Photothermal Conversion Effect Research Articles

Near-infrared light photothermally induced shape memory and self-healing effects of epoxy resin coating with polyaniline nanofibers

Polyaniline (PANI) nanofibers were synthesized by interfacial polymerization at 20 °C. The ultraviolet–visible–near-infrared light (NIR) absorption spectra indicated two absorptions at 450 nm and 848 nm, which exhibited the NIR-absorbing characteristic of PANI. The photothermal conversion temperature of PANI nanofibers increased with the NIR power density of 808 nm. The nanofibers were added to the epoxy resin to prepare NIR-induced shape memory and self-healing coating. The shape memory effect of the composites was measured via NIR irradiation of 2 W cm−2 808 nm. The surface morphologies of the scratched and healed coatings were investigated by optical stereomicroscopy. The healing performance of the intact, damaged, and healed coatings was also evaluated by linear sweep voltammetry and polarization curves. Results indicated that the shape recovery time of the composite decreased as PANI content increased. The composite with 5 wt% PANI exhibited the best shape memory effect and multiple self-healing performances. Moreover, PANI nanofibers improved the protection performance of the epoxy resin coatings. The electrochemical results indicated that the coating with 5 wt% PANI had good self-healing performance when the scratched area was irradiated by NIR. This finding was attributed to the photothermal conversion effect and passivation function of the PANI nanofibers.

Enhanced photothermal conversion performances with ultra‐broad plasmon absorption of Au in Au/Sm2O3 composites

AbstractLanthanide oxides are ideal candidates as photothermal conversion agents owing to their larger photon energy and advantages in biomedical applications. However, the small absorption cross section of rare earth is not conducive of absorbing near infrared light, which will affect the photothermal conversion efficiency of lanthanide oxides. Herein, Au particles are successfully introduced into Sm2O3 to form Au/Sm2O3 composites. The investigation of broadband emission and thermal performances in Sm2O3 and Au/Sm2O3 composites confirm the ultra‐broad plasmon absorption of Au induced thermal effect is in favor of the formation of broadband emission, meanwhile, enhances the photothermal conversion capability of Au/Sm2O3 composites. The temperature increases of the Au/Sm2O3 composites are 5.5°C and 19.6°C compared to Sm2O3 particles under the irradiation of near infrared laser with power density of 11.5 and 29.0 mW/mm2, respectively. In additional, the enhanced photothermal conversion effect is confirmed by the alcohol volatilization experiment and visual infrared thermal images. We present here an idea for enhancing the photothermal conversion capabilities of lanthanide oxides and highlight the promise of using this kind of materials for photothermal therapy.

Tumor Cell Membrane‐Coated Liquid Metal Nanovaccine for Tumor Preventionǂ

Summary of main observation and conclusionHerein, we report on a tumor nanovaccine LMNP@CM that enhances the process of antigen‐presenting by stimulating the immune system to uptake tumor antigens actively. The nanovaccine is comprised of polyethylene glycol modified liquid metal nanoparticles (LMNP) and tumor cell membranes (CM) as antigens. Under 808 nm irradiation, the photothermal conversion effect of injected LMNP can cause mild local inflammation, and subsequently induces antigen‐presenting cells active recruitment and facilitates cellular uptake of tumor antigens. Meanwhile, because of the immune adjuvant effect of metal materials, the nanovaccine LMNP@CM promotes the maturation and activation of antigen‐presenting cells and induces anti‐tumor immune response effectively. By priming the host immune recognition of tumor antigens, this nanovaccine displays prophylactic effects and significantly suppresses tumor growth in a mouse breast tumor model. The nanovaccine LMNP@CM represents a novel strategy of utilizing light‐controlled means to actively induce anti‐tumor immune processes, showing advanced therapeutic potentials and robust adaptability for treating multiple tumors by changing the loaded antigens.

