Adsorption Properties of Tetracycline onto Graphene Oxide: Equilibrium,Kinetic and Thermodynamic Studies

Graphene oxide (GO) nanoparticle is a high potential effective absorbent. Tetracycline (TC) is a broad-spectrum antibiotic produced, indicated for use against many bacterial infections. In the present research, a systematic study of the adsorption and release process of tetracycline on GO was performed by varying pH, sorption time and temperature. The results of our studies showed that tetracycline strongly loads on the GO surface via π–π interaction and cation–π bonding. Investigation of TC adsorption kinetics showed that the equilibrium was reached within 15 min following the pseudo-second-order model with observed rate constants of k₂ = 0.2742–0.5362 g/mg min (at different temperatures). The sorption data has interpreted by the Langmuir model with the maximum adsorption of 323 mg/g (298 K). The mean energy of adsorption was determined 1.83 kJ/mol (298 K) based on the Dubinin–Radushkevich (D–R) adsorption isotherm. Moreover, the thermodynamic parameters such as ΔH°, ΔS° and ΔG° values for the adsorption were estimated which indicated the endothermic and spontaneous nature of the sorption process. The electrochemistry approved an ideal reaction for the adsorption under electrodic process. Simulation of GO and TC was done by LAMMPS. Force studies in z direction showed that tetracycline comes close to GO sheet by C₈ direction. Then it goes far and turns and again comes close from amine group to the GO sheet.     

Association of AHSG gene polymorphisms with serum Fetuin-A levels in individuals with cardiovascular calcification in west of Iran

Molecular Biology Reports - Fetuin-A (AHSG) is a multifunctional secretory protein and acts as an ectopic valve and artery calcification inhibitor. We assessed the correlation between serum levels...     

A comparison between osteogenic differentiation of human unrestricted somatic stem cells and mesenchymal stem cells from bone marrow and adipose tissue

To evaluate the potential of three stem cells for cell therapy and tissue engineering applications, the biological behavior and osteogenic capacity of the newly introduced cord-blood-derived, unrestricted somatic stem cells (USSC) were compared with those of mesenchymal stem cells isolated from bone marrow (BM-MSC) and adipose tissue (AT-MSC). There was no significant difference between the rates of proliferation of the three stem cells. During osteogenic differentiation, alkaline phosphatase (ALP) activity peaked on day 7 in USSC compared to BM-MSC which showed the maximum value of ALP activity on day 14. However, BM-MSC had the highest ALP activity and mineralization during osteogenic induction. In addition, AT-MSC showed the lowest capacity for mineralization during differentiation and had the lowest ALP activity on days 7 and 14. Although AT-MSC expressed higher levels of collagen type I, osteonectin and BMP-2 in undifferentiated state, but these genes were expressed higher in BM-MSC during differentiation. BM-MSC also expressed higher levels of ALP, osteocalcin and Runx2 during induction. Taking together, BM-MSC showed the highest capacity for osteogenic differentiation and hold promising potential for bone tissue engineering and cell therapy applications.     

Analysis of microRNA signatures using size-coded ligation-mediated PCR

The expression pattern and regulatory functions of microRNAs (miRNAs) are intensively investigated in various tissues, cell types and disorders. Differential miRNA expression signatures have been revealed in healthy and unhealthy tissues using high-throughput profiling methods. For further analyses of miRNA signatures in biological samples, we describe here a simple and efficient method to detect multiple miRNAs simultaneously in total RNA. The size-coded ligation-mediated polymerase chain reaction (SL-PCR) method is based on size-coded DNA probe hybridization in solution, followed-by ligation, PCR amplification and gel fractionation. The new method shows quantitative and specific detection of miRNAs. We profiled miRNAs of the let-7 family in a number of organisms, tissues and cell types and the results correspond with their incidence in the genome and reported expression levels. Finally, SL-PCR detected let-7 expression changes in human embryonic stem cells as they differentiate to neuron and also in young and aged mice brain and bone marrow. We conclude that the method can efficiently reveal miRNA signatures in a range of biological samples.     

