Bicontinuous\nNanoparticles from Spontaneous Self-Assembly\nof Block Copolymer Prodrug in Aqueous Medium for Potential Cancer\nTherapy

Despite having several advantages, bicontinuously structured\npolymeric\nnanoparticles (BSPNPs) are far less explored in the field of controlled\ndrug delivery owing to the requirement of complex precursor copolymers\nand the associated multistep synthetic procedures. In this work, we\nreport the synthesis of a redox-sensitive diblock copolymer (P1),\nwhich was subsequently utilized to prepare doxorubicin (DOX) containing\na pH-labile prodrug (P2). P1 and P2 spontaneously self-assembled in\naqueous media above their critical aggregation concentration, forming\nmicellar nanoparticles with rare bicontinuous morphology that promotes\nloading of both hydrophobic and hydrophilic cargoes in different compartments.\nTo the best of our knowledge, the formation of BSPNPs through direct\nself-assembly in aqueous media has not yet been reported. <i>In vitro</i> cellular studies asserted the higher safety profile\nof the nanoparticles against noncancerous cells (HEK293T) than free\nDOX, whereas they displayed higher drug-induced cytotoxicity against\ncancer cells (MCF-7) in comparison to free DOX, establishing them\nas promising cancer drug delivery systems.