Team:Tongji Shanghai/Results Tongji Shanghai


Our project is our story.

Result of materials synthesis

Part 1. synthesising

    We got AuNRs with an aspect ratioof~3.9(41.9 × 10.6 nm). The transmission electron microscopy(TEM) image is shown as figure1(a),the TEM image clearly indicates that the products are single crystals and the shape is relatively even.
    As to the AuNRs with the aspect ratio of 3.9, two LSPR (Localized Surface Plasmon Resonance) peaks respectively at 546 and 770 nm are observed (figure 1(b)).The former arises from the transverse resonant oscillation, while the latter results from the longitudinal resonant oscillation[1].The LSPR range of the AuNRs is wide in near infrared region.
    The temperature variation of the AuNRs is revealed by irradiating a 200μl aqueous solution using an 808 nm laser.The temperature increases obviously(figure 1(c)) as AuNRs concentrationmounting.In addition,as the laser power density grows,the temperature increment is higher, because more energy is absorbed by the solution (figure 1(d)).Figure 1(e) shows that the top temperature is almost unchanged after four cycles, which indicates the photothermal stability of AuNRs.These results indicate that the AuNRs synthesized by us possess good photothermal property and stability.

Part 2. in vitro cytotoxicity test

    The results shows that AuNRs do not affect the metabolic activities of the cells up to 100μl/mg..And they are stably dispersed in serum-containing medium without aggregation. Therefore, we proved that the AuNRs used in this study do not cause any acute cytotoxic effect or aggregation during ciculaiton in in vivo applications.

Result of plasmid construction

Part1.The result of transfection

    Co-transfected GFP for the data analysis of laser experiment could be obviously seen from the cell.

Part2. Fluorescence-activated cell sorter analysis

    The transfection efficiency in 293T cell line:

    The transfection efficiency in hcc 1937 cell line:
    To make the analysis of cell survival rate more accurate, a GFP plasmid was co-transfected into the cell, we could get the efficiency of transfection by FACS.

Result of cell experiment

part 1: fluorescent proving

    Our part require hTERT promoter to reach specifically targeting, so we have designed experiment to illustrate that the part works as we expected.
    Discussion: From the picture can we conclude that the hTERT promoter is working only in telomerase expressed cells, this promoter can be used as tumor specific promoter for downstream gene expression.

part 2: western blot

    Now that we have proved that the hTERT promoter is working, we need to further illustrate that hsp promoter will work. We use p53 as downstream gene instead of GFP, and run western blot to check if the P53 protein will express higher when heated. We use 293T cells for positive reference. Most tumor cells don’t have high expression of p53 protein in general because the gene is inhibited or mutated. HCC1937 is no exception. However, 293T cells have higher expression level of p53 naturally, which makes the result easier to be detected.
    From the result, we can see that p53 is higher expressed inside cell when heat shocked, both in HCC1937 and 293T. In comparison, both cells remaining untreated has lower expressed p53, but still detectable. The hsp-p53 system is proved working in tumor cells.

Part3. Measuring cell viability

    This chat showed the relationship between different groups. Without NIR, the plasmids hsp-p53 and hTert-p53 is relatively harmless. Yet after exposed under NIR, the cellular viability reduces sharply. This experiment suggests that the plasmids actually improve the efficiency of killing cancer cells.

Result of Mice experiment

    As time is limited, the vivo experiment is still in the progress. But we are glad to have see some fantastic changes.
    The six-day tumor volume shows that after infected hsp-p53 and hTERT-p53, the tumors are more likely to be depressed. With AuNRs and NIR, the depression is enhanced. It is likely that the system we developed actually work in vivo experiment.