Near-Infrared-Induced Heating of Confined Water in Polymeric Particles for Efficient Payload Release

Abstract

Near-infrared (NIR) light-triggered release from polymeric capsules could make a major impact on biological research by enabling remote and spatiotemporal control over the release of encapsulated cargo. The few existing mechanisms for NIR-triggered release have not been widely applied because they require custom synthesis of designer polymers, high-powered lasers to drive inefficient two-photon processes, and/or coencapsulation of bulky inorganic particles. In search of a simpler mechanism, we found that exposure to laser light resonant with the vibrational absorption of water (980 nm) in the NIR region can induce release of payloads encapsulated in particles made from inherently non-photo-responsive polymers. We hypothesize that confined water pockets present in hydrated polymer particles absorb electromagnetic energy and transfer it to the polymer matrix, inducing a thermal phase change. In this study, we show that this simple and highly universal strategy enables instantaneous and controlled release of payloads in aqueous environments as well as in living cells using both pulsed and continuous wavelength lasers without significant heating of the surrounding aqueous solution.

Visible light and near-infrared-responsive chromophores for drug delivery-on-demand applications

“…A study in BALB/c mice showed that 13nm-sized gold nanoparticles induced inflammation and apoptosis in liver tissue after 7 days [46]. Recently, a NIR actuated delivery system was designed where water was confined within poly (lactic-co-glycolic acid) (PLGA) particles and released fluorescein as the water was heated above the polymer's glass transition temperature [47]. A key strength of the system is the biocompatibility since PLGA is already used in FDA-approved implantable devices; however, the system is slow to respond as it takes 5 min of light exposure to trigger release and all light cycles occurred within 90 min.…”

Zeta Inhibitory Peptide Disrupts Electrostatic Interactions That Maintain Atypical Protein Kinase C in Its Active Conformation on the Scaffold p62

“…Fluorescence Lifetime Imaging-Fluorescence lifetime imaging microscopy (FLIM) was performed as described previously (40). Briefly, live COS-7 cells were imaged with a SliceScope two-photon microscope (Scientifica) using a 60ϫ water immersion objective (LUMPLFLN 60XW, NA ϭ 1.0, Olympus) and a Chameleon Ultra II IR laser (Coherent) tuned at 930 nm for the excitation of GFP.…”

Engineered photo-responsive materials for near-infrared-triggered drug delivery

“…7) [54]. Upon exposure to 980 nm NIR light, water molecules absorb optical energy through vibrational transitions, rapidly converting it into heat [55].…”