electrospun PHB polymeric scaffolds by using Alcaligenes eutrophus DSM 545 strain to PHB production. The produced PHB was characterized by Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Nanofibrous scaffolds were fabricated via electrospinning method that has a fiber diameter approximately 700800 nm. To investigate cell attachment, cell growth, and antioxidant enzyme activity on positively and negatively charged PHB scaffold, PHB surface was modified by plasma polymerization technique using polyethylene glycol (PEG) and ethylenediamine (EDA). According to the results of superoxide dismutase (SOD) activity study, PEG-modified nanofibrillar scaffolds indicated more cellular resistance against oxidative stress compared to the EDA modification. As can be seen in cell proliferation results, EDA modification enhanced the cell proliferation more than PEG modification, while PEG modification is better as compared with nonmodified scaffolds. In general, through plasma polymerization technique, surface modified nanofibrillar structures are effective substrates for cell attachment and outgrowth. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013, Hacettepe University, Scientific Researches Unit, This study was carried out under the auspices of the Hacettepe University, Scientific Researches Unit. The authors would like to thank Koray Mizrak and Cem Bayram for their help in SEM and XPS characterizations.

WOS: 000306941400011, PubMed: 22888751, Polyhydroxyalkanoates (PHA) are natural, thermoplastic polyesters and due to their biocompatible and biodegradable properties they are good alternatives for the production of scaffolds for engineered tissues or nanoparticles for drug delivery. As a member of polyhydroxyalkanoate family, polyhydroxybutyrates (PHB) have been widely used as a biomaterial for in vitro and in vivo studies since their mechanical properties are very similar to conventional plastics. By using multi-emulsion technique, iron oxide particles were coated with polyhydroxybutyrate (PHB) polymer synthesized from Alcaligenes eutrophus bacteria and the magnetic carrier system was prepared accordingly. The bare nanoparticles and magnetic nanoparticles were morphologically, structurally and magnetically characterized by using Scanning electron microscope (SEM) and Atomic force microscope (AFM); Fourier Transform Infrared Spectrometry (FTIR), and Electron Spin Resonance (ESR) and Vibrating Sample Magnetometer (VSM) techniques, respectively. Particle size of PHB nanoparticles was determined by Zeta Sizer. It was found that the smallest particles were in the range of 239,43+/-5,25 nm in diameter. Concanavalin-A (Con-A) was used for targeting the Cancer cells while etoposide was used as drug. Con-A and etoposide were loaded onto the particles. Release studies of etoposide were evaluated and the system was optimized for the further in vivo applications. Finally different formulation magnetic PHB nanoparticles cytotoxicity were evaluated in cell culture studies and used He La cell line (cervical cancer cells) as a cancer cells and L929 cells (mouse fibroblast cells) as a non-cancer cell line., Hacettepe University Scientific Researches Unit, This project was supported by Hacettepe University Scientific Researches Unit and the authors would like to thank Bilkent University, Institute of Materials Science and Nanotechnology (UNAM).

Bayram, Cem (Aksaray, Yazar) Erol Demirbilek, Melike (Aksaray, Yazar), Early phase osseointegration is crucial for orthopedic implants. For the improvement of osseointegrative properties of orthopedic implants several surface modification methods such as acid etching, hydroxyapatite (HA) coating and sandblasting can be applied. In this article titanium implants were anodized to possess nanotubular titania structures on the surface. Titania nanotube structures with a 45-50 nm of average inner diameter were obtained and to enhance bioactivity, samples were soaked in 10X simulated body fluid (SBF) for apatite deposition on surface for different time periods (1, 2, 3, 5, 8 hours). Apatitic calcium phosphate deposited surfaces were analyzed with infrared spectrometry and wettability studies. Effect of soaking time on osteoblast cell was investigated by cell viability, alkaline phosphatase activity tests and morphological evaluations. As a result, 3 hours of soaking time was found as the optimum time period (p < 0.005). This in vitro study indicated that soaking in 10X SBF can be a rapid and economical technique to enhance osseointegration of anodized titanium implants however excess and/or uncontrolled HA coating of titania layer limits the bioactive potential of the implant.

WOS: 000291218200006, PubMed: 21312003, Oxidative stress may produce high level of reactive oxygen species (ROS) following cell exposure to endogenous and exogenous factors. Recent experiments implicate oxidative stress as playing an essential role in cytotoxicity of many materials. The aim of this study was to measure intracellular malondialdehyde (MDA), advanced oxidation protein product (AOPP) levels, and superoxide dismutase (SOD) activities of L929 fibroblasts cultured on PDLLA, polyethylene glycol (PEG), or ethylenediamine (EDA) grafted PDLLA by plasma polymerization method. Cell proliferation on these scaffolds was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. The study showed that MDA, AOPP levels, and SOD activities in L929 fibroblast cells cultured on all scaffolds were significantly different compared to the control group and each other. The highest MDA (0.42 +/- 0.76 nmol/mg protein), AOPP (14.99 +/- 4.67 nmol/mg protein) levels, and SOD activities (7.49 +/- 3.74 U/mg protein) were observed in cells cultured on non-modified scaffolds; meanwhile, the most cell proliferation was obtained in EDA-modified scaffolds (MDA 0.15 +/- 0.14 nmol/mg protein, AOPP 13.12 +/- 3.86 nmol/mg protein, SOD 4.82 +/- 2.64 U/mg protein). According to our finding, EDA- or PEG-modified scaffolds are potentially useful as suitable biomaterials in tissue engineering.