Cancer nanomedicine based on polyethylenimine-mediated multifunctional nanosystems

Owing to the unique structural characteristics and abundant amine groups, polyethylenimine (PEI) plays a remarkable role in the construction of multifunctional nanosystems for versatile biomedical applications, particular for cancer nanomedicine. Nanoparticles (NPs), polymers, fluorophores, targeting molecules or/and different cargos can be integrated within one single system via PEI-mediated chemistry, thereby allowing for the generation of a range of PEI-based nanoplatforms. On the molecular imaging front, PEI-based NPs serve as contrast agents to transduce biomolecular interactions into various types of signals for single-, dual- or multi-mode imaging of tissues and diseases. With rational modifications, PEI-based nanocarriers can be developed and utilized for targeted and responsive delivery of drugs, genes and proteins. Utilizing the unique features of PEI-based NPs that can convert external stimuli (e.g., magnetic field, light and X-ray) into heat or free radical, in vivo magnetic hyperthermia, phototherapy, and radiotherapy can be realized, achieving excellent anti-tumor therapeutic outcomes. In this review, we summarize the recent progress in the development of PEI-based multifunctional nanosystems for versatile biomedical applications in cancer nanomedicine and discuss the current challenges and future prospects in this related field.