Synthesis and characterization of new spiropyran micrometer-sized photochromic fluorescent polymeric particles of narrow size distribution by a swelling process

Dual‐responsive reversible photo/thermogelling polymers exhibiting high modulus change

“…Dihydroxy‐spiropyran (SP), also known as (2‐(8‐(hydroxymethyl)−3,3′‐dimethyl‐6‐nitrospiro [chromene‐2,2′‐indolin]‐1′‐yl)ethanol) was synthesized according to references . d, First, indolium bromide 1 was grinded with potassium hydroxide in open air to a fine paste to obtain indole 2 .Methylhydroxy substituted salicylaldehyde 4 was obtained by hydrolysis of 3‐chloromethyl‐5‐nitrosalicylaldehyde.After recrystallization from water, it can be used for the next step.…”

“…(a)] demonstrated the reversible isomerization from spiropyran to merocyanine and consistent amount of merocyanine formed on UV irradiation regardless the number of rounds of light exposure. As photochromism is an inherit property of spiropyran, d, and other two segments PEG, PPG or the copolymer of PEG‐PPG do not possess photochromic property, the change of absorbance is solely attributed to spiropyran. The color conversion was very fast in the range of 5 s to 1 min depending on the concentration of the polymer solution, which is much faster than the previous report on copolymer of PNIPPAM and spiropyran (20 days exposure to daylight) …”

“…Light, as a trigger, provides high spatiotemporal control. Spiropyran, azobenzene, coumarin, o ‐nitrobenzyl derivatives, and diarylethene have been used to generate light‐responsive polymers. However, the current light responsive polymers are restricted by limited conversion and slow kinetics since the change is usually induced by isomerization of the photosensitive molecules.…”

Fluorescent Dyes Used in Polymer Carriers as Imaging Agents in Anticancer Therapy

“…One molecule alternately emits two distinct fluorescent colors and photoexcitation can switch one fluorescence color to the other [261][262][263]. The UV illumination induces the spiropyran (SP) to merocyjanine (MC) conversion and switches on fluorescence ( Figure 27).…”

FRET-based acrylic nanoparticles with dual-color photoswitchable properties in DU145 human prostate cancer cell line labeling

“…Spiropyran derivatives respond to incident light and involve in a photoinduced ringopening reaction that spiro (SP) form changes to merocyanine (MC) form with different spectroscopic properties [18][19][20]. Merocyanin isomer of spiropyran can receive energy from a fluorescent dye through fluorescence resonance energy transfer.…”