Abstract

Background: Polymers play a key-role in the drug delivery technology. They allow for the controlled release of therapeutic agents under an external stimulus if a sensitive segment is suitable incorporated in the polymer matrix. Actually, polymer capsules containing noble metal nanostructures are regarded as promising light-responsive drug carriers. Among polymers, poly(methacrylic acid), PMA, offers manifold advantages: i) solubility in water, ii) coordination ability for Ag-Au nanoparticles, and iii) ability to act as capping agent. However, the preparation of Ag/PMA nanocolloids involves complex procedures the use of reagents with severe environmental impact.

Objective: The goal of this work is to develop Ag/PMA nanocolloids for the controlled release of the encapsulated therapeutic agent (Sorafenib Tosylate) through a simple and cost effective synthesis process and the use of biocompatible, implantable materials. The light- and heat-responsiveness of fibrous scaffolds of Ag/PMA nanocolloids produced by electrospinning is investigated and compared with that of Ag/PMA nanocolloids.

Methods: The goal of this work is to develop Ag/PMA nanocolloids for the controlled release of the encapsulated therapeutic agent (Sorafenib Tosylate) through a simple and cost effective synthesis process and the use of biocompatible, implantable materials. The light- and heat-responsiveness of fibrous scaffolds of Ag/PMA nanocolloids produced by electrospinning is investigated and compared with that of Ag/PMA nanocolloids.

Results: In both the investigated systems, Ag/PMA nanocolloids and electrospun scaffolds of Ag/PMA nanocolloids, the drug release is significantly favored by the considered stimuli. Upon heat stimulus, Ag/PMA nanocolloids provide greater cumulative drug release with respect to the electrospun scaffold. Conversely, upon light stimulus, the scaffold is able to release a larger amount of Sorafenib at a faster rate, thanks to the Ag-mediated laser irradiation heating effect.

Conclusion: The electrospun fibrous scaffold of Ag/PMA nanocolloids is demonstrated to be an efficient system for the remotely-triggered delivery of drug in a target area. The values of its loading efficiency (60%) and drug content (5.5%) are comparable to the ones obtained from amphiphilic copolymer structures prepared via complex chemical procedures with the use of toxic solvents and surfactant to stabilize the nanocolloids.

Keywords: Drug delivery, PMA, Ag nanoparticles, surface plasmon resonance, UV-enhanced chemical process, metalpolymeric colloids, stimuli-responsive scaffolds, electrospinning.

Graphical Abstract