Efficient photothermal conversion of Fe2O3–RGO guided from ultrafast quenching effect of photoexcited state

AbstractIn solar thermal utilization, effective photo capture and photothermal conversion are crucial. Improving the nonradiative transition rate of photoexcited electrons is important to enhance the photothermal conversion efficiency and develop efficient solar thermal utilization. Herein, we designed a new kind of light absorption‐enhanced and efficient photothermal conversion material, namely, Fe2O3‐functionalized reduced graphene oxide (Fe2O3–RGO). On the basis of the selective absorption (350–560 nm) of Fe2O3 and the synergistic effect of RGO on the quenching energy transfer of the excited state of Fe2O3 and ultrafast nonradiative thermal decay of RGO, the optical absorption capacity, and photothermal conversion efficiency of the composites were effectively improved. Fe2O3–RGO can be successfully applied to photothermal conversion phase change materials and seawater solar desalination, showing excellent photothermal conversion ability and application prospect.

Mesoporous CuO with full spectrum absorption for photothermal conversion in direct absorption solar collectors

Many semiconductors with broad solar spectrum absorption have always been pursuing for the effective photothermal conversion process. However, it is still a challenge to modulate the structural and bandgap of semiconductors to enhance the photothermal activity synergistically. In this work, facile prepared mesoporous CuO displays a narrower bandgap than non-porous CuO, leading to highly efficient solar-thermal conversion. Mesoporous CuO shows obvious broad and strong optical absorption, especially in the visible light region. It is noteworthy that the mesoporous CuO nanofluids exhibit good dispersibility in water. Different concentrations of mesoporous CuO nanofluids have higher temperature rise than non-porous CuO nanofluids. The photothermal conversion efficiency of 50 ppm mesoporous CuO/water nanofluid is 83.66%, compared with 58.86% for 50 ppm CuO/water nanofluid. Mesoporous CuO will bring a new paradigm for mesoporous metal oxide nanofluids as working fluids in direct absorption solar collectors.

Photothermal-reinforced and glutathione-triggered in Situ cascaded nanocatalytic therapy

Tumor microenvironment (TME)-responsive nanoformulations that catalyze a cascade of intracellular redox reactions showed promise for tumor treatment with high specificity and efficiency. In this study, we report Cu2+-doped zeolitic imidazolate frameworks-coated polydopamine nanoparticles (PDA@Cu/ZIF-8 NPs) for glutathione-triggered and photothermal-reinforced sequential catalytic therapy against breast cancer. In the TME, the PDA@Cu/ZIF-8 NPs could initially react with antioxidant glutathione (GSH), inducing GSH depletion and Cu+ generation. Whereafter, the generated Cu+ would catalyze local H2O2 to produce highly toxic hydroxyl radicals (·OH) through an efficient Fenton-like reaction even in weakly acidity. Importantly, the PDA could exert excellent photothermal conversion effect to simultaneously accelerate GSH consumption and improve the Fenton-like reaction for further expanding the intracellular oxidative stress, which innovatively achieves a synergistic photothermal-chemodynamic therapy for highly efficient anticancer treatment.

Photothermal hierarchical carbon nanotube/reduced graphene oxide microspherical aerogels with radially orientated microchannels for efficient cleanup of crude oil spills

High viscosity and low fluidity of heavy crude oils usually hinder their rapid diffusion into porous adsorbents, causing a low efficiency of oil spill remediation. Photothermal effect is thus adopted to rapidly reduce the viscosity of heavy crude oil by in situ solar light heating. Photothermal carbon nanotube/reduced graphene oxide (CNT/RGO) microspherical aerogels are synthesized by fabrication of graphene oxide (GO)-based microspherical aerogels with numerous radially orientated microchannels, followed by growing CNTs inside the microchannels and high-temperature reduction of the GO components. Thanks to the efficient photothermal conversion effect and the rough and oleophilic surface of the microchannels with large surface area, such aerogels facilitate the solar light absorption and hence enhance the crude oil adsorption. Furthermore, the CNTs grown on the RGO skeleton by a chemical vapor deposition approach promote the photothermal conversion efficiency by trapping and absorbing broadband solar light. Under 1 sun irradiation, the surface temperature of the aerogel quickly rises to 83 °C in 1 min, resulting in a sharp decrease in crude oil viscosity. The optimal microspherical aerogels deliver an extraordinary adsorption capacity of heavy crude oil, up to 267 g g−1 within 10 min, superior to those of other oil adsorbents reported so far.

