Near-infrared Light Research Articles

La3Sc2Ga3O12:Cr3+, Nd3+ near-infrared phosphor for nondestructive detection and luminescence thermometry

To develop continuous broadband emission near-infrared (NIR) phosphors compatible with blue LED chips, numerous Cr3+-Yb3+ co-doped phosphors have been synthesized. However, the emission spectra of Cr3+ vary significantly across different matrix materials, while Yb3+ maintains a relatively stable emission spectrum. This variation leads to notable luminescence depressions between 850 and 900 nm in many Cr3+-Yb3+ co-doped phosphors. To address this emission spectrum gap, we utilized Cr3+ as a sensitizer and introduced Nd3+ as the luminescence center within the La3Sc2Ga3O12 matrix material, establishing a Cr3+-Nd3+ energy transfer channel. Under 480 nm excitation, we tuned emission peaks at 800 nm (Cr3+) and 881 nm (Nd3+). The stable NIR emission of Nd3+ effectively compensates for the missing spectrum in Cr3+-Yb3+ co-doping. The Cr3+-Nd3+ energy transfer process was thoroughly analyzed using diffuse reflection spectrum, excitation spectrum, and fluorescence decay curves. The LSGO:0.125Cr3+, 0.03Nd3+ compound with the best optical performance was packaged with a 480 nm LED chip to create a NIR light source. At a working current of 10 mA, it achieved a photoelectric conversion efficiency of 9.45 %, demonstrating its potential for applications in non-destructive detection and luminescence thermometry. This work presents a novel strategy for tuning NIR spectral distribution and developing continuous broadband NIR phosphors.

Photodynamic therapy with NIR-II probes: review on state-of-the-art tools and strategies.

In 2022 10% of the world's population was aged 65+, and by 2100 this segment is expected to hit 25%. These demographic changes place considerable pressure over healthcare systems worldwide, which results in an urgent need for accurate, inexpensive and non-invasive ways to treat cancers, a family of diseases correlated with age. Among the therapeutic tools that gained important attention in this context, photodynamic therapies (PDT), which use photosensitizers to produce cytotoxic substances for selectively destroying tumor cells and tissues under light irradiation, profile as important players for next-generation nanomedicine. However, the development of clinical applications is progressing at slow pace, due to still pending bottlenecks, such as the limited tissue penetration of the excitation light, and insufficient targeting performance of the therapeutic probes to fully avoid damage to normal cells and tissues. The penetration depth of long-wavelength near infrared (NIR) light is significantly higher than that of short-wavelength UV and visible light, and thus NIR light in the second window (NIR-II) is acknowledged as the preferred phototherapeutic means for eliminating deep-seated tumors, given the higher maximum permissible exposure, reduced phototoxicity and low autofluorescence, among others. Upon collective multidisciplinary efforts of experts in materials science, medicine and biology, multifunctional NIR-II inorganic or organic photosensitizers have been widely developed. This review overviews the current state-of-the art on NIR-II-activated photosensitizers and their applications for the treatment of deep tumors. We also place focus on recent efforts that combine NIR-II activated PDT with other complementary therapeutic routes such as photothermal therapy, chemotherapy, immunotherapy, starvation, and gas therapies. Finally, we discuss still pending challenges and problems of PDT and provide a series of perspectives that we find useful for further extending the state-of-the art on NIR-II-triggered PDT.

Bleaching protection and axial sectioning in fluorescence nanoscopy through two-photon activation at 515 nm

Activation of caged fluorophores in microscopy has mostly relied on the absorption of a single ultraviolet (UV) photon of ≲400 nm wavelength or on the simultaneous absorption of two near-infrared (NIR) photons >700 nm. Here, we show that two green photons (515 nm) can substitute for a single photon (~260 nm) to activate popular silicon-rhodamine (Si-R) dyes. Activation in the green range eliminates the chromatic aberrations that plague activation by UV or NIR light. Thus, in confocal fluorescence microscopy, the activation focal volume can be matched with that of confocal detection. Besides, detrimental losses of UV and NIR light in the optical system are avoided. We apply two-photon activation (2PA) of three Si-R dyes in different superresolution approaches. STED microscopy of thick samples is improved through optical sectioning and photobleaching reduced by confining active fluorophores to a thin layer. 2PA of individualized fluorophores enables MINSTED nanoscopy with nanometer-resolution.

