Near-infrared Light Stimulation Research Articles

Patterned Photonic Actuators with Dynamic Shape‐Morphing and Color‐Changing Capabilities Fabricated by Athermal Embossing Technology

Stimuli‐responsive patterned photonic actuators, characterized by their patterned nano/microscale structures and capacity to demonstrate synergistic color changes and shape morphing in response to external stimuli, have attracted intense scientific attention. However, traditional patterned photonic actuator systems still face limitations such as cumbersome and time‐consuming preparation processes and small‐scale deformations. Herein, we introduce a facile approach involving an athermal embossing technique to rapidly fabricate patterned photonic actuators based on near‐infrared (NIR) light‐responsive liquid crystal elastomers. The resulting patterned photonic actuators demonstrate remarkable features, including brilliant angle‐dependent structural color, complex three‐dimensional actuation, and good color durability under NIR light stimulation. As illustrative demonstrations of the proof‐of‐concept, we fabricate two light‐fuelled patterned photonic soft actuators: a butterfly‐inspired actuator that can produce wing‐flapping dynamic changes in structural color, and an origami crane‐shaped actuator with shape memory, structural color information storage, and dynamic display properties. This strategy provides distinct insights into the design and fabrication of various patterned photonic soft robotic devices and intelligent actuators.

Patterned Photonic Actuators with Dynamic Shape-Morphing and Color-Changing Capabilities Fabricated by Athermal Embossing Technology.

Stimuli-responsive patterned photonic actuators, characterized by their patterned nano/microscale structures and capacity to demonstrate synergistic color changes and shape morphing in response to external stimuli, have attracted intense scientific attention. However, traditional patterned photonic actuator systems still face limitations such as cumbersome and time-consuming preparation processes and small-scale deformations. Herein, we introduce a facile approach involving an athermal embossing technique to rapidly fabricate patterned photonic actuators based on near-infrared (NIR) light-responsive liquid crystal elastomers. The resulting patterned photonic actuators demonstrate remarkable features, including brilliant angle-dependent structural color, complex three-dimensional actuation, and good color durability under NIR light stimulation. As illustrative demonstrations of the proof-of-concept, we fabricate two light-fuelled patterned photonic soft actuators: a butterfly-inspired actuator that can produce wing-flapping dynamic changes in structural color, and an origami crane-shaped actuator with shape memory, structural color information storage, and dynamic display properties. This strategy provides distinct insights into the design and fabrication of various patterned photonic soft robotic devices and intelligent actuators.

Modulatory Effects on Laminar Neural Activity Induced by Near-Infrared Light Stimulation with a Continuous Waveform to the Mouse Inferior Colliculus In Vivo.

Infrared neural stimulation (INS) is a promising area of interest for the clinical application of a neuromodulation method. This is in part because of its low invasiveness, whereby INS modulates the activity of the neural tissue mainly through temperature changes. Additionally, INS may provide localized brain stimulation with less tissue damage. The inferior colliculus (IC) is a crucial auditory relay nucleus and a potential target for clinical application of INS to treat auditory diseases and develop artificial hearing devices. Here, using continuous INS with low to high-power density, we demonstrate the laminar modulation of neural activity in the mouse IC in the presence and absence of sound. We investigated stimulation parameters of INS to effectively modulate the neural activity in a facilitatory or inhibitory manner. A mathematical model of INS-driven brain tissue was first simulated, temperature distributions were numerically estimated, and stimulus parameters were selected from the simulation results. Subsequently, INS was administered to the IC of anesthetized mice, and the modulation effect on the neural activity was measured using an electrophysiological approach. We found that the modulatory effect of INS on the spontaneous neural activity was bidirectional between facilitatory and inhibitory effects. The modulatory effect on sound-evoked responses produced only an inhibitory effect to all examined stimulus intensities. Thus, this study provides important physiological evidence on the response properties of IC neurons to INS. Overall, INS can be used for the development of new therapies for neurological disorders and functional support devices for auditory central processing.

