Fabrication of a pH-responsive nanoparticle for drug delivery

Targeted nano-drug delivery has been an effective and promising treatment of cancer since nanoparticles are equipped with numerous advantageous properties compared to traditional chemotherapy. This invention proposes an endosomal pH-responsive micellar nanoparticles. These pH-responsive nanoparticles were prepared by self-assembly of an amphiphilic poly(ethylene glycol)-imine-doxorubicin(PEG-imine-DOX) prodrug, and free DOX could be encapsulated in the hydrophobic core of the nanoparticles. The PEG-imine-DOX prodrug is synthesized by three organic reactions with reactants PEG-OH, P-carboxybenzaldehyde and DOX. To achieve the prolonged systemic circulation time and quick release of the drug, biocompatible PEG and highly hydrophilic DOX are used as reactive materials. The prodrug PEG-imine-DOX nanoparticles exhibited excellent strong stability under normal physiological conditions but disassembled quickly in response to the faintly acidic environment. The method mentioned in this invention carries out a breakthrough in preceding cancer therapy that the hydrophilic nanoparticles possess high targeting capability to cancerous cells and mitigate the damage to healthy cells.