Revolutionizing Tetracycline Hydrochloride Remediation: 3D Motile Light-Driven MOFs Based Micromotors in Harsh Saline Environments.

Traditional light-driven metal-organic-frameworks (MOFs)-based micromotors (MOFtors) are typically constrained to two-dimensional (2D) motion under ultraviolet or near-infrared light and often demonstrate instability and susceptibility to ions in high-saline environments. This limitation is particularly relevant to employing micromotors in water purification, as real wastewater is frequently coupled with high salinity. In response to these challenges, ultrastable MOFtors capable of three-dimensional (3D) motion under a broad spectrum of light through thermophoresis and electrophoresis are successfully synthesized. The MOFtors integrated photocatalytic porphyrin MOFs (PCN-224) with a photothermal component made of polypyrrole (PPy) by three distinct methodologies, resulting in micromotors with different motion behavior and catalytic performance. Impressively, the optimized MOFtors display exceptional maximum velocity of 1305±327µms-1 under blue light and 2357±453µms-1 under UV light. In harsh saline environments, these MOFtors are not only maintain high motility but also exhibit superior tetracycline hydrochloride (TCH) removal efficiency of 3578±510mgg-1, coupling with sulfate radical-based advanced oxidation processes and peroxymonosulfate. This research underscores the significant potential of highly efficient MOFtors with robust photocatalytic activity in effectively removing TCH in challenging saline conditions, representing a substantial advancement in applying MOFtors within real-world water treatment technologies.

Can infrared light really be doing what we claim it is doing? Infrared light penetration principles, practices, and limitations.

Near infrared (NIR) light has been shown to provide beneficial treatment of traumatic brain injury (TBI) and other neurological problems. This concept has spawned a plethora of commercial entities and practitioners utilizing panels of light emitting diodes (LEDs) and promising to treat patients with TBI and other disorders, who are desperate for some treatment for their untreatable conditions. Unfortunately, an LED intended to deliver photonic energy to the human brain does not necessarily do what an LED pointed at a mouse brain does. There is a problem of scale. Extensive prior research has shown that infrared light from a 0.5-watt LED will not penetrate the scalp and skull of a human. Both the properties of NIR light and the manner in which it interacts with tissue are examined. Based on these principles, the shortcomings of current approaches to treating neurological disorders with NIR light are explored. Claims of clinical benefit from low-level LED-based devices are explored and the proof of concept challenged. To date, that proof is thin with marginal benefits which are largely transient. Extensive research has shown fluence at the level of the target tissue which falls within the range of 0.9 J/cm2 to 15 J/cm2 is most effective in activating the biological processes at the cellular level which underlie direct photobiomodulation. If low-level infrared light from LED devices is not penetrating the scalp and skull, then these devices certainly are not delivering that level of fluence to the neurons of the subjacent brain. Alternative mechanisms, such as remote photobiomodulation, which may underlie the small and transient benefits for TBI symptoms reported for low-power LED-based NIR studies are presented. Actionable recommendations for the field are offered.

Development of dual-crosslinked Pluronic F127/Chitosan injectable hydrogels incorporating graphene nanosystems for breast cancer photothermal therapy and antibacterial applications

Nanomaterials with responsiveness to near-infrared light can mediate the photoablation of cancer cells with an exceptional spatio-temporal resolution. However, the therapeutic outcome of this modality is limited by the nanostructures’ poor tumor uptake. To address this bottleneck, it is appealing to develop injectable in situ forming hydrogels due to their capacity to perform a tumor-confined delivery of the nanomaterials with minimal off-target leakage. In particular, injectable in situ forming hydrogels based on Pluronic F127 have been emerging due to their FDA-approval status, biocompatibility, and thermosensitive sol–gel transition. Nevertheless, the application of Pluronic F127 hydrogels has been limited due to their fast dissociation in aqueous media. Such limitation may be addressed by combining the thermoresponsive sol–gel transition of Pluronic F127 with other polymers with crosslinking capabilities. In this work, a novel dual-crosslinked injectable in situ forming hydrogel based on Pluronic F127 (thermosensitive gelation) and Chitosan (ionotropic gelation in the presence of NaHCO3), loaded with Dopamine-reduced graphene oxide (DOPA-rGO; photothermal nanoagent), was developed for application in breast cancer photothermal therapy. The dual-crosslinked hydrogel incorporating DOPA-rGO showed a good injectability (through 21 G needles), in situ gelation capacity and cytocompatibility (viability > 73 %). As importantly, the dual-crosslinking improved the hydrogel’s porosity and prevented its premature degradation. After irradiation with near-infrared light, the dual-crosslinked hydrogel incorporating DOPA-rGO produced a photothermal heating (ΔT ≈ 22 °C) that reduced the breast cancer cells’ viability to just 32 %. In addition, this formulation also demonstrated a good antibacterial activity by reducing the viability of S. aureus and E. coli to 24 and 33 %, respectively. Overall, the dual-crosslinked hydrogel incorporating DOPA-rGO is a promising macroscale technology for breast cancer photothermal therapy and antimicrobial applications.