Poly(ethylene-co-vinyl acetate)/Fe3O4 with near-infrared light active shape memory behavior

The use of near-infrared (NIR) to drive shape memory composites can compensate for the shortcomings of heat-driven shape memory composites in environmental applications such as outer space, in vivo and in cold regions. Here we report, a shape memory composites that can respond to NIR light stimulation were prepared by blending EVA with Fe3O4 nanoparticles. With the addition of Fe3O4 nanoparticles, the EVA/Fe3O4 composites exhibited excellent NIR light responsiveness. When the mass fraction of Fe3O4 is 1 % of EVA, it shows excellent shape memory properties with 95.1 % one-way shape fixity ratio and 97.9 % one-way shape recovery ratio. The non-contact manipulation and segmented response of the EVA/Fe3O4 composites were achieved by irradiation with NIR light.

Sunflower pollen-derived microcapsules adsorb light and bacteria for enhanced antimicrobial photothermal therapy.

Bacterial infection is one of the most serious clinical complications, with life-threatening outcomes. Nature-inspired biomaterials offer appealing microscale and nanoscale architectures that are often hard to fabricate by traditional technologies. Inspired by the light-harvesting nature, we engineered sulfuric acid-treated sunflower sporopollenin exine-derived microcapsules (HSECs) to capture light and bacteria for antimicrobial photothermal therapy. Sulfuric acid-treated HSECs show a greatly enhanced photothermal performance and a strong bacteria-capturing ability against Gram-positive bacteria. This is attributed to the hierarchical micro/nanostructure and surface chemistry alteration of HSECs. To test the potential for clinical application, an in situ bacteria-capturing, near-infrared (NIR) light-triggered hydrogel made of HSECs and curdlan is applied in photothermal therapy for infected skin wounds. HSECs and curdlan suspension that spread on bacteria-infected skin wounds of mice first capture the local bacteria and then form hydrogels on the wound upon NIR light stimulation. The combination shows a superior antibacterial efficiency of 98.4% compared to NIR therapy alone and achieved a wound healing ratio of 89.4%. The current study suggests that the bacteria-capturing ability and photothermal properties make HSECs an excellent platform for the phototherapy of bacteria-infected diseases. Future work that can fully take advantage of the hierarchical micro/nanostructure of HSECs for multiple biomedical applications is highly promising and desirable.

Heterostructures Combining Upconversion Nanoparticles and Metal–Organic Framework: Fundamental, Classification, and Theranostic Applications

AbstractIntegrating biocompatible metal–organic frameworks (MOFs) with upconversion nanoparticles (UCNPs), capable of converting near‐infrared (NIR) light into visible or ultraviolet emissions, affords unique UCNPs@MOFs heterostructures for nanomedicine. Alongside inherited advantages from parent UCNPs on imaging and parent MOFs with porous structure on chemodrugs delivery, upconversion Förster resonance energy transfer (FRET) from UCNPs to molecular moieties in MOFs offers unique abilities to probe or modulate intracellular and tumor microenvironments at high spatiotemporal precision. As a result, UCNPs@MOFs heterostructures allow to detect hint number of biomolecules, regulate intracellular ion concentrations for tumor cell killing and lamellipodia‐induced cell metastasis, on‐demand release NO gas molecules for antibacterial therapy and neurotherapy, and perform tumor microenvironment‐responsive multimodal therapy, all achieved possible using tissue‐penetrating NIR light stimulation of low photon flux. In this work, recent progress on the construction and applications of UCNPs@MOFs heterostructures toward these regards is surveyed. An emphasis is placed on the classification of heterostructures (Janus, core@satellite, core@shell) with distinct geometric shapes as well as the fundamental upconversion FRET mechanism underpinning all their theranostic applications. Cutting‐edge applications on combined therapies, drug delivery, multimodal imaging, and biosensing are also highlighted, along with provided perspectives on the future development.

Distributed interfacing by nanoscale photodiodes enables single-neuron light activation and sensory enhancement in 3D spinal explants.

Among emerging technologies developed to interface neuronal signaling, engineering electrodes at the nanoscale would yield more precise biodevices opening to progress in neural circuit investigations and to new therapeutic potential. Despite remarkable progress in miniature electronics for less invasive neurostimulation, most nano-enabled, optically triggered interfaces are demonstrated in cultured cells, which precludes the studies of natural neural circuits. We exploit here free-standing silicon-based nanoscale photodiodes to optically modulate single, identified neurons in mammalian spinal cord explants. With near-infrared light stimulation, we show that activating single excitatory or inhibitory neurons differently affects sensory circuits processing in the dorsal horn. We successfully functionalize nano-photodiodes to target single molecules, such as glutamate AMPA receptor subunits, thus enabling light activation of specific synaptic pathways. We conclude that nano-enabled neural interfaces can modulate selected sensory networks with low invasiveness. The use of nanoscale photodiodes can thus provide original perspective in linking neural activity to specific behavioral outcome.

