Search Results (20)

Male infertility is a growing global concern, with asthenozoospermia being an important contributing factor. Mitochondrial dysfunction and changes in the metabolism of nitric oxide (NO) are key determinants of reduced sperm motility. This study investigates the effects of photobiomodulation (PBM) with visible and near-infrared (NIR) laser light on sperm of asthenozoospermic patients, focusing on mitochondrial energetic status, oxidative stress, and NO dynamics. Semen samples were irradiated at 450 nm, 635 nm, 810 nm, 940 nm, and 1064 nm at different power levels (0.25, 0.50, 1.00, and 2.00 W) for 60 s on a spot area of 1 cm². ATP and AMP levels, oxidative stress markers, and NO concentrations were assessed at 10 and 60 min after irradiation, with the ATP/AMP ratio calculated as an index of cellular energy balance. The results show that the PBM modulates the energetic status of spermatozoa in a way dependent on wavelength and dose. Irradiation at 810 nm produced the most marked improvement in energetic status, whereas 635 nm exposure led to a significant decrease in cellular energy levels. NO levels showed a biphasic response, correlated with the visible range and with energy metabolism at 810 nm. Irradiation with 635 nm induced higher NO production with respect to the other wavelengths. Our findings suggest that PBM mainly involves mitochondrial photoreceptors and potentially the heme and flavin groups of nitric oxide synthases, facilitating electron transitions, enhancing the effectiveness of oxidative phosphorylation, and optimizing enzymatic activity. At longer wavelengths (940 nm and 1064 nm), interactions with water and lipids may introduce additional variables that affect membrane fluidity and mitochondrial function differently from shorter wavelengths. Full article

Photothermal therapy operated in the second near-infrared (NIR-II, 1000–1700 nm) window and fluorescence imaging in the NIR-IIb (1500–1700 nm) region have become the most promising techniques in phototheranostics. Their combination enables simultaneous high-resolution optical imaging and deep-penetrating phototherapy, which is essential for high-performance phototheranostics. Herein, carboxyl-functionalized small organic photothermal molecules (Se-TC) and multi-layered NIR-IIb emissive rare-earth-doped nanoparticles (NaYF₄:Yb,Er,Ce@NaYF₄:Yb,Nd@NaYF₄, RENP) were rationally designed and successfully synthesized. Then, high-performance hybrid phototheranostic nanoagents (Se-TC@RENP@F) were easily constructed through the coordination between Se-TC and RENP and followed by subsequent F127 encapsulation. The carboxyl groups of Se-TC can offer strong binding affinity towards rare-earth-doped nanoparticles, which help improving the stability of Se-TC@RENP@F. The multilayered structure of RENP largely enhance the NIR-IIb emission under 808 nm excitation. The obtained Se-TC@RENP@F exhibited high 1064 nm absorption (extinction coefficient: 24.7 L g⁻¹ cm⁻¹), large photothermal conversion efficiency (PCE, 36.9%), good NIR-IIb emission (peak: 1545 nm), as well as great photostability. Upon 1064 nm laser irradiation, high hyperthermia can be achieved to kill tumor cells efficiently. In addition, based on the excellent NIR-IIb emission of Se-TC@RENP@F, in vivo angiography and tumor detection can be realized. This work provides a distinguished paradigm for NIR-IIb-imaging-guided NIR-II photothermal therapy and establishes an artful strategy for high-performance phototheranostics. Full article

Photothermal therapy (PTT) has received constant attention as a promising cancer treatment. However, PTT-induced inflammation can limit its effectiveness. To address this shortcoming, we developed second near-infrared (NIR-II) light-activated nanotheranostics (CPNPBs), which include a thermosensitive nitric oxide (NO) donor (BNN6) to enhance PTT. Under a 1064 nm laser irradiation, the conjugated polymer in CPNPBs serves as a photothermal agent for photothermal conversion, and the generated heat triggers the decomposition of BNN6 to release NO. The combination of hyperthermia and NO generation under single NIR-II laser irradiation allows enhanced thermal ablation of tumors. Consequently, CPNPBs can be exploited as potential candidates for NO-enhanced PTT, holding great promise for their clinical translational development. Full article