Photothermal therapy and cell imaging tracking of porous silicon nanoparticle by magnesiothermic reduction and surface modification

The synthesis of silicon nanoparticles (PSi NPs) from silica nanoparticles (SiO₂) via magnesium (Mg) reduction is a promising technique due to its simplicity and cost-effectiveness. In this study, silica is utilized as the primary precursor and is subjected to a reduction process using magnesium powder as the reducing agent. By covalently attaching Fluorescein Isothiocyanate (FITC) to the surface of PSi NPs, we aim to enhance their fluorescence intensity and stability while also improving their surface reactivity and biocompatibility. The modified PSi NPs system was characterized using various microscopic techniques, Raman spectra, porosity and morphology analysis, Zeta potential, and analysis of organic functional groups to confirm successful conjugation and to evaluate changes in surface morphology, fluorescence properties, and colloidal stability. By leveraging the inherent photothermal conversion efficiency of PSi NPs, we explore their capacity to generate localized heat upon near-infrared (NIR) light irradiation, effectively inducing cancer cell apoptosis. Concurrently, the natural fluorescence of PSi NPs is harnessed to enable high-resolution imaging, facilitating real-time tracking and monitoring of therapeutic processes. The PSi NPs were subjected to a series of in vitro experiments to assess their photothermal efficiency, cytotoxicity, and imaging capabilities. Results demonstrate that PSi NPs exhibit excellent photothermal effects, leading to significant cell death in targeted cancer cells upon NIR exposure, while their fluorescence properties provide clear and detailed imaging. These findings highlight the potential of PSi NPs as multifunctional agents in cancer therapy, combining effective photothermal treatment with non-invasive imaging, thereby enhancing the precision and efficacy of therapeutic interventions.

Integration of single-atom photothermal catalysts with surface-localized high temperature in peroxymonosulfate-based Fenton-like systems for enhanced antibiotics degradation

This study delves into integrating single-atom catalysts with photothermal effect in peroxymonosulfate (PMS)-based Fenton-like systems for enhanced pollutant degradation. A single-atom photothermal catalyst (Co/PMCNs) was designed using mesoporous carbon spheres as both a single-atom support and a photothermal material. Near-infrared (NIR) light was employed due to its superior thermal effect and penetration capacity in water. It was found that Co/PMCNs could generate surface-localized high temperatures for accelerating PMS activation and reducing energy gap of activation reactions, leading to improved degradation performance. Surface-localized high temperatures were demonstrated as key in distinguishing photothermal heating from external heat sources for PMS activation. Moreover, this system performed well across various operating conditions and water matrices, with Co/PMCNs showing promising recyclability. This study highlights the impact of surface-localized high temperatures on heterogeneous catalysis under NIR irradiation, and underscores the potential of integrating single-atom catalysts with photothermal effects into advanced oxidation processes for effective water pollution control.

Near-infrared light transillumination (NIR-LT) vs clinical-visual inspection/FOTI to detect interproximal caries lesions in vivo.

