Achievement

Thanks to the developments in DNA self-assembly and nano biomolecular technique, we have adopted an effective and convenient approach to identify molecular probes to recognize membrane protein EpCAM and achieve the goal to identify and enrich non-small cancer tumor cells. Using our NanoHunter work, CTCs will be successfully recovered from the whole blood of patients with high purity and efficiency and further CTC-based molecular analysis and cancer therapy can be accomplished more easily.

 

Result

We used gel electrophoresis to test the formation of branched DNA and the ligation of aptamer and branched DNA. The electrophoresis experiments were performed as described in protocols.

First, we compared Y-shaped DNA with the oligonucleotides after reaction. The picture shows that we have got the Y-shaped DNA.

Figure 1. Preparation of Y-shaped DNA.

And then, we confirmed that Y-shaped DNA connected to each other to form the branched DNA.

Figure 2. Formation of branched DNA

The following step is to connect the aptamer to the branched DNA.

Figure 3. Ligation of aptamer and branched DNA.

Figure 4. The fluorescence under UV light.

Meanwhile, we prepared the magnetic nanoparticles.

Figure 5. Dry (left) and wet (right) magnetic nanoparticles.

Finally, our CTC NanoHunter was constructed through the thiol groups reaction of branched DNA and magnetic nanoparticles.

Figure 6. CTC Nanohunter can be enriched in magnetic field.

 

Future Work

Branched DNA and DNA aptamers are introduced to apply into identification and enrichment of CTCs in the course of our project. Based on our goals and methods, we have carried out some innovative research and achieved some useful results. However, there are still quite a few areas where our project can be optimized and improved so that it can be used in a wider range of applications.

(1)Multi-dimensional complex structure: based on the design strategies and assembly approach of branched DNA, more complicated DNA building block can be easily constructed in order to capture target cells with higher affinity and sensitivity.

(2)Wide range of targets: the interaction can be enhanced through conjugations with different functional groups like dye, medicine, and various aptamers, whose targets can be CD45, EGFR and folate.

(3)Benign tag method: staining agent and fluorescent substances can be introduced into the project, making sure that most of collected cells are living cells.

(4)Application of microfluidic technology: microfluidic devices can facilitate on-chip molecular separation, protein analysis, immunosensing, and electronics cooling.