Penetration ability and biological activity of fusion protein PTD4-Cu, Zn-SOD in human astrocytes in vitro by immunofluorescence test / 西安交通大学学报(医学版)

【Objective】 To observe the penetration and biological activity of PTD4-Cu, Zn-SOD into human astrocytes and whether it can mitigate hypoxia damages. 【Methods】 ①Immunohistochemistry and fluorescence test: We labeled the Cu, Zn-SOD by a monoclonal antibody, combined it with the fluorescent secondary antibody labeled with fluorescein isothiocyanate (FITC) to observe the effect of transduced PTD4-Cu, Zn-SOD on the viability of human astrocytes. ② The experimental group: After hypoxic damage model, the cells were divided into three groups: blank control, group Cu, Zn-SOD, and group PTD4-Cu, Zn-SOD. Group blank was added with DMEM medium (excluding serum) as control; DMEM medium was added to the other two for one hour (excluding serum) with its fusion proteins (Cu, Zn-SOD and PTD4 -Cu, Zn-SOD) with the final concentration of 2 μmoL/L. After the intervention, we used SOD and MDA test kits to observe PTD4-Cu, Zn-SOD and Cu, Zn-SOD in astrocytes after fusion protein intervention. 【Results】 The PTD4-Cu, Zn-SOD fusion protein could have aggregation distribution in the nucleus by FITC fluorescently labeled. After the intervention, it could increase the SOD activity in astrocytes in group PTD4-Cu, Zn-SOD and group Cu, Zn-SOD compared with control group, but the SOD activity was more obvious in the fusion proteins PTD4-Cu, Zn-SOD group. And the dose of MDA was reduced in group PTD4-Cu, Zn-SOD compared with group Cu, Zn-SOD and control group. 【Conclusion】 PTD4-Cu, Zn-SOD fusion protein can transcellular membrane of human astrocytes. The fusion protein PTD4-Cu, Zn-SOD can increase the SOD activity and reduce the content of MDA by human astrocytes from hypoxia injury.

In-vitro comparative study of marginal leakage and penetration ability of moisture-tolerant and conventional resin-based pit and fissure sealants with different surface preparations

This in-vitro study aimed to evaluate and compare the marginal leakage and penetration ability of a moisture-tolerant (Embrace WetBondTM) and a conventional (ClinproTM) resin-based sealants under three different enamel surface preparations (acid etched, acid etched and saliva contaminated and bur preparation and acid etched). One hundred and twenty extracted caries free human premolars teeth were cleaned and randomly divided into six groups of equal numbers, according to the type of sealants used and surface preparations. All the sealed teeth were subjected to thermocycling and immersed in a methylene blue dye. Each tooth was then embedded into acrylic resin before it was sectioned into four sections per tooth. Marginal leakage and unfilled surface area (indicating penetration depth of resin) were then measured using an optical 3D measurement device (Alicona Infinite Focus®). Both sealants exhibited comparable proportion of marginal leakage on acid etched only surfaces. Moisture-tolerant sealant showed the least proportion of marginal leakage on bur prepared and etched surfaces. Presence of saliva has detrimental effect on adhesion of both sealants. Nevertheless, depth of penetration of sealant into the fissures is comparable with both sealant types irrespective of the surface preparations.