Polymer Science

Biological activity In vitro, absorption, BBB penetration and tolerability of nanoformulation of BT44, a RET agonist with disease-modifying potential for the treatment of neurodegeneration

Authors

  • Malik Salman Haider Functional Polymer Materials, Chair for Advanced Materials Synthesis, Institute for Functional Materials and Biofabrication, Department of Chemistry and Pharmacy, Julius-Maximilians-University Würzburg, Röntgenring 11, 97070 Würzburg, Germany ,
  • Arun Kumar Mahato Laboratory of Molecular Neuroscience, Institute of Biotechnology, HiLIFE, University of Helsinki, 00014, Helsinki, Finland ,
  • Anastasiia Kotliarova Laboratory of Molecular Neuroscience, Institute of Biotechnology, HiLIFE, University of Helsinki, 00014, Helsinki, Finland ,
  • Stefan Forster Functional Polymer Materials, Chair for Advanced Materials Synthesis, Institute for Functional Materials and Biofabrication, Department of Chemistry and Pharmacy, Julius-Maximilians-University Würzburg, Röntgenring 11, 97070 Würzburg, Germany ,
  • Bettina Böttcher Biocenter and Rudolf Virchow Centre, Julius-Maximilians-University Würzburg, Haus D15, Josef-Schneider-Str. 2, 97080 Würzburg, Germany ,
  • Philipp Stahlhut Department of Functional Materials in Medicine and Dentistry, Institute of Functional Materials and Biofabrication and Bavarian Polymer Institute, Julius-Maximilians-University Würzburg, Pleicherwall 2, 97070 Würzburg, Germany ,
  • Yulia Sidorova Laboratory of Molecular Neuroscience, Institute of Biotechnology, HiLIFE, University of Helsinki, 00014, Helsinki, Finland ,
  • Robert Luxenhofer Soft Matter Chemistry, Department of Chemistry, and Helsinki Institute of Sustainability Science, Faculty of Science, University of Helsinki, PB 55, 00014 Helsinki, Finland

Abstract

BT44 is a novel, second generation glial cell line-derived neurotropic factor (GDNF) mimetic, with improved biological activity and a lead compound for the treatment of neurodegenerative disorders. Like many other small molecules, it suffers from intrinsic poor aqueous solubility, posing significant hurdles at various levels for its preclinical development and clinical translation. Herein, we report a poly(2-oxazoline)s (POx) based BT44 micellar nanoformulation with ultra-high drug loading capacity of 47 wt.%. The BT44 nanoformulation was comprehensively characterized by 1H-NMR spectroscopy, differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), dynamic light scattering (DLS) and cryo-transmission/scanning electron microscopy (cryo-TEM/SEM). The DSC, XRD and redispersion studies collectively confirmed that the BT44 formulation can be stored as a lyophilized powder and can be redispersed upon need. The DLS suggested that the redispersed formulation is suitable for parenteral administration (Dh ≈ 70 nm). The cryo-TEM measurements showed the presence of worm-like structures both in plain polymer and BT44 formulation. The BT44 formulation retained biological activity in immortalized cells and in cultured dopamine neurons. The micellar nanoformulation of BT44 exhibited improved absorption (after subcutaneous injection) and blood-brain barrier (BBB) penetration and no acute toxic effects in mice were observed. In conclusion, herein, we have developed an ultra-high BT44 loaded aqueous injectable nanoformulation, which can be used to pave way for its preclinical and clinical development for the management of neurodegenerative disorders.

Version notes

minor change in title, some updates in results and discussion part, Figure 6 (SEM) is updated, A new figure is added to the SI.

Content

Thumbnail image of BT44 Manuscript.pdf

Supplementary material

Thumbnail image of BT44 SI.pdf
Supporting information for BT44 Micellar formulation
Synthesis of 2-n-pentyl-2-oxazoline monomer and triblock copolymers, DSC thermogram of three POx based triblock copolymer, groups contributing towards HSPs determination, quantification of BT44 by HPLC, visual appearance of BT44 formulation, 1H-NMR spectra of polymers and formulation, DSC thermogram of lyophilized formulation.