The Construction And Application Of Polyethyleneimine-based Nanoparticles For Imaging And Therapy

Here we developed novel, multifunctional nanoparticles which can encapsulatedrugs and act as an imaging tag. The multifunctional nanoparticles were producedfrom an amphiphilic polymer based on polyethyleneimine (PEI) and hydrophobicpolylactide (PLA). Drugs can be easily encapsulated into the multifunctionalnanoparticles through a modified emulsion/evaporation method. Moreover, themultifunctional nanoparticles possess an unexpectedly bright, multicolor fluorescencein comparison to the weak fluorescence of PEI alone. Most importantly, due to theunique proton sponge effect of PEI, the drug-loaded multifunctional nanoparticleseffectively overcame a major hurdle for drug delivery vehicles by escaping fromendosomes into the cytoplasm. In addition, the drug-loaded multifunctionalnanoparticles have higher antineoplastic activity compared with free drug. Hence,multifunctional nanoparticles derived from amphiphilic PEI could be ideal theranostictools for imaging-guided drug delivery.In addition, by employing PEI as carbon source, we established a simple andeffective passivation-free route to produce multifunctional carbon dots (PCDs) forimaging and gene delivery. These PCDs showed excellent properties for combinedimaging and gene delivery. The quantum yield of the PCDs was calculated to be54%,which is one the highest value among the carbon dots reported to date. A significantadvantage of this kind of carbon dots lies in their partially unchanged bPEI chainaround the surface of carbon dots, which demonstrated the potential for gene delivery.Moreover, the PCDs exhibited extremely good biocompatibility and successfullymediated and visualized the gene transfection process in cells, demonstrating the greatpotential in bioimaging and gene delivery.