Endothelial injury and its repair strategies after intravascular stents implantation / 生物医学工程学杂志

Coronary atherosclerotic heart disease is a serious threat to human life and health. In recent years, the main treatment for it is to implant the intravascular stent into the lesion to support blood vessels and reconstruct blood supply. However, a large number of experimental results showed that mechanical injury and anti-proliferative drugs caused great damage after stent implantation, and increased in-stent restenosis and late thrombosis risk. Thus, maintaining the integrity and normal function of the endothelium can significantly reduce the rate of thrombosis and restenosis. Stem cell mobilization, homing, differentiation and proliferation are the main mechanisms of endothelial repair after vascular stent implantation. Vascular factor and mechanical microenvironmental changes in implanted sites have a certain effect on re-endothelialization. In this paper, the process of injury caused by stent implantation, the repair mechanism after injury and its influencing factors are expounded in detail. And repairing strategies are analyzed and summarized. This review provides a reference for overcoming the in-stent restenosis, endothelialization delay and late thrombosis during the interventional treatment, as well as for designing drug-eluting and biodegradation stents.

Research Progress of NOS3 Participation in Regulatory Mechanisms of Cardiovascular Diseases / 生物医学工程学杂志

Cardiovascular disease has been a major threat to human's health and lives for many years. It is of great importance to explore the mechanisms and develop strategies to prevent the pathogenesis. Generally, cardiovascular disease is associated with endothelial dysfunction, which is closely related to the nitric oxide (NO)-mediated vasodilatation. The release of NO is regulated by NOS3 gene in mammals' vascular system. A great deal of evidences have shown that the polymorphism and epigenetic of NOS3 gene play vital roles in the pathological process of cardiovascular disease. To gain insights into the role of NOS3 in the cardiovascular diseases, we reviewed the molecular mechanisms underlying the development of cardiovascular diseases in this paper, including the uncoupling of NOS3 protein, epigenetic and polymorphism of NOS3 gene. The review can also offer possible strategies to prevent and treat cardiovascular diseases.

Application of an R-group search strategy into three-dimensional quantitative structure-activity relationship of HEA beta-secretase inhibitors and molecular virtual screening / 生物医学工程学杂志

The beta-secretase is one of prospective targets against Alzheimer's disease (AD). A three-dimensional quan titative structure-activity relationship (3D-QSAR) model of Hydroethylamines (HEAs) as beta-secretase inhibitors was established using Topomer CoMFA. The multiple correlation coefficient of fitting, cross validation and external validation were r2 = 0.928, q(loo)2 = 0.605 and r(pred)2 = 0.626, respectively. The 3D-QSAR model was used to search R groups from ZINC database as the source of structural fragments. As a result, a series of R groups with relatively high activity contribution was obtained to design a total of 15 new compounds, with higher activity than that of the template molecule. The molecular docking was employed to study the interaction mode between the new compounds as ligands and beta-secretase as receptors, displaying that hydrogen bond and hydrophobicity played important roles in the binding affinity between the new compounds and beta-secretase. The results showed that Topomer CoMFA and To pomer Search could be effectively used to screen and design new molecules of HEAs as beta-secretase inhibitors, and the designed compounds could provide new candidates for drug design targeting AD.

Potential applications of beta-elemene in anti-atherosclerosis and anti-restenosis / 生物医学工程学杂志

It is well known that beta-elemene is a broadly effective antitumor drug. In recent years, many studies suggested that beta-elemene also has potential value in the treatment of atherosclerosis and restenosis. In this paper, the effect of beta-elemene in inhibition of angiogenesis, inhibition of thrombus formation, improvement of hemorheology, protection against oxidative injuries, anti-inflammation and suppression of restenosis after percutaneous transluminal coronary angioplasty (PTCA) are summarized and reviewed.

