Multidrug encapsulation within self-assembled 3D structures formed by biodegradable nanoparticles

•Oppositely charged biodegradable NPs were synthesized.•Self-assembly of NPs in 3D macrostructure was studied.•A strategy to load both hydrophilic and hydrophobic drug in the network was optimized.•The final 3D network is promising as multiple drug delivery device.

Polymer nanoparticles (NPs) have recently attracted increasing attention and represent one of the main and important novelties in nanomedicine. In particular, they exhibit several advantages like the ability to tailor and sustain the release of hydrophobic drugs, high biocompatibility and degradability, together with the possibility to be highly cell selective. However, the usage of NPs in several diseases can be limited by their route of administration: in fact their diffuse distribution in tissues and organs does not allow to address them specifically in the target situ limiting therapeutic outcome and increasing potential side effects. In this work we studied the self-assembly of opposite charged polymer nanoparticles able to retain aqueous solutions, with the aim of creating self-assembled macrostructures that can release both hydrophobic and hydrophilic compounds. NPs were synthesized with a two-steps process starting from ε-caprolactone and hydroxyethyl methacrylate to create biodegradable macromonomers which were then co-polymerized in an emulsion polymerization with methacrylic acid and either a positive charged surfmer (HEMA-Ch+) or a negative one (HEMA-SO3−). The feasibility to assemble these NPs into macrostructures was studied and the structures of the final products as well as their ability to release mimetic drugs were evaluated.

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