The transmissive mode laser micro-ablation performance of near-infrared (NIR) dye-optimized ammonium dinitramide (ADN)-based liquid propellant was investigated in laser plasma propulsion using a pulse YAG laser with 5 ns pulse width and 1064 nm wavelength. Miniature fiber optic near-infrared spectrometer, differential scanning calorimeter (DSC) and high-speed camera were used to study laser energy deposition, thermal analysis of ADN-based liquid propellants and the flow field evolution process, respectively. Experimental results indicate that two important factors, laser energy deposition efficiency and heat release from energetic liquid propellants, obviously affect the ablation performance. The results showed that the best ablation effect of 0.4 mL ADN solution dissolved in 0.6 mL dye solution (40%-AAD) liquid propellant was obtained with the ADN liquid propellant content increasing in the combustion chamber. Furthermore, adding 2% ammonium perchlorate (AP) solid powder gave rise to variations in the ablation volume and energetic properties of propellants, which enhanced the propellant enthalpy variable and burn rate. Based on the AP optimized laser ablation, the optimal single-pulse impulse (I)~9.8 μN·s, specific impulse (I_sp)~234.9 s, impulse coupling coefficient (C_m)~62.43 dyne/W and energy factor (η)~71.2% were obtained in 200 µm scale combustion chamber. This work would enable further improvements in the small volume and high integration of liquid propellant laser micro-thruster. Full article

The accurate diagnosis and treatment of prostate cancer at an early stage is crucial to reduce mortality rates. However, the limited availability of theranostic agents with active tumor-targeting abilities hinders imaging sensitivity and therapeutic efficiency. To address this challenge, we have developed biomimetic cell membrane-modified Fe₂O₃ nanoclusters implanted in polypyrrole (CM-LFPP), achieving photoacoustic/magnetic resonance dual-modal imaging-guided photothermal therapy of prostate cancer. The CM-LFPP exhibits strong absorption in the second near-infrared window (NIR-II, 1000–1700 nm), showing high photothermal conversion efficiency of up to 78.7% under 1064 nm laser irradiation, excellent photoacoustic imaging capabilities, and good magnetic resonance imaging ability with a T2 relaxivity of up to 48.7 s⁻¹ mM⁻¹. Furthermore, the lipid encapsulation and biomimetic cell membrane modification enable CM-LFPP to actively target tumors, leading to a high signal-to-background ratio of ~30.2 for NIR-II photoacoustic imaging. Moreover, the biocompatible CM-LFPP enables low-dose (0.6 W cm⁻²) photothermal therapy of tumors under 1064 nm laser irradiation. This technology offers a promising theranostic agent with remarkable photothermal conversion efficiency in the NIR-II window, providing highly sensitive photoacoustic/magnetic resonance imaging-guided prostate cancer therapy. Full article

The choice of parameters for laser beams used in the treatment of musculoskeletal diseases is of great importance. First, to reach high penetration depths into biological tissue and, secondly, to achieve the required effects on a molecular level. The penetration depth depends on the wavelength since there are multiple light-absorbing and scattering molecules in tissue with different absorption spectra. The present study is the first comparing the penetration depth of 1064 nm laser light with light of a smaller wavelength (905 nm) using high-fidelity laser measurement technology. Penetration depths in two types of tissue ex vivo (porcine skin and bovine muscle) were investigated. The transmittance of 1064 nm light through both tissue types was consistently higher than of 905 nm light. The largest differences (up to 5.9%) were seen in the upper 10 mm of tissue, while the difference vanished with increasing tissue thickness. Overall, the differences in penetration depth were comparably small. These results may be of relevance in the selection of a certain wavelength in the treatment of musculoskeletal diseases with laser therapy. Full article