Probing Neuropeptide Volume Transmission In Vivo by Simultaneous Near-Infrared Light-Triggered Release and Optical Sensing.

Neuropeptides are abundant signaling molecules in the central nervous system. Yet remarkably little is known about their spatiotemporal spread and biological activity. Here, we developed an integrated optical approach using Plasmonic nAnovesicles and cell-based neurotransmitter fluorescent engineered reporter (CNiFER), or PACE, to probe neuropeptide signaling in the mouse neocortex. Small volumes (fL to pL) of exogenously supplied somatostatin-14 (SST) can be rapidly released under near-infrared light stimulation from nanovesicles implanted in the brain and detected by SST2 CNiFERs with nM sensitivity. Our measurements reveal reduced but synchronized SST transmission within 130 μm, and markedly smaller and delayed transmission at longer distances. These measurements enabled a quantitative estimation of the SST loss rate due to peptide degradation and binding. PACE offers a new tool for determining the spatiotemporal scales of neuropeptide volume transmission and signaling in the brain.

Multifunctional Carbon Monoxide Prodrug-Loaded Nanoplatforms for Effective Photoacoustic Imaging-Guided Photothermal/Gas Synergistic Therapy.

Multifunctional cancer treatments based on gas therapy combined with other cancer treatments have gained tremendous attention and hold great promise in biomedical applications. In this study, a carbon monoxide-releasing nanoplatform combined with near-infrared (NIR) laser-triggered photothermal therapy (PTT) was constructed. The nanoplatform was composed of manganese pentacarbonyl bromide (MnCO)-loaded g-carbon nitride/polypyrrole (CNPpy) nanomaterials (MnCO@CNPpy). MnCO can be triggered to produce CO under H2O2 conditions. Upon exogenous NIR light stimulation and tumor microenvironment-overexpressed H2O2, MnCO@CNPpy exhibited excellent CO generation performance and photothermal effect. The generation of CO induced intracellular oxidative stress and caused cell apoptosis. Additionally, photoacoustic (PA) imaging was performed to track the delivery and accumulation of the nanomaterial in tumor sites because of the great photothermal conversion of CNPpy. The presented MnCO@CNPpy nanoplatform displayed desirable PTT and CO therapy in the inhibition of tumor growth and may provide a promising strategy for multifunctional antitumor synergistic treatments.

Transformable nanotherapeutics enabled by ICG: towards enhanced tumor penetration under NIR light irradiation.

Tumor penetration is the bottleneck for current cancer nanomedicine, limiting the ultimate antitumor efficacy in the clinic. Herein, by exploiting the well-known instability of indocyanine green (ICG), we report the preparation of near infrared (NIR) light responsive nanoparticles (NP) for enhanced tumor penetration. ICG crosslinks hydroxyethyl starch (HES) and doxorubicin (DOX) conjugates (HES-SS-DOX) via noncovalent interactions, facilitating the formation of ICG@HES-SS-DOX NP. The light triggered degradation of ICG leads to the dissociation of such NP, and the resulting HES-SS-DOX has been shown to penetrate deeper in both H22 tumor spheroids and tumor bearing mice, due to the photothermal effect of ICG. Therefore, the disintegrable ICG@HES-SS-DOX NP have better tumor penetration capacity than their counterparts, which originally cannot dissociate under NIR light stimulation. The reported ICG@HES-SS-DOX NP might be potent in treating malignant tumors with dense extracellular matrices, such as liver and pancreatic cancers. This study opens up a novel functionality of FDA-approved ICG for cancer nanotherapeutics.

