Interfacially active polydopamine for nanoparticle stabilized nanocapsules in a one-pot assembly strategy toward efficient drug delivery.

Nanoscale colloidal capsules are promising drug delivery carriers currently while the demand for multiple-step syntheses and the difficulties in achieving high capsule stability are key obstacles that have greatly restricted their development. Herein, we report a polydopamine (PDA) nanoparticle stabilized nanocapsule as a drug delivery system based on the combination of nanoparticle formation and capsule assembly/stabilization in one pot. In this system, an arginine modified linoleic acid nanoemulsion was employed as the template for the in situ generation/assembly of interfacially active PDA nanoparticles, while directional interaction pairs of carboxylate-guanidine and amino-PDA linked by arginine are involved in the assembly process. The nanocapsules possess an average size of 100 nm, high stability in biological media, and efficient lipophilic transfer of the loaded lipophilic cargo. Notably, the high biocompatibility of the nanocapsules and the non-endocytotic delivery to the cytosol of cancer cells were demonstrated in vitro. Furthermore, the efficient delivery of paclitaxel, as well as paclitaxel/doxorubicin dual cargo, was realized, resulting in the high inhibition of cancer cells. Altogether, the PDA nanoparticle stabilized nanocapsules open new opportunities for the development of promising nanocapsule platforms for biomedical delivery.