Magneto-plasmonic Ag/Ni and Ag/Fe nanoparticles (NPs) were synthesized in this work using the environmentally safe and contaminant-free dual-pulsed Q-switched Nd:YAG 1064 nm laser ablation method. The optical and magnetic characteristics of synthesized nanomaterials were investigated using a vibrating sample magnetometer and an ultraviolet-visible absorption spectrometer. According to transmission electron microscopy (TEM), the shape of Ag/Ni and Ag/Fe NPs seems to be spherical, with mean diameters of 7.3 nm and 11.5 nm, respectively. X-ray diffraction (XRD) was used in order to investigate and describe the phase structures of the synthesized nanomaterials. The synthesized NPs reached maximum temperatures such as 48.9, 60, 63.4, 70, 75, and 79 °C for Ag/Ni nanofluid and 52, 56, 60, 68, 71, and 72 °C for Ag/Fe nanofluid when these nanofluids were subjected to an NIR 808 nm laser with operating powers of 1.24, 1.76, 2.36, 2.91, 3.5, and 4 W, respectively. Because of the plasmonic hyperthermia properties of nanoparticles, nanofluids display higher temperature profiles than pure water. According to these findings, plasmonic nanoparticles based on silver might be used to treat hyperthermia. Full article

This paper shows the laser irradiation effect on optical characteristics on PbSe chalcogenide films as a result of irreversible structural modification. The features of film structure and property modification under the action of a continuous wave (CW) laser with a 405 nm wavelength and nanosecond laser pulses with a 1064 nm wavelength are studied. The valence and conduction bands boundaries displacement as a laser radiation result of photothermal action on the film until it darkens and bleaches, is demonstrated. Under CW near ultraviolet (NUV) laser action, the film was modified at a power density of 0.74 to 1.09 kW/cm². The near-infrared (NIR) laser pulses used ensured the film structure modification at a power density of 1.45 kW/cm² and a pulse duration of 4 to 20 ns. Scanning with a laser spot in these modes provides the desired change in the film’s optical characteristics, and this becomes a serious alternative to the technology of heat treatment in an oven. Full article

Pursuing novel materials with efficient photothermal conversion under irradiation at the near-infrared region windows (NIR, 750–850 nm; NIR-I and NIR-II, 1000–1320 nm)) is of great importance due to their irreplaceable applications, especially in the biomedical field. Herein, on the basis of a coordination chemistry strategy, an iron-based metal-organic framework (MOF) of [N(CH₃)₄]₂[Fe₃(NDC)₄]·DMF·3H₂O (Fe-NDC, 1,4-H₂NDC = 1,4-naphthalenedicarboxylic acid, N(CH₃)₄⁺ = tetramethyl-ammonium, and DMF = N,N-dimethylformamide) was prepared and characterized. Due to the d-d transition effect introduced by coordination with the transition-metal ion of iron and the highly conjugated naphthalenic moiety in 1,4-H₂NDC, guaranteeing an energy transfer between iron and the organic module, Fe-NDC shows a remarkable broad absorption, which could be extended into the NIR-II section. As a result, Fe-NDC could be irradiated by NIR laser (both 808 and 1064 nm) to achieve photothermal conversion. This work sets a good example to inspire the future designation of NIR light-irradiated photothermal materials based on the first-row transition metals. Full article

