Near-infrared Irradiation Research Articles

Radical-Scavenging Violet Phosphorus Nanosheets for Attenuating Hyperinflammation and Promoting Infected Wound Healing.

Antibacterial therapy targeting the regulation of macrophage polarization may be a useful approach for normalizing the immune environment and accelerating wound healing. Inspired by black phosphorus-based nanoplatforms, more stable yet less-explored violet phosphorus nanosheets (VPNSs) are expected to provide a superior solution for effectively combating bacterial infections. In this study, an average thickness of 5-7nm VPNSs arefabricated through the liquid-phase exfoliation method to serve as an immunoregulatory dressing for the treatment of infected wounds. VPNSs attenuated excessive reactive oxygen species (ROS) and reduced the accumulation of proinflammatory M1 macrophages, showing notable antioxidant and anti-inflammatory properties. Comprehensive RNA sequencing further elucidated the potential immunoregulatory mechanisms of VPNSs, including modulation of the inflammatory response and enzyme regulator activity. Additionally, the inherent photothermal properties of the VPNSs contributed significantly to their antibacterial efficacy. When combined with near-infrared laser irradiation, VPNSs showed remarkable effectiveness in reducing infection-related complications and expediting wound healing in infected skin wound models. The rapid promotion of wound healing through ROS clearance, the regulation of macrophage polarization, and hyperthermia generation underscores the potential of the violet-phosphorus-based nanoplatforms as clinically viable agents for treating infected wounds. This study suggests that VPNSs are promising candidates for clinical anti-infective and anti-inflammatory applications.

Synergistic pH-responsive MUC-1 aptamer-conjugated Ag/MSN Janus nanoparticles for targeted chemotherapy, photothermal therapy, and gene therapy in breast cancer

Drug resistance in cancer treatment, primarily attributed to the overexpression of the multidrug resistance (MDR) gene, significantly hampers the effectiveness of chemotherapy. This mechanism, driven by the increased production of P-glycoprotein (P-gp) efflux pumps, highlights the urgent need for innovative strategies to combat drug resistance in cancer patients. This study explores the application of antisense technology to suppress MDR gene expression, while addressing the challenges of instability and limited cellular uptake associated with antisense oligonucleotides. We synthesized Janus silver-mesoporous silica nanoparticles (Ag/MSN JNPs) using a sol-gel method, characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS), revealing uniformly sized, dumbbell-shaped nanoparticles with an average size of 285 ± 5.12 nm. Doxorubicin (DOX) was loaded into the porous structure of the mesoporous silica, and JNPs were functionalized with chitosan (CS) to incorporate P-gp antisense and a MUC-1 aptamer, serving as a pH-responsive gatekeeper. Our findings indicate that the Ap-As-DOX-JNPs achieved a remarkable 89 ± 0.59 % cell death in drug-resistant MCF-7/ADR cells after 48 h, alongside an 80 % reduction in P-gp expression. The combination of DOX, antisense technology, and photothermal therapy utilizing these JNPs demonstrates a promising strategy to effectively overcome drug resistance. Notably, normal MCF-7 cells exhibited reduced viability from 39.11 ± 1.12 % to 30.05 ± 1.07 % when treated with DOX-JNPs under near-infrared (NIR) irradiation. These results underscore the potential of utilizing MUC-1 aptamer-conjugated Janus nanoparticles in conjunction with chitosan as a gatekeeper to enhance the efficacy of chemotherapy, photothermal therapy, and gene therapy in overcoming multidrug resistance in cancer treatment.

Dual-action defense: A photothermal and controlled nitric oxide-releasing coating for preventing biofilm formation

Biofilms formed by pathogenic bacteria on biomedical devices and implants pose a considerable challenge due to their resistance to conventional treatments and their role in severe infections. Preventing biofilm formation is strategically more advantageous than attempting to eliminate the mature biofilms, particularly in addressing the persistence of such formations. In this context, a dual-action antibiofilm coating is developed, utilizing S-nitrosothiols functionalized candle soot (CS), which capitalizes on CS’s strong light absorption for photothermal therapy and the controlled release of nitric oxide (NO) from S-nitrosothiols to inhibit biofilm formation. This coating exhibits stable and efficient light-to-heat conversion, along with the ability to release NO gradually at physiological temperatures and to rapidly release NO on demand when triggered by a near-infrared (NIR) laser. Under NIR irradition, the coating generates heat swiftly and releases substantial amounts of NO, which synergistically disrupts bacterial membranes, leading to the leakage of intracellular components and the effective eradication of surface-adhered bacteria. In the absence of NIR irradiation, the coating continuously releases low concentrations of NO, which depletes exopolysaccharides and impedes biofilm formation. The antibiofilm efficacy of this coating is assessed against Staphylococcus aureus and Pseudomonas aeruginosa, demonstrating marked reductions in bacterial viability and biofilm formation in vitro. Additionally, the coating exhibits minimal cytotoxicity and can be easily applied to diverse substrates. This study underscores the potential of this coating as a broad-spectrum, non-toxic approach for preventing biofilm-related complications in biomedical applications.

