Rescue of mitochondrial function in parkin-mutant fibroblasts using drug loaded PMPC-PDPA polymersomes and tubular polymersomes

Neurosci Lett. 2016 Sep 6:630:23-29. doi: 10.1016/j.neulet.2016.06.065. Epub 2016 Jul 10.

Abstract

Mutations in parkin cause autosomal recessive Parkinsonism and mitochondrial defects. A recent drug screen identified a class of steroid-like hydrophobic compounds able to rescue mitochondrial function in parkin-mutant fibroblasts. Whilst these possess therapeutic potential, the size and high hydrophobicity of some may limit their ability to penetrate the blood-brain barrier from systemic circulation, something that could be improved by novel drug formulations. In the present study, the steroid-like compounds Ursolic Acid (UA) and Ursocholanic Acid (UCA) were successfully encapsulated within nanoscopic polymersomes formed by poly(2-(methacryloyloxy)ethyl phosphorylcholine)-poly(2-di-isopropylamino)ethyl methacrylate) (PMPC-PDPA) and separated into spherical and tubular morphologies to assess the effects of nanoparticle mediated delivery on drug efficacy. Following incubation with either morphology, parkin-mutant fibroblasts demonstrated time and concentration dependent increases in intracellular ATP levels, resembling those resulting from treatment with nascent UA and UCA formulated in 0.1% DMSO, as used in the original drug screen. Empty PMPC-PDPA polymersomes did not alter physiological measures related to mitochondrial function or induce cytotoxicity. In combination with other techniques such as ligand functionalisation, PMPC-PDPA nanoparticles of well-defined morphology may prove a promising platform for tailoring the pharmacokinetic profile and organ specific bio-distribution of highly hydrophobic compounds.

Keywords: Anisotropic nanoparticle; Mitochondria; PMPC-PDPA; Parkin; Parkinson’s disease; Polymersome.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Cells, Cultured
  • Cholic Acids / pharmacology*
  • Drug Delivery Systems / methods*
  • Fibroblasts / drug effects*
  • Fibroblasts / metabolism
  • Humans
  • Mitochondria / drug effects*
  • Mitochondria / metabolism
  • Mutation
  • Nanocapsules / administration & dosage*
  • Nanocapsules / toxicity
  • Nanocapsules / ultrastructure
  • Phosphorylcholine / analogs & derivatives*
  • Phosphorylcholine / pharmacology
  • Phosphorylcholine / toxicity
  • Polymethacrylic Acids / pharmacology*
  • Polymethacrylic Acids / toxicity
  • Triterpenes / pharmacology*
  • Ubiquitin-Protein Ligases / genetics*
  • Ursolic Acid

Substances

  • Cholic Acids
  • Nanocapsules
  • Polymethacrylic Acids
  • Triterpenes
  • poly(2-(methacryloyloxy)ethyl phosphorylcholine)-block-(2-(diisopropylamino)ethyl methacrylate)
  • Phosphorylcholine
  • Adenosine Triphosphate
  • Ubiquitin-Protein Ligases
  • parkin protein
  • cholanic acid