Photothermal Response Research Articles

Construction and Performance Study of an Injectable Dual-Network Hydrogel Dressing with Inherent Drainage Function.

With the widespread utilization of moist wound dressings, the extended healing time and increased risk of wound infection caused by excessively moist environments have garnered significant attention. The development of hydrogel dressings that can effectively control the wound moisture level and promote healing is very important. Inspired by the pore-opening perspiration effect of the skin, this study constructed an injectable dual-network hydrogel, CMCS-OSA/AG/MXene, by the composition of a dynamic covalent network of carboxymethyl chitosan and oxidized sodium alginate based on the Schiff base and hydrogen bond network of the thermosensitive low-melting-point agar with the advantage of the upper critical solution temperature (UCST) effect. Under near-infrared (NIR) light stimulation, the CMCS-OSA/AG/MXene hydrogel shows characteristics conducive to rapid removal of wound exudate while maintaining an appropriate moist environment for the wound and excellent antibacterial effects with its photothermal responses. The excellent conductivity of the hydrogel can also promote cell proliferation under external electrical stimulation (ES). Further validation through animal experiments on a full-thickness skin defect model demonstrates the excellent capability of CMCS-OSA/AG/MXene in accelerating wound healing. This work provides an innovative approach to the development of injectable hydrogel dressing materials with inherent drainage functionality and shows a new avenue to wound moisture control and wound healing promotion.

An Experimental Investigation on Synthesis, Characterization, and Photothermal Conversion Efficiency of Stable Aqueous Nanofluids Containing Multiwalled Carbon Nanotubes for Direct Absorption Solar Collectors

The nanofluids are the potential substitute in solar collectors as working fluids for better photothermal conversion efficiency. The present investigation focuses on the development of aqueous‐based nanofluids comprising multiwalled carbon nanotubes (MWCNTs) with and without surfactants to enhance the capacity of photothermal conversion in direct absorption solar collectors. To improve the stability of the nanofluid, the gum Arabic (GA) and polyvinyl alcohol (PVA) are used as the surfactants. The stable nanofluid was characterized using UV‐visible spectroscopy, zeta potential, fourier‐transform infrared spectroscopy, field emission scanning electron microscopy, and energy dispersive X‐ray spectroscopy (EDS) analysis. The results indicated that the thermal conductivity was enhanced by 94.57% and 91.19% for the MWCNT/GA/deionized (DI) water and MWCNTs/PVA/DI water based nanofluids in presence of surfactants at 90 °C and 0.02 wt%. The presence of surfactant in MWCNTs/DI water nanofluids exhibit excellent stability and enhanced MWCNTs dispersion. In the photothermal response analysis, the highest temperature of 62.8 °C, which is 16 °C higher than the base fluid, is obtained from 0.02wt% MWCNT/GA nanofluid. The highest efficiency of 27.94% is recorded when 0.02wt% MWCNT/GA nanofluid is used, which shows 71.24% enhancement as compared to the DI water after exposure of 30 minutes under solar irradiation. The use of MWCNTs/GA nanofluid as light‐absorbing working fluids in solar collectors is encouraged in the present investigation.

Dynamic tunability of NIR absorption in a plasmonic grating through nonlinear kerr-effect of graphene-oxide and photothermal phase transition of GSST

