13 research outputs found
Lomustine Nanoparticles Enable Both Bone Marrow Sparing and High Brain Drug Levels – A Strategy for Brain Cancer Treatments
Purpose The blood brain barrier compromises glioblastoma chemotherapy. However high blood concentrations of lipophilic, alkylating drugs result in brain uptake, but cause myelosuppression. We hypothesised that nanoparticles could achieve therapeutic brain concentrations without dose-limiting myelosuppression. Methods Mice were dosed with either intravenous lomustine Molecular Envelope Technology (MET) nanoparticles (13 mg kg-1) or ethanolic lomustine (6.5 mg kg-1) and tissues analysed. Efficacy was assessed in an orthotopic U-87 MG glioblastoma model, following intravenous MET lomustine (daily 13 mg kg-1) or ethanolic lomustine (daily 1.2 mg kg-1 - the highest repeated dose possible). Myelosuppression and MET particle macrophage uptake were also investigated. Results The MET formulation resulted in modest brain targeting (brain/ bone AUC0-4h ratios for MET and ethanolic lomustine = 0.90 and 0.53 respectively and brain/ liver AUC0-4h ratios for MET and ethanolic lomustine = 0.24 and 0.15 respectively). The MET formulation significantly increased mice (U-87 MG tumours) survival times; with MET lomustine, ethanolic lomustine and untreated mean survival times of 33.2, 22.5 and 21.3 days respectively and there were no material treatment-related differences in blood and femoral cell counts. Macrophage uptake is slower for MET nanoparticles than for liposomes. Conclusions Particulate drug formulations improved brain tumour therapy without major bone marrow toxicity
Lomustine Nanoparticles Enable Both Bone Marrow Sparing and High Brain Drug Levels – A Strategy for Brain Cancer Treatments
A Self-Assembling Lipidic Peptide and Selective Partial V2 Receptor Agonist Inhibits Urine Production
Polymeric Nanoparticles
Self-assembling polymers, which are either amphiphilic block copolymers with hydrophobic and hydrophilic blocks, hydrophilic polymer backbones substituted with hydrophobic units or polymers with a low aqueous solubility, may all be used to prepare aqueous dispersions of polymeric nanoparticles. The amphiphilic variants form polymeric micelles and polymeric bilayer vesicles. The hydrophobic polymers form dense amorphous polymeric particles. Polymeric particles, of whichever nature, may be loaded with hydrophobic and hydrophilic drugs, and the bioavailability of the drug compound is altered by this encapsulation within a polymeric nanoparticle. This simple concept has been exploited heavily to yield enhancements in oral, tumour and brain bioavailability and some of these polymeric nanoparticle formulations have undergone clinical testing and even been commercialised, e.g. the nanoparticle paclitaxel formulation AbraxaneNon peer reviewe