Lauryl-gemcitabine loaded nanomedicine hydrogel for the local treatment of glioblastoma

Glioblastoma (GBM) is one of the greatest challenges in oncology. The standard of care therapy of this highly malignant brain tumor includes surgical resection followed, one month after, by radiotherapy and chemotherapy with Temozolomide. However, GBM still remains incurable mainly because of its anatomical location, high intra - and inter-tumor heterogeneity and intrinsic characteristics that inevitably lead to the formation of recurrences [1]. Considering that 80-90% of GBM recurrences are localized in proximity of resection cavity borders we hypothesized to deliver an injectable nanomedicine hydrogel directly in the tumor resection cavity after surgery in order to obtain a sustained release of the drug. This could avoid the formation of recurrences before starting the conventional treatment. The hydrogel that we have developed and selected is formed of lipid nanocapsules (LNC) loaded with the prodrug Lauroyl -gemcitabine (GemC12), which shows excellent radio-sensitizing properties, could potentiate cancer immunotherapy and has a MGMT -independent mechanism of action [2,3]. This nanomedicine hydrogel is injectable, adapted for brain implantation and able to release the drug over one month in vitro [2]. In vivo, the anti-tumor efficacy studies in a subcutaneous and ortothopic GBM rodent models have shown, respectively, to decrease the tumor growth and increase the survival of the mice after intratumoral injection of the hydrogel compared to the controls. Also, to better mimic the clinical conditions, we have developed and validated a resection model of the GBM orthotopic tumor and on -going anti -tumor efficacy studies after administration of the treatment in the resection cavity are showing promising results. Moreover, short -, mid- and long- term tolerability studies (1 week, 2 months and 6 months) indicated that this system is well tolerated in the brain. In conclusion, we have demonstrated the fe asibility, safety and efficiency of the GemC12 -LNC hydrogel for the local treatment of GBM. This system, which has a very simple formulation and combines the properties and advantages of nanomedicines and hydrogels, could be considered as a promising platform for the delivery of GemC12 for the local treatment of GBM

<i>In Vivo</i> 9.4T MRI and <sup>1</sup>H MRS for Evaluation of Brain Structural and Metabolic Changes in the Ts65Dn Mouse Model for Down Syndrome

International audienceIn the present study we investigated structural and metabolic modifications of the brain in the Ts65Dn mouse model of Down syndrome(DS)using both in vivo magnetic resonance imaging(MRI)and proton magnetic resonance spectroscopy(MRS). MRI was performed for further texture analysis and changes in texture parameters, including mean grey levels, contrast and homogeneity, and they were found in Ts65Dn compared to diploid littermates (2n). These phenotypic changes were different in the hippocampus and cerebellum, since in Ts65Dn mean grey levels increased in the cerebellum and decreased in the hippocampus. In addition, proton NMR spectra revealed differences in metabolite ratios. Levels of N-acetylaspartate(NAA)and glutamate(Glu), were lower compared to total creatine levels (CX), in the Ts65Dn brain. However, the most striking finding was an increase in the concentration of myo-inositol(Ins)and choline(Cho)in the hippocampus, whereas the Ins concentration was reduced in the cerebellum. Overall, these data illustrate that MRI and MRS are valuable assesment tools sufficiently sensitive to detect associated changes in different brain areas, thus providing new insight into the causative role of dosage-sensitive genes in the Ts65Dn DS mouse model

Magnetic targeting of paclitaxel-loaded poly(lactic-co-glycolic acid)-based nanoparticles for the treatment of glioblastoma

Lakshmi Pallavi Ganipineni,1 Bernard Ucakar,1 Nicolas Joudiou,2 John Bianco,1 Pierre Danhier,2 Mengnan Zhao,1 Chiara Bastiancich,1 Bernard Gallez,2 Fabienne Danhier,1,* Véronique Préat1,* 1Université catholique de Louvain, Advanced Drug Delivery and Biomaterials Research Group, Louvain Drug Research Institute, Brussels, Belgium; 2Université catholique de Louvain, Louvain Drug Research Institute, NEST Nuclear and Electron Spin Technologies Platform, Brussels, Belgium *These authors contributed equally to this work Introduction: Glioblastoma (GBM) therapy is highly challenging, as the tumors are very aggressive due to infiltration into the surrounding normal brain tissue. Even a combination of the available therapeutic regimens may not debulk the tumor completely. GBM tumors are also known for recurrence, resulting in survival rates averaging <18 months. In addition, systemic chemotherapy for GBM has been challenged for its minimal desired therapeutic effects and unwanted side effects. Purpose: We hypothesized that paclitaxel (PTX) and superparamagnetic iron oxide (SPIO)-loaded PEGylated poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs; PTX/SPIO-NPs) can serve as an effective nanocarrier system for magnetic targeting purposes, and we aimed to demonstrate the therapeutic efficacy of this system in an orthotopic murine GBM model. Materials and methods: PTX/SPIO-NPs were prepared by emulsion–diffusion–evaporation method and characterized for physicochemical properties. In vitro cellular uptake of PTX/SPIO-NPs was evaluated by fluorescence microscopy and Prussian blue staining. Orthotopic U87MG tumor model was used to evaluate blood–brain barrier disruption using T1 contrast agent, ex vivo biodistribution, in vivo toxicity and in vivo antitumor efficacy of PTX/SPIO-NPs. Results: PTX/SPIO-NPs were in the size of 250 nm with negative zeta potential. Qualitative cellular uptake studies showed that the internalization of NPs was concentration dependent. Through magnetic resonance imaging, we observed that the blood–brain barrier was disrupted in the GBM area. An ex vivo biodistribution study showed enhanced accumulation of NPs in the brain of GBM-bearing mice with magnetic targeting. Short-term in vivo safety evaluation showed that the NPs did not induce any systemic toxicity compared with Taxol® (PTX). When tested for in vivo efficacy, the magnetic targeting treatment significantly prolonged the median survival time compared with the passive targeting and control treatments. Conclusion: Overall, PTX/SPIO-NPs with magnetic targeting could be considered as an effective anticancer targeting strategy for GBM chemotherapy. Keywords: nanomedicine, glioblastoma, magnetic targeting, nanoparticles, PLGA-based nanoparticle