Biocompatible scaffolds based on collagen and oxidized dextran for endothelial cell survival and function in tissue engineering

Angiogenesis is a vital step in tissue regeneration. Hence, the current study aimed to prepare oxidized dextran (Odex)/collagen (Col)-hydrogels with laminin (LMN), as an angiogenic extracellular matrix (ECM) component, for promoting human umbilical vein endothelial cell (HUVEC) proliferation and function. Odex/Col scaffolds were constructed at various concentrations and temperatures. Using oscillatory rheometry, scanning electron microscopy (SEM), and cell viability testing, the scaffolds were characterized, and then HUVEC proliferation and function was compared with or without LMN. The gelation time could be modified by altering the Odex/Col mass ratio as well as the temperature. SEM showed that Odex/Col hydrogels had a more regular three-dimensional (3D) porous structure than the Col hydrogels. Moreover, HUVECs grew faster in the Col scaffold (12 mg/mL), whereas the Odex (30 mg/mL)/Col (6 mg/mL) scaffold exhibited the lowest apoptosis index. Furthermore, the expression level of vascular endothelial growth factor (VEGF) mRNA in the group without LMN was higher than that with LMN, and the Odex (30 mg/mL)/Col (6 mg/mL) scaffold without LMN had the highest VEGF protein secretion, allowing the cells to survive and function effectively. Odex/Col scaffolds, with or without LMN, are proposed as a tissue engineering construct to improve HUVEC survival and function for angiogenesis.     

Alternative metabolic fates of thymine nucleotides in human cells.

Three types of experiments have been used to study the metabolism of thymine nucleotides by human cells. (1) Cells were labelled continuously with [3H]thymidine and the incorporation of label into DNA compared with the specific radioactivities of pools of individual thymine nucleotides separated by chromatography on polyethylene-imine-cellulose. (2) Cellular thymine nucleotides were labelled with [3H]thymidine at 13 degrees C, followed by incubation at 37 degrees C in unlabelled medium. Incorporation of label into DNA and loss of label from the nucleotide pools were monitored during the 'chase' period at 37 degrees C. (3) The experiments described in (2) above were repeated in the presence of the DNA-synthesis inhibitor cytosine arabinoside, in order to demonstrate more clearly and to quantify degradative pathways for thymine nucleotides. In phytohaemagglutinin-stimulated lymphocytes and in bone-marrow cells, only a proportion (25-60%) of labelled thymine nucleotide was incorporated into DNA, the rest being rapidly degraded and lost from the cell. In contrast, an established cell line (HPB-ALL) from a patient with acute lymphoblastic leukaemia of thymic origin incorporated 100% of its exogenously labelled thymine nucleotides into DNA. These results indicated that alternative metabolic routes are open to thymine nucleotides in human cells. In lymphocytes from patients with megaloblastic anaemia and in normal lymphocytes treated with methotrexate, the utilization of labelled thymine nucleotides for DNA synthesis was more efficient than in controls. These results offer an explanation for the observation of a normal pool of thymidine triphosphate in the cells of patients with untreated megaloblastic anaemia even though the amount of this compound available for DNA synthesis appears to be decreased.     

Evaluating the Effects of Separate and Concomitant Use of MK-2206 and Salinomycin on Prostate Cancer Cell Line

Background:Prostate cancer is known as one of the most prevalent health disorders in the male population globally. The aim of the current study was to evaluate the effects of separate and concomitant use of MK-2206 and salinomycin on prostate cancer cell line.Methods:The antitumor potential of separate and concomitant use of MK-2206 and salinomycin was evaluated in a panel of prostate cancer cell line (PC-3). To get insights into the underlying mechanism of action, different assays including the rate of apoptosis, cell viability, and gene expression were performed in treated prostate cancer cells.Results:A significant reduction was detected in the viability percentage of prostate cancer cells (p< 0.001) and the rate of Akt expression (p< 0.001) in all salinomycin, MK-2206, and salinomycin+MK-2206 groups compared to the negative control group. Furthermore, in comparison with the negative control group, there was a notable increase in both the rate of Bad expression (p< 0.001) and prostate cancer cells apoptosis after salinomycin, MK-2206, and salinomycin+MK-2206 treatments. Moreover, the concomitant use of salinomycin+MK-2206 revealed synergistic improvements regarding the viability of prostate cancer cells and the rate of the Akt and Bad expressions compared to the separate administration of salinomycin and MK-2206 (all p< 0.05)Conclusion:The findings of the present study may contribute to improving the efficacy of the therapies regarding the management of prostate cancer and providing a beneficial strategy in clinical trials.Key Words: Apoptosis, Gene Expression, MK 2206, Prostatic Neoplasms, Salinomycin     