To evaluate the ability of near-infrared light transillumination (NIR-LT) to detect interproximal enamel and dentinal caries lesions compared to clinical-visual inspection (VI) aided by fibre-optic transillumination (FOTI). From 170 Finnish adolescents aged 15-17 years, 5294 interproximal surfaces of premolars and molars were examined first clinical-visually aided by FOTI (VI&#43;FOTI) using the International Caries Detection and Assessment System (ICDAS) classification. Subsequently, the surfaces were examined using NIR-LT. The extent of lesions was determined using the modified NIR-LT classification based on the Söchtig criteria. For the analyses, data on upper and lower premolars and molars were combined. Distributions of lesions were presented as frequencies. Differences between VI&#43;FOTI and NIR-LT at the tooth and tooth surface levels were analysed by Chi-square and Fisher's exact tests. Sensitivity and specificity of the NIR-LT method to detect any lesion was performed using VI&#43;FOTI as the gold standard. By VI&#43;FOTI, 92.4% surfaces were classified as sound and by NIR-LT, 88.2%. Enamel caries lesions were found on 7.0% of the surfaces by VI&#43;FOTI and on 11.6% by NIR-LT. Enamel lesions identified by NIR-LT were nearly double for all examined teeth groups, except for lower molars it was 1.3-fold. In 66% of the surfaces, the differences between NIR-LT and VI&#43;FOTI findings were statistically significant (p<0.001). The sensitivity for all teeth of NIR-LT was 48.4% and the specificity was 91.1%. Radiation-free NIR-LT method shows considerable potential as a supplementary method for early detection of caries lesions among low caries prevalence adolescents.

Visible-NIR responsive Ag2O couple with MIL-53(Fe) on CS as S-scheme photocatalyst for efficient simultaneous removal of Cr(VI) and norfloxacin

This study addresses the urgent need to develop easily recoverable and efficient photocatalysts for the treatment of compound polluted wastewater. Herein, S-scheme MIL-53(Fe)/Ag2O heterojunctions on a charcoal sponge (CS) were constructed by solvothermal-chemical precipitation method, exhibiting high separation efficiency of photoinduced carriers and reduction–oxidation (REDOX) capacity. The synthesized CS/MIL-53(Fe)/Ag2O was characterized by SEM, TEM, XRD, and XPS, confirming the successful deposition and uniform distribution of MIL-53(Fe) and Ag2O nanoparticles on CS. Moreover, CS/MIL-53(Fe)/Ag2O exhibits an extensive light absorption range from visible to near-infrared (NIR) light, thereby significantly enhancing its photocatalytic activity. In present of H2O2, CS/MIL-53(Fe)/Ag2O demonstrated outstanding removal efficacy of norfloxacin (NFX, 96 %, pH=7) or Cr(VI) (100 %, pH=3) through the photocatalytic-Fenton reaction, which was notably superior to that of CS/MIL-53(Fe) (50.4 % NFX, 56.8 % Cr(VI)) and CS/Ag2O (44.3 % NFX, 38 % Cr(VI)). Importantly, when CS/MIL-53(Fe)/Ag2O was used to treat combined polluted wastewater containing both Cr(VI) and NFX, the removal efficiency of Cr(VI) and NFX showed a significant synergistic effect. Additionally, inhibition zone tests demonstrated that the toxicity of NFX intermediates to E. coli gradually decreased as the degradation of NFX progressed. Furthermore, density functional theory (DFT) calculation and relevant characterization were conducted to elucidate the reaction mechanism of S-scheme heterojunctions, highlighting the enhanced separation rate of photo-induced carriers and REDOX capability. This work not only offers a promising approach for construction of MOF-based S-scheme semiconductor heterojunctions, but also presents promising prospects for the purification of compound polluted wastewater containing norfloxacin and Cr(VI).

Design of dark-colored acrylic coatings for increased LiDAR detection in autonomous vehicles

Light Detection and Ranging (LiDAR) is the major sensor for autonomous vehicles. It emits near-infrared (NIR) pulsed light at 905 nm and detects the reflected portion of this light from the surrounding objects. Location and surface determination of the surrounding objects is performed using the time-of-flight (the elapsed time from launch of a pulsed beam to detection of the reflected returned beam). Solvent borne acrylic paints gained wide currency for the exterior automotive coatings over the years and topcoats with conventional dark-colored pigment dispersions exhibit low reflectivity in the NIR region. The formulation of innovative topcoats with high reflectivity in this region is an urgent task for leading paint manufacturers. In this study, pigment dispersions to be incorporated in LiDAR-detectable solvent borne acrylic automotive topcoats were designed considering the surface charges of individual pigment particles for dispersant selection. Stability of designed dispersions was demonstrated and color matching studies were realized. Three dark colors encoded RAL 9011 (Graphite black), RAL 5017 (Traffic blue), and RAL 5015 (Sky blue) from the RAL 841-GL color chart were formulated as acrylic topcoats with NIR reflective pigments. Based on the surface properties of the dry films, such as gloss, haze and distinctness of image, a significant increase in LiDAR detection was achieved for each color. The results affirmed the potential use of the developed formulations as end-product paints for coating the exterior surfaces of autonomous vehicles.