Graphene‐Based Light‐Driven Soft Robot with Snake‐Inspired Concertina and Serpentine Locomotion

AbstractAs a kind of reptile that can move in a sophisticated environment by periodic changes in body shape, a snake's locomotion mode has inspired the design of several novel robots. Yet, most of those conventional robots are constructed by rigid components and powered by electricity. Herein, a novel snake‐inspired soft robot by fabricating triple‐layer reduced graphene oxide and polydopamine is reported. Such soft material is capable of bidirectional deformation while near‐infrared (NIR) light is projected at different regions. It allows the robot to move continuously by periodically changing body shape on demand without external forces or torques. The designed robot can achieve two locomotion modes like a snake, i.e., concertina locomotion and serpentine locomotion modes, corresponding to external NIR light stimulation. It paves a new way for the fabrication and control of soft robot which can be applied to medical treatment, rescue operation, and so on in the future.

Near-Infrared Photoactivatable Nitric Oxide Donors with Integrated Photoacoustic Monitoring.

Photoacoustic (PA) tomography is a noninvasive technology that utilizes near-infrared (NIR) excitation and ultrasonic detection to image biological tissue at centimeter depths. While several activatable small-molecule PA sensors have been developed for various analytes, the use of PA molecules for deep-tissue analyte delivery and monitoring remains an underexplored area of research. Herein, we describe the synthesis, characterization, and in vivo validation of photoNOD-1 and photoNOD-2, the first organic, NIR-photocontrolled nitric oxide (NO) donors that incorporate a PA readout of analyte release. These molecules consist of an aza-BODIPY dye appended with an aryl N-nitrosamine NO-donating moiety. The photoNODs exhibit chemostability to various biological stimuli, including redox-active metals and CYP450 enzymes, and demonstrate negligible cytotoxicity in the absence of irradiation. Upon single-photon NIR irradiation, photoNOD-1 and photoNOD-2 release NO as well as rNOD-1 or rNOD-2, PA-active products that enable ratiometric monitoring of NO release. Our in vitro studies show that, upon irradiation, photoNOD-1 and photoNOD-2 exhibit 46.6-fold and 21.5-fold ratiometric turn-ons, respectively. Moreover, unlike existing NIR NO donors, the photoNODs do not require encapsulation or multiphoton activation for use in live animals. In this study, we use PA tomography to monitor the local, irradiation-dependent release of NO from photoNOD-1 and photoNOD-2 in mice after subcutaneous treatment. In addition, we use a murine model for breast cancer to show that photoNOD-1 can selectively affect tumor growth rates in the presence of NIR light stimulation following systemic administration.

Mesoporous Carbon Nanospheres as a Multifunctional Carrier for Cancer Theranostics.

Optical nanomaterials with intense absorption in near-infrared (NIR) region hold great promise for biomedical applications such as photothermal therapy (PTT) and photoacoustic imaging (PAI). In this work, we report mesoporous carbon nanospheres (Meso-CNs) with broadband and intense absorption in the UV-Vis-NIR region (300-1400 nm) and explore their potential as a multifunctional platform for photoacoustic imaging and chemo-photothermal therapy.Methods: Meso-CNs were prepared by a “silica-assisted” synthesis strategy and characterized by transmission electron microscope and optical spectroscopy. We investigated the photothermal conversion and photoacoustic imaging of Meso-CNs in comparison with single-walled carbon nanotubes (SWCNTs), graphene and gold nanorods (GNRs). In vitro cellular assays and in vivo chemo-photothermal combination therapy were performed.Results: The absorption coefficients of Meso-CNs are 1.5-2 times higher than those of SWCNTs and graphene and are comparable to those of GNRs in both the first and the second near-infrared optical windows (NIR-I and NIR-II) of tissues. When exposed to an NIR laser, the photothermal and photoacoustic signal generation of Meso-CNs are also stronger than those of SWCNTs, graphene, and GNRs. DOX was loaded into Meso-CNs with a high efficiency (35 wt%) owing to the unique mesoporous structure. Particularly, the drug release from Meso-CNs is sensitive to both pH and NIR light stimulation. In vivo chemo-photothermal combination therapy demonstrates a remarkable inhibition effect on tumor growth under NIR laser treatment.Conclusions: We have developed Meso-CNs for photothermal conversion and photoacoustic imaging. The porous structure also serves as a drug carrier and the drug release can be controlled by pH and external light. The high drug loading capacity, superior photothermal and photoacoustic generation, together with the apparent chemo-photothermal therapeutic effect, make Meso-CNs a promising platform for cancer theranostics.