In this paper, we present an in-depth examination of the absorption dynamics of a silver plasmonic grating incorporating Kerr-type nonlinear graphene-oxide (GO) nanoslits and a Ge2Sb2Se4Te1 (GSST) phase-change material, both in linear and nonlinear regimes. Linear absorption approaches unity at the resonant wavelength when GSST is amorphous. Upon exposure to a nanosecond Gaussian pulse laser irradiation with appropriate fluences, the amorphous GSST partially crystallizes through a thermoplasmonic-induced process, resulting in a significant reduction of the linear on-resonance absorption in the form of a step-like curve. Additionally, the weak off-resonance linear absorption of the system can be enhanced owing to the non-uniform phase-transition within the GSST. Transitioning to a nonlinear regime, considering the third-order nonlinearity of GO nanoslits, reveals distinct absorption behaviors. Temporal analysis reveals that at the on-resonance wavelength, the unit absorption decreases with increasing laser intensity, reaching a minimum at the pulse peak due to the Kerr nonlinearity in the GO. Intriguingly, the absorption exhibits a U-shaped curve at lower fluences, while at higher fluences, it stabilizes at a lower value post-pulse peak where the amorphous GSST undergoes a thermally driven partially crystallization phase transformation. In the off-resonance mode, the weak absorption enhances dramatically by increasing the fluence, tracing an imperfect parabolic trajectory that reaches nearly unit at the trailing edge of the pulse, attributed to the Kerr nonlinearity within the GO nanoslits. By further increasing the laser fluence, the photothermal response of the GSST emerges as the dominant factor, diminishing the unity absorption observed at the trailing edge of the pulse. These findings underscore the dynamic responsiveness of the proposed grating to pulsed laser illumination, driven by the nonlinear Kerr effect and GSST reconfigurability, offering promising opportunities for developing active optical switching devices.

Investigating intermolecular interactions of surfactant solutions using femtosecond thermal lens spectroscopy

In this study, we examined the impact of various surfactants (oleic acid, butyric acid, Span-20, and CTAB) on the thermophysical properties of methanol (MeOH) using a femtosecond laser-induced thermal lens (TL) spectroscopic technique. Methanol was chosen for its unique convective properties under intense localized heating, making it a promising candidate for studying photothermal responses. We discovered that the TL characteristics of both pure methanol and methanol-surfactant mixtures are significantly influenced by the molecular interactions and physical properties of the components. Our experimental results indicate that the addition of surfactants notably alters the heat transfer dynamics of the solvent by restricting natural molecular movement and modifying thermal properties, which in turn affect the TL signatures. Beyond the surfactant concentration, we observed that the extent of variation in steady-state TL signals, inflection points, and heat transfer mechanisms depends on the molecular properties of the surfactants, such as chain length, the number of active (hydrophilic) groups per molecule, thermal conductivity, viscosity, and intermolecular interactions. Our TL findings provide a detailed investigation into the effect of surfactants on the photothermal response and heat transfer process of a solvent for the first time.

Fracture-driven power amplification in a hydrogel launcher.

Robotic tasks that require robust propulsion abilities such as jumping, ejecting or catapulting require power-amplification strategies where kinetic energy is generated from pre-stored energy. Here we report an engineered accumulated strain energy-fracture power-amplification method that is inspired by the pressurized fluidic squirting mechanism of Ecballium elaterium (squirting cucumber plants). We realize a light-driven hydrogel launcher that harnesses fast liquid vapourization triggered by the photothermal response of an embedded graphene suspension. This vapourization leads to appreciable elastic energy storage within the surrounding hydrogel network, followed by rapid elastic energy release within 0.3 ms. These soft hydrogel robots achieve controlled launching at high velocity with a predictable trajectory. The accumulated strain energy-fracture method was used to create an artificial squirting cucumber that disperses artificial seeds over metres, which can further achieve smart seeding through an integrated radio-frequency identification chip. This power-amplification strategy provides a basis for propulsive motion to advance the capabilities of miniaturized soft robotic systems.

Green synthesis of Au nanoparticles by Scutellaria barbata extract for chemo-photothermal anticancer therapy

