His name is Song Guosheng, and he is currently a professor at the School of Chemistry and Chemical Engineering, Hunan University. Since he finished his post-doctoral research at Stanford University School of Medicine in 2018, he has returned to teach in China. After coming to Hunan, was selected for the Ministry of Education’s “Yangtze River Scholar Award Program”-Youth Project and won the title of “Global Highly Cited Scientist” in 2021.
Picture | Song Guosheng (Source: Song Guosheng)
It is reported that Song Guosheng mainly focuses on life analysis chemistry, multimodal in vivo imaging, early tumor diagnosis and treatment, etc. Recently, a new paper of his reviewer commented: "This material can overcome the long-standing in vivo toxicity problems of most inorganic nanomaterials, and can be used for multimodal imaging and photothermal therapy of tumors, which can exert excellent photothermal effects for multimodal imaging-guided cancer treatment. On the other hand, this concept is also relatively novel, and provides a solution for the transformation of inorganic nanomaterials in the body of biomedical application. provides a solution to allow the materials to show good application prospects in cancer treatment and diagnosis."
4 On April 5, the relevant paper used "Hydroxy ion triggering luminous sound and MR Degradable Magnetic Nanoplatform with Hydroxide Ions Triggered Photoacoustic, MR Imaging, and Photothermal Conversion for Precise Cancer Theranostic, published on Nano Letters [1].
Figure | Related papers (Source: Nano Letters)
This research starts with inorganic nanomaterials, which have specific electrical, optical, magnetic and other properties, which gives it great application prospects in cancer imaging and treatment. It can change the composition, shape, size, structure and surface modification of inorganic materials to have different properties to play a role in the field of medicine.
Inorganic materials often accumulate in tumors through enhanced permeability and retention effect, and have higher concentrations and longer retention time inside the tumor, thereby achieving effective cancer imaging and treatment. For example, inorganic materials such as iron oxide have been widely used in the field of biomedical science.
iron oxide has many attractive characteristics, such as high biocompatibility , excellent magnetic properties, etc., and its biological functions can be increased through modification. In addition, iron oxide can produce different contrasts, which can be used for magnetic resonance imaging detection, or externally applied magnetic fields, thermal energy or drug release, thereby imaging or treatment of guide materials at designated locations.
Thermal therapy is a treatment technology that generates heat near the tumor area through energy such as radio waves, microwaves, ultrasonic energy and magnetic forces. This method is mainly used in surface tissues. Due to the different temperature tolerance between healthy cells and tumor cells, tumor cells will die without affecting healthy cells.
photothermal therapy (PTT, photothermal therapy) refers to the use of light absorption materials to generate high heat (42°C) under near-infrared laser irradiation, and has been widely used to effectively ablate various solid tumors. As an effective non-invasive treatment, PTT can improve the administration efficiency, regulate the tumor microenvironment, stimulate the release of tumor-specific antigen , etc., and treat a variety of different types of tumors.
Although many research groups have developed photothermal agents, some of them are not biodegradable in vivo, which limits their clinical transformation. During photothermal therapy, infrared thermal imaging devices are usually used to monitor changes in tumor surface temperature. However, it is difficult for the thermal imager to image temperature changes inside the tumor.
At the same time, although inorganic material has shown good potential in cancer diagnosis and treatment, inorganic materials cannot be quickly excreted from the body after systemic administration, which will lead to accumulation on reticular endothelial system , resulting in long-term toxicity, which is very likely to trigger an inflammatory response, or even fibrosis or cancer. Therefore, in order to reduce the toxic side effects of inorganic materials on organisms in normal tissues and reduce the damage to normal tissues during photothermal treatment, it is necessary to develop inorganic nanomaterials with good biosafety to achieve specific imaging and treatment of tumors while reducing damage to normal tissues. can accurately and real-time monitoring of temperature distribution in the tumor during photothermal treatment.
Song Guosheng's team found that nanoparticles with magnetic ion coordination with Prussian blue similar structure have specificity in alkali response. Based on this, they developed alkali-responsive magnetic nanoparticles for tumor-specific photothermal, photothermal, MRI (Magnetic Resonance Imaging, magnetic resonance imaging, ) imaging and photothermal therapy.
In addition, with the coordination effect of metal ions with -CN, they prepared Fe/Mn/Gd-CN coordinated magnetic nanoparticles (MICN, Magnetic Ions Coordinated Nanoplatform) which have good NIR absorption and relaxation effects. Specifically, when MICN is present in an acidic solution (pH 6.4), the MICN structure is stable and has high photothermal effects, photoacoustic and MRI signals. When MICN is present in neutral and alkaline solutions (pH ≥ 7.4), hydroxide can destroy the MICN structure, reduce NIR absorption and changes in nuclear magnetic signals, thereby significantly reducing the photothermal effect, photoacoustic and MRI signals.