Photobiomodulation with Near Infrared Light Helmet in a Pilot, Placebo Controlled Clinical Trial in Dementia Patients Testing Memory and Cognition.

Alzheimer's disease (AD) is a common, chronic expensive debilitating neurodegenerative disease with no current treatments to prevent the physical deterioration of the brain and the consequent cognitive deficits. The current pathophysiology of Alzheimer's disease is the accumulation of neurofibrillary tangles (NFTs) of hyperphosphorylated tau protein and amyloid-beta (Aβ) plaques. Antibody therapy of Tau and Amyloid beta, vaccines and other methods to decrease Tau and or Amyloid have not been successful after considerable pharmaceutical and biotech efforts. For example, Eli Lilly announced a major change to its closely watched clinical trial for the Alzheimer's drug solanezumab which failed to reach statistical significance. Recently, a report on animal models using photomodulation with near infrared light to treat AD pathology in K369I tau transgenic model (K3) l engineered to develop neurofibrillary tangles, and the APPs/PSEN1dE9 transgenic model (APP/PS1) to develop amyloid plaques. Mice were treated with NIR 20 times over a four-week period and NIR treatment (600-1000 nm) was associated with a reduction in the size and number of amyloid-β plaques in the neocortex and hippocampus. We now report a small pilot double blind, placebo-controlled trial (n=11) 6 active, 3 controls and 2 dropouts assessing the effect of 28 consecutive, sixminute transcranial sessions of near infrared (NIR) stimulation using 1060-1080 nm light emitting diodes. Subjects were independently diagnosed with dementia conducted in an outpatient behavioral healthcare clinic. IRB approval was obtained through the Quietmind Foundation's institutional review Board (IRB). Results showed changes in executive functioning; clock drawing, immediate recall, praxis memory, visual attention and task switching (Trails A&B) as well as a trend of improved EEG amplitude and connectivity measures. Neuroplasticity has also been reported with NIR light stimulation and mitochondrial enhancement.

Controlled optical characteristics of lanthanide doped upconversion nanoparticles for emerging applications.

Lanthanide-doped upconversion nanoparticles (UCNPs) can convert long wavelength excitation radiation in the near-infrared region to higher energy emission radiation from ultraviolet to near-infrared. The anti-Stokes luminescence process will result in high tissue penetration depth, low background noise and low photo-damage in bioimaging applications. Considering these excellent optical performances, UCNPs have been considered as the next generation of fluorescent probes for sensing and bioimaging based on near-infrared light stimulation. In this mini review, we highlight the recent advances of UCNPs in the field of emerging applications, such as dye sensitized UCNPs, photogene regulation, anti-counterfeiting, and super-resolution imaging, which depend on the optical modulation. Finally, we discuss the challenges and opportunities in the development of these new applications.

Protein Activity Regulation: Inhibition by Closed-Loop Aptamer-Based Structures and Restoration by Near-IR Stimulation.

Regulation of protein activity is vital for understanding the molecular mechanism of biological activities. In this work, protein activity is suppressed by proximity-dependent surface hybridization and subsequently restored by near-infrared (NIR) light stimulation. Specifically, by constructing closed-loop structures with two aptamer-based affinity ligands, significantly enhanced inhibition of thrombin activity is achieved compared to traditional single affinity ligand based inhibitors. Furthermore, the activity of inhibited thrombin is efficiently recovered under NIR light stimulation by using gold nanorods (AuNRs) as photothermal agents to disrupt the closed-loop structures. Real-time and in situ monitoring of the conversion of fibrinogen into fibrin catalyzed by both inhibited and recovered thrombin was performed with light scattering spectroscopy and laser scanning confocal microscopy (LSCM). Thrombin trapped in the closed-loop structures shows slow reaction kinetics, while the photothermally liberated thrombin displays largely recovered catalytic activity. Human plasma was further employed to demonstrate that both the inhibited and restored thrombin can be applied to clotting reaction in reality. This strategy provides protein activity regulation for studying the molecular basis of biological activities and can be further applied to potential areas such as metabolic pathway regulation and the development of protein-inhibitor pharmaceuticals.