IntroductionThe combination of photothermal therapy and chemotherapy has emerged as a promising strategy for cancer treatment. The green synthesis of gold nanoparticles (Au NPs) using extracts from traditional Chinese medicine Scutellaria barbata D. Don (Scu) has revealed an economical, sustainable, and eco-friendly approach for the outstanding anticancer activities. MethodsScu extract was mixed with HAuCl4 solution to fabricate Scu-Au NPs. The synthesis process was optimized by varying the reaction temperature, reaction time, and HAuCl4 concentration. The changes in the components of Scu before and after synthesis were analyzed using the 3,5-dinitrosalicylic acid (DNS) reduction test, the rutin colorimetric method, and the Folin–Ciocalteu method. The morphology, size, and structure of Scu-Au NPs were characterized by TEM, DLS, XRD, and XPS. The photothermal characteristics induced by near-infrared (NIR) irradiation were assessed by continuously monitoring the temperature elevation. The anticancer activity and mechanisms of Scu-Au NPs were investigated using MTT assay, cell uptake studies, ROS level detection, cell apoptosis and necrosis assays, flow cytometry analysis, intracellular Caspase-3 protein activity fluorescence detection, and Western blot analysis on A549, 4T1, and RAW264.7 cells. ResultsScu-Au NPs were successfully fabricated using Scu extract as a reducing agent. The Scu-Au NPs were spherical with a size of 50 nm. During the synthesis process, the levels of reducing sugars, flavonoids, and polyphenols in the Scu extract decreased by 80.8%, 54.3%, and 70.1%, respectively. Scu-Au NPs demonstrated excellent photothermal responsiveness, thermostability, and biocompatibility. For chemo-photothermal anticancer therapy, the cytotoxicity of Scu-Au NPs on 4T1 cells reached approximately 85% upon exposure to 808 nm NIR irradiation. The anticancer activity was attributed to the induction of apoptosis and necrosis, achieved by increasing intracellular ROS levels, causing cell cycle arrest at the S phase, and modulating the expression of apoptosis-related proteins. DiscussionOur synthesized Scu-Au NPs exhibit favorable photothermal conversion characteristics, demonstrating excellent therapeutic efficacy and safety for cancer treatment.

Effects of organic ligands and photoactive substances on MOFs-derived Co3O4@MnOx hollow-sphere structure for efficient energy transfer and photothermocatalysis of acetone and NO

A set of MOFs-derived Co3O4@MnOx hollow-sphere were synthesized to develop a catalyst for the photothermal catalytic removal of NO using acetone as a reducing agent. The study systematically investigated the impact of organic ligands and photoactive substances on energy transfer and photothermocatalytic reactions involving acetone and NO under 5 vol % H2O with the catalysts. At 240°C, sample C-5/1 (with an organic ligand added and Co/Mn molar ratio of 5/1) demonstrated 75 % NO conversion and 65 % acetone conversion. The highest catalytic performance was observed in the L-Py sample (with photoactive substance was added), achieving 80 % NO and 69 % acetone conversion at 240°C. The catalyst demonstrated low crystallinity, and the introduction structural defects through ligands adjusted the ratio of active components. Meanwhile, enhanced catalytic performance was attributed to light energy scattering in the inner space of microspheres, resulting in the efficient transfer of 2.17 eV energy with the addition of two photoactive substances. The elevated concentration of surface-active oxygen facilitated oxidation, while Mn/Mn+1 (Mn3+/Mn4+ and Co2+/Co3+) redox cycling supplied surface oxygen in the photothermal low-temperature response. The proposed mechanism for the simultaneous degradation of acetone and NO was elucidated using Density Functional Theory calculations.

Development of MnO2 nanosheets nanozyme-based colorimetric and photothermal dual-signal platform for monitoring alkaline phosphatase activity

Herein, a dual-signal biosensing platform for monitoring alkaline phosphatase (ALP) activity was developed. This platform combined the oxidase-mimicking activity of MnO2 nanosheets (NS) with the colorimetric and photothermal properties of oxidized 3,3′,5,5′-tetramethylbenzidine (oxTMB). MnO2 NS effectively catalyzed the oxidation of TMB to oxTMB, resulting in a color change from colorless to blue and a significant light absorption band at 652 nm. Meanwhile, oxTMB demonstrated pronounced photothermal properties, with the solution exhibiting a notable increase in temperature upon irradiation with an 808 nm laser. In the presence of ALP, 2-Phospho-L-ascorbic acid trisodium salt (AAP) was converted into L-ascorbic acid (L-AA), which then reacted with MnO2 NS. Consequently, MnO2 NS was inhibited from oxidizing TMB to oxTMB. Based on this principle, a dual-readout assay that integrated both colorimetric and photothermal signals for ALP detection was developed. The detection limits were 0.08 mU/mL for the colorimetric method and 0.12 mU/mL for the photothermal method. Furthermore, the platform was successfully applied to human serum samples, demonstrating its effectiveness in detecting ALP in complex biological matrices. The combination of colorimetric and photothermal responses enhanced both the accuracy and reliability of ALP detection, making this platform a promising tool for biomedical applications.

