Platelets against cancer
Researchers from the Institute of Technological Design (IPE) of the Chinese Academy of Sciences and the University of the Chinese Academy of Sciences (UCAS) have developed a new platelet-based drug that has demonstrated powerful therapeutic effects against cancer in mice.
To solve the main problems of photothermal antitumor therapy – targeting the tumor and penetrating into it – scientists used platelet aggregation and activation. A new drug containing photothermal nanoparticles and immunostimulants provided effective combination therapy for several types of cancer.
Schematic representation of the platelet-based composition and its application in photothermal and immunological combination therapy of cancer. Source: WEI Wei.
Recently, photothermal therapy (FTT) of cancer has attracted increasing attention of scientists. The prospects of the method are limited by the complexity of the delivery and ingestion of photosensitizers into the tumor, associated with the heterogeneity of cancer and dense extracellular matrix.
In the new study, platelets used as a vector for the delivery of photosensitizers showed themselves to be suitable candidates for targeting and penetration into the tumor.
A local increase in temperature in the tumor, which develops during FTT, causes cancer cells to secrete antigens. This response not only shows the relationship between the main mechanisms of FTT and immunoactivation, but also justifies the combination of FTT and immunotherapy as a complex antitumor therapy.
In the new platelet-based preparation, photothermal nanoparticles and immunostimulators were neatly and simply integrated into platelets. The photothermal conversion efficiency of this new photothermal nanoparticle has reached 69.2%. Thus, low-power irradiation in the near infrared range was sufficient for the formation of local hyperthermia and the destruction of tumor cells.
Vector platelets worked as a patrol in the bloodstream, responding to vascular damage. As a result, some of them acted as initiators of adhesion to defective endothelial cells of tumor vessels.
After low-power irradiation in the near infrared range, local hyperthermia led to acute vascular damage, which subsequently caused intensive aggregation of platelets carrying photosensitizers sufficient to form a targeted arsenal for FTT in situ.
Subsequently, nanoscale prothrombocytes (nPLT) were generated on these activated platelets, which transferred the load to deep tumor tissues, expanding the therapy area.
After ablation of the tumor induced by photothermal therapy, immunostimulants enhanced the immune response to the released tumor antigens, which additionally contributed to the destruction of residual, metastatic and recurrent tumors.
A new platelet drug for combined FTT and cancer immunotherapy has been tested on nine different mouse models, including complex models based on human platelets, humanized mice and xenografts of tumors obtained from patients.
The result demonstrates the effectiveness of the new platform in combined antitumor therapy. The authors hope that later their work will be successfully translated into clinical practice.
Article Y.Lu et al. Near-infrared light–triggered platelet arsenal for combined photothermal-immunotherapy against cancer is published in the journal Science Advances.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of the Chinese Academy of Sciences: Scientists Develop a New Platelet-based Formulation for Combination Anticancer Therapy.