Mimicking the structure of extracellular matrix (ECM) of myocardium is necessary for fabrication of functional cardiac tissue. The superparamagnetic iron oxide nanoparticles (SPIONs, Fe3O4), as new generation of magnetic nanoparticles (NPs), are highly intended in biomedical studies. Here, SPION NPs (1 wt%) were synthesized and incorporated into silk-fibroin (SF) electrospun nanofibers to enhance mechanical properties and topography of the scaffolds. Then, the mouse embryonic cardiac cells (ECCs) were seeded on the scaffolds for in vitro studies. The SPION NPs were studied by scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM). SF nanofibers were characterized after incorporation of SPIONs by SEM, TEM, water contact angle measurement, and tensile test. Furthermore, cytocompatibility of scaffolds was confirmed by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. SEM images showed that ECCs attached to the scaffolds with elongated morphologies. Also, the real-time PCR and immunostaining studies approved upregulation of cardiac functional genes in ECCs seeded on the SF/SPION-casein scaffolds including GATA-4, cardiac troponin T, Nkx 2.5, and alpha-myosin heavy chain, compared with the ones in SF. In conclusion, incorporation of core-shells in SF supports cardiac differentiation, while has no negative impact on ECCs' proliferation and self-renewal capacity. 相似文献
To evaluate the biological preference of [Yb(phen)2(OH2)Cl3](H2O)2 (phen is 1,10-phenanthroline) for DNA, interaction of Yb(III) complex with DNA in Tris–HCl buffer is studied by various biophysical and spectroscopic techniques which reveal that the complex binds to DNA. The results of fluorescence titration reveal that [Yb(phen)2(OH2)Cl3](H2O)2 has strongly quenched in the presence of DNA. The binding site number n, apparent binding constant Kb, and the Stern–Volmer quenching constant KSV are determined. ΔH0, ΔS0, and ΔG0 are obtained based on the quenching constants and thermodynamic theory (ΔH0?>?0, ΔS0?>?0, and ΔG0?<?0). The experimental results show that the Yb(III) complex binds to DNA by non-intercalative mode. Groove binding is the preferred mode of interaction for [Yb(phen)2(OH2)Cl3](H2O)2 to DNA. The DNA cleavage results show that in the absence of any reducing agent, Yb(III) complex can cleave DNA. The antimicrobial screening tests are also recorded and give good results in the presence of Yb(III) complex. 相似文献
Mesenchymal stem cells (MSCs) obtained from various sources have been used for different therapeutic applications including tissue regeneration. Reamer/irrigator/aspirator (RIA) has been increasingly used in recent years for the derivation of MSCs. Here in this investigation we have comparatively analyzed MSCs obtained from iliac crest bone marrow (ICBM) and RIA for their morphology, cluster determinant (CD) markers, and adipogenic differentiation capacity. MSCs were isolated, cultured, and purified from both sources and then flow cytometric studies were performed to study their characteristics. The differentiation potential of RIA and ICBM was examined by an Oil Red O staining protocol. Moreover, the tissue-specific markers related to adipogenesis were analyzed by real-time polymerase chain reaction (RT-PCR). The cells were cultured in the relevant induction medium and then adipogenic lineage differentiation was tested and confirmed for all MSC preparations. Additionally, analysis by flow cytometer was indicative of RIA derived MSCs (RIA-MSCs) having a more homogenous population than ICBM derived MSCs. The RIA-MSCs differentiation toward adipogenic lineage was more efficient compared with ICBM-MSCs. Direct comparative analysis of RIA to ICBM-MSCs indicated that the RIA-MSCs had a higher potential toward adipocyte lineage differentiation compared with ICBM-MSCs. 相似文献
