Photo-thermal effect enhances the efficiency of radiotherapy using Arg-Gly-Asp peptides-conjugated gold nanorods that target αvβ3 in melanoma cancer cells.

Wen-Cai Xu,Yi-Wen Shi,Bing-Xin Li,Chuanqing Zhou,Ping Li,Ze-Liang Shi,Shen Fu

doi:10.1186/s12951-015-0113-5

Abstract

BackgroundThermotherapy has been known to be one of the most effective adjuvants to radiotherapy (RT) in cancer treatment, but it is not widely implemented clinically due to some limitations, such as, inadequate temperature concentrations to the tumor tissue, nonspecific and non-uniform distribution of heat. So we constructed arginine-glycine-aspartate peptides-conjugated gold nanorods (RGD-GNRs) that target the alpha(v) beta(3) Integrin (αvβ3) and investigate whether the photo-thermal effect of RGD-GNRs by near infrared radiation (NIR) could enhance the efficiency of RT in melanoma cancer cells.ResultsRGD-GNRs could be seen both on the surface of the cell membranes and cytoplasm of A375 cells with high expression of αvβ3. After exposed to 808 nm NIR, RGD-GNRs with various concentrations could be rapidly heated up. Compared to other treatments, flow cytometric analysis indicated that RT + NIR + RGD-GNRs increased apoptosis (p < 0.001) and decreased the proportion of cells in the more radioresistant S phase (p = 0.014). Treated with NIR + RGD-GNRs, the radiosensitivity was also significantly enhanced (DMFSF2: 1.41).ConclusionResults of the current study showed the feasibility of using RGD-GNRs for synergetic RT with photo-thermal therapy. And it would greatly benefit the therapeutic effects of refractory or recurrent malignant cancers.

Highlights

Thermotherapy has been known to be one of the most effective adjuvants to radiotherapy (RT) in can‐ cer treatment, but it is not widely implemented clinically due to some limitations, such as, inadequate temperature concentrations to the tumor tissue, nonspecific and non-uniform distribution of heat
These results indicated that cell uptake of RGD-Gold nanorods (GNRs) were mediated by αvβ3
In summary, we showed that RGD-GNRs significantly enhanced radiosensitivity in A375 cells with high expression of αvβ3

Summary

Introduction

Thermotherapy has been known to be one of the most effective adjuvants to radiotherapy (RT) in can‐ cer treatment, but it is not widely implemented clinically due to some limitations, such as, inadequate temperature concentrations to the tumor tissue, nonspecific and non-uniform distribution of heat. Thermotherapy, as a promising approach for killing radioresistant cancer, has been known to be one of the most effective adjuvants to radiotherapy. The use of this combined therapy approach has not been adopted in routine clinical practice. This can probably be attributed to the limitations of thermotherapy, such as inadequate temperature concentrations to the deep tumor tissue, nonspecific and non-uniform distribution of heat [6]

Methods

Results

Conclusion