PEGylated liposomes associate with Wnt3A protein and expand putative stem cells in human bone marrow populations
Agnieszka A Janeczek1, Edoardo Scarpa1, Mathew H Horrocks2
1Human Development & Health Academic Unit, Faculty of Medicine, Centre for Human Development, Stem Cells & Regeneration, Bone & Joint Research Group & Institute for Life Sciences, Institute for Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, UK.
Aim:
To fabricate PEGylated liposomes which preserve the activity of hydrophobic Wnt3A protein, and to demonstrate their efficacy in promoting expansion of osteoprogenitors from human bone marrow.
Methods:
PEGylated liposomes composed of several synthetic lipids were tested for their ability to preserve Wnt3A activity in reporter and differentiation assays. Single-molecule microspectroscopy was used to test for direct association of protein with liposomes.
Results:
Labeled Wnt3A protein directly associated with all tested liposome preparations. However, Wnt3A activity was preserved or enhanced in PEGylated 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) liposomes but not in PEGylated 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) liposomes. PEGylated Wnt3A liposomes associated with skeletal stem cell populations in human bone marrow and promoted osteogenesis.
Conclusion:
Active Wnt protein-containing PEGylated liposomes may have utility for systemic administration for bone repair.