BackgroundSelf-Medication (SM), i.e. using medications to treat oneself, is a major concern for health researchers and policy makers. The terms “self medication” or “self-medication” (SM terms) have been used to explain various concepts while several terms have also been employed to define this practice. Hence, retrieving relevant publications would require exhaustive literature screening. So, we assessed the current situation of SM terms in the literature to improve the relevancy of search outcomes.MethodsIn this Systematic exploration, SM terms were searched in the 6 following databases and publisher’s portals till April 2012: Web of Science, Scopus, PubMed, Google scholar, ScienceDirect, and Wiley. A simple search query was used to include only publications with SM terms. We used Relative-Risk (RR) to estimate the probability of SM terms use in related compared to unrelated publications. Sensitivity and specificity of SM terms as keywords in search query were also calculated. Relevant terms to SM practice were extracted and their Likelihood Ratio positive and negative (LR+/-) were calculated to assess their effect on the probability of search outcomes relevancy in addition to previous search queries. We also evaluated the content of unrelated publications. All mentioned steps were performed in title (TI) and title or abstract (TIAB) of publications.Results1999 related and 1917 unrelated publications were found. SM terms RR was 4.5 in TI and 2.1 in TIAB. SM terms sensitivity and specificity respectively were 55.4% and 87.7% in TI and 84.0% and 59.5% in TIAB. “OTC” and “Over-The-Counter Medication”, with LR+ 16.78 and 16.30 respectively, provided the most conclusive increase in the probability of the relevancy of publications. The most common unrelated SM themes were self-medication hypothesis, drug abuse and Zoopharmacognosy.ConclusionsDue to relatively low specificity or sensitivity of SM terms, relevant terms should be employed in search queries and clear definitions of SM applications should be applied to improve the relevancy of publications. 相似文献
Here we report on a novel platform based on buckypaper for the design of high-performance electrochemical biosensors. Using glucose oxidase as a model enzyme, we constructed a biocompatible mediator-free biosensor and studied the potential effect of the buckypaper on the stability of the biosensor with both amperometry and FTIR spectroscopy. The results showed that the biosensor responses sensitively and selectively to glucose with a considerable functional lifetime of over 80 days. The fabricated enzymatic sensor detects glucose with a dynamic linear range of over 9 mM and a detection limit of 0.01 mM. To examine the efficiency of enzyme immobilization, the Michaelis–Menten constant was calculated to be 4.67 mM. In addition, the fabricated electrochemical biosensor shows high selectivity; no amperometric response to the common interference species such as ascorbic acid, uric acid and acetamidophenol was observed. The facile and robust buckypaper-based platform proposed in this study opens the door for the design of high-performance electrochemical biosensors for medical diagnostics and environmental monitoring. 相似文献
International Journal of Peptide Research and Therapeutics - RADA 16-I is an amphiphilic peptide which can form macroscopic scaffolds through self-assembly and has found many applications in tissue... 相似文献
This study aimed to investigate the thermoluminescent properties of ZrO2:Mg irradiated with a 6 MV X-ray beam and its potential application in radiotherapy dosimetry. ZrO2 powder was synthesized using the sol–gel method and Mg was used as a dopant. Irradiations were performed with ZrO2:Mg chips located at the center of a 10 × 10 cm2 radiation field at a source surface distance of 100 cm, below a stack of solid water slabs, at the depth of maximum absorbed dose. The investigated characteristics of the material included linearity with radiation dose, reproducibility, accuracy, sensitivity and fading. Regarding the intrinsic difference of the samples, the glow curves of the investigated ZrO2:Mg chips exposed to 1 Gy of 6 MV X-rays exhibited three or four peaks. The ZrO2:Mg samples showed a 47% fading at 24 h after irradiation, and the reproducibility of the thermoluminescence reading of ZrO2:Mg for equal irradiation conditions was ± 21%. The thermoluminescence response of the investigated ZrO2:Mg samples to various absorbed doses from 0.5 to 2.5 Gy showed a gentle increase of the thermoluminescence intensity with increasing absorbed dose. The obtained results show that ZrO2:Mg is not an appropriate candidate for X-ray photons in radiotherapy, due to low thermoluminescence peak temperature, low reproducibility, low sensitivity to various absorbed doses and significant fading.