Photothermal graphene/UiO-66-NH2 fabrics for ultrafast catalytic degradation of chemical warfare agent simulants

Lightweight and wearable fabrics with rapid self-detoxification functions are highly desired to resist chemical warfare agents (CWAs). Metal organic frameworks (MOFs) with high specific surface area and customizability are singularly attractive because of their ability to effectively capture and catalytically degrade CWAs. Herein, photothermal graphene-based nanocomposite fabrics are designed by wet-spinning and chemical reduction of graphene oxide fibers followed by in situ growth of UiO-66-NH2. The flexible graphene fabrics decorated with UiO-66-NH2 nanoparticles exhibit an ultrafast photothermal catalytic decontamination of dimethyl 4-nitrophenyl phosphate (DMNP), a typical simulant of CWAs. The half-life of the degradation reaction decreases from 3.4 to 1.6 min under simulated solar light irradiation, a significant gain over the values reported in the literature. Furthermore, DMNP can be degraded in 20 min by the graphene/UiO-66-NH2 fabric, and even after 5 cycles the degradation efficiency still retains more than 92 %. More importantly, the photothermal conversion of graphene and its instantaneous heat transfer to the UiO-66-NH2 catalyst effectively accelerate the catalytic reaction kinetics, achieving the fast detoxification of DMNP. The combination of catalytic degradation of MOFs with photothermal conversion effect of graphene makes the lightweight and flexible fabrics promising for protection against CWAs and other pollutants.

Controllable Black or White laser patterning of polypropylene induced by carbon nanotubes

Carbon nanotubes (CNTs) were used to enhance the laser patterning performance of polypropylene (PP). The three-dimensional network structure formed by CNTs can effectively improve the photothermal conversion effect of PP/CNT composites. The results show that the addition of 10 ppm CNTs endowed PP with a clear black laser patterning performance. As the content of CNTs is increased from 10 ppm to 200 ppm, the grayscale of the laser-induced patterns changed from black to white. An amorphous carbon material constituted the laser-induced pattern, which was confirmed by Raman spectroscopy. In addition, the SEM results revealed that the morphology of the laser-induced carbonized points can affect the grayscale of the laser-induced patterns. This study proposes a simple and efficient method for improving the laser patterning performance of polymer materials using CNTs. In addition, this work provides an effective direction for practical applications of grayscale-controlled (black and white) laser-induced patterns.

Photothermally enhanced photodynamic therapy based on glutathione-responsive pheophorbide a-conjugated gold nanorod formulations for cancer theranostic applications

Nanocarriers have provided a new platform for the selective delivery of therapeutic agents into targeted cells and tissues using safe, efficient, and tractable routes. In particular, the integration of multiple therapeutic/diagnostic modalities into a single system has the great potential of enhancing theranostic efficiency against serious diseases with reduced side effects. In this study, a new light-triggered theranostic system using photosensitizer-conjugated gold nanorods (AuNR) with glutathione (GSH)-sensitive linkages was developed for cancer imaging and combinational phototherapy of photodynamic therapy (PDT) and photothermal therapy (PTT) to achieve a synergistic cancer treatment. AuNRs with various aspect ratios were prepared as photothermal agents, and then a folic acid (FA)-PEG block copolymer (FAP) and pheophorbide a (Pheo) were chemically conjugated to the surface of AuNRs for active tumor targeting and PDT, respectively. The configuration of Pheo-conjugated AuNR nanocarriers has been precisely controlled through adjusting the feed composition ratio and the relationship between aspect ratio and absorption band of AuNRs. In particular, an AuNR with an aspect ratio of 3.84 and longitudinal plasmon resonance at 873nm (Pheo-conjugated AuNR100) exhibited superior performance in singlet oxygen generation, photothermal conversion effect, and GSH-mediated selective release of Pheo. Moreover, it also showed tumor targeting activity and a PDT-PTT synergistic effect. These results indicate that this multifunctional AuNR system with tumor targeting ability and GSH-sensitive linkages would be highly efficient for noninvasive cancer treatment by integrating cancer imaging diagnostics and synergistic therapy.

