Application of an assay Cascade methodology for a deep preclinical characterization of polymeric nanoparticles as a treatment for gliomas

Abstract

Glioblastoma multiforme (GBM) is the most devastating primary brain tumor due to its infiltrating and diffuse growth characteristics, a situation compounded by the lack of effective treatments. Currently, many efforts are being devoted to find novel formulations to treat this disease, specifically in the nanomedicine field. However, due to the lack of comprehensive characterization that leads to insufficient data on reproducibility, only a reduced number of nanomedicines have reached clinical phases. In this context, the aim of the present study was to use a cascade of assays that evaluate from physical-chemical and structural properties to biological characteristics, both in vitro and in vivo, and also to check the performance of nanoparticles for glioma therapy. An amphiphilic block copolymer, composed of polyester and poly(ethylene glycol; PEG) blocks, has been synthesized. Using a mixture of this copolymer and a polymer containing an active targeting moiety to the Blood Brain Barrier (BBB; Seq12 peptide), biocompatible and biodegradable polymeric nanoparticles have been prepared and extensively characterized. In vitro studies demonstrated that nanoparticles are safe for normal cells but cytotoxic for cancer cells. In vivo studies in mice demonstrated the ability of the Seq12 peptide to cross the BBB. Finally, in vivo efficacy studies using a human tumor model in SCID mice resulted in a significant 50% life-span increase, as compared with non-treated animals. Altogether, this assay cascade provided extensive pre-clinical characterization of our polymeric nanoparticles, now ready for clinical evaluation.

Silica-Coated Magnetic Nanoparticles Decrease Human Bone Marrow-Derived Mesenchymal Stem Cell Migratory Activity by Reducing Membrane Fluidity and Impairing Focal Adhesion

“…Size distribution and morphology are important factors determining the uniformity of nanoparticles and were analyzed using electron and atomic microscopy [44]. Hydrodynamic size, polydispersity, and surface charge were determined using dynamic light scattering [45]. The purity and contents of nanoparticles are usually analyzed using an X-ray based technique [44].…”

Role of Survivin in Bladder Cancer: Issues to Be Overcome When Designing an Efficient Dual Nano-Therapy

“…Goat anti-rabbit IgG conjugated Alexa 488 was purchased from Ther-moFisher (ThermoFisher Scientific, Waltham, MA, USA). Protein Bromelain (PB), poly (beta aminoesters (pBAEs) and polymer P were synthesized by other group members, as previously detailed [16,22,23,27]. siRNA non-targeting pool was obtained from Dharmacon (D-001 206-13-05) (GE Healthcare, CO, USA) and siRNA-F AF 546 was obtained from Qiagen (Qiagen, Germany).…”

“…Synthesis of P polymer nanoparticles encapsulating PTX: Nanoparticles (named PTX-NP) were prepared according to a modified nanoprecipitation method published before [16]. Briefly, 20 mg of P polymer dissolved in 600 µL of acetone and 400 µL of PTX (1 mg/mL PTX in acetone) were mixed together, to form the diffusing phase.…”

“…Regarding the chemotherapeutic drug, paclitaxel was selected as a taxane example of retained activity and improved tolerability, as compared to traditional MVAC (methotrexate, vinblastine, doxorubicin and cisplatin). As we previously described [16,17], it was encapsulated in our proprietary block co-polymer P nanoparticles (rigid hydrophobic polyester block + flexible hydrophilic PEG block). As for silencing therapy, we selected survivin as the target gene, a protein that plays an important role in the suppression of apoptosis and regulation of cell division [9,[18][19][20][21].…”

Nanoparticle Crossing of Blood–Brain Barrier: A Road to New Therapeutic Approaches to Central Nervous System Diseases

“…• Receptor-mediated transcytosis, where nanoparticles decorated with different ligands on their surface are able to bind specific receptors and thus promote endocytosis. Several receptors and transporters have been used as targets, such as GLUT1, lactoferrin (Lf ), transferrin (Tf ) [10] or different peptides including angiopep-2 or Seq12 [11].…”