Due to the characteristics of tumor microacids, when MICN is enriched in tumors, MICN can exert good photothermal therapy, photoacoustic imaging and MRI imaging effects; on the contrary, when MICN is present in normal tissues, the photothermal therapy, photoacoustic imaging and MRI imaging signals of MICN are significantly reduced, thus significantly improving the specificity of tumor imaging and photothermal therapy.
Song Guosheng said: "Our material has alkali-responsive photothermal properties, which can be used to amplify the difference in photothermal differences between tumors and normal tissues, and there is a good correlation between changes in imaging signals and temperature changes in the photothermal process. Therefore, this material provides more possibilities for improving the ability to distinguish between tumors and normal tissues, thereby improving the specificity and signal-to-noise ratio of photoacoustic/magnetic resonance imaging, and reducing the toxic side effects of photothermal therapy. In addition, the material has outstanding biodegradability, which allows it to be effectively removed from the body, thus avoiding the long-term toxicity brought by inorganic materials, so it has the application of cancer treatment before using cancer treatment. ”
In order to improve the ability to distinguish between tumors and normal tissues, it provides more possibilities
According to reports, the team has been committed to research on tumor imaging technology. In this regard, in the research project, after summarizing and discussing the current progress of inorganic materials in biological diagnosis and treatment, they consulted relevant literature and formed research ideas to develop inorganic materials with biosafety, and then determined the material type through multiple discussions.
Then, through experiments, the feasibility of the research idea is exploring the degradability of the inorganic material and the absorption changes in the near-infrared region. After the preliminary feasibility, Song Guosheng and others conducted a number of experiments, including the synthesis and optimization of materials, the preparation and characterization of nanoparticles , the responsiveness changes of materials, photoacoustic/magnetic resonance imaging, photothermal therapy and imaging, and biosafety research, which involved the operation of cells and animals and the use of various instruments.
Not only that, in order to further fully illustrate the scientific issues, they also conducted more in-depth research on the implementation phenomenon, and further explored the implementation mechanism of the reaction and whether the reaction can undergo reversible phenomena. In addition, they have continued to increase the research depth and discussed and supplemented explanations of the research data that has been obtained.
What made Song Guosheng the most memorable was the selection of materials in the early stage of research. During this period, they used the unstable characteristics of metal ion coordination nanomaterials, which are alkaline instability, to solve the shortcomings of inorganic materials themselves, and at the same time improve the contrast between imaging and treatment. Although the COVID-19 pandemic has affected the team's scientific research life by force majeure, for the sake of scientific rigor and exploration, they have reviewed the literature and discussed it many times, and have conducted a large number of exploration experiments to optimize the impact of different synthesis temperatures, synthesis methods, synthesis ratios, and different surfactants on material stability.
"After continuous optimization, we finally selected the most suitable performance and parameters for characterization and responsiveness testing. At the same time, we continued to increase the research depth in biological imaging and made continuous improvements. Finally, we also conducted in-depth exploration of the responsiveness of the materials, such as the research on response mechanism and reversibility of the response, so that the research was successfully completed." He said.
Figure | The team (Source: Song Guosheng)
allows imaging probes and efficacy to establish reliable relationships
According to Song Guosheng, with its excellent non-invasiveness and real-time quantitative performance, photoacoustic imaging and magnetic resonance imaging have received great attention in monitoring and treatment. However, the commonly used contrast agents currently do not meet the needs of precise treatment, and many studies have also focused on the effects of optimizing the contrast of target imaging. The imaging signal of
targeted therapeutic agents mostly depends on their own characteristics. Combining non-invasive imaging technology with therapeutic agents can improve the therapeutic effect, while monitoring the treatment process itself, and adjusting the therapeutic dose for different stages and individuals. This material showed good correlation between the PA/MRI signal changes and the temperature increase during laser irradiation.
Therefore, the team hopes to use PA (photoacoustic) imaging and MRI imaging to monitor the transformation process of the material and predict its photothermal performance in in vivo photothermal therapy. The ability of cancer treatment is evaluated through non-invasive imaging probes, and the imaging probes are further used to understand the reagents, reagent concentrations, precise temperature increases, or dynamic changes in tumor microenvironment changes in tumor treatment sites. and further explore in-depth application of cancer diagnosis and treatment by establishing a reliable relationship between imaging probes and efficacy.
Next step, the team will continue to explore the changes in imaging contrast of probes from different systems, as well as their application on different biological models , and conduct in-depth research on the potential of imaging probes in disease diagnosis and treatment to find the best diagnosis and treatment effects. Song Guosheng said: "In fact, this part of our work is underway and has made some relatively good progress. We will continue to investigate the application prospects in nanomaterials and biomedical applications, and we will make some phased progress in the future."
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Reference:
1, Yudan Yang. et al. Degradable Magnetic Nanoplatform with Hydroxide Ions Triggered Photoacoustic, MR Imaging, and Photothermal Conversion for Precise Cancer Theranostic. Nano Letters. 2022
