A Comparison of the Effects of Silica and Hydroxyapatite Nanoparticles on Poly(ε-caprolactone)-Poly(ethylene glycol)-Poly(ε-caprolactone)/Chitosan Nanofibrous Scaffolds for Bone Tissue Engineering

BACKGROUND: The major challenge of tissue engineering is to develop constructions with suitable properties which would mimic the natural extracellular matrix to induce the proliferation and differentiation of cells. Poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL, PCEC), chitosan (CS), nano-silica (n-SiO₂) and nano-hydroxyapatite (n-HA) are biomaterials successfully applied for the preparation of 3D structures appropriate for tissue engineering. METHODS: We evaluated the effect of n-HA and n-SiO₂ incorporated PCEC-CS nanofibers on physical properties and osteogenic differentiation of human dental pulp stem cells (hDPSCs). Fourier transform infrared spectroscopy, field emission scanning electron microscope, transmission electron microscope, thermogravimetric analysis, contact angle and mechanical test were applied to evaluate the physicochemical properties of nanofibers. Cell adhesion and proliferation of hDPSCs and their osteoblastic differentiation on nanofibers were assessed using MTT assay, DAPI staining, alizarin red S staining, and QRT-PCR assay. RESULTS: All the samples demonstrated bead-less morphologies with an average diameter in the range of 190–260 nm. The mechanical test studies showed that scaffolds incorporated with n-HA had a higher tensile strength than ones incorporated with n-SiO₂. While the hydrophilicity of n-SiO₂ incorporated PCEC-CS nanofibers was higher than that of samples enriched with n-HA. Cell adhesion and proliferation studies showed that n-HA incorporated nanofibers were slightly superior to n-SiO₂ incorporated ones. Alizarin red S staining and QRT-PCR analysis confirmed the osteogenic differentiation of hDPSCs on PCEC-CS nanofibers incorporated with n-HA and n-SiO₂. CONCLUSION: Compared to other groups, PCEC-CS nanofibers incorporated with 15 wt% n-HA were able to support more cell adhesion and differentiation, thus are better candidates for bone tissue engineering applications.

Development of a high-resolution melting analysis method for CYP2C19*17 genotyping in healthy volunteers

Background: Genetic polymorphisms of drug metabolisms by cytochrome P450 [P450s] could affect drug response, attracting particular interest in the pharmacogenetics. Due to the importance of CYP2C19* 17 allele and its capability of super- fast metabolism and also lack of information about distribution of the alleles in Iranian population, this research aimed to use High Resolution Melting [HRM] method compared to PCR-RFLP for genotyping healthy Iranian population

Methods: Blood samples were collected from 100 healthy Iranian volunteers. DNA was extracted by salting out method. Real-time PCR was used for amplification of the CYP2C19 gene and the alleles were identified by HRM. Sequencing was used to confirm the amplified DNA fragments and data were analyzed using SPSS software ver.18

Results: The frequency of alleles CYP2C19*1/*1, CYP2C19*1/*17 and CYP2C19*17/*17 were estimated as 58.33, 29.1 and 11.1%, respectively. Specificity and sensitivity of HRM method were 90% and 100%, with respect to PCR-RFLP. Also, HRM analysis has been evaluated as a faster and more effective approach

Conclusion: Comparison of our results based on HRM analysis with PCR-RFLP showed that our developed method is rapid, accurate, fast and economic to study the CYP2C19*17 allele and it is appropriate for other similar population genetic studies

Preclinical studies of [68]Ga-DOTATOC: biodistribution assessment in Syrian rats and evaluation of absorbed dose in human organs

Objective[s]: Gallium-68 DOTA-DPhe[1]-Tyr[3]-Octreotide [[68]Ga-DOTATOC] has been applied by several European centers for the treatment of a variety of human malignancies. Nevertheless, definitive dosimetric data are yet unavailable. According to the Society of Nuclear Medicine and Molecular Imaging, researchers are investigating the safety and efficacy of this radiotracer to meet Food and Drug Administration requirements. The aim of this study was to introduce the optimized procedure for [68]Ga-DOTATOC preparation, using a novel germanium-68 [[68]Ge]/[68]Ga generator in Iran and evaluate the absorbed doses in numerous organs with high accuracy

Methods: The optimized conditions for preparing the radiolabeled complex were determined via several experiments by changing the ligand concentration, pH, temperature and incubation time. Radiochemical purity of the complex was assessed, using high-performance liquid chromatography and instant thin-layer chromatography. The absorbed dose of human organs was evaluated, based on biodistribution studies on Syrian rats via Radiation Absorbed Dose Assessment Resource Method

