Visible Light‐Triggered On‐Demand Drug Release from Hybrid Hydrogels and its Application in Transdermal Patches

Abstract

On-demand release from stimuli-responsive hydrogels has received great attention due to an increasing clinical need. Here, we have prepared spherical hydrogel beads showing visible light-induced volume change at body temper-ature. By spray injection of the monomer solution using the alginate templ-ating method, hybrid beads of several hundred micrometers, consisting of temperature-responsive poly(N-isopropylacrylamide-co-vinyl-2-pyrrolidinone) hydrogel and magnetite nanoparticles (MNP), are produced. MNP dispersed in the hydrogel matrix absorbed visible light and generated heat, increasing the temperature of the matrix and resulting in shrinkage of the beads proportional to light intensity. It is demonstrated that light-induced volume change of dexamethasone-loaded hybrid beads result in on-demand and localized release of the drug by exposure to moderate visible light. As a potential application of the light-sensitive hybrid hydrogel beads, a transdermal patch is developed that incorporates drug-loaded hydrogel beads in multiple drug reservoirs, achieving enhanced release of a model drug when exposed to visible light. This platform should be applicable to on-demand, sequential, and long-term release of drugs via light exposure.

Visible light to switch-on desorption from goethite

“…The visible light triggered release of adsorbed ions/molecules from the surface of nanoparticles could open a wide range of novel applications including drug delivery, sedimentation, desalination, change in pH, optical devices based on ionic dyes and sensing. 1,2 Light can be further used to induce the mechanical response of materials 3,4 or fluorescence switching which is applicable in sensors and fluorescent logic devices. [5][6][7] Access to this untapped abundant source of energy offers a safe, easy and readily accessible means to switch-on or switchoff different phenomena.…”

“…Some release mechanisms include a tailored polymer to favor release, but most release triggers are coupled to nanoparticles that activate delivery. 1 The most eloquent release mechanism involves the change in the conformation of organic compounds, from one isomer to another after exposure to UV light, 2,3 thereby altering the molecule's adsorption affinity. This is restrictive to a limited number of transportable molecules.…”

“…4 However, there are simpler approaches with functional nanoparticles to facilitate the release from a carrier. 1 The functional particles in previous cases rely on nanoparticles to heat the polymer to promote delivery. [5][6][7] In the first mechanism, light absorbed in nanoparticles heats the nanoparticles, which shrinks the hydrogel and squeezes absorbed species from within its core.…”

Synergistically enhanced selective intracellular uptake of anticancer drug carrier comprising folic acid-conjugated hydrogels containing magnetite nanoparticles

“…Thus, the hydrogel was designed to induce sharp volume phase transition slightly above the body temperature by copolymerization of VP with NIPAm. In our previous study, we revealed that the incorporating hydrophilic VP moieties into the PNIPAm chain lead to the increase of LCST17. For the shell formation, AA was added as amine source for conjugating FA through amide coupling and bisAA was used as the crosslinker.…”

Recent Advances in light-responsive on-demand drug-delivery Systems

“…For instance, magnetite (iron oxide) nanoparticles, which produce a photothermal response with visible light irradiation, were added to NiPAAm microgels. These microgels were encapsulated inside alginate hydrogels and further incorporated into PDMS skin patches for transdermal drug delivery [96]. Typically, transdermal drug-delivery systems are used for long-term delivery and are unable to achieve immediate release when drug action is needed.…”