Electro-responsive controlled drug delivery from melanin nanoparticles.

Mariana Caldas,Irina Pereira,Ana Cláudia Santos,Rui L Reis,Vitor M Correlo,Rita Rebelo,Francisco Veiga

doi:10.1016/j.ijpharm.2020.119773

Mariana Caldas, Irina Pereira + Show 5 more

Open Access

https://doi.org/10.1016/j.ijpharm.2020.119773

Copy DOI

Abstract

Electro-responsive controlled drug delivery has been receiving an increasing interest as one of the on-demand drug delivery systems, aiming the improvement of the therapeutics efficacy by controlling the amount of drug release at a specific time and target site. Herein, we report a simple method to develop an electro-responsive controlled drug delivery system using functionalized melanin nanoparticles (FMNPs) with polydopamine and polypyrrole to precisely control the release of dexamethasone (Dex). Optimized FMNPs showed 376.77±62.05nm of particle size, a polydispersity index of 0.26±0.09 and a zeta-potential (ZP) of -32.59±3.61mV. FMNPs evidenced a spherical shape, which was confirmed by scanning electron microscopy. Fourier-transform infrared spectrometry analysis confirmed the deposition of the polymers on the FMNPs' surface. The incorporation efficiency of the optimized Dex-loaded FMNPs was 94.45±0.63% and the increase of ZP to -40.34±4.65mV was attributed to the anionic nature of Dex. In vitro Dex release studies without stimuli revealed a maximum Dex release below 10%. Applying electrical stimulation, Dex release was augmented, with a maximum of ca. 32% after 24h. The designed FMNPs provide a powerful biomaterial-based technological tool for electro-responsive controlled drug delivery, capable of surpassing the associated lack of efficiency and stability of current carriers.

Highlights

Controlled drug delivery has been one of the major topics from of the current scientific medical research
Preparation and functionalization of melanin nanoparticles Melanin from cuttlefish (Sepia officinalis) was obtained after several purification steps to remove the impurities, and it was naturally presented in the form of NPs with no need of synthetic procedures to reduce the particle size
After the incorporation of Dex into the polymers film formed on the surface of the functionalized melanin NPs (FMNPs)-1 with a size ca. 382.63 nm, the incorporation efficiency of 94.45 ± 0.63% was achieved due to the strong chemical bonds formed between drug and polymers

Summary

Introduction

Controlled drug delivery has been one of the major topics from of the current scientific medical research. Among the “smart materials”, inherently conductive polymers (ICPs) present electrical, magnetic and optical properties. [5] Through alterations in the redox state of ICPs, by controllable and reversible redox reactions, it is possible to change drug release profiles. Electro-responsive polymers-based nanoconstructs with the encapsulating of a drug may be an interesting drug delivery system, hypothesizing that the drug release profile can be controlled by applying an external electrical current as stimulus. The synthesis of these conductive polymers usually involves oxidative polymerization. The oxidation of ICPs creates “holes” along the backbone, through the removal of the electrons, and neighboring electrons are able to move into such “holes” and, allow the progression of the charge along the polymer. [6, 7]

Objectives

Methods

Results

Conclusion