scholarly journals Synthesis of a Smart Conductive Block Copolymer Responsive to Heat and Near Infrared Light

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1744 ◽  
Author(s):  
Silvestre Bongiovanni Abel ◽  
Kevin Riberi ◽  
Claudia R. Rivarola ◽  
Maria Molina ◽  
Cesar A. Barbero
Keyword(s):  
Block Copolymer ◽  
Near Infrared ◽  
Local Heating ◽  
Oxidative Polymerization ◽  
Polymerization Reaction ◽  
Infrared Light ◽  
Solution Temperature ◽  
Synthetic Approach ◽  
Nir Light ◽  
Nir Absorption

A method for the synthesis of a linear block copolymer (PNIPAM-b-PANI), containing a thermoresponsive block (poly(N-isopropylacrylamide), PNIPAM) and a Near Infrared (NIR) light-absorbing block (polyaniline, PANI), is reported. The synthetic approach involves a two-step successive polymerization reaction. First, the radical polymerization of NIPAM is done using 4-aminothiophenol as a chain transfer agent for the obtention of thermosensitive block terminated with an aniline (ANI) moiety. Second, the oxidative polymerization of ANI is initiated in ANI moiety of thermosensitive block to grow the second conductive PANI block. 1H nuclear magnetic resonance (NMR) and FT-IR spectroscopy shows the characteristics peaks of both polymeric blocks revealing the successful copolymerization process. Static Light Scattering (SLS) and UV-Visible combined measurements allowed the determination of the Mw for PNIPAM-b-PANI macromolecule: 5.5 × 105 g mol−1. The resulting copolymer is soluble in water (8.3 g L−1) and in non-aqueous solvents, such as ethanol, formic acid, acetonitrile, and others. Both polymer blocks chains show the properties of the polymer chains. The block copolymer shows a lower critical solution temperature (LCST) at the same temperature (32–34 °C) than PNIPAM, while the copolymer shows pH dependent UV-vis-NIR absorption similar to PANI. The PNIPAM block suffers a coil to globule transition upon NIR light irradiation (785 nm, 100 mW), as shown by turbidimetry and Atomic Force Microscopy (AFM), due to local heating (more than 9 °C in 12 min) induced by the NIR absorption at the PANI block. Furthermore, the electrical conductivity of PNIPAM-b-PANI thin films is demonstrated (resistivity of 5.3 × 10−4 Ω−1 cm−1), indicating that the PANI block is present in its conductive form.

scholarly journals Enhanced Delivery of Thermoresponsive Polymer-Based Medicine into Tumors by Using Heat Produced from Gold Nanorods Irradiated with Near-Infrared Light

Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 5005
Author(s):  
Kohei Sano ◽  
Yumi Ishida ◽  
Toshie Tanaka ◽  
Tatsuya Mizukami ◽  
Tomono Nagayama ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Near Infrared ◽  
Drug Carrier ◽  
Light Irradiation ◽  
Infrared Light ◽  
Solution Temperature ◽  
Dependent Manner ◽  
Thermoresponsive Polymer ◽  
Tumor Bearing ◽  
Nir Light

The aim of this study was to establish a drug delivery system (DDS) for marked therapy of tumors using a thermoresponsive polymer, polyoxazoline (POZ). The effectiveness of the following was investigated: (i) the delivery of gold nanorods (GNRs) to tumor tissues, (ii) heat production of GNR upon irradiation with near-infrared (NIR) light, and (iii) high accumulation of an intravenously injected radiolabeled POZ as a drug carrier in tumors by sensing heat produced by GNRs. When the GNR solution was irradiated with NIR light (808 nm), the solution temperature was increased both in a GNR-concentration-dependent manner and in a light-dose-dependent manner. POZ, with a lower critical solution temperature of 38 °C, was aggregated depending on the heat produced by the GNR irradiated by NIR light. When it was intratumorally pre-injected into colon26-tumor-bearing mice, followed by NIR light irradiation (GNR+/Light+ group), the tumor surface temperature increased to approximately 42 °C within 5 min. Fifteen minutes after irradiation with NIR light, indium-111 (111In)-labeled POZ was intravenously injected into tumor-bearing mice, and the radioactivity distribution was evaluated. The accumulation of POZ in the tumor was significantly (approximately 4-fold) higher than that in the control groups (GNR+/without NIR light irradiation (Light–), without injection of GNR (GNR–)/Light+, and GNR–/Light– groups). Furthermore, an in vivo confocal fluorescence microscopy study, using fluorescence-labeled POZ, revealed that uptake of POZ by the tumor could be attributed to the heat produced by GNR. In conclusion, we successfully established a novel DDS in which POZ could be efficiently delivered into tumors by using the heat produced by GNR irradiated with NIR light.