Using a Bacterial Protein to Selectively Target Bacterial Biofilms: Treatment of S. epidermidis Biofilms with Targeted Photothermal Gold Nanoparticles.

Biofilm-related infections are associated with high mortality and morbidity, combined with increased treatment costs. Traditional antibiotics are becoming less effective due to the emergence of drug-resistant bacterial strains. The need to treat biofilms on medical implants is particularly acute, and one persistent challenge is selectively directing nanoparticles to the biofilm site. Here, we present a protein-based functionalization strategy that targets the extracellular matrix of biofilms. The protein, derived from the extracellular Staphylococcus epidermidis autolysin, directs nanoparticles to S. epidermidis cell wall components, which are not expected to be present in mammalian tissues. This functionalization is applied to a gold nanoparticle (AuNP) core, along with elastin-like polypeptides (ELPs), which generate a robust photothermal response. In addition to biofilm targeting, the particles exhibit low protein binding, and the photothermal conversion can be modulated by changing the ELP transition temperature. These functionalized AuNPs strongly interact with biofilms under static and flow conditions but exhibit weak interactions with serum-coated surfaces. Near-infrared laser irradiation resulted in a 10,000-fold improvement in killing efficiency compared to untreated controls (p < 0.0001). The targeting strategy utilized here represents a versatile approach to targeting drug-resistant infections and could be readily expanded to other anti-biofilm nanoparticle platforms.

Strong and Healable Elastomers with Photothermal-Stimulus Dynamic Nanonetworks Enabled by Subnano Ultrafine MoO3-x Nanowires.

One-dimensional nanomaterials have become one of the most available nanoreinforcing agents for developing next-generation high-performance functional self-healing composites owing to their unique structural characteristics and surface electron structure. However, nanoscale control, structural regulation, and crystal growth are still enormous challenges in the synthesis of specific one-dimensional nanomaterials. Here, oxygen-defective MoO3-x nanowires with abundant surface dynamic bonding were successfully synthesized as novel nanofillers and photothermal response agents combined with a polyurethane matrix to construct composite elastomers, thus achieving mechanically enhanced and self-healing properties. Benefiting from the surface plasmon resonance of the MoO3-x nanowires and interfacial multiple dynamic bonding interactions, the composite elastomers demonstrated strong mechanical performance (with a strength of 31.45 MPa and elongation of 1167.73%) and ultrafast photothermal toughness self-healing performance (20 s and an efficiency of 94.34%). The introduction of MoO3-x nanowires allows the construction of unique three-dimensional cross-linked nanonetworks that can move and regulate interfacial dynamic interactions under 808 nm infrared laser stimulation, resulting in controlled mechanical and healing performance. Therefore, such special elastomers with strong photothermal responses and mechanical properties are expected to be useful in next-generation biological antibacterial materials, wearable devices, and artificial muscles.

Thermophysical &amp; photothermal characteristics of surfactant free graphene oxide, functionalized graphene oxide and reduced graphene oxide nanofluids

Graphene nanostructures-based dispersions, owing to their improved thermophysical and optical characteristics are being actively explored for use in thermal energy conversion and management. Here, thermophysical and photothermal characteristics of graphene oxide (GO), functionalized graphene oxide (f-GO), and reduced graphene oxide (rGO) based nanofluids (without surfactants) of various concentrations (0.05–0.23 wt.%) are evaluated. The structural, morphology and stability of the nanofluids are determined by XRD analysis, Transmission electron microscopy, UV- visible spectroscopy and zeta potential analysis. Subsequently, thermal conductivity and contact angle measurements are performed. Photothermal behaviour is investigated experimentally. Overall, it is found that among the prepared nanofluids, the f-GO nanofluids performed better compared to GO and rGO nanofluids. Maximum stability of f-GO nanofluids is obtained at 0.05 wt.% while the thermal conductivity and photothermal response is best obtained at 0.23 wt.% concentration.

Silica-Ti3C2Tx MXene Nanoarchitectures with Simultaneous Adsorption and Photothermal Properties.

