Low-Molecular-Weight Heparin and Protamine-Based Polyelectrolyte Nano Complexes for Protein Delivery (A Review Articles)

We produced low-molecular-weight heparin/protamine micro (nano) particles (LMW-H/P MPs·NPs) as a carrier for heparin-binding growth factors (GFs), such as fibroblast growth factor (FGF)-2 and various GFs in platelet-rich plasma (PRP). A mixture of LMW-H (MW: approximately 5000 Da, 6.4 mg/ml) and protamine (MW: approximately 3000 Da, 10 mg/ml) at a ratio of 7:3 (vol:vol) yields a dispersion of micro (nano) particles (200 nm 3 μm in diameter). The diluted LMW-H solution in saline (0.32 mg/ml) mixed with diluted protamine (0.5 mg/ml) at a ratio at 7:3 (vol:vol) resulted in soluble nanoparticles (approximately 100 nm in diameter). The generated NPs could be then stabilized by adding 2 mg/ml dextran (MW: 178-217 kDa) and remained soluble after lyophilization of dialyzed LMW-H/P NPs solution. The LMW-H/P MPs·NPs adsorb GFs, control their release, protect GFs and activate their biological activities. Furthermore, administration of GFs-containing F/P MPs·NPs exhibited significantly higher inductions of vascularization and fibrous tissue formation in vivo than GFs alone. LMW-H/P MPs·NPs can also efficiently bind to tissue culture plates and retain the binding of GFs. The LMW-H/P MPs·NP-coated matrix with various GFs or cytokines provided novel biomaterials that could control cellular activity such as proliferation and differentiation. Thus, LMW-H/P MPs·NPs are an excellent carrier for GFs and are a functional coating matrix for various kinds of cell cultures.