Results: [68]Ga-DOTATOC was prepared with radiochemical purity of >98% and specific activity of 39.6 MBq/nmol. The complex demonstrated great stability at room temperature and in human serum at 37[degree]C at least two hours after preparation. Significant uptake was observed in somatostatin receptor-positive tissues such as pancreatic and adrenal tissues [12.83%ID/g and 0.91%ID/g, respectively]. Dose estimations in human organs showed that the pancreas, kidneys and adrenal glands received the maximum absorbed doses [0.105, 0.074 and 0.010 mGy/MBq, respectively]. Also, the effective absorbed dose was estimated at 0.026 mSv/MBq for [68]Ga-DOTATOC

Conclusion: The obtained results showed that [68]Ga-DOTATOC can be considered as an effective agent for clinical PET imaging in Iran

Application of live, dead and dried biomasses of Aspergillus versicolor for cadmium biotreatment

Background: Various industries produce and discharge wastes containing different heavy metals into the environment. Apart from using living biomass, dead and dried biomasses have been introduced as a new field of biotreatment technology

Method: The cadmium [Cd] [II] removal characteristics of live [growing], dead [autoclaved], and oven-dried biomasses of Aspergillus versicolor were examined as a function of initial pH, contact time, and initial Cd concentration

Result: Maximum bioaccumulation of Cd for live biomass [11.63 [mg g[-1]]] occurred at an optimal pH of 4 and incubation time of 4 days. The maximum biosorption of 27.56 [mg g[-1]] for dead biomass occurred at 1.5 h and at a pH of 4. The maximum biosorption [18.08 [mg g[-1]]] with dried biomass was reached at an equilibrium time of 3 h at a pH of 6

Conclusion: The present study confirmed that heat treatment promoted the removal capacity of fungi. Cd removal was increased by decreasing the pH in live and dead-mode experiments. Inversely, Cd removal was increased with increasing pH for the dried biomass of A. versicolor. Varying responses to environmental conditions [pH and contact time] clearly proved the different removal mechanisms used by three biomasses of A. versicolor. Higher Cd concentration increased the removal ability of three types of biomasses. The results indicated that all biomasses of A. versicolor used in this study, particularly dead biomass, are a suitable biosorbent for the removal of Cd [II] ions from aqueous solution

Comparative proteomics study of streptozotocin-induced diabetic nephropathy in rats kidneys transfected with adenovirus-mediated fibromodulin gene

Transforming Growth Factor-beta [TGF-beta] activation appears to be crucial for tissue injury in Diabetic Nephropathy [DN]. Fibromodulin, the small leucine-rich proteoglycan, has been proposed to be the potent TGF-beta modulator. In this study, the therapeutic effects of fibromodulin in the kidneys of streptozotocin [STZ]-induced diabetic rats were investigated. Diabetic rats received intraperitoneal [IP] injections of recombinant adenovirus expression vectors [RAd5] containing fibromodulin [RAd- FMOD] and were killed after 10 weeks. Proteins were isolated from the rat kidney and separated using two-dimensional gel electrophoresis. The differentially expressed proteins were analyzed using Matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry [MALDI-TOF-MS]. Ten spots were identified using MALDI-TOF-MS. The identified proteins were primarily responsible for cell metabolism, cytoskeleton formation, and oxidative stress. RAd- FMOD treatment markedly attenuated the albuminuria in diabetic rats. Taken together, these results provide a valuable clue in exploring the mechanism underlying the therapeutic effects of fibromodulin in diabetic nephropathy suggesting that it can be a potential agent in the treatment of this disease

Identification and clinical isolates of metallo-beta-lactamases producing Pseudomonas aeruginosa clinical isolates in university hospital from Zanjan province, Iran

Infectious by Pseudomonas aeruginosa has spread worldwide and metallo-beta-lactamases [MBL] are being reported with increasing frequency. The aim of this study was to investigate the antibiotic susceptibility and distribution of bla[VIM] and bla[IMP] genes in P. aeruginosa isolates from Zanjan Province of Iran. A total of 70 P. aeruginosa isolates were identified from patients admitted at intensive care units. The antimicrobial susceptibility was tested by disk diffusion [Kirby-Bauer] method and for production of MBL using double-disk synergy test [DDST]. After DNA extraction, the presence of bla[VIM] and bla[IMP] genes and class 1 integron were detected by PCR. Most of the isolates were resistant to meropenem, cefotaxime and imipenem [IPM]. Also, 44/70 [62.85%] IPM resistant isolates were confirmed by DDST. Of the 44 clinical isolates, 41 [93%] isolates showed MIC >/= 4 micro g/ml for IPM. Based on the DDST results, 36 [87.8%] were confirmed to be MBL producers. PCR amplification showed that 23/41 [56%] carried bla[VIM] and 10/41 [24.3%] possessed bla[IMP] gene. Also, 31/44 [70.5%] isolates contained class 1 integron gene. Our results highlight that the genes for Verona integron-encoded metallo- beta -lactamase, IPM beta -lactamases and class 1 integrons were predominantly present among the IPM-resistant P. aeruginosa tested in our province and also the frequency of bla[VIM] type is higher than bla[IMP]. This is the first report of P. aeruginosa strains producing blaIMP with high frequency from Zanjan province of Iran