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Light Controlled In Vitro Gene Delivery Using Polymer-Tethered Spiropyran as a Photoswitchable Photosensitizer
摘要： A gene delivery system using spiropyran as a photoswitchable photosensitizer for controlled photochemical internalization effect was developed by engineering the outer coating of polyethylenimine/DNA complex with a small amount of spiropyran-containing cationic copolymers. The successful binding of cationic polymers by the polyethylenimine coating was detected by the distance-sensitive fluorescence resonance energy transfer technique that evidenced occurrence of energy transfer between fluorescein-labeled cationic copolymers and polyethylenimine-condensed rhodamine-labeled DNA. The ternary polyplexes feature reversible controllability of singlet oxygen generation based on the dual effect of spiropyrans in photochromism and aggregation-induced enhanced photosensitization, allowing significant light-induced amplification of bPEI-mediated in vitro transgene efficiency (from original 15% to final 91%) at a low DNA dose, with the integrity of supercoiled DNA structure unaffected. The use of spiropyran without the need of other photosensitizers circumvents the issue of uncontrolled long-lasting photocytotoxicity in gene delivery.
关键词： gene delivery,spiropyran,photoswitching,singlet oxygen,fluorescence resonance energy transfer
更新于2025-11-21 11:08:12
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Preparation and photochromic behavior of spiropyran-containing fluorinated polyacrylate hydrophobic coatings
摘要： In this study, spiropyran (SP)-containing fluorinated polyacrylate (F-PA-SP) latex was prepared by emulsion polymerization using fluorinated and SP-based acrylic monomers as raw materials. FT-IR and 1H-NMR demonstrate that the F-PA-SP copolymer has been successfully synthesized, and DLS and TEM analyses indicate that the synthesized latex has presented a uniform particle size of approximately 200 nm. XPS, AFM and water contact angle (WCA) analysis were used to investigate the surface properties of the F-PA-SP coating and demonstrate that its hydrophobicity is enhanced by addition of a fluorinated acrylic monomer. The photochromic properties of the coating were investigated by UV-Vis spectroscopy, and the results reveal that the F-PA-SP coating possesses better photo-responsiveness, fatigue resistance, and photo-reversibility under UV/Vis irradiation than the coating prepared using fluorinated polyacrylate/SP blended latex. Moreover, the WCA of the F-PA-SP coating subjected to UV/Vis irradiation shows minimal changes and retains its excellent hydrophobicity. Finally, the F-PA-SP latex was applied to cellulosic paper, and the resulting photochromic paper exhibits outstanding reversible color changes and hydrophobicity.
关键词： emulsion polymerization,hydrophobicity,fluorinated polyacrylate,spiropyran,photochromic
更新于2025-09-23 15:21:01
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Rewritable Optical Patterns in Light Responsive Ultra High Molecular Weight Polyethylene
摘要： Spiropyran is used as a photochromic dye to create colored patterns in highly drawn ultra high molecular weight polyethylene (UHMW PE) films. The dye is incorporated in highly crystalline, drawn UHMW PE tapes and fibers and isomerizes to its merocyanine state upon UV light irradiation, resulting in a color change from transparent to purple. The isomerization from merocyanine to spiropyran to erase the color can be simply induced using heat or a green LED light. The combination of the use of a mask and the reversibility of the isomerization results in colored patterns which can be written, erased and re-written using UV light and heat or green LED light.
关键词： Polymer fibers,ultra high molecular weight polyethylene,photochromism,light responsive materials,rewritable optical materials,spiropyran
更新于2025-09-19 17:15:36
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Fast responsive photo-switchable dual-color fluorescent cyclodextrin nanogels for cancer cell imaging
摘要： Photo-switchable dual-color fluorescent nanogels were fabricated via nanoprecipitation in aqueous solution. The spiropyran-modified β-cyclodextrin (β-CD-SP) and 4-amino-7-nitro-1,2,3-benzoxadiazole (NBDNH2) were encapsulated into nanogels in the presence of 1,6-hexamethylene diisocyanate (HMDI). In the nanogels, spiropyran moiety acted as fluorescence molecule acceptors under the irradiation of UV or visible light to quench or recover the fluorescence of the NBDNH2 to achieve reversible dual-color fluorescence. The feed ratio of the two fluorophores played vital role on the energy transfer efficiency (E) of the nanogels, and the results showed that high E (90.7%) can be achieved when the feed ratio of NBDNH2/β-CD-SP is 1:2 (mol/mol). In addition, the nanogels can maintain good photo-switchable fluorescent behavior as long as 5 weeks. With rapid photo-responsiveness (within 60 s), good reversibility, long-term stability, and excellent cytocompatibility, the as-prepared nanogels have been successfully applied to photo-switchable dual-color fluorescent imaging in cancer cell.
关键词： Photo-switchable,Spiropyran,Cyclodextrin,Nanogel
更新于2025-09-19 17:15:36
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Design and Synthesis of a Well-Controlled Mechanoluminescent Polymer System Based on Fluorescence Resonance Energy Transfer with Spiropyran as a Force-Activated Acceptor and Nitrobenzoxadiazole as a Fluorescent Donor
摘要： Colorimetric mechanophores, which change color through force-induced covalent bond breakage, have been incorporated into polymer chains to create mechanochromic materials. However, the color change of most mechanophores is a turn-on response. In this work, we designed and synthesized a novel mechanoluminescent polymer system, PBA-SP-P(MMA-co-NBD), based on fluorescence resonance energy transfer (FRET) with spiropyran (SP) as a force-activated "on/off" mechanophore acceptor and nitrobenzoxadiazole (NBD) as a fluorescent donor. It is a comb polymer having NBD-bearing poly(methyl methacrylate) (PMMA) side chains grafted onto a poly(butyl acrylate) (PBA) backbone through SP groups. The processed polymer yields a morphology having NBD-containing PMMA nanodomains embedded into a PBA matrix with SP at the interface. The distance between NBD and SP functionalities is less than 10 nm with confinement of the nanophase separation, which effectively facilitates their fluorescence resonance energy transfer. Under uniaxial stretch, the materials change color at strains as low as about 18% and undergo a green-to-red fluorescence color switch. The two colors are ratiometric, exhibiting a linear correlation with strain after the onset of mechanoactivation. The color change is greatly enhanced right after failure. The fluorescence emission performance can be well controlled through regulating the PMMA/PBA and SP/NBD ratios in the synthesis. The synthesized polymer system exhibits a good potential as an indicator in monitoring microscale cut damages.