Optical thermometry using efficient upconversion luminescence in Er3+ self-sensitized NaYS2 under multi-wavelength excitation

Herein, a series of Er3+ self-sensitized NaYS2 phosphors are synthesized by the solid-gas reaction method for a novel upconversion luminescence thermometer. Er3+ possesses abundant excited state energy levels in the near-infrared region, enabling efficient upconversion luminescence by absorbing different near-infrared wavelength light. Compared to 980 nm excitation, the emission intensity is enhanced by nearly an order of magnitude under 1532 nm excitation, which can be attributed to the larger absorption cross-section of 4I13/2 and stronger absorption efficiency for Er3+. Based on the luminescence intensity ratio technique, the optical thermometry behaviors of NaYS2:Er3+ under different wavelength excitation are evaluated by employing the thermally coupled energy levels of 2H11/2/4S3/2. It can be deduced that the excitation wavelength has no significant effect on the temperature sensing parameters. Compared to other typical upconversion luminescence thermometers, NaYS2:Er3+ thermometer exhibits not only excellent sensitivity performance but also high upconversion luminescence efficiency, which is expected to be applied in wide-temperature-range and highly-sensitive temperature sensing.

Tumor Microenvironment-Responsive Magnetotactic Bacteria-Based Multi-Drug Delivery Platform for MRI-Visualized Tumor Photothermal Chemodynamic Therapy.

Cancer cells display elevated reactive oxygen species (ROS) and altered redox status. Herein, based on these characteristics, we present a multi-drug delivery platform, AMB@PDAP-Fe (APPF), from the magnetotactic bacterium AMB-1 and realize MRI-visualized tumor-microenvironment-responsive photothermal-chemodynamic therapy. The Fe3+ in PDAP-Fe is reduced by the GSH at the tumor site and is released in the form of highly active Fe2+, which catalyzes the generation of ROS through the Fenton reaction and inhibits tumor growth. At the same time, the significant absorption of the mineralized magnetosomes in AMB-1 cells in the NIR region enables them to efficiently convert near-infrared light into heat energy for photothermal therapy (PTT), to which PDAP also contributes. The heat generated in the PTT process accelerates the process of Fe2+ release, thereby achieving an enhanced Fenton reaction in the tumor microenvironment. In addition, the magnetosomes in AMB-1 are used as an MRI contrast agent, and the curing process is visualized. This tumor microenvironment-responsive MTB-based multi-drug delivery platform displays the potency to combat tumors and demonstrates the utility and practicality of understanding the cooperative molecular mechanism when designing multi-drug combination therapies.

Bi2Se3/PAAS Hydrogels with Photothermal and Antioxidant Properties for Bacterial Infection Wound Therapy by Improving Vascular Function and Regulating Glycolipid Metabolism.

Skin is the largest organ in the human body, and it is also the most important natural barrier. However, some accidents can cause skin damage. Bacterial infections and inflammatory reactions can hinder wound healing. Therefore, eliminating bacterial infections and regulating oxidative stress are essential. The use of antibiotics is no longer sufficient because of bacterial resistance. The development of new nanomaterials provides another way of thinking about bacterial drug resistance. In this study, bismuth selenide is modified with polyethylpyrrolidone to obtain a 2D nanomaterial with negligible toxicity and then added to a sodium polyacrylate hydrogel, which is nontoxic and has strong tissue adhesion and a weak antibacterial effect. To further enhance antibacterial performance, photothermal therapy is a good strategy. Under near-infrared light, Bi2Se3/PAAS shows a strong bactericidal effect. Bi2Se3/PAAS hydrogels also have certain antioxidant effects and are used to remove excess free radicals from wound infections. The effective therapeutic effect of Bi2Se3/PAAS/NIR on methicillin-resistant Staphylococcus aureus (MRSA) infection is further verified in animal models. Transcriptome analysis reveals that the Bi2Se3/PAAS hydrogel improves the function of vascular endothelial cells, regulates glucose and lipid metabolism, and promotes the healing of infected wounds.