Deposition of iron titanate/titania ceramic composite thin films from a single molecular precursor

A heterobimetallic single molecular precursor, [Fe₂Ti₄(μ-O)₆(TFA)₈(THF)₆] (1) [TFA = trifluoroacetate, THF = tetrahydrofuran], was synthesized by the simple reaction of [Fe₃O(OAc)₆(H₂O)₃]NO₃·4H₂O [OAc = acetato] with tetrakis(2-ethoxyethanalato)titanium(IV) in the presence of trifluoroacetic acid in THF. The synthesized precursor was analyzed by melting point, CHN analysis, FTIR, single crystal X-ray diffraction and thermogravimetric analysis. Complex (1) crystallizes in the orthorhombic space group Pca2₁ with cell dimensions a = 19.2114(14), b = 20.4804(15) and c = 17.2504(12) Å, and the complex undergoes thermal decomposition at 490 °C to give a residual mass corresponding to an Fe₂TiO₅-TiO₂ composite mixture. The synthesized precursor was utilized for deposition of Fe₂TiO₅-TiO₂ composite thin films by aerosol-assisted chemical vapor deposition (AACVD) on glass substrates at 500 °C using argon as the carrier gas. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray powder diffraction (XRD) analyses of the thin films suggest the formation of good quality crystalline thin films of an Fe₂TiO₅-TiO₂ composite with an average grain size of 0.105-0.120 μm.     

Direct evidence of lipid translocation between adipocytes and prostate cancer cells with imaging FTIR microspectroscopy

Various epidemiological studies show a positive correlation between high intake of dietary FAs and metastatic prostate cancer (CaP). Moreover, CaP metastasizes to the bone marrow, which harbors a rich source of lipids stored within adipocytes. Here, we use Fourier transform infrared (FTIR) microspectroscopy to study adipocyte biochemistry and to demonstrate that PC-3 cells uptake isotopically labeled FA [deuterated palmitic acid (D(31)-PA)] from an adipocyte. Using this vibrational spectroscopic technique, we detected subcellular locations in a single adipocyte enriched with D(31)-PA using the upsilon(as+s)(C-D)(2+3) (D(31)-PA): upsilon(as+s)(C-H)(2+3) (lipid hydrocarbon) signal. In addition, larger adipocytes were found to consist of a higher percentage of D(31)-PA of the total lipid found within the adipocyte. Following background subtraction, the upsilon(as)(C-D)(2+3) signal illuminated starved PC-3 cells cocultured with D(31)-PA-loaded adipocytes, indicating translocation of the labeled FA. This study demonstrates lipid-specific translocation between adipocytes and tumor cells and the use of FTIR microspectroscopy to characterize various biomolecular features of a single adipocyte without the requirement for cell isolation and lipid extraction.     

miR-9: From function to therapeutic potential in cancer

Malignant neoplasms are regarded as the main cause of death around the world; hence, many research studies were conducted to further perceive molecular mechanisms, treatment, and cancer prognosis. Cancer is known as a major factor for health-related problems in the world. The main challenges associated with these diseases are prompt diagnosis, disease remission classification and treatment status forecast. Therefore, progressing in such areas by developing new and optimized methods with the help of minimally invasive biological markers such as circular microRNAs (miRNAs) can be considered important. miRNA interactions with target genes have specified their role in development, apoptosis, differentiation, and proliferation and also, confirm direct miRNA function in cancer. Different miRNAs expression levels in various types of malignant neoplasms have been observed to be associated with prognosis of various carcinomas. miR-9 seems to implement opposite practices in different tissues or under various cancer incidences by influencing different genes. Aberrant miR-9 levels have been observed in many cancer types. Therefore, we intended to investigate the precise role of miR-9 in patients with malignant neoplasms. To this end, in this study, we attempted to examine different studies to clarify the overall role of miR-9 as a prognostic marker in several human tumors. The presented data in this study can help us to find the novel therapeutic avenues for treatment of human cancers.