Synthesis and characterization of bioreducible heparin-polyethyleneimine nanogels: application as imaging-guided photosensitizer delivery vehicle in photodynamic therapy
Abstract
Herein, we synthesized and characterized novel bioreducible heparin polyethyleneimine (HPC) nanogels consisting of heparin, branched polyethyleneimine (PEI) and L-cysteine. 1H-NMR and FTIR analysis confirmed the formation of HPC nanogels while TEM and dynamic light scattering revealed uniform spherical nanoparticles with average diameter of <200 nm. Zinc phthalocyanine (ZnPC) was encapsulated via the dialysis method and the drug is released in vitro from disulfide-containing HPC nanogels in a redox-sensitive manner at low pH. Additionally, HPC nanogels possess bright blue fluorescence which eliminates the use of additional probing agent in image-guided drug delivery. Moreover, singlet oxygen detection revealed that nanogels prevented ZnPc aggregation thus enhancing 1O2 generation and photodynamic therapy (PDT) efficacy. These results showed that disulfide crosslinked HPC nanogels are promising vehicles for stimulated photosensitizer delivery in advanced PDT.