This article describes the synthesis and characterization of two nanocarriers consisting of β-cyclodextrin-based nanosponges (NSs) inclusion compounds (ICs) and gold nanorods (AuNRs) for potential near-infrared II (NIR-II) drug-delivery systems. These nanosystems sought to improve the stability of two drugs, namely melphalan (MPH) and curcumin (CUR), and to trigger their photothermal release after a laser irradiation stimulus (1064 nm). The inclusion of MPH and CUR inside each NS was confirmed by field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, Fourier transform infrared spectroscopy, (FT-IR) differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and proton nuclear magnetic resonance (¹H-NMR). Furthermore, the association of AuNRs with both ICs was confirmed by FE-SEM, energy-dispersive spectroscopy (EDS), TEM, dynamic light scattering (DLS), ζ-potential, and UV–Vis. Moreover, the irradiation assays demonstrated the feasibility of the controlled-photothermal drug release of both MPH and CUR in the second biological window (1000–1300 nm). Finally, MTS assays depicted that the inclusion of MPH and CUR inside the cavities of NSs reduces the effects on mitochondrial activity, as compared to that observed in the free drugs. Overall, these results suggest the use of NSs associated with AuNRs as a potential technology of controlled drug delivery in tumor therapy, since they are efficient and non-toxic materials. Full article

Photoacoustic imaging and photothermal therapy that employ organic dye in the second near-infrared window (NIR-II) became an attractive theranostical strategy for eliminating solid tumors, in which IR1048 was previously reported to be a good candidate. However, the further biomedical application of IR1048 was blocked by its poor water-solubility and lack of tumor-targeting. To solve this problem, liposome camouflaged with 4T1 cell membrane fragments was employed to encapsulate IR1048 (thereafter called MLI), and its application for photoacoustic and thermo-imaging and photothermal therapy were explored in vitro and in vivo. The results showed that MLI exhibited spherical morphology around 92.55 ± 5.41 nm coated by monolayer adventitial fragments, and uniformly dispersed in PBS with high loading efficiency and encapsulation efficiency to IR1048. In addition, both free IR1048 and MLI presented strong absorption in NIR-II, and upon 1064 nm laser irradiation the MLI showed awesome photothermal performance that could rapidly elevate the temperature to 50.9 °C in 6 min. Simultaneously, phantom assay proved that MLI could dramatically enhance the photoacoustic amplitudes by a linear concentration-dependent way. Moreover, either flow cytometry or confocal analysis evidenced that MLI was the most uptaked by 4T1 cells among other melanoma B16 cells and Hek293 cells and coexist of IR1048 and 1064 nm laser irradiation were indispensable for the photothermal cytotoxicity of MLI that specifically killed 96.16% of 4T1 cells far outweigh the B16 cells while hardly toxic to the Hek293 normal cells. Furthermore, PA imaging figured out that 4 h post tail-vein injection of MLI was the best time to give 1064 nm irradiation to conduct the photothermal therapy when the average tumor-accumulation of MLI achieved the highest. In the NIR-II photothermal therapy, MLI could significantly inhibit the tumor growth and almost ablated the tumors with slight body weight variation and the highest average life span over the therapy episode and caused no damage to the normal organs. Hence, MLI could pave the way for further biomedical applications of IR-1048 by homologous tumor-targeting and dual-modal imaging directed NIR-II accurate photothermal therapy with high efficacy and fine biosafety. Full article

In terms of synergistic cancer therapy, biological nanomaterials with a second near-infrared (NIR-II) window response can greatly increase photothermal effects and photoacoustic imaging performance. Herein, we report a novel stimuli-responsive multifunctional drug-loading system which was constructed by integrating miniature gold nanorods (GNR) as the NIR-II photothermal nanorods and cyclic ternary aptamer (CTA) composition as a carrier for chemotherapy drugs. In this system, doxorubicin hydrochloride (DOX, a chemotherapy drug) binds to the G-C base pairs of the CTA, which exhibited a controlled release behavior based on the instability of G-C base pairs in the slightly acidic tumor microenvironment. Upon the 1064 nm (NIR-II biowindow) laser irradiation, the strong photothermal and promoted cargo release properties endow gold nanorods@CTA (GNR@CTA) nanoparticles displaying excellent synergistic anti-cancer effect. Moreover, the GNR@CTA of NIR also possesses thermal imaging and photoacoustic (PA) imaging properties due to the strong NIR region absorbance. This work enables to obtaining a stimuli-responsive “all-in-one” nanocarrier, which are promising candidate for bimodal imaging diagnosis and chemo-photothermal synergistic therapy. Full article