Effects of rotational culture on morphology, nitric oxide production and cell cycle of endothelial cells

Devices for the rotational culture of cells and the study of biological reactions have been widely applied in tissue engineering. However, there are few reports exploring the effects of rotational culture on cell morphology, nitric oxide (NO) production, and cell cycle of the endothelial cells from human umbilical vein on the stent surface. This study focuses on these parameters after the cells are seeded on the stents. Results showed that covering of stents by endothelial cells was improved by rotational culture. NO production decreased within 24 h in both rotational and static culture groups. In addition, rotational culture significantly increased NO production by 37.9% at 36 h and 28.9% at 48 h compared with static culture. Flow cytometry showed that the cell cycle was not obviously influenced by rotational culture. Results indicate that rotational culture may be helpful for preparation of cell-seeded vascular grafts and intravascular stents, which are expected to be the most frequently implanted materials in the future.

Advances of research of hydrophilic/hydrophobic surface effect on cell biologic behaviors in vitro / 生物医学工程学杂志

Hydrophilicity/hydrophobicity, the same as chemical signals and mechanical stimuli, is an important characteristic of material surface, induces a cascade events of intercelluar proteins and genes, and determines cells biologic behaviors in vitro eventually. In this review, we summarize the available reports to review the methods of hydrophilic/hydrophobic surface modification, and its effects on protein adsorption and cells biologic behaviors.

Optimization on Oil Suspension Formulation of Cordyceps sinensis Spawn / 微生物学通报

The particularities of oil suspension formulation can raise the invasive rate of Hirsutella sinensis to host of Hepialidae for the commercialization of artificial cultivation of Cordyceps sinensis. So it is important to develop a high cell viability oil suspension formulation of C. sinensis spawn. According to the characteristics of the oil suspension formulation, MTT assay is adapted and optimized. The result is as follows: reaction time 120 min, reaction temperature 37?C, methylbenzene as extracting agent, and a positive linear correlation established between active cell weights and cell viability. Varieties and concentrations of assistance agents in oil suspension formulation have been selected with the refined MTT assay, and further optimized together with cell concentrations through orthogonal experiment. The optimal combination project was obtained, namely, cell concentration 0.15 g/mL, aluminium stearate 60 mg/mL, and SPAN-80 50 ?L/mL. Results of stability test on the oil suspension formulation indicate that cell viability can maintain above 90% at 4?C after one month.

Biological effects and their applications in medicine of pulsed electric fields / 生物医学工程学杂志

Pulsed electric fields can induce various kinds of biological effects that are essentially different from the normal electric fields, especially the interactions of Nanosecond Pulsed electric field (nsPEF) with cells. The biological effects of different pulsed electric fields on cell membranes, cytoplasmic matrixes, cell growth are introduced in this paper. Based on these effects, some applications of pulsed electric fields in cancer therapy, gene therapy, and delivery of drugs are reviewed in details.

Analysis for reason of negative HBeAg result in HBV DNA-positive patients / 临床检验杂志

Objective To explore the reason of negative HBeAg result detected by ELISA in the specimen with both positive HBV DNA and positive PreS1 in order to provide objective analysis of HBV replication.Methods Senty-six sera with negative HBeAg,but positive PreS1 and HBVDNA were included in this study.(1) HBeAg was detected again by ELISA after the specimen was diluted at a ratio of 1:100.(2) HBeAg/IC was detected by solid ELISA using monoclonal antibody against HBeAg.(3) The gene mutation of Pre C region was detected by oligonucleotide hybridization.Results HBeAg was positive in 5 specimen which were detected in dilution of 1:100 and HBeAg/IC was detectable in 38 specimen.The gene mutation of Pre C region was found in 24 specimen.Conclusion Hook effect of post-zone,formation of HBeAg/IC and gene mutation of Pre C region were the main reasons of negative HBeAg result by ELISA in the specimen with positive HBV DNA.The specimen with positive HBV DNA and negative HBeAg were presented in the patients who were mostly infected by wild type of HBV.Formation of HBeAg/IC result in the undetectable HBeAg in serum by routine ELISA.