Hollow Copper Sulfide Nanocubes Loaded with Pt(IV) Complexes for Cancer Multimodal Therapy.

Chemotherapy (CT) can significantly inhibit tumor growth, metastasis, and recurrence during cancer therapy. People have widely used platinum drugs in cancer treatment. However, as most chemotherapeutic drugs, platinum drugs still have shortcomings such as poor solubility, low cell uptake, nonspecific distribution, multidrug resistance, and adverse side effects. Therefore, we synthesized hollow copper sulfide (CuS) nanocubes with photothermal and photodynamic properties as carriers for Pt(IV) drugs. Hollow CuS nanocubes have attracted considerable interest in the field of cancer photothermal therapy (PTT) using multiple biological windows. Under near-infrared (NIR) laser irradiation, Cu2+ can be reduced into Cu+ in the presence of hydrogen peroxide in the tumor microenvironment. The resulting Cu+ can be used for photodynamic therapy (PDT), which can perform a Fenton-like reaction under acidic conditions (pH 5.5-6.5) and catalyze hydrogen peroxide to produce ·OH in the tumor microenvironment. In addition, compared with Pt(II) drugs, Pt(IV) drugs not only have lower systemic toxicity but also consume glutathione (GSH), thereby increasing reactive oxygen species (ROS) levels in tumor cells and effectively promoting PDT. In this study, we oxidized ethylenediamine platinum chloride to its tetravalent state, loaded the Pt(IV) complexes using hollow CuS nanocubes, and modified the surfaces of the nanoparticles with PEG to improve the EPR effect. The Pt(IV)-loaded hollow CuS nanocubes modified with PEG (Pt(IV)-CuS@PEG) are expected to be used for tumor chemo/photothermal/photodynamic therapy.

Epitaxial Growth of a Three-Dimensional Hollow and Chestnut Shell Photothermal p-n Junction Photoanode.

The p-n junction, a widely studied semiconductor material structure, offers only limited improvements in photoelectrochemical (PEC) efficiency. Herein, a three-dimensional (3D) p-n junction h-Ta3N5@CoN featuring a stable chestnut shell hollow sphere structure and photothermal effect was synthesized by using an epitaxial growth strategy. The fine fibers within the sphere induce Rayleigh scattering, which scatters unabsorbed light, thereby enabling secondary absorption and enhancing light utilization. The quantum confinement effects generated by CoN fine fibers, which are sized in a few nanometers, inhibit the recombination of electron-hole pairs. Moreover, the lattice matching between Ta3N5 and CoN allows for smoother movement of carriers and nonradiative relaxation phonons along the lattice, thereby enhancing the transport of both carriers and heat. The obtained h-Ta3N5@CoN/FTO p-n junction photoanode, under near-infrared (NIR) auxiliary irradiation, demonstrates a photocurrent of 8.71 mA cm-2 at 1.23 VRHE. Moreover, the h-Ta3N5@CoN+NIR/FTO photoanode can sustain operation for 168 h, which, to my knowledge, surpasses the operational durations of all other Ta3N5-based photoanodes. This study synthesizes three-dimensional hollow chestnut shell photothermal p-n heterojunctions through an epitaxial growth strategy, endowing the material with a more efficient carrier separation and photothermal transfer efficiency.

Construction of Methotrexate-Loaded Bi2S3 Coated with Fe/Mn-Bimetallic Doped ZIF-8 Nanocomposites for Cancer Treatment Through the Synergistic Effects of Photothermal/Chemodynamic/Chemotherapy.