Catalyst Halogenation Enables Rapid and Efficient Polymerizations with Visible to Near-Infrared Light

2020 ◽  
Author(s):  
Alex Stafford ◽  
Dowon Ahn ◽  
Emily Raulerson ◽  
Kun-You Chung ◽  
Kaihong Sun ◽  
...  
Keyword(s):  
Near Infrared ◽  
Transient Absorption ◽  
Reaction Times ◽  
Infrared Light ◽  
Structure Property ◽  
Light Emitting ◽  
Structure Property Relationships ◽  
Nir Light ◽  
Light Intensities ◽  
Emission Quenching

Driving rapid polymerizations with visible to near-infrared (NIR) light will enable nascent technologies in the emerging fields of bio- and composite-printing. However, current photopolymerization strategies are limited by long reaction times, high light intensities, and/or large catalyst loadings. Improving efficiency remains elusive without a comprehensive, mechanistic evaluation of photocatalysis to better understand how composition relates to polymerization metrics. With this objective in mind, a series of methine- and aza-bridged boron dipyrromethene (BODIPY) derivatives were synthesized and systematically characterized to elucidate key structure-property relationships that facilitate efficient photopolymerization driven by visible to NIR light. For both BODIPY scaffolds, halogenation was shown as a general method to increase polymerization rate, quantitatively characterized using a custom real-time infrared spectroscopy setup. Furthermore, a combination of steady-state emission quenching experiments, electronic structure calculations, and ultrafast transient absorption revealed that efficient intersystem crossing to the lowest excited triplet state upon halogenation was a key mechanistic step to achieving rapid photopolymerization reactions. Unprecedented polymerization rates were achieved with extremely low light intensities (< 1 mW/cm<sup>2</sup>) and catalyst loadings (< 50 μM), exemplified by reaction completion within 60 seconds of irradiation using green, red, and NIR light-emitting diodes.

scholarly journals Photothermal Therapy Using Gold Nanorods and Near-Infrared Light in a Murine Melanoma Model Increases Survival and Decreases Tumor Volume

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mary K. Popp ◽  
Imane Oubou ◽  
Colin Shepherd ◽  
Zachary Nager ◽  
Courtney Anderson ◽  
...  
Keyword(s):  
Light Source ◽  
Gold Nanorods ◽  
Photothermal Therapy ◽  
Near Infrared ◽  
Tumor Volume ◽  
Infrared Light ◽  
Led Light ◽  
Murine Melanoma ◽  
Nir Light ◽  
Melanoma Model

Photothermal therapy (PTT) treatments have shown strong potential in treating tumors through their ability to target destructive heat preferentially to tumor regions. In this paper we demonstrate that PTT in a murine melanoma model using gold nanorods (GNRs) and near-infrared (NIR) light decreases tumor volume and increases animal survival to an extent that is comparable to the current generation of melanoma drugs. GNRs, in particular, have shown a strong ability to reach ablative temperatures quickly in tumors when exposed to NIR light. The current research tests the efficacy of GNRs PTT in a difficult and fast growing murine melanoma model using a NIR light-emitting diode (LED) light source. LED light sources in the NIR spectrum could provide a safer and more practical approach to photothermal therapy than lasers. We also show that the LED light source can effectively and quickly heatin vitroandin vivomodels to ablative temperatures when combined with GNRs. We anticipate that this approach could have significant implications for human cancer therapy.

Photothermal liquid release from arrayed Au nanorod/hydrogel composites for chemical stimulation

2021 ◽  
Vol 32 (1) ◽  
pp. 015003
Author(s):  
Sang-Woo Seo ◽  
Youngsik Song ◽  
Hojjat Rostami Azmand
Keyword(s):  
Near Infrared ◽  
Local Heating ◽  
Temperature Response ◽  
Device Fabrication ◽  
Fluorescent Imaging ◽  
Silicon Membrane ◽  
Chemical Release ◽  
Nir Light ◽  
Fluorescein Dye ◽  
Hydrogel Composites

Abstract Controlled photothermal actuation of liquid release is presented using periodically arrayed hydrogel columns in a macroporous silicon membrane. Thermo-responsive hydrogel is mixed with Gold (Au) nanorods, and surface plasmon-induced local heating by near-infrared (NIR) light is utilized as an actuation method. We adopted theoretical modeling, which treats the hydrogel as a poro-viscoelastic medium to understand the mechanical and liquid transport properties of the hydrogel. To demonstrate the feasibility of the liquid release control using NIR light, we first characterized the temperature response of Au nanorod embedded hydrogel in the silicon membrane using its optical transmission behavior to confirm the successful device fabrication. Next, the liquid release characteristics from the structure were studied using fluorescent imaging of fluorescein dye solution while pulsed NIR light was illuminated on the structure. We successfully demonstrate that the liquid release can be controlled using remote NIR illumination from the presented structure. Considering the periodically arrayed configuration with high spatial resolution, this will have a potential prospect for optically-addressable chemical release systems, which benefit retina prosthesis interfaces.