Deep near infrared light-excited stable synergistic photodynamic and photothermal therapies based on P-IR890 nano-photosensitizer constructed via a non-cyanine dye

The cyanine dyes represented by IR780 can achieve synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) under the stimulation of near-infrared (NIR) light (commonly 808 nm). Unfortunately, the stability of NIR-excited cyanine dyes is not satisfactory. These cyanine dyes can be attacked by self-generated reactive oxygen species (ROS) during PDT processes, resulting in structural damage and rapid degradation, which is fatal for phototherapy. To address this issue, a novel non-cyanine dye (IR890) was elaborately designed and synthesized by our team. The maximum absorption wavelength of IR890 was located in the deep NIR region (ca. 890 nm), which was beneficial for further improving tissue penetration depth. Importantly, IR890 exhibited good stability when continuously illuminated by deep NIR light. To improve the hydrophilicity and biocompatibility, the hydrophobic IR890 dye was grafted onto the side chain of hydrophilic polymer (POEGMA-b-PGMA-g-CCH) via click chemistry. Then, the synthesized POEGMA-b-PGMA-g-IR890 amphiphilic polymer was utilized to prepare P-IR890 nano-photosensitizer via self-assembly method. Under irradiation with deep NIR light (850 nm, 0.5 W/cm2, 10 min), the dye degradation rate of P-IR890 was less than 5%. However, IR780 was almost completely degraded with the same light output power density and irradiation duration. In addition, P-IR890 could stably generate a large number of ROS and heat at the same time. It was rarely reported that the stable synergistic combination therapy of PDT and PTT could be efficiently performed by a single photosensitizer via irradiation with deep NIR light. P-IR890 exhibited favorable anti-tumor outcomes through apoptosis pathway. Therefore, the P-IR890 could provide a new insight into the design of photosensitizers and new opportunities for synergistic combination therapy of PDT and PTT.

Multifunctional magneto-plasmonic lipogel based on peptide hydrogel for application in combined cancer therapy.

Supramolecular hydrogels, particularly low-molecular-weight peptide hydrogels, are promising drug delivery systems due to their ability to change the solubility, targeting, metabolism and toxicity of drugs. Magneto-plasmonic liposomes, in addition to being remotely controllable with the application of an external magnetic field, also increase the efficiency of encapsulated drug release through thermal stimulation, for example, with magnetic and optical hyperthermia. Thus, the combination of those two materials-giving magneto-plasmonic lipogels-brings together several functionalities, among which are hyperthermia and spatiotemporally controlled drug delivery. In this work, a novel dehydrodipeptide hydrogelator was synthesised, and the respective hydrogel was functionalized with magneto-plasmonic liposomes. After individually characterising the components with regard to their rheological, spectroscopic and magnetic properties, the magneto-plasmonic lipogel was equally characterised and evaluated concerning its ability to deliver drugs in a controlled fashion. To this end, the response of the 5(6)-carboxyfluorescein-loaded magneto-plasmonic lipogel to near-infrared light was assessed. The results showed that the system is a proper carrier of hydrophilic drugs and allows to envisage photo-responsive drug delivery. These facts, together with the magnetic guidance and hyperthermia capabilities of the developed composite gel, may pave the way to a new era in the treatment of cancer and other diseases.

Photobiomodulation Dose-Response on Adipose-Derived Stem Cell Osteogenesis in 3D Cultures.

Osteoporosis and other degenerative bone diseases pose significant challenges to global healthcare systems due to their prevalence and impact on quality of life. Current treatments often alleviate symptoms without fully restoring damaged bone tissue, highlighting the need for innovative approaches like stem cell therapy. Adipose-derived mesenchymal stem cells (ADMSCs) are particularly promising due to their accessibility, abundant supply, and strong differentiation potential. However, ADMSCs tend to favor adipogenic pathways, necessitating the use of differentiation inducers (DIs), three-dimensional (3D) hydrogel environments, and photobiomodulation (PBM) to achieve targeted osteogenic differentiation. This study investigated the combined effects of osteogenic DIs, a fast-dextran hydrogel matrix, and PBM at specific wavelengths and fluences on the proliferation and differentiation of immortalized ADMSCs into osteoblasts. Near-infrared (NIR) and green (G) light, as well as their combination, were used with fluences of 3 J/cm2, 5 J/cm2, and 7 J/cm2. The results showed statistically significant increases in alkaline phosphatase levels, a marker of osteogenic differentiation, with G light at 7 J/cm2 demonstrating the most substantial impact on ADMSC differentiation. Calcium deposits, visualized by Alizarin red S staining, appeared as early as 24 h post-treatment in PBM groups, suggesting accelerated osteogenic differentiation. ATP luminescence assays indicated increased proliferation in all experimental groups, particularly with NIR and NIR-G light at 3 J/cm2 and 5 J/cm2. MTT viability and LDH membrane permeability assays confirmed enhanced cell viability and stable cell health, respectively. In conclusion, PBM significantly influences the differentiation and proliferation of hydrogel-embedded immortalized ADMSCs into osteoblast-like cells, with G light at 7 J/cm2 being particularly effective. These findings support the combined use of 3D hydrogel matrices and PBM as a promising approach in regenerative medicine, potentially leading to innovative treatments for degenerative bone diseases.