Two-dimensional (2D) materials, such as graphene and transition metal dichalcogenides (TMDCs), are highly appealing in the fields of electronics, optoelectronics, energy, etc. Graphene, with high conductivity and high carrier mobility, is an excellent candidate for transparent electrodes. TMDCs have remarkably strong light absorption in the range of visible to infrared wavelength. High-performance photodetectors are expected to achieve through the combination of graphene and TMDCs. Nowadays, near-infrared (NIR) photodetectors play significant roles in many areas. MoTe₂ with bandgap energy of about 1.0 eV in its bulk form is a promising material for cost-saving NIR photodetectors. Thus far, only a few of the reported studies on NIR photodetectors built on MoTe₂/graphene heterostructures have achieved high responsivity and short response time simultaneously in one device. In this study, we fabricate graphene–MoTe₂–graphene vertical van der Waals heterostructure devices through chemical vapor deposition (CVD) growth, wet transfer method, and dry etching technique. Under 1064 nm laser illumination, we acquire responsivity of as high as 635 A/W and a response time of as short as 19 μs from the as-fabricated device. Moreover, we acquire higher responsivity of 1752 A/W and a shorter response time of 16 μs from the Al₂O₃-encapsulated device. Our research drives the application of 2D materials in the NIR wavelength range. Full article

Our group previously examined 8 min photobiomodulation (PBM) by 1064 nm laser on the human forearm in vivo to determine its significant effects on vascular hemodynamics and cytochrome c oxidase redox activity. Since PBM uses a wide array of wavelengths, in this paper, we investigated (i) whether different wavelengths of lasers induced different PBM effects, and (ii) if a light-emitting diode (LED) at a similar wavelength to a laser could induce similar PBM effects. A broadband near-infrared spectroscopy (bbNIRS) system was utilized to assess concentration changes in oxygenated hemoglobin (Δ[HbO]) and oxidized cytochrome c oxidase (Δ[oxCCO]) during and after PBM with lasers at 800 nm, 850 nm, and 1064 nm, as well as a LED at 810 nm. Two groups of 10 healthy participants were measured before, during, and after active and sham PBM on their forearms. All results were tested for significance using repeated measures ANOVA. Our results showed that (i) lasers at all three wavelengths enabled significant increases in Δ[HbO] and Δ[oxCCO] of the human forearm while the 1064 nm laser sustained the increases longer, and that (ii) the 810-nm LED with a moderate irradiance (≈135 mW/cm²) induced measurable and significant rises in Δ[HbO] and Δ[oxCCO] with respect to the sham stimulation on the human forearm. Full article

Food adulteration is in the focus of research due to its negative effect on safety and nutritional value and because of the demand for the protection of brands and regional origins. Portugieser and Sauvignon Blanc wines were selected for experiments. Samples were made by water dilution, the addition of sugar and then a combination of both. Near infrared (NIR) spectra were acquired in the range of 900–1700 nm. Partial least squares regression was performed to predict the adulteration level. The model including all wines and adulterations achieved a prediction error of 0.59% added sugar and 6.85% water dilution. Low-power laser modules were used to collect diffuse reflectance signals at wavelengths of 532, 635, 780, 808, 850, 1064 nm. The general linear model resulted in a higher prediction error of 3.06% added sugar and 20.39% water dilution. Instead of classification, the present study investigated the feasibility of non-destructive methods in the prediction of adulteration level. Laser scattering successfully detected the added sugar with linear discriminant analysis (LDA), but its prediction accuracy was low. NIR spectroscopy might be suitable for rapid non-destructive estimation of wine adulteration. Full article