Detection of residual varicose veins with near infrared light in the early period after varicose surgery and near infrared light assisted sclerotherapy

Vascular ◽  
2021 ◽  
pp. 170853812110514
Author(s):  
Nail Kahraman ◽  
Gündüz Yümün ◽  
Deniz Demir ◽  
Kadir K Özsin ◽  
Sadık A Sünbül ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Saphenous Vein ◽  
Venous Insufficiency ◽  
Near Infrared ◽  
Varicose Veins ◽  
Infrared Light ◽  
Foam Sclerotherapy ◽  
Near Infrared Light ◽  
Nir Light ◽  
Male Patients

Objectives Varicose veins that cannot be seen with the naked eye can be easily detected with Near Infrared (NIR) light. With a minimally invasive procedure performed with NIR light guided, the need for reoperation is reduced, while optimal treatment of venous insufficiency and symptoms is provided. In this study, the detection of residual varicose veins after varicose vein surgery using NIR light and the results of treatment of sclerotherapy were investigated. Methods In this retrospective study, treatment and clinical outcomes of patients’ who underwent NIR light-guided foam sclerotherapy for Clinical-Etiology-Anatomy-Pathophysiology (CEAP) (C1, C2) stage residual varicose veins after surgical varicose treatment between 2014 and 2017 were examined. Data of patients who underwent foam sclerotherapy with NIR light were collected and analyzed. Results A total of 151 patients and 171 lower extremity varicose veins were treated with surgery. 55 (35.7%) of the patients were male, and 96 (62.3%) were female. Their age ranges from 20 to 64, with an average age of 45.38. 4 (2.6%) of the patients had phlebectomy. 137 of patients (90.7%) had ligation of perforated veins, phlebectomy, and great saphenous vein (GSV) stripping, 10 of patients (6.6%) had GSV stripping, perforating vein ligation, phlebectomy, and small saphenous vein (SSV) surgery. No residual leakage was observed in the controls of GSV, SSV, and perforating veins by duplex ultrasonography (DUS). In the first month after varicose surgery, an average of 1.64 ± 1.05 sessions of sclerotherapy was applied to patients with CEAP C1, C2 stage residual varicose veins. 70 patients had one session of sclerotherapy, 37 patients had two sessions of sclerotherapy, 20 patients had three sessions of sclerotherapy, and 11 patients had four sessions of sclerotherapy administrated. The need for complementary therapy was required for all female patients; 13 of the male patients did not require complementary sclerotherapy. While single-session sclerotherapy was applied to most male patients (32 (58.18%), 10 (18.18%) patients received two sclerotherapy sessions. After completing sclerotherapy, 7 (4.63%) patients had superficial venous thrombosis, and 13 (8.60%) patients had hyperpigmentation. Conclusion Surgical treatment is a safe and effective technique in venous insufficiency. Nevertheless, residual varicose veins may remain, and these can be detected noninvasively with NIR light. Foam sclerotherapy with NIR light is a minimally invasive and safe treatment method for small residual varicose veins after the operation. We think that sclerotherapy with NIR light as a complementary treatment is a practical, reliable, and demanding treatment for clinical improvement, especially in female patients.

Near-infrared light-triggered drug release from UV-responsive diblock copolymer-coated upconversion nanoparticles with high monodispersity

2018 ◽  
Vol 6 (21) ◽  
pp. 3531-3540 ◽  
Author(s):  
Jun Xiang ◽  
Xia Tong ◽  
Feng Shi ◽  
Qiang Yan ◽  
Bing Yu ◽  
...  
Keyword(s):  
Drug Release ◽  
Diblock Copolymer ◽  
Near Infrared ◽  
Controlled Drug Release ◽  
Infrared Light ◽  
Upconversion Nanoparticles ◽  
Near Infrared Light ◽  
Nir Light ◽  
Triggered Drug Release

The preparation of a new near-infrared (NIR) light-responsive nanocarrier for controlled drug release is demonstrated.

Vasodilatation Measurement Using Finger Vascular Images by Near-Infrared Light and Comparison with RH-PAT

2022 ◽  
Vol 54 ◽  
pp. 41-50
Author(s):  
Satoshi Shimawaki ◽  
Izumi Urakami
Keyword(s):  
Near Infrared ◽  
Cuff Pressure ◽  
Reactive Hyperemia ◽  
Middle Finger ◽  
Infrared Light ◽  
Upper Arm ◽  
Peripheral Arterial Tonometry ◽  
Average Brightness ◽  
Nir Light ◽  
Digital Pulse

