Preclinical evaluation of the efficacy of doped conjugated polymer nanoparticles in-vitro and in-vivo.

CAVERZAN M.D.; BEAUGE L.; PALACIOS R.E.; CHESTA C.A.; IBARRA L.E.*

Zaragoza

Conferencia; 4th Spanish Conference on Biomedical Applications of Nanomaterials (SBAN); 2021

CSIC

Glioblastoma (GBM) is the most aggressive type of malignant gliomas (WHO grade IV) andconstitutes 45% of all gliomas. Tumor ablation, chemotherapy and / or radiotherapy are themain therapeutic options available to the present, however, the average survival of patients afterdiagnosis is only 15 months. The clinical applications of photodynamic therapy (PDT) formalignant brain tumors has attracted significant attention. PDT involves the generation ofreactive oxygen species (ROS) in target tissues using a combination of light, a photosensitizer(PS), and molecular oxygen to kill cancer cells by adding massive oxidative stress. Somenanoaggregates are excellent PSs due to their physicochemical characteristics. We havedeveloped CPN using the fluorescent semiconductor polymerpoly[(9,9-diocetylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1′,3}-thiadiazole)] (F8BT); acomb-like polymer (PS-PEG), and the porphyrin Pt(II) octaethylporphyrin (PtOEP). Theparticle dispersion produced was filtered through a 0.2 μm pore size acetate filter to removelarge aggregates and sterilize the sample. Three GBM human tumor cell lines were used toevaluate CPN-PDT efficacy: U-87 MG; M059K and T98G. GBM cells were cultured inDulbecco's modified Eagle's medium supplemented with 10% v / v fetal bovine serum (FBS),1% v / v glutamine, 1% v / v antibiotic. CPN dispersion (different concentrations) was added tothe cells and incubated for 24 h in the absence of light. Particle incorporation was analyzedusing a flow cytometer and also antioxidant enzymes gene expression was analize in the threeGBM cell lines in order to predict the therapeutic response to ROS generate by CPN-PDT.T96G showed the highest levels of antioxidant enzyme gene expression and the highest CPNuptake in our experiments. T98G was significantly more resistant to CNP-PDT. This superiorresistance of T98G could be related to its higher levels of antioxidant enzyme gene expression.Then, heterotopic GBM models were developed injecting 1.5 x106 GBM cells (U87MG orT98G) in the flank of nude Balb/c mice. Subsequently, tumor growth was measured andcompared between GBM cell lines. Mice that developed consistent nodular structures receivedCPN intravenously and then underwent PDT. We observe cutaneous and subcutaneousreactions in tumor areas after PDT such as petechiae, ecchymosis, and also a decrease in tumorvolume compared to control groups demonstrating CPN-PDT in vivo efficacy. Finally, tumorand other organs were collected and evaluated by histological technique.