A combination of therapeutic modalities in a single nanostructure is crucial for a successful cancer treatment. Synergistic photothermal therapy (PTT) can enhance the effects of chemodynamic therapy (CDT) and chemotherapy, which could intensify the therapeutic efficacy to induce cancer cell apoptosis. In this study, Fe and Mn on a zeolitic imidazolate framework (ZIF-8) (Fe/Mn-ZIF-8; FMZ) were synthesized through ion deposition. Furthermore, bismuth sulfide nanorods (Bi2S3 NRs; BS NRs) were synthesized via a hydrothermal process and coated onto FMZ to generate the core-shell structure of the Bi2S3@FMZ nanoparticles (B@FMZ). Next, methotrexate (MTX) was loaded effectively onto the porous surface of ZIF-8 to form the B@FMZ/MTX nanoparticles. The Fenton-like reaction catalyzes Fe2+/Mn2+ ions by decomposing H2O2 in the tumor microenvironment, resulting in the formation of toxic hydroxyl radicals (·OH), which promotes the CDT effect of killing cancer cells. Furthermore, under 808 nm laser irradiation, these B@FMZ nanoparticles showed a strong PTT effect, owing to the presence of intense BS NRs as a photothermal agent. The B@FMZ nanoparticles exhibited a prominent drug release efficiency of 87.25% at pH 5.5 under near-infrared laser irradiation due to the PTT effect can promote the drug delivery performance. The B@FMZ nanoparticles were subjected to dual-modal imaging, guided magnetic resonance imaging, and X-ray computed tomography imaging. Both in vitro and in vivo results suggested that the B@FMZ/MTX nanoparticles exhibited enhanced antitumor effects through the combined therapeutic effects of PTT, CDT, and chemotherapy. Therefore, these nanoparticles exhibit good biocompatibility and are promising candidates for cancer treatment.

Dipolar-hollowed α-Fe2O3@Au/Polydopamine nanospindle for photothermal-photodynamic coupling antibacterial and drug-delivery

With the prevalence of drug-resistant bacteria and the waning effects of antibiotics, nanoplatform has become an effective strategy for fighting infections. This work reports a dipolar-hollowed α-Fe2O3@Au/Polydopamine (PDA) nanospindle which possesses both photothermal-photodynamic (PTT-PDT) coupling antibacterial and drug carrying performance. Firstly, the spindle type α-Fe2O3@Au/PDA particle was prepared by a simple one-step strategy and then the dipolar-hollow structure was obtained by controlling etching the inside α-Fe2O3 core with hydrochloric acid. After further loading the photosensitizer zinc phthalocyanine (ZnPc), the dipolar-hollowed α-Fe2O3@Au/PDA-ZnPc nanospindles were obtained. Owing to the dipolar-hollowed interior, the nanospindles are also effective in carrying antitumor drug doxorubicin (DOX) and shows a good drug loading-release behavior. The dipolar-hollowed α-Fe2O3@Au/PDA nanospindles exhibits a high antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) under near-infrared (NIR) and Xenon lamp irradiation. When α-Fe2O3@Au/PDA-ZnPc nanospindles concentration was increased to 100 μg/mL, the antibacterial rate was close to 100 %. In comparison to the original α-Fe2O3@Au/PDA nanospindles, the product achieved a lower effective antibacterial temperature. This triple-mode therapy (PTT/PDT/Drug) provides an interesting design idea for anisotropic therapeutic nanoplatform which can be applied in low-temperature antibacterial and drug delivery.

Near-infrared-driven dual-photoelectrode photoelectrochemical sensing for fumonisin B1: Integrating a photon up-conversion bio-photocathode with an enhanced light-capturing photoanode

Fumonisin B1 (FB1), the most prevalent and highly toxic mycotoxin within the fumonisins family, poses threats to humans, especially in children and infants, even at trace levels. Therefore, it is essential to design an easy and sensitive detection strategy. Herein, a brand-new dual-photoelectrode photoelectrochemical (PEC) sensing platform for FB1 detection under near-infrared irradiation was unveiled. This platform integrated a photon up-conversion bio-photocathode substrate (UCNPs/Au/CuInS2, UCNPs: NaYF4: Yb3+, Er3+, Nd3+) and used a SnO2/SnS2@Bi/Bi2S3 heterojunction photoanode to greatly enhance light capture. Additionally, ZnO coated with polydopamine (ZnO@PDA) was utilized as a signal inhibitor. The restoration of photocurrent occurred due to the strong binding affinity between FB1 and its aptamer (FB1-Apt), facilitating the dissociation of FB1-Apt/ZnO@PDA from the photoelectrode. The PEC sensing performance and the electron transfer process were thoroughly examined. The developed “signal-restoration” PEC aptasensor exhibited a wider dynamic linear range from 1.0 × 10−3 to 1.0 × 102 ng/mL, with a lower limit of detection (0.13 pg/mL). It has demonstrated excellent practical detection performance in unspiked real samples, such as corn paste, with the FB1 enzyme-linked immunosorbent assay (ELISA) Kit serving as a reference, indicating its potential for routine analysis of other mycotoxins. Thus, this research establishes a feasible dual-photoelectrode PEC framework for the effective detection of mycotoxins and other hazardous substances.

