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Synthesis of PVA-based Hydrogels Network
Vahid Hooshangi,Mojtaba Abasian,Peyman Najafi Moghadam,Ziba Jahanbakhsh Naghadeh 한국고분자학회 2016 폴리머 Vol.40 No.6
Poly(vinyl alcohol) (PVA) is a biocompatible, highly hydrophilic and nontoxic polymer which has great potential for modification and can be use as beneficial hydrogels. In the present work, PVA was firstly modified by bromoacetyl bromide to produce bromoacetylated PVA. Then various diamines such as ethylene diamine, propylene diamine and hexamethlene diamine were used for crosslinking of bromoacetylated PVA to synthesize three-dimensional hydrogels. The swelling behavior of prepared hydrogels was investigated in which ethylene diamine-crosslinked PVA by ethylene diamine showed a fast initial swelling followed by a mild increase before attaining equilibrium. The loading of cefftreiaxon antibiotic on the hydrogels was carried out and in vitro drug release of drug loaded hydrogels was investigated. The results show that the drug release rate was enhanced by an increase in pH. The PVA hydrogels were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy.
Hossein Abdollahi,Vahid Najafi,Farshid Ziaee,Kourosh Kabiri,Farhad Narimani 한국고분자학회 2014 Macromolecular Research Vol.22 No.12
Alternative copolymers of acrylic acid (AA) and oligo(ethylene glycol) methyl ether methacryate (475 g/mol (OEGMA475)) macromer, having various amounts of two monomers, were synthesized using aqueous solutionfree radical copolymerization at 50 °C with ammonium persulfate (APS) as an initiator. The structures of the copolymerswere confirmed by nuclear magnetic resonance (NMR) spectroscopy. In fact, samples with different molarratios of two monomers in deionized water were prepared and subsequently copolymerization reaction was performedto low conversion levels (below 10%). Monomer reactivity ratios of OEGMA475, AA pair were estimatedusing the Finemann-Ross (FR), inverted Finemann-Ross (IFR), Kelen-Tüdös (KT), extended Kelen-Tüdös (EKT),Mayo-Lewis (ML) and Yezrelieve-Brokhina-Roskin (YBR) graphical methods. The value ranged from 0.908 to0.963 for rOEGMA and from 0.208 to 0.243 for rAA depending on conversion percentage and calculation methods ofmonomer reactivity ratios. In all the cases, rOEGMA×rAA<1 and rOEGMA>rAA indicate that the resulting copolymer has atendency toward alternation with an azeotropic point in MOEGMA=0.905. Structural parameters of the copolymerswere obtained by calculating the dyad monomer sequence fractions and the mean sequence length. Keywords: oligo(ethylene glycol) methyl ether methacrylate, acrylic acid, monomer reactivity ratios, altern
False-Positive Mycobacterium tuberculosis Detection: Ways to Prevent Cross- Contamination
( Mohammad Asgharzadeh ),( Mahdi Asghari Ozma ),( Jalil Rashedi ),( Behroz Mahdavi Poor ),( Vahid Agharzadeh ),( Ali Vegari ),( Behrooz Shokouhi ),( Khudaverdi Ganbarov ),( Nima Najafi Ghalehlou ),( H 대한결핵 및 호흡기학회 2020 Tuberculosis and Respiratory Diseases Vol.83 No.3
The gold standard method for diagnosis of tuberculosis is the isolation of Mycobacterium tuberculosis through culture, but there is a probability of cross-contamination in simultaneous cultures of samples causing false-positives. This can result in delayed treatment of the underlying disease and drug side effects. In this paper, we reviewed studies on falsepositive cultures of M. tuberculosis . Rate of occurrence, effective factors, and extent of false-positives were analyzed. Ways to identify and reduce the false-positives and management of them are critical for all laboratories. In most cases, falsepositive is occurring in cases with only one positive culture but negative direct smear. The three most crucial factors in this regard are inappropriate technician function, contamination of reagents, and aerosol production. Thus, to reduce false-positives, good laboratory practice, as well as use of whole-genome sequencing or genotyping of all positive culture samples with a robust, extra pure method and rapid response, are essential for minimizing the rate of false-positives. Indeed, molecular approaches and epidemiological surveillance can provide a valuable tool besides culture to identify possible false positives.
Anticancer Properties of Teucrium persicum in PC-3 Prostate Cancer Cells
Tafrihi, Majid,Toosi, Samane,Minaei, Tayebeh,Gohari, Ahmad Reza,Niknam, Vahid,Arab Najafi, Seyed Mahmoud Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2
Crude extracts or phytochemicals obtained from some plants have potential anti-cancer properties. Teucrium persicum is an Iranian endemic plant belonging to the Lamiaceae family which has traditionally been used to relieve abdominal pains. However, the anti-cancer properties of this species of the Teucrium genus have not been investigated previously. In this study, we have used a highly invasive prostate cancer cell line, PC-3, which is an appropriate cell system to study anti-tumor properties of plants. A methanolic extract obtained from T persicum potently inhibited viability of PC-3 cells. The viability of SW480 colon and T47D breast cancer cells was also significantly decreased in the presence of the T persicum extract. Flow cytometry suggested that the reduction of cell viability was due to induction of apoptosis. In addition, the results of wound healing and gelatin zymography experiments supported anti-cell invasion activity of T persicum. Interestingly, sublethal concentrations of T persicum extract induced an epithelial-like morphology in a subpopulation of cells with an increase in E-Cadherin and ${\beta}$-Catenin protein levels at the cell membrane. These results strongly suggest that T persicum is a plant with very potent anti-tumor activity.