Platinum(II) Drug-Loaded Gold Nanoshells for Chemo-Photothermal Therapy in Colorectal Cancer.

In the present study, we utilize a poly[2-(N,N-dimethylamino)ethyl methacrylate]-poly(ε-caprolactone) (PDMA-PCL) micellar template-based gold nanoshell as a nanocarrier of a platinum-based chemotherapeutic drug, dichloro(1,2-diaminocyclohexane)platinum(II) (DACHPt). The gold nanoshells not only function as a drug delivery platform but also provide a remarkable photothermal effect, resulting in synergistically combined chemo-photothermal therapy. With the positively charged outstretched hydrophilic PDMA segments, chloroauric anions are attracted to the PDMA-PCL micellar surface and reduced to gold atoms in situ, forming small seeds that nucleate the subsequent growth of gold nanoshells. The DACHPt-loaded gold nanoshells possess strong absorption in the near-infrared (NIR) region and outstanding photothermal conversion effect; thus, they can promote a temperature increase that is sufficient to ablate tumor cells under NIR laser irradiation at a moderate power density (1 W/cm2). Furthermore, by exploiting the synergistic effects of platinum-based chemotherapy and photothermal therapy, the DACHPt-loaded gold nanoshells exhibited a profound inhibition of tumor growth compared to chemotherapy or photothermal therapy alone. Therefore, the platinum(II)-loaded gold nanoshells that we proposed herein may be a potential alternative for efficient curative therapy for colorectal cancer.

AgFeS2 nanoparticles as a novel photothermal platform for effective artery stenosis therapy.

Ternary I-III-VI2 semiconductors usually have narrow band gaps and large absorption coefficients arising from the unique characteristics of their outer-d valence electrons, which are intimately connected with the photothermal conversion properties. AgFeS2 is known as one such material that has the potential to absorb near-infrared light. In this work, we utilized density functional theory (DFT) calculations to evaluate the electronic structure and optical absorption properties of AgFeS2. Strong absorptions were predicted over a wide Vis-NIR region due to the localized 3d electron of Fe atoms, which agree quite well with the UV-Vis-NIR spectra measured by experiment. The as-prepared AgFeS2 nanoparticles were then modified with mPEG-DSPE, an efficient photothermal agent for artery stenosis therapy. Its photothermal conversion effect has been systematically studied, indicating the potential for causing the hyperthermia of macrophages, an essential part of the artery inflammation response. More importantly, both in vitro cell experiments and in vivo mouse-model studies show that the induction of hyperthermia in artery stenosis by using AgFeS2 nanoparticles is safe and effective when injected at a very low concentration. This study provides a novel photothermal platform derived from the inheritability of bandgap structure and also promotes the process of artery inflammation and stenosis therapy.

Multifunctional theranostic nanosystems enabling photothermal-chemo combination therapy of triple-stimuli-responsive drug release with magnetic resonance imaging.

Theranostic nanosystems are emerging as a promising approach for controlled drug delivery, diagnosis and multimodal therapeutics. Herein, a multifunctional theranostic nanoplatform is reported for photothermal-chemo combination therapy functioned with magnetic and thermal imaging. Hyaluronic acid (HA) coated Fe3O4@polydopamine nanoparticles equipped with redox-sensitive disulfide linkers have been subsequently deposited with an anticancer drug, doxorubicin (DOX) (termed as FPCH-DOX NPs). These nanocomposites possess an average diameter of 120 nm, a saturation magnetization of 28.5 emu g-1, DOX loading capacity of 7.13% and a transverse relaxation rate of 171.76 mM-1 s-1. The drug release could be triggered by pH, glutathione (GSH) concentration and light irradiation. Prussian blue staining and confocal microscopy demonstrate that these nanoplatforms have improved biocompatibility and cellular uptake in CD44-positive HeLa cell lines rather than in CD44-negative NIH 3T3 normal cell lines. In vitro evaluations demonstrate that the combination therapy of FPCH-DOX NPs lowers the cell viability to 16.2%, less than that of individual chemotherapy (55.3%) or PTT (52.1%). In vivo MRI indicates that the tumor accumulation of FPCH-DOX NPs provides enhanced MRI contrast, and in vivo thermal imaging verified their localized photothermal conversion effect in tumor tissues. Importantly, FPCH-DOX NPs present remarkable anti-tumor efficacy by photothermal-chemo combination therapy. H&E and Ki67 staining tests show obvious necrosis and weak cell proliferation at the region of the tumor. Thus, FPCH-DOX NPs are promising multifunctional nanoplatforms for highly effective cancer theranostics.