Long wavelength near-infrared and red light-driven consecutive photo-induced electron transfer for highly effective photoredox catalysis

Consecutive photoinduced electron transfer (conPET) processes accumulate the energies of two photons to overcome the thermodynamic limit of traditional photoredox catalysis. However, the excitation wavelength of conPET systems mainly focused on short wavelength visible light, leading to photodamage and incompatibility with large-scale reactions. Herein, we report on conPET systems triggered by near-infrared (NIR) and red light. Specifically, a blue-absorbing conPET photocatalyst, perylene diimide (PDI) is sensitized by a palladium-based photosensitizer to triplet excited state (3PDI*), which generates PDI radical anion (PDI•–) over 100-fold faster than that in the conventional conPET. Accordingly, photoreduction with superior reaction rate and penetration depth, as well as reduced photodamage is detected. More importantly, our work offers comprehensive design rules for the triplet-mediated conPET strategy, whose versatility is confirmed by metal-free dye pairs and NIR-active PtTNP/PDI. Notably, our work achieves NIR-driven atom transfer radical polymerization using an inert aromatic halide as the initiator.

The effect of near-infrared Photobiomodulation therapy on the ion content of 50B11 sensory neurons measured through XRF analysis

Photobiomodulation therapy (PBMT) is a form of treatment commonly used for routine clinical applications, such as wound healing of the skin and reduction of inflammation. Additionally, PBMT has been explored for its potential in pain relief.In this work, we investigated the effect of PBMT on ion content within the 50B11 sensory neurons cell line in vitro using X-Ray fluorescence (XRF) and atomic force microscope (AFM) analysis.Two irradiation protocols were selected utilizing near-infrared laser lights at 800 and 970 nm, with cell fixation immediately following irradiation.Results showed a decrease in Calcium content after irradiation with both protocols, and with lidocaine, used as an analgesic control. Furthermore, a reduction in Potassium content was observed, particularly evident when normalized to cellular volume.These findings provide valuable insights into the molecular impact of PBMT within 50B11 sensory neurons under normal conditions. Such understanding may contribute to the wider adoption of PBMT as a therapeutic approach.

Triarylamine-based polyimide COFs for achieving high performance ambipolar multi-color electrochromic energy-storage films

Electrochromic energy storage materials that possess both electrochromic and electrochemical energy-storage properties have attracted significant attention for applications in visual energy-storage, energy-efficient windows, as well as displays. To fulfill their comprehensive applications, electrochromic energy-storage materials require specific characteristics, such as transparency, ambipolarity, multi-color capabilities, and high capacitance. Here, the polyimide covalent-organic framework based on triarylamine (PM-TPI and NT-TPI) COF films were grown successfully on FTO glass through solvothermal polycondensation, and exhibited crystallization, hierarchical porous structures, and ambipolar electrochemical redox activity. Notably, NT-TPI COF film displayed transparent bleached state, ambipolar electrochromism, multi-color (transparent, orange-red, cyan, gray), and high optical contrast. Due to their large specific surface area and efficient electron/ion transport ability, the NT-TPI COF film effectively controlled visible and near-infrared light, achieving optical contrasts of 49.8 % and 70.0 % at 420 and 850 nm, respectively. Moreover, the NT-TPI COF films showed promising electrochemical energy-storage properties and excellent charge–discharge rate performance, with a specific capacitance of 141.0 mAh/g. Additionally, NT-TPI COF/WO3-based ambipolar eclectrochromic energy-storage devices also exhibited high optical contrast from visible to near-infrared regions, and large capacitance. In summary, the NT-TPI COF film effectively combines the electrochromic and electrochemical energy-storage capabilities, making it a promising candidate for electrochromic energy-storage materials with transparency, ambipolarity, high optical contrast, multi-color functionality, and high specific capacitance.