Photothermal-Induced Multimodal Antibacterial Dressing Comprising N-Halamine Hydrogel Loaded with Cow Dung Biochar for Infected Wound Healing.

Disposal of the cow dung pollutants arising from cattle farming threatens the environment and public safety in diverse ways. To date, researchers have worked on developing new pathways to control and manage cattle farming wastes, but most do not involve the reuse of these wastes. Herein, a cow dung biochar-modulated photothermal N-halamine hydrogel (i.e., PAN/CA/CoBC/pMAG-Cl) was designed for converting cow dung into biochar (CoBC), which was then coupled with a 3D interpenetrating hydrogel network to treat infected wounds. The PAN/CA/CoBC/pMAG-Cl hydrogel exhibited excellent synergistic antibacterial performance against 106 CFU·mL-1 Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 60 min. The bactericidal effect was multimodal, involving CoBC-based photothermal killing (i.e., temperature as high as 80.5 °C) after 808 nm near-infrared light irradiation for 10 min, contact killing through the strong oxidative characteristic of N-halamine (pMAG-Cl), and release killing via active halogens (i.e., Cl+) reinforced by the photothermal action of CoBC. The S. aureus-infected wound model in vivo demonstrated that the PAN/CA/CoBC/pMAG-Cl hydrogel worked as an ideal wound dressing, capable of resisting bacterial infection, accelerating the healing process, and promoting epithelial regeneration. This proposed strategy could indicate a new way for the disposal of cow dung pollutant and its reuse in antibacterial-associated applications.

Dual-Carbon Dots Composite: A Multifunctional Photo-Propelled Nanomotor Against Alzheimer's β-Amyloid.

The abnormal accumulation of β-amyloid protein (Aβ) is considered as the main pathological hallmark of Alzheimer's disease (AD). The design of potent multifunctional theranostic agents targeting Aβ is one of the effective strategies for AD prevention and treatment. Nanomotors as intelligent, advanced, and multifunctional nanoplatforms can perform many complex tasks, but their application in AD theranostics is rare. Herein, sub-10nm multifunctional dual-carbon dots composites (ERCD) with photo-propelled nanomotor behavior are fabricated by conjugating near-infrared (NIR) carbon dots (RCD) of thermogenic and photodynamic capability with the previously reported epigallocatechin gallate-derived carbonized polymer dots (ECD). ERCD-1 (ECD:RCD = 1:2.5) showed potent inhibitory capability similar to ECD in the absence of NIR light, and exhibited photooxygenation activity and nanomotor behavior powered by "self-thermophoretic force" under NIR irradiation, significantly enhancing the inhibition, disaggregation, and photooxygenation capabilities. The nanomotor suppressed Aβ fibrillization and rapidly disaggregated mature Aβ fibrils at very low concentrations (0.5µg mL-1). Moreover, the NIR-activated ERCD-1 imaged Aβ plaques in vivo and prolonged nematode lifespan by 6 d at 2µg mL-1. As a proof-of-concept, this work opened a new avenue to the design of multifunctional sub-10nm nanomotors targeting Aβ for AD theranostics.

A Near-Infrared Retinomorphic Device with High Dimensionality Reservoir Expression.

Physical reservoir-based reservoir computing (RC) systems for intelligent perception have recently gained attention because they require fewer computing resources. However, the system remains limited in infrared (IR) machine vision, including materials and physical reservoir expression power. Inspired by biological visual perception systems, the study proposes a near-infrared (NIR) retinomorphic device that simultaneously perceives and encodes narrow IR spectral information (at ≈980nm). The proposed device, featuring core-shell upconversion nanoparticle/poly (3-hexylthiophene) (P3HT) nanocomposite channels, enables the absorption and conversion of NIR into high-energy photons to excite more photo carriers in P3HT. The photon-electron-coupled dynamics under the synergy of photovoltaic and photogating effects influence the nonlinearity and high dimensionality of the RC system under narrow-band NIR irradiation. The device also exhibits multilevel data storage capability (≥8 levels), excellent stability (≥2000 s), and durability (≥100 cycles). The system accurately identifies NIR static and dynamic handwritten digit images, achieving recognition accuracies of 91.13% and 90.07%, respectively. Thus, the device tackles intricate computations like solving second-order nonlinear dynamic equations with minimal errors (normalized mean squared errorof 1.06 × 10⁻3 during prediction).