Near-infrared photothermal liposomal nanoantagonists for amplified cancer photodynamic therapy.

Photodynamic therapy (PDT) has been demonstrated to be a promising strategy for the treatment of cancer, while its therapeutic efficacy is often compromised due to excessive concentrations of glutathione (GSH) as a reactive oxygen species (ROS) scavenger in cancer cells. Herein, we report the development of near-infrared (NIR) photothermal liposomal nanoantagonists (PLNAs) for amplified PDT through through the reduction of intracellular GSH biosynthesis. Such PLNAs were constructed via encapsulating a photosensitizer, indocyanine green (ICG) and a GSH synthesis antagonist, l-buthionine sulfoximine (BSO) into a thermal responsive liposome. Under NIR laser irradiation at 808 nm, PLNAs generate mild heat via a ICG-mediated photothermal conversion effect, which leads to the destruction of thermal responsive liposomes for a controlled release of BSO in a tumor microenvironment, ultimately reducing GSH levels. This amplifies intracellular oxidative stresses and thus synergizes with PDT to afford an enhanced therapeutic efficacy. Both in vitro and in vivo data verify that PLNA-mediated phototherapy has an at least 2-fold higher efficacy in killing cancer cells and inhibiting tumor growth compared to sole PDT. This study thus demonstrates a NIR photothermal drug delivery nanosystem for amplified photomedicine.

Gold nanocages for effective photothermal conversion and related applications

Gold nanocages are highly effective in converting light to heat, making them versatile for an array of photothermal applications.

Fabrication of Novel Gold Nanoparticles Decorated Cerasome for Ultrasound Contrast Imaging and Photothermal Evaluation for Cancer Treatment

In order to succeed in tumor targeted therapy and Ultrasound (US) imaging of tumors, several nano formulations of perfluorocarbon were demonstrated till date. At the same time, large size distribution and small sonographic period were the major reasons for limiting their application. With the help of l-menthol loaded Au@cerasome particles (LMGC), we have developed a unique theranostic agent in this study. LMGC displayed excellent performance in enhancing the contrast of US imaging, which is because of its controllable and sustained production of l-menthol foams under the irradiation of NIR laser. The LMGC showed an effective photothermal conversion along with low cytotoxicity for localized photothermal removal of tumor cells. The necessary heating required to generate LM bubbles was obtained by near-infrared laser irradiation of LMGC in vitro, this might also result in sustained and significant ultrasound signal improvement. Depending on these outcomes, it is evident that LMGC can be a perfect candidate for developing multiuse nano medicines to combine the therapeutic functions and US imaging for treating cancer.

Photoactivated Trifunctional Platinum Nanobiotics for Precise Synergism of Multiple Antibacterial Modes.

