A photo-responsive modulation of trans-zeatin

Photo-irradiation of an appropriately designed caged hormones enables the control and manipulation of the corresponding biological processes with high spatial and temporal resolution. Caged trans-zeatin of various types of nitrobenzene carbonate related photoremovable protecting groups have been synthesized. A rapid irradiation liberates the trapped trans-zeatin molecule, permitting targeted perturbation of biological processes including degradation, glucosylation and recognition by appropriate enzymes.

A photo-responsive modulation of trans-zeatin

Photo-irradiation of an appropriately designed caged hormones enables the control and manipulation of the corresponding biological processes with high spatial and temporal resolution. Caged trans-zeatin of various types of nitrobenzene carbonate related photoremovable protecting groups have been synthesized. A rapid irradiation liberates the trapped trans-zeatin molecule, permitting targeted perturbation of biological processes including degradation, glucosylation and recognition by appropriate enzymes.

Red-Light Triggered Photouncaging from Dicyanomethylene-4H-pyran Phototrigger in Aqueous Solution: Applied as a Single Component Nano-Drug Delivery System for Cancer Therapy

The development of Photoremovable protecting groups (PRPGs), which can be activated in the ʽphototherapeutic windowʼ for biological applications, is highly challenging. Only PRPGs based on BODIPY dye have been developed so far, which can be excited ≥600 nm. Herein, we developed for the first time NIR dye hydroxystyryl dicyanomethylene-4H-pyran (DCM) as a PRPG that can be operated in the phototherapeutic window. Ours easily synthesized DCM photocages efficiently released aromatic and aliphatic carboxylic acids in an aqueous solution on irradiation using the light of wavelength ≥600 nm and 650 nm, separately. As an application, we used our DCM-PRPG as a single component nanocarrier drug delivery system (DDS) to uncage valproic acid (a known histone deacetylase inhibitor) for cancer treatment. In vitro studies revealed that our DDS, hydroxystyryl dicyanomethylene-4H-pyran valproic acid conjugate nanoparticles (DCM-VPA-NPs) exhibited good cellular internalization, biocompatibility, and enhanced cytotoxicity upon irradiation.

8-[4-(2-Hydroxypropane-2-yl)Phenyl]-1,3,4,4,5,7-Hexamethyl-4-Boron-3a,4a-Diaza-S-Indacene

During recent years, the BODIPY core became a popular scaffold for designing photoremovable protecting groups (PPG). In this paper, we report the synthesis of a new molecule—8-[4-(2-hydroxypropane-2-yl)phenyl]-1,3,4,4,5,7-hexamethyl-4-boron-3a,4a-diaza-S-indacene—by the treatment of meso-(4-CO2Me-phenyl)-BODIPY with excess of MeMgI. The product was characterized by 1H, 13C NMR and HRMS. The combination of BODIPY core with tertiary benzilyc alcohol might be promising for utilizing this molecule as visible light removable PPG.

Targeted Cancer Therapy Using Compounds Activated by Light

Cancer chemotherapy is affected by a modest selectivity and toxic side effects of pharmacological interventions. Among novel approaches to overcome this limitation and to bring to therapy more potent and selective agents is the use of light for selective activation of anticancer compounds. In this review, we focus on the anticancer applications of two light-activated approaches still in the experimental phase: photoremovable protecting groups (“photocages”) and photoswitches. We describe the structural considerations behind the development of novel compounds and the plethora of assays used to confirm whether the photochemical and pharmacological properties are meeting the stringent criteria for an efficient in vivo light-dependent activation. Despite its immense potential, light activation brings many challenges, and the complexity of the task is very demanding. Currently, we are still deeply in the phase of pharmacological tools, but the vivid research and rapid development bring the light of hope for potential clinical use.

Long wavelength single photon like driven photolysis via triplet triplet annihilation

Photolysis has enabled the occurrence of numerous discoveries in chemistry, drug discovery and biology. However, there is a dearth of efficient long wavelength light mediated photolysis. Here, we report general and efficient long wavelength single photon method for a wide array of photolytic molecules via triplet-triplet annihilation photolysis. This method is versatile and “LEGO”-like. The light partners (the photosensitizers and the photolytic molecules) can be energetically matched to adapt to an extensive range of electromagnetic spectrum wavelengths and the diversified chemical structures of photoremovable protecting groups, photolabile linkages, as well as a broad array of targeted molecules. Compared to the existing photolysis methods, our strategy of triplet-triplet annihilation photolysis not only exhibits superior reaction yields, but also resolves the photodamage problem, regardless of whether they are single photon or multiple photon associated. Furthermore, the biological promise of this “LEGO” system was illustrated via developing ambient air-stable nanoparticles capable of triplet-triplet annihilation photolysis.

Amplifying the reactivity of BODIPY photoremovable protecting groups

Conjugated polymer nanoparticles (CPNs or Pdots) are used to sensitize the photorelease reaction of a BODIPY photoremovable protecting group.