Photocontrolled Drug Release From Donor–Acceptor Stenhouse Adduct Amphiphile Doped Laden Polymeric Hydrogel

In chemotherapy, drug dosage should be carefully planned with precise pharmacokinetics. Compared to direct, soluble drug administration, a stimuli-responsive drug delivery material system provided an on-demand medication with minimum adverse effects. Among many stimuli, the use of external red light enables manual remote functionality compared to physiological stimuli such as pH. Herein, a 650 nm red-light-responsive, metal-free hydrogel scaffold for stimuli-responsive drug delivery is reported. The hydrogel network is built by poly(ethylene) glycol thiol and poly(ethylene) glycol acrylate via Michael addition. Donor-acceptor Stenhouse adduct amphiphile (DA), which acts as the moderator of hydrophobic drug doxorubicin, is encapsulated in a polyethylene glycol network to create a drug-loaded hydrogel scaffold. The preparation of DA is purely aqueous and shows a broad absorbance band over 430-800 nm, which enables potential operation in deep tissue. During the drug release experiments, the presence of amphiphile greatly slows the drug release rate in vitro. By using 650 nm laser irradiation, the drug release from amphiphile-encapsulated hydrogel can be triggered after the passive diffusion period. The proposed hydrogel serves as an example of the combination of a photo-switch conjugated amphiphile and a conventional, commercially available polymer hydrogel network, which could serve as a potential smart material for drug delivery.