Integrating multiple strategies of antibacterial mechanisms into one has been proven to have tremendous promise for improving antimicrobial efficiency. Hence, dual-valent platinum nanoparticles (dvPtNPs) with a zero-valent platinum core (Pt0 ) and bi-valent platinum shell (Pt2+ ions), combining photothermal and photodynamic therapy, together with "chemotherapy," emerge as spatiotemporally light-activatable platinum nano-antibiotics. Under near-infrared (NIR) exposure, the multiple antibacterial modes of dvPtNPs are triggered. The Pt0 core reveals significant hyperthermia via effective photothermal conversion while an immediate release of chemotherapeutic Pt2+ ions occurs through hyperthermia-initiated destabilization of metallic interactions, together with reactive oxygen species (ROS) level increase, thereby resulting in synergistic antibacterial effects. The precise cooperative effects between photothermal, photodynamic, and Pt2+ antibacterial effects are achieved on both Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus, where bacterial viability and colony-forming units are significantly reduced. Moreover, similar results are observed in mice subcutaneous abscess models. Significantly, after NIR treatment, dvPtNP exhibits a more robust bacteria-killing efficiency than other PtNP groups, owing to its integration of dramatic damage to the bacterial membrane and DNA, and alteration to ATP and ROS metabolism. This study broadens the avenues for designing and synthesizing antibacterial materials with higher efficiency.

Facile synthesis of yolk-shell structured Fe3O4@C-Au nanoparticles for thermotherapic application

Abstract Yolk-shell nanostructures haves promising applications in cancer therapy due to their great potential for multi-functions. However, the control over its structure and morphology still remains a big challenge. Herein, yolk-shell Fe3O4@C-Au composite nanostructure has been successfully synthesized with magnetic Fe3O4 nanoparticles encapsulated in hollow carbon shells and Au nanoparticles well dispersed. The yolk-shell structure has a uniform size of ~80 nm and a high surface area of 325.13 m2/g. The Fe3O4 and Au nanoparticles are 10 and 3 nm, respectively. The as-prepared Fe3O4@C-Au showed good biocompatibility during endocytosis process. The Fe3O4@C-Au suspension (150 μg/ml) shows efficient photothermal conversion effect and effectively damage 4T1 cells. The composite nanostructure Fe3O4@C-Au show promising applications in cancer diagnosis and therapy.

Copper(I) Phosphide Nanocrystals for In Situ Self‐Generation Magnetic Resonance Imaging‐Guided Photothermal‐Enhanced Chemodynamic Synergetic Therapy Resisting Deep‐Seated Tumor

AbstractFe‐based Fenton agents can generate highly reactive and toxic hydroxyl radicals (·OH) in the tumor microenvironment (TME) for chemodynamic therapy (CDT) with high specificity. However, the strict condition (lower pH environment: 3–4) of the highly efficient Fenton reaction limits its practical application in the clinic. Development of new CDT agents more suitable for TME is significant and challenging. A highly efficient Cu(I)‐based CDT agent, copper(I) phosphide nanocrystals (CP NCs), which is more adaptable to the pH value of TME than Fe‐based agents, thereby producing more ·OH to trigger the apoptosis of cancer cells, is prepared. Moreover, the excess glutathione (GSH) in TME can reduce the Cu(II) produced by a Fenton‐like reaction to Cu(I), further increasing the generation rate of ·OH and relieving tumor antioxidant ability. Furthermore, owing to their strong absorption in the NIR II region, CP NCs exhibit an excellent photothermal conversion effect, which can further improve the Fenton reaction. What is more, CP NCs can act as in situ self‐generation magnetic resonance imaging (MRI) agents owing to the generation of paramagnetic Cu(II) in response to excess H2O2 in the TME. These properties may open up the exploration of copper‐based materials in clinical application of self‐generation imaging‐guided synergetic treatment.

Photothermally Enhanced Molecular Delivery and Cellular Positioning on Patterned Plasmonic Interfaces.

Photothermal conversion effect of plasmonic nanostructures is considered as a promising technique for cellular and molecular manipulations owing to controllability of local temperature. Therefore, this technique has been extensively applied to biological studies such as controlling cellular behavior, delivery of biologics, and biomolecular detection. Herein, we propose a novel method for directed cell positioning and photothermally modulated molecular delivery to the cells using patterned plasmonic interfaces. Plasmonic substrates with gold nanorods (GNRs) and cell adhesion molecules fabricated by microcontact printing are optimized for cellular positioning on designated patterns. Through the photothermal conversion effect of GNRs on the pattern, we further demonstrate on-demand, light-induced delivery of drug molecules to the target cells. We expect that this approach will provide a new way to study single cellular behaviors and enhance molecular delivery to the target cells.