Light Switchable Bioorthogonal Reaction Manifold for Modulation of Hydrogel Properties.

Chemical reaction systems that can occur via multiple pathways in a controllable fashion are highly attractive for advanced materials applications and biological research. In this report, we introduce a bioorthogonal reaction manifold based on a chalcone pyrene () moiety that can undergo either red-shifted photoreversible [2 + 2] cycloaddition or thiol-Michael addition click reaction. By coupling the to a water-soluble poly(ethylene glycol) end group, we demonstrate the efficient polymer dimerization and cleavage by blue light (λ = 450 nm) and UV light (λ = 340 nm), respectively.

Wavelength-Selective Xanthene-Based Monochromophoric Photoremovable Protecting Groups for Tuning Soft Matter Material Properties.

Photocontrolled deprotection of specific functional groups has garnered significant interest over the past two decades. Notably, the selective deprotection of distinct groups based on wavelength has emerged as a prominent focus in recent research. The achievement of this objective has primarily involved the utilization of linker-based bichromophoric systems and diverse cocktail mixtures of photoresponsive protecting groups (PRPGs), each responsive to varying wavelengths of light.

Temporal Release of Cell Cycle Regulator α-Lipoic Acid: An NIR-Light (Two-Photon) Activatable Quinoxaline-Based Nano-Prodrug Delivery System.

The regulation of the cell cycle has recently opened up a new research perspective for cancer treatment. So far, no effort has been made for temporal control of cell cycles using a photocleavable linker. Presented herein is the first report of regulation of disrupted cell cycles through the temporal release of a well-known cell cycle regulator α-lipoic acid (ALA), enabled by a newly designed NIR-active quinoxaline-based photoremovable protecting group (PRPG).

Spatiotemporal photo-release of hydrogen sulphide from β-carboline-derived nanoparticles for therapeutic applications.

Hydrogen sulfide (HS) is an important gasotransmitter that plays a significant role in the regulation of various physiological activities. The therapeutic effect of HS is highly concentration-dependent and has recently been recognized for wound healing applications. Until now, the reported HS delivery systems for wound healing applications have been focused on polymer-coated cargo systems for the encapsulation of HS donors that are based just on endogenous stimuli-responsive systems such as pH or glutathione.

Recent Advances on Stimuli-Responsive Combination Therapy against Multidrug-Resistant Bacteria and Biofilm.

The widespread occurrence of infections from multidrug-resistant (MDR) bacteria is a global health problem. It has been amplified over the past few years due to the increase in adaptive traits in bacteria and lack of advanced treatment strategies. Because of the low bioavailability and limited penetration at infected sites, the existing antibiotics often fail to resist bacterial growth.

A Natural Alkaloid, β-Carboline, as a One- and Two-Photon Responsive Fluorescent Photoremovable Protecting Group: Sequential Release of the Same or Different Carboxylic Acids.

The β-carboline moiety, substituted at the C1 and C3 benzylic positions with a leaving group, has been demonstrated for the first time as a photoremovable protecting group for time-dependent sequential release of two (same or different) carboxylic acids upon one- and two-photon light irradiation. Density functional theory calculations suggest that the electronic environment of the β-carboline moiety at C1 and C3 positions plays a key role in the rate of photorelease.

Wavelength-Orthogonal Photocleavable Monochromophoric Linker for Sequential Release of Two Different Substrates.

A wavelength-orthogonal photocleavable monochromophoric linker was developed that is based on a 3-acetyl-9-ethyl-6-methylcarbazole (AEMC) moiety substituted at both the phenacyl and benzylic positions with different carboxylic acids. The different carboxylic acids were released sequentially upon irradiation with light of λ ≥ 365 nm and λ ≥ 290 nm, respectively.