An electrochemical biosensor for prostate cancer biomarker detection using graphene oxide–gold nanostructures

In this paper, a most sensitive electrochemical biosensor for detection of prostate‐specific antigen (PSA) was designed. To reach the goal, a sandwich type electrode composed of reduced graphene oxide/ gold nanoparticles (GO/AuNPs), Anti‐Total PSA monoclonal antibody, and anti‐Free PSA antibody was assembled. The functionalized materials were thoroughly characterized by atomic force microscope spectroscopy, transmission electron microscopy, and X‐ray diffraction techniques. The electrochemical properties of each of the modification step were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The results presented that the proposed biosensor possesses high sensitivity toward total and free PSA. Furthermore, the fabricated biosensor revealed an excellent selectivity for PSA in comparison to the other tumor markers such as BHCG, Alb, CEA, CA125, and CA19‐9. The limit of detection for the proposed electrochemical biosensor was estimated to be around 0.2 and 0.07 ng/mL for total and free PSA antigen, respectively.     

Changes in anti-heat shock protein 27 antibody and C-reactive protein levels following cardiac surgery and their association with cardiac function in patients with cardiovascular disease

The relationship between serum anti-heat shock protein (Hsp)27 antibody and high sensitive C-reactive protein (hs-CRP) levels and indices of cardiac function were investigated in patients undergoing coronary artery bypass grafting (CABG) or heart valve replacement. The changes in anti-Hsp27 antibody titers and hs-CRP levels were compared among patients undergoing off-pump and on-pump CABG or valvular heart replacement. Fifty-three patients underwent off-pump, on-pump CABG, and heart valvular replacement in each group. Serum anti-Hsp27 titers and hs-CRP values were measured 24 h before and after the operation and at discharge. Echocardiography was performed before surgery and before discharge. The results were compared with values from 83 healthy controls. hs-CRP levels increased and anti-Hsp27 antibody decreased following surgery (P < 0.001 and P < 0.05, respectively), although these changes were independent of operative procedure (P = 0.361 and P = 0.120, respectively). Anti-Hsp27 antibody levels were higher at the time of discharge (P = 0.016). Only in coronary patients were anti-Hsp27 antibody levels negatively associated with E/E′ (r = −0.268, P = 0.022), a marker of pulmonary capillary wedge pressure. In conclusions, anti-Hsp27 antibody levels are associated with indices of cardiac function in coronary patients. Cardiopulmonary bypass had no significant effect on the induction of changes in anti-Hsp27 levels. Moreover, anti-Hsp27 antibody levels fell in all groups postoperatively; this may be due to the formation of immune complexes of antigen–antibody, and antibody levels were higher at the time of discharge.

Electronic supplementary material

The online version of this article (doi:10.1007/s12192-012-0358-y) contains supplementary material, which is available to authorized users.     

Design and synthesis of new fused carbazole-imidazole derivatives as anti-diabetic agents: In vitro α-glucosidase inhibition,kinetic, and in silico studies

Twenty three fused carbazole–imidazoles 6a–w were designed, synthesized, and screened as new α-glucosidase inhibitors. All the synthesized fused carbazole-imidazoles 6a-w were found to be more active than acarbose (IC₅₀?=?750.0?±?1.5?µM) against yeast α-glucosidase with IC₅₀ values in the range of 74.0?±?0.7–298.3?±?0.9?µM. Kinetic study of the most potent compound 6v demonstrated that this compound is a competitive inhibitor for α-glucosidase (K_i value?=?75?µM). Furthermore, the in silico studies of the most potent compounds 6v and 6o confirmed that these compounds interacted with the key residues in the active site of α-glucosidase.     

Aging of mesenchymal stem cell in vitro

Background  

A hot new topic in medical treatment is the use of mesenchymal stem cells (MSC) in therapy. The low frequency of this subpopulation of stem cells in bone marrow (BM) necessitates their in vitro expansion prior to clinical use. We evaluated the effect of long term culture on the senescence of these cells.     

Bimetallic Core-Shell with Graphene Coating Nanoparticles: Enhanced Optical Properties and Slow Light Propagation

Plasmonics - In this paper, we study the optical properties and surface plasmon resonance of a bimetallic core-shell spherical nanoparticle exhibiting monolayer graphene coatings. The extinction...     

Nesfatin-1 Ameliorate Learning and Memory Deficit via Inhibiting Apoptosis and Neuroinflammation Following Ethanol-Induced Neurotoxicity in Early Postnatal Rats

International Journal of Peptide Research and Therapeutics - Fetal exposure to alcohol can cause a wide range of long-lasting physiological and behavioral effects, collectively referred to as fetal...