Layered Ti3C2Tx MXene has been successfully intercalated and exfoliated with the simultaneous generation of a 3D silica network by treating its cationic surfactant intercalation compound (MXene-CTAB) with an alkoxysilane (TMOS), resulting in a MXene-silica nanoarchitecture, which has high porosity and specific surface area, together with the intrinsic properties of MXene (e.g., photothermal response). The ability of these innovative MXene silica materials to induce thermal activation reactions of previously adsorbed compounds is demonstrated here using NIR laser irradiation. For this purpose, the pinacol rearrangement reaction has been selected as a first model example, testing the effectiveness of NIR laser-assisted photothermal irradiation in these processes. This work shows that Ti3C2Tx-based nanoarchitectures open new avenues for applications that rely on the combined properties inherent to their integrated nanocomponents, which could be extended to the broader MXene family.

Self‐healing, adhesive, photothermal responsive, stretchable, and strain‐sensitive supramolecular nanocomposite hydrogels based on host–guest interactions

AbstractThe development of multifunctional supramolecular nanocomposite hydrogels remains challenging. Here, the dynamic host–guest interactions involving the host molecule CB[8] and guest units were utilized to prepare Fe3O4 hybrid supramolecular nanocomposite hydrogels. The results showed that the hydrogels obtained possessed a porous structure. The CB[8]‐modified Fe3O4 (Fe3O4@CB[8]) nanoparticles served as cross‐linkers in forming the network of hydrogels. By adjusting the Fe3O4@CB[8] content, the mechanical properties of the hydrogels could be controlled. The tensile stress was measured at 160 kPa with a fracture strain of 1380%, while the compression stress was 230 kPa at 70% compression strain. The self‐healing efficiency of the hydrogels at room temperature reached 95% after 24 h. The as‐obtained hydrogels show strain sensitivity and have the potential for applications in detecting elbow and finger movements. Our supramolecular nanocomposite hydrogels exhibit multiple functions, including self‐healing, injectability, photothermal responsiveness, and conductivity, making them suitable for integration into flexible electronics.Highlights Fe3O4@CB[8] nanoparticles serve as cross‐linkers for the nanocomposite hydrogels. CB[8] based host–guest interactions enable hydrogels to self‐heal. Fe3O4@CB[8] endow hydrogels with stretchability and photothermal responsiveness. Hydrogels exhibit injectability, NIR responsiveness, and conductive ability.

Investigated numerically nanoshell thickness on photothermal response of hybrid nanostructures in an aqueous medium

The current study describes the effect of changing a shell thickness on photothermal response of a hybrid nanostructures, using theoretical investigation based on the Finite Element Method (FEM) of the COMSOL multi-physics program. The hybrid nanostructures are the Core/Shell nanoparticles (C/S NPs) and the Core/Multi-Shell nanoparticles (C/MS NPs), with fixed core diameter (30 nm) and variable shell thickness (10–20 nm) to create a new type of hybrid nanostructures usable in photonic and optoelectronic applications. For these hybrid nanostructures, gold (Au) and silver (Ag) as a partner of titanium dioxide (TiO2) were used in thermo-plasmonic part. Hybrid multi-shell nanostructures consist of silver-gold and gold-silver sandwich with titanium dioxide shell in between, all of which are dispersed in an aqueous medium (n = 1.33). The optical properties, the local field distribution, and local heating control of plasmonic nanostructures have been studied under the influence of illumination at plasmonic wavelengths (405, and 532 nm). The results revealed to a clear tunable and adjustable optical and thermo-plasmonic properties by controlling the structure of the core/shell NPs. This results can be enhanced by changing the shell thickness, shape, size, and the nanostructure. The temperature elevation of the core/shell NPs was about 1–5 °C under different wavelengths of laser irradiation. Based on those results, there is possibility of using the core/shell nanoparticles as an efficient heat source in many applications, such as in the sterilization and disinfection of medical equipments.

