Search

Introduction: Metformin (MET), an old anti-diabetic drug, has proven unexpected anti-glioblastoma effects, by impacting cell proliferation, migration and invasion. However, its remarkable anti-cancer efficacy is mainly limited to the use of high millimolar concentrations in in vitro studies, which are hard to be attained in the clinical setting. Aim: The aim of this paper was to synthetize gold nanoparticles loaded with MET and to test if an enhanced drug delivery via nanotechnology could overcome the limitations of small drug concentrations. Materials and Methods: Gold nanoparticles were functionalized with chitosan (GNPc) and loaded with 80 µM of MET. Their size, zeta potential and stability were characterized and their internalization within tumor cells was assayed through dark field microscopy. Three primary glioblastoma stem cell lines were treated with 5, 10 and 20 µg/mL concentrations of nanoparticles and irradiated. The anti-tumoral effect was evaluated through the MTT cell viability assay. Results: MET-GNPc are easily synthetized and have a positive zeta potential, spherical shape and a median size of 26 nm. MET-GNPc have an increased cell internalization and affect the viability of all three glioblastoma cell lines used compared to control and free MET. However, their anti-cancer effect is not statistically different when compared to GNPc, although a slight tendency to a better response may be observed. Conclusion:Despite an increased cell internalization, the small micromolar concentrations of metformin does not bring an additional benefit to chitosan-based GNPs. Novel delivery methods being able to carry a higher drug concentration of metformin should be tested.

GlioStat (patent pending) denotes an invention that addresses the current deficiencies of glioblastoma (GBM) chemotherapy by developing a molecularly imprinted drug reservoir that is specifically designed for post-surgical recovery. The goal of our research was to guarantee the long-term release of the antitumor drug ruxolitinib (RUX), which is specifically designed to target residual infiltrative cancer cells, while simultaneously reducing the risk of adverse effects. In order to achieve this goal, we have successfully developed and characterized four distinctive molecularly imprinted polymers (MIPs), with one of them advancing to in vivo experimentation. The selection of one MIP for further in vivo investigations was guided by the Alamar Blue viability assay on C6 GBM cell cultures, which took into account both the efficacy and the potential toxicity of residual monomers. Over the course of 96 hours, MIP 2 demonstrated the most favorable risk-benefit profile, providing superior efficacy against GBM C6 cells. In contrast, its non-imprinted counterpart (NIP 2) exhibited minimal toxicity. The protocol involved anesthetising the male Wistar rats, immobilising them on a corkboard, without the use of a stereotactic headholder. After shaving the head and local disinfection with iodine solution, we made a linear sagittal incision and exposed the parietal bones. A 3x3 mm burr hole was made with a pneumatic drill in the right parietal bone, revealing the dura mater. Subsequently, we injected 20,000 C6 GBM cells suspended in 5 microliters of solution in the cerebral parenchyma at a depth of 3 mm. Clinical and imaging control was performed. For the animals that developed tumors, a second therapeutic intervention was performed. The rats were anesthetised, disinfected, and readied in the same manner as before. The burr hole was exposed, with the tumor being partially resected via a “microscooping” technique. Next, 5-10 microliters of MIP2 solution (4 mg/mL) were injected into the parenchyma respective of the tumor bed. Five microliters of thrombin solution were then added (100 UI/mL) to form the fibrin network. In comparison to the untreated controls and animals treated with free RUX, animals treated with MIP2 exhibited a substantial increase in survival time during the in vivo evaluation, extending from 20 to 50 days. As such, our research had yielded a potentially life-changing drug delivery system in GBM, with the capacity to significantly increase postoperative survival. More in vivo tests should be conducted to validate our findings.