Progress in the migration of vascular endothelial cells and related factors / 国际生物医学工程杂志

The migration of vascular endothelial cells plays an important role in the vascular growth, repair of wounds, and repair of vascular endothelial cells. At the same time, the migration of endothelial cells plays an important role in the progress of vascular diseases, especially atherosclerosis. Thus, the characteristics of endothelial cell migration and related factors are very important for us to understand the role of endothelial cells in the progress of physiology and pathology. In this article, the factors of promotion and inhibition, and blood flow, cytoskeleton and extracellular matrix are recommended in details. Furthermore, at the end of the article, we discuss the close relationship between endothelial cells and repair of vascular endothelial cells, even new vascular growth in the plaques of atherosclerosis.

The research progress in intravascular stent endothelialization / 生物医学工程学杂志

Since the introduction of percutaneous transluminal coronary stenting, restenosis has remained the most challenging problem facing interventional cardiologist. Recently, evidences indicate that endothelial cell, especially endothelial stem cell planting stent might provide more insights. In this review several factors related to stent endothelialization are discussed.

Research progress of the drug-coated stents / 生物医学工程学杂志

Emplacing a stent in the coronary artery has many characteristics. The installation is easy to do and the stent has evident curative effect. However, it will cause thrombosis and immunoreaction because it is metal. So suburgent thrombosis and restenosis after surgeries are still two major complications. The drug-coated stent is one kind of the drug-eluting stents, whose metal surface is coated by some polymer that combines with a sort of effective drug or antibody. It can transport the drug or antibody to the localily of pathological changes and there in it improves the local drug concentration. In this paper the research progress of interrelated issues about the drug-coated stent is reviewed.

Application of atomic force microscopy in cell biology / 生物医学工程学杂志

The atomic force microscopy(AFM), an important instrument for the study of cell biology, has been used to image the living cells and localize the cell surface receptors under physiological conditions by perfect high resolution. It was also utilized in the investigations of the cytoskeleton, biological process and interactions between cells. The applications of AFM in cell biology have been achieved greatly in recent years and many results present a good promise in biomedical and clinical medical fields.

Coating for dexamethasone-eluting intravascular stent and its drug sustained release in vitro / 第三军医大学学报

Objective To prepare the coating of dexamethasone-eluting intravascular stent and observe the features of its delayed release in vitro.Methods Spray painting and dipping coating were used respectively to prepare stent coating,and then high performance liquid chromatography(HPLC)was used to detect the drug loading.The stents prepared by dipping coating were set in a flow of 50 ml PBS buffer at a velocity of 20 ml/min,and 0.5 ml buffer was collected at 6 h and 1,2,4,6,8,10,12,15 d respectively with another 0.5 ml fresh PBS being added immediately.The drug content of the 0.5 ml buffer was detected by HPLC for drug sustained release in vitro.Results The drug loading of stents prepared by spray painting was(24.26?5.23)?g,while that stents prepared by dipping coating for 4 d was(93.15?7.83)?g.Drugs were released slowly and the release rate reached 84% at 15 d.Conclusion The dipping coating-prepared stents have evident effect of sustained release.

Correlation of length of vascular segment in vitro with endothelin-1 metabolism of endothelial cells--study on accumulative effect of tensile stress in the upper endothelial cell membrane. III / 生物医学工程学杂志

A few of flow experiments were utilized to verify a theoretical hypothesis proposed by Fung and coworker which showed that the tensile stress in the upper cell membrane of the vascular endothelium could accumulate upstream against the direction of blood flow. Endothelial cells from replicate human umbilical vein segment (HUVSEC) in vitro with length of 11 cm and 21 cm were exposed to the same pulsatile laminar shear stress averaged of 0.12 N/m2 for 42 hours. The average production rate of endothelin-1(ET-1), at 11 cm segment is 50% lower than that at 21 cm segment(16.93 +/- 0.89) vs. (26.13 +/- 1.79) pg/cm2.h respectively. The average production rate of ET-1 under pulsatile laminar flow was significantly higher than that under steady laminar flow. It showed that, high correlation of the length of HUVSEC with their ET-1 metabolism exists, suggesting that the tensile stress in the upper endothelial cell membrane could accumulate.