Screening Functionalised Polymersomes Targeting Transcytosis Across Blood-Brain Barrier

The aims of this research project were to manufacture and characterise PDPA-based pH-sensitive functionalised polymersomes using a medium-high content screening method, suitable for CNS drug delivery. Angiopep-2 functionalised polymersome formulations have been found that are able to penetrate the blood-brain barrier (BBB) effectively in both in vitro models and in vivo. Using Transmission Electron Microscopy, Dynamic Light Scattering, FACS analysis, and 2D in vitro screening gave information on the physical and biological features of polymersomes based on their different chemistries, including size distribution, architecture, topology, cellular localisation, cellular uptake kinetic and immune response. The studies showed the possibility of controlling cellular internalization and cargo destinations by manipulating polymersome surface chemistry and specific ligand(s). The subsequent in vitro and in vivo studies built on these screening results. Using extensive Confocal Laser Microscopy and image analysis, Ang-POEGMA-PDPA polymersomes showed effective receptor-mediated transcytosis (RMT) in the 3D in vitro BBB model established, while the RVG- functionalised formulation did not. Further in vivo studies showed that the Ang-functionalised polymersomes were able to penetrate the mouse BBB via effective RMT. Moreover, primary cargo delivery studies showed successful IgG transport into brain by Angiopep-2-functionalised POEGMA-PDPA polymersomes. The results in this thesis can provide a useful platform for further examination of CNS delivery of polymersomes and their cargos.