Multifunctional chitosan-based composite hydrogels engineered for sensing applications

Chitosan-based hydrogels, as natural high-molecular-weight flexible materials, are widely utilized due to their outstanding properties. In this research, we developed a one-pot method for synthesizing a novel PVA/CS@PPy-PDAx% conductive hydrogel and explored the internal bonding patterns through molecular dynamics simulations. By adding PPy-PDA nanoparticles into a hydrogel matrix, an interpenetrating conductive network established successfully. The uniform distribution of PPy-PDA nanoparticles endowed the hydrogel with good electrical conductivity (0.171 S/m), significantly enhanced mechanical properties, and strain sensing (S = 5.04), as well as near-infrared photothermal responsiveness (temperature increase of 41.9 °C within 30 s). Additionally, due to the hydrogel's significant photothermal conversion efficiency under near-infrared radiation, it exhibits rapid elimination of Escherichia coli with an antibacterial efficiency exceeding 90 %. The unique hydrogen-bonded crosslinked structure provides the hydrogel with excellent re-healing properties, allowing for restoration through a freeze-thaw process after damage. The conductivity remains nearly unchanged after re-healing, maintaining the material's integrity and functionality. The flexible sensor based on this hydrogel has a response time of 100 ms and can sensitively detect large-scale deformations (e.g., joint bending at various angles), different gravitational forces, and recognize human handwriting. These characteristics make this hydrogel a promising candidate for advancing intelligent wearable technologies and human-machine interaction systems.

Biomimetic Functional Nanocomplexes for Photothermal Cancer Chemoimmunotheranostics

This study presents a novel multimodal cancer theranostic platform developed using tumor cell‐coated biomimetic carbon nanohorn (CNH) complexes that encapsulate the anticancer drug paclitaxel (PTX). This platform combines photothermal therapy, chemotherapy, and immunotherapy to fight against malignant colorectal cancer. These engineered nanocomplexes are designed to deliver sufficient PTX molecules into a targeted solid tumor in a light‐controllable manner while inducing significant photothermal and antitumor immune responses. The outstanding photothermal conversion property of the CNHs under near‐infrared light enables effective cancer cell ablation and awakening of cytotoxic immune responses. Tumor cell membrane‐coated CNHs show improved water dispersibility, immune evasion, and targeting capabilities alongside enhanced immune activation against tumors. The efficacy of the biomimetic functional CNH nanocomplexes is demonstrated through excellent tumor‐targeting, controlled drug‐releasing behavior, and induction of cancer cell death, contributing to a robust antitumor response. This study provides a promising approach to cancer treatment by integrating multiple therapeutic modalities into a single platform, potentially enhancing treatment efficacy to combat intractable cancer.

Copper (II)-catalyzed polydopamine mediated photothermal sensors for visual quantitative point-of-care testing

BackgroundTemperature sensing is commonly used in point-of-care (POC) detection technologies, yet the portability and convenience of use are frequently compromised by the complexity of thermosensitive processes and signal transduction. Especially, multi-step target recognition reactions and temperature measurement in the reaction vessel present challenges in terms of stability and integration of detection devices. To further combine photothermal reaction and signal readout in one assay, these two processes enable to be integrated into miniaturized microfluidic chips, thereby facilitating photothermal sensing and achieving a simple visual temperature sensing as POC detection. ResultsA copper ion (Cu2+)-catalyzed photothermal sensing system integrated onto a microfluidic distance-based analytical device (μDAD), enabling the visual, portable, and sensitive quantitative detection of multiple targets, including ascorbic acid, glutathione, and alkaline phosphatase (ALP). The polydopamine nanoparticles (PDA NPs) were synthesized by the regulation of free Cu2+ through redox or coordination reactions, facilitating the transduction of distinct photothermal response signals and providing the versatile Cu2+-responsive sensing systems. Promoted by integration with a photothermal μDAD, the system combines PDA's photothermal responsiveness and thermosensitive gas production of ammonium bicarbonate for improved sensitivity of ALP detection, reaching the detection limit of 9.1 mU/L. The system has successfully achieved on-chip detection of ALP with superior anti-interference capability and recoveries ranging from 96.8 % to 104.7 %, alongside relative standard deviations below 8.0 %. Significance and noveltyThe μDAD design accommodated both the photothermal reaction of PDA NPs and thermosensitive gas production reaction, achieving the rapid sensing of visual distance signals. The μDAD-based Cu2+-catalyzed photothermal sensing system holds substantial potential for applications in biochemical analysis and clinical diagnostics, underscored by the versatile Cu2+ regulation mechanism for a broad spectrum of biomarkers.