关键词： mechanochromic materials,nitrobenzoxadiazole,spiropyran,fluorescence resonance energy transfer,mechanoluminescent polymer
更新于2025-09-16 10:30:52
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Optically controlled field effect transistors based on photochromic spiropyran and fullerene C60 films
摘要： Optically controlled organic field effect transistors containing a binary mixture of fullerene C60 (n-semiconductor) and spiropyran (photoresponsive conductivity modulator) as the active layer were designed and fabricated. The obtained transistors demonstrated higher transfer characteristics (source-drain current), charge carrier mobility in the active layer, and response rate to an external influence than the multilayer transistor (wherein these semiconductor and photo responsive material are in different layers), which makes them promising candidates for the design of optical memory elements.
关键词： Optically controlled field effect transistors,photochromic spiropyran,fullerene C60,optical memory elements
更新于2025-09-12 10:27:22
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Reversibly Photoswitchable Dual-Color Fluorescence and Controlled Release Properties of Polymeric Nanoparticles
摘要： Here, we report a novel polymeric nanoparticle prepared by the self-assembly of amphiphilic copolymers containing a ?uorescent naphthalimide (NAPH) and a photochromic spiropyran (SP), which possesses reversibly photoswitchable dual-color ?uorescence and controlled release properties. The amphiphilic copolymers were synthesized by incorporating NAPH and SP into methyl ether poly(ethylene glycol)-poly(β-amino esters) (MPEG-PAE) via quaternization. The nanoparticles would change between yellow and purple reversibly upon UV and visible light irradiation because of the photoisomerization between SP and merocyanine (MC). The corresponding ?uorescence would be switched between green and orange-red reversibly upon blue light excitation through the ?uorescence resonance energy transfer from the excited NAPH to the photoisomerized MC. Meanwhile, the prepared spherical nanoparticles could be swollen under UV irradiation as the hydrophobic SP isomerized to hydrophilic MC; the nanoparticles could also be swollen under acidic conditions because of the protonation of the amino groups of PAE. Upon UV light irradiation and acidic stimulation, the cargoes, hydrophobic Coumarin 102, encapsulated in the nanoparticles would be released. The prepared nanoparticles, which exhibit not only excellent reversible dual-color ?uorescence properties but also prominent controlled release performance, will open up new possibilities for the combined application of ?uorescence imaging and controlled release.
关键词： naphthalimide,Coumarin 102,spiropyran,polymeric nanoparticles,photoswitchable,amphiphilic copolymers,acidic conditions,quaternization,self-assembly,FRET,UV/vis light irradiation,dual-color ?uorescence,MPEG-PAE,controlled release
更新于2025-09-11 14:15:04
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Photochromic Materials by Postpolymerisation Surface Modification
摘要： Photochromic materials are available by a postpolymerization surface modi?cation of diverse polymers in a multistep sequential process mediated, ?rst, by carbene insertion chemistry, second, by diazonium coupling with a tethered precursor, and ?nally by coupling to a spiropyran. This three-step sequence is e?cient, and surface loading densities of 1013 molecules cm?2 are typically achievable, leading to materials with observable photochromic and wettability behavior, which operate over multiple cycles without signi?cant photobleaching or loss of e?cacy. Materials suitable for application in this process include both reactive, but also lower surface energy polymers. Although the process is particularly e?cient for high surface area materials, surface modi?cation onto lower surface area substrates, while being intrinsically less e?cient, is nonetheless su?ciently e?ective that changes in macroscopic photochromic properties are readily observable.
关键词： wettability behavior,carbene insertion chemistry,Photochromic materials,postpolymerization surface modi?cation,spiropyran,diazonium coupling
更新于2025-09-10 09:29:36
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A phototactic liquid micromotor
摘要： In recent years, micromotors, which possess unique autonomous moving properties inside a solution, have shown great potential in a variety of applications ranging from environmental remediation to the biomedical field. However, most of the micromotors are based on solid materials. In this paper, we report a liquid (water, serum or urine) micromotor, which exhibits self-propelling behavior in an oil solution upon white light irradiation. Interestingly, the liquid micromotor exhibits both positive and negative phototaxis, which relies on the photochromism of the surrounding spiropyran molecules dissolved in oil or the thermal effect, respectively. In addition, light shows great versatility in controlling the motion behavior of the liquid micromotor so that it can move in a desired fashion. Furthermore, we have demonstrated that the liquid-based micromotor has great advantages over the solid ones. It not only enables fusion and reaction between different reactant-loaded liquid micromotors based on the combined positive and negative phototaxis, but also allows controlled cargo capture and transportation. We thus believe the liquid micromotor reported in the current study may have potential applications in various fields such as glucose detection.
关键词： micromotors,glucose detection,liquid micromotor,white light irradiation,phototaxis,spiropyran
更新于2025-09-09 09:28:46