Nano-gold Raman probe: draw detailed construction drawings for tumor surgery
The Raman probe designed and constructed in this research is equipped with nano-gold, the surface is covered with sea urchin-like burr structure, and is connected to the Raman reporter DTTC (a near-infrared dye).
The Raman signal generated by the probe under near-infrared laser irradiation has high sensitivity and strong signal. The most important thing is that the uniform and selective accumulation of gold nanoparticles and DTTC particles in the tumor can help to delineate the edge of the tumor through Raman imaging.
Zhou Min, Professor, Institute of Translational Medicine, Zhejiang University
For most malignant tumors, comprehensive treatment based on surgery is a routine clinical diagnosis and treatment plan.
However, abdominal tumors such as colon cancer and ovarian cancer have extensive abdominal dissemination and metastasis characteristics, which are easy to infiltrate the surrounding vital organs or nerve structures, and are difficult to accurately remove by surgery.
To this end, the team of Professor Zhou Min from the Institute of Translational Medicine of Zhejiang University has constructed a diagnostic and therapeutic integrated nanoprobe with high-sensitivity diagnostic function and photothermal performance based on the preparation of nano-gold, and combined with new Raman imaging technology to achieve The precise resection and postoperative dissection of abdominal tumors have been achieved.
Zhou Min said in an interview with a reporter from Science and Technology Daily that the study revealed the potential of Raman imaging technology in the field of biomedicine and provided new strategies for the diagnosis and treatment of metastatic tumors.
Raman imaging technology can make up for the lack of tumor imaging technology
Zhou Min said that looking for more accurate intraoperative tumor imaging technology and surgical resection guided by imaging technology has become the focus and difficulty of clinical research in recent years.
At present, imaging techniques such as positron emission tomography (PET) and magnetic resonance imaging (MRI) can be used clinically to determine the position of the tumor before surgery. However, the tissue will be displaced during the operation, and the preoperative image of the tumor is usually different from the actual image. The positions are inconsistent, and real-time observation and positioning cannot be achieved.
The Raman imaging technology can effectively make up for the deficiencies of the above-mentioned imaging technology.
However, in general, the signal of Raman spectroscopy is very weak and it is difficult to carry out effective application.
Until the 1970s, foreign scientists discovered that the absorption of molecules to be measured on the surface of rough nano-metallic materials can increase the Raman signal of the object to be measured by 10 to the 15th power of the spectral phenomenon, thereby developing the surface Enhanced Raman spectroscopy technology is Raman probe technology.
This technology is now widely used in food composition testing, environmental pollutant testing and other fields.
Nano-gold Raman probes help precise removal of millimeter-sized tiny tumors
"The Raman probe designed and constructed in this research is equipped with nano-gold, the surface is covered with sea urchin-like burr structure, and is connected to the Raman reporter DTTC (a near-infrared dye). The probe produces The Raman signal has high sensitivity and strong signal. The most important thing is the uniform and selective accumulation of gold nanoparticles and DTTC particles in the tumor. Raman imaging helps to describe the edge of the tumor." Zhou Min told reporters that using this technology, a single time The injection can achieve preoperative and intraoperative imaging, and can accurately determine the tumor edge, which is equivalent to drawing a more detailed construction drawing for the development of the operation.
Nano-gold Raman probes have the advantages of specific fingerprint spectrum and ultra-low signal interference. It can be understood as having multiple receiving channels, which can be changed when there is interference to ensure the continuity and accuracy of signal reception.
Through animal experiments, the research team proved that the probe has good biological safety and can stay at the tumor site for a long enough time.
"Given the Raman signal enhanced by nanoparticles, they can accurately detect the residual diameter of small tumors less than 1 mm." Zhou Min said that in this study, Raman image-guided surgery can be promoted in a relatively short period of time. For the removal of most tumor tissues, in general, the matching effect of image guidance and tumor resection is good.
Combination treatment program effectively inhibits recurrence and improves patient survival rate
The use of specific photothermal therapy to eradicate residual small tumors is one of the main clinical treatments for disseminated abdominal tumors.
"Photothermal therapy is the use of heat generated by laser to kill cancer cells. It has been used to treat various cancers and other diseases with less side effects. We use'nano-gold Raman probe technology to remove surgery + photothermal therapy' for small After treatment of mice, it was found that the survival rate of mice was increased by 75% and the tumor recurrence was significantly delayed. The combination of the two technologies has a better therapeutic effect. The preliminary results are very encouraging, but more research is needed. Evaluation." Zhou Min said.