Examination of vascular endothelial function can help infer atherosclerosis progression. This study investigated whether vascular visualization by near-infrared (NIR) light can detect vasodilatation after cuff pressure release of the upper arm and what the correlation is between the brightness decrease ratio (R1) corresponding to vasodilation and the reactive hyperemia index (RHI). We obtained finger vascular images of 53 male subjects by photographing NIR light (wavelength 850 nm) transmitted through the middle phalanx of the middle finger with a charge-coupled device camera. The upper arm was compressed for 10 min using a cuff (200 mmHg), and vascular images before and after cuff compression release were obtained. We analyzed the finger vascular images by NIR light and digital pulse volume using endothelial peripheral arterial tonometry (Endo-PAT). We also calculated the average brightness of each vascular image. Using only the data of the ischemic finger, R1 was defined using the average brightness just before cuff release and the minimum average brightness after cuff release. The brightness of vascular images of the ischemic finger decreased after cuff release probably because of vasodilation. We found significant correlation between R1 and the RHI (r = 0.52; P < 0.001). R1 in the lowest RHI quartile was significantly smaller compared to the highest and second-highest RHI quartiles (P < 0.05). Vascular visualization by NIR light can detect vasodilation after cuff release. This is significantly correlated with the RHI on Endo-PAT.

scholarly journals Improving Upconversion Efficiency Based on Cross-Patterned Upconversion Material Slot Waveguides on a Silicon Layer

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 520
Author(s):  
Youngsoo Kim ◽  
Kihwan Moon ◽  
Young Lee ◽  
Seokhyeon Hong ◽  
Soon-Hong Kwon
Keyword(s):  
Near Infrared ◽  
Double Resonance ◽  
Silicon Layer ◽  
Optical Devices ◽  
Semiconductor Layer ◽  
Slot Waveguide ◽  
Nir Light ◽  
Emission Enhancement ◽  
Nir Absorption ◽  
Array Structure

Upconversion (UC) materials can be used to harvest near-infrared (NIR) light and convert it into visible light. Although this improves optical device operating spectral range and efficiency, e.g., solar cells, typical UC material conversion efficiency is too low for practical devices. We propose a cross-patterned slot waveguide constructed from UC material embedded in a high index semiconductor layer to improve UC. Since the slot waveguide mode is induced in the low index UC slot, NIR absorption (~970 nm) increased 25-fold compared with film structures. Furthermore, the spontaneous emission enhancement rate at 660 nm increased 9.6-fold compared to the reference film due to resonance excited in the UC slot (Purcell effect). Thus, the proposed UC slot array structure improved UC efficiency 240-fold considering absorption and emission enhancements. This double resonance UC improvement can be applied to practical optical devices.

Construction of perfluorohexane/IR780@liposome coating on Ti for rapid bacteria killing under permeable near infrared light

2018 ◽  
Vol 6 (9) ◽  
pp. 2460-2471 ◽  
Author(s):  
Xiuhua Wang ◽  
Lei Tan ◽  
Xiangmei Liu ◽  
Zhenduo Cui ◽  
Xianjin Yang ◽  
...  
Keyword(s):  
Antibacterial Therapy ◽  
Near Infrared ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Nir Light ◽  
Penetration Ability ◽  
Bacteria Killing

Near infrared (NIR) light induced photodynamic antibacterial therapy (PDAT) is a promising antibacterial technique in rapidin situdisinfection of bacterially infected artificial implants due to its penetration ability into tissues.

H2O2/near-infrared light-responsive nanotheronostics for MRI-guided synergistic chemo/photothermal cancer therapy

Nanomedicine ◽  
2019 ◽  
Vol 14 (16) ◽  
pp. 2189-2207
Author(s):  
Yiming Yu ◽  
Li Zhang ◽  
Miao Wang ◽  
Zhe Yang ◽  
Leping Lin ◽  
...  
Keyword(s):  
Near Infrared ◽  
Tumor Model ◽  
Mri Contrast Agent ◽  
Infrared Light ◽  
Antitumor Effects ◽  
Mri Contrast ◽  
Nir Light ◽  
Nir Laser

Aim: To develop a H2O2/near-infrared (NIR) laser light-responsive nanoplatform (manganese-doped Prussian blue@polypyrrole [MnPB@PPy]) for synergistic chemo/photothermal cancer theranostics. Materials & methods: Doxorubicin (DOX) was loaded onto the surface of polypyrrole shells. The in vitro and in vivo MRI performance and anticancer effects of these nanoparticles (NPs) were evaluated. Results: The MnPB@PPy NPs could not only generate heat under NIR laser irradiation for cancer photothermal therapy but also act as an excellent MRI contrast agent. The loaded DOX could be triggered to release by both NIR light and H2O2 to enhance synergistic therapeutic efficacy. The antitumor effects were confirmed by in vitro cellular cytotoxicity assays and in vivo treatment in a xenograft tumor model. Conclusion: The designed H2O2/NIR light-responsive MnPB@PPy-DOX NPs hold great potential for future biomedical applications.

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