Immunomodulatory R848-Loaded Anti-PD-L1-Conjugated Reduced Graphene Oxide Quantum Dots for Photothermal Immunotherapy of Glioblastoma.

Glioblastoma multiforme (GBM) is the most severe form of brain cancer and presents unique challenges to developing novel treatments due to its immunosuppressive milieu where receptors like programmed death ligand 1 (PD-L1) are frequently elevated to prevent an effective anti-tumor immune response. To potentially shift the GBM environment from being immunosuppressive to immune-enhancing, we engineered a novel nanovehicle from reduced graphene oxide quantum dot (rGOQD), which are loaded with the immunomodulatory drug resiquimod (R848) and conjugated with an anti-PD-L1 antibody (aPD-L1). The immunomodulatory rGOQD/R8/aPDL1 nanoparticles can actively target the PD-L1 on the surface of ALTS1C1 murine glioblastoma cells and release R848 to enhance the T-cell-driven anti-tumor response. From in vitro experiments, the PD-L1-mediated intracellular uptake and the rGOQD-induced photothermal response after irradiation with near-infrared laser light led to the death of cancer cells and the release of damage-associated molecular patterns (DAMPs). The combinational effect of R848 and released DAMPs synergistically produces antigens to activate dendritic cells, which can prime T lymphocytes to infiltrate the tumor in vivo. As a result, T cells effectively target and attack the PD-L1-suppressed glioma cells and foster a robust photothermal therapy elicited anti-tumor immune response from a syngeneic mouse model of GBM with subcutaneously implanted ALTS1C1 cells.

Biobased photothermal responsive shape memory polythioether/MXene nanocomposites with self-extinguishing performance

Thermosetting shape memory polymers (TS-SMPs) have a higher shape fixity ratio (Rf) and shape recovery (Rr) due to their structure integrity and thermal stability, and the glass transition temperature (Tg) usually influences the transition temperature (Ttrans) of TS-SMPs. Therefore, it is significant to tailor the Tg range and mechanical properties for TS-SMPs. In this work, the inherently flame-retarding bio-based MXene-reinforced polythioether nanocomposites with excellent shape memory performance, driven by photothermal response, were designed. Firstly, a photopolymerizable MXene nanomonomer (MPS-MXene) was obtained by introducing 3-(methacryloxy) propyltrimethoxysilane onto the surface of the MXene monolayer. Then, the bis(4-allyl-2-methoxyphenyl) phenyl phosphonate (BEP) was synthesized by eugenol (a lignin derivative) with phenyl phosphonic dichloride. The polythioether/MXene composites (BEP-T-xM) were synthesized through in-situ thiol-ene photopolymerization of MPS-MXene, BEP, and tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate. Surprisingly, compared with neat polythioether, the Tg of BEP-T-0.2 M composite increased from 19.6 to 34.6 °C, when only 0.2 wt% MPS-MXene was added. The photothermal conversion efficiency (η = 73.8 %) and shape memory performance with Rr (>98 %) were greatly improved. Consequently, the interesting phenomena such as “sunflowers growing towards the sunlight” and “thermal shrinkage” can be observed. Meanwhile, the tensile strength and Young’s modulus increased significantly by 141 % and 91 %, respectively, due to the good dispersion of rigid MPS-MXene nanosheets. Furthermore, all the polythioether/MXene composites showed self-extinguishing performance. This study will provide a novel strategy for designing biobased photothermal-responsive TS-SMPs.

Hydrothermal synthesis of carbon quantum dots from Citrus limetta peels: Exploration of pH sensing, non-hemolytic activity and thermoluminescent properties

This study introduces a novel hydrothermal green method for synthesized carbon quantum dots (CQDs) using dried powders of Citrus limetta peels as a carbon source. The synthesized CQDs were evaluated for their photothermal response, pH sensing under various conditions and biocompatibility through non-hemolytic activity. CQDs had low crystallinity and an average size of 3 nm, ranging from 1 to 6 nm. CQDs have biocompatible properties, which makes them suitable for developing pH sensors. The study also revealed that the temperature of CQDs increases up to 37 °C under laser light irradiation of 808 nm, which might have potential applications in the biomedical field.