Light-Responsive Smart Nanoliposomes: Harnessing the Azobenzene Moiety for Controlled Drug Release under Near-Infrared Irradiation.

The azobenzene moiety is an intriguing structure that deforms under UV and visible light, indicating a high potential for biomedical applications. However, its reaction to UV radiation is problematic because of its high energy and low tissue penetration. Unlike previous research on azobenzene structures in photoresponsive materials, this study presents a novel method for imparting photostimulation-responsive properties to liposomes by incorporating the azobenzene moiety and extending the light wavelength with up-conversion nanoparticles. First, the azobenzene structure was incorporated into a phospholipid molecule to create Azo-PSG, which could spontaneously form vesicle assemblies in aqueous solutions and isomerizes within 1 h of light exposure. Furthermore, orthogonal up-conversion nanoparticles with a core-shell structure were created by sequentially growing lanthanide rare earths in the shell layer, which efficiently converts near-infrared light into ultraviolet (400 nm) and blue-green (540 nm) light. Combining these core-shell structured up-conversion nanomaterials with Azo-PSG molecules resulted in the creation of a near-infrared light-responsive smart nanoliposome system. Under near-infrared light irradiation, UCNPs emit UV and blue-green light, causing conformational changes in Azo-PSG molecules that allow drug release within 6 h. The reversible structural shift of Azo-PSG in response to light stimulation holds enormous promise for improving drug release techniques. This novel technique also expands the usage of UV-responsive compounds beyond their constraints of low penetration and high biotoxicity, allowing for rapid medication release under NIR light.

Double-camouflaged tellurium nanoparticles for enhanced photothermal immunotherapy of tumor

The photothermal conversion properties of tellurium (Te) nanoparticles have been extensively investigated, rendering them a promising candidate for tumor photothermal therapy. However, there is still room for improvement in the development of efficient Te-based drug delivery systems. Here, Te nanoparticles are mineralized with bioactive molecules within attenuated Salmonella (S-Te), which are subsequently taken up by macrophages (RAW264.7) to construct a double-camouflaged delivery platform (RS-Te). Remarkably, RS-Te retains superior photothermal properties under near-infrared irradiation. The mineralization process eliminates bacterial proliferation potential, thereby mitigating the risk of excessive bacterial growth in vivo. Furthermore, the uptake of bacteria by macrophages not only polarizes them into M1 macrophages to induce an anti-tumor immune response but also circumvents any adverse effects caused by complex antigens on the bacterial surface. The results show that RS-Te can effectively accumulate and retain in tumors. RS-Te-mediated photothermal immunotherapy largely promotes the maturation of dendritic cells and priming of cytotoxic T cells induced by near-infrared laser irradiation. Moreover, RS-Te can switch the activation of macrophages from an immunosuppressive M2 phenotype to a more inflammatory M1 state. The double-camouflaged delivery system may offer highly efficient and safe cancer treatment.

Photoactivated Hydrogel Therapeutic System with MXene-Based Nanoarchitectonics Potentiates Endogenous Bone Repair Through Reshaping the Osteo-Vascularization Network.

The repair and reconstruction of large-scale bone defects face enormous challenges because of the failure to reconstruct the osteo-vascularization network. Herein, a near-infrared (NIR) light-responsive hydrogel system is reported to achieve programmed tissue repair and regeneration through the synergetic effects of on-demand drug delivery and mild heat stimulation. The spatiotemporal hydrogel system (HG/MPa) composed of polydopamine-coated Ti3C2Tx MXene (MP) nanosheets decorated with acidic fibroblast growth factor (aFGF, a potent angiogenic drug) and hydroxypropyl chitosan/gelatin (HG) hydrogel is developed to orchestrate the reconstruction of the osteo-vascularization network and boost bone regeneration. Upon exposure to NIR light irradiation, the engineered HG/MPa hydrogel can achieve the initial complete release of aFGF to induce rapid angiogenesis and provide sufficient blood supply, maximizing its biofunction in the defect area. This integrated hydrogel system demonstrated good therapeutic efficacy in promoting cell adhesion, proliferation, migration, angiogenesis, and osteogenic differentiation through periodic NIR irradiation. In vivo, animal experiments further revealed that the spatiotemporalized hydrogel platform synergized with mild photothermal treatment significantly accelerated critical-sized bone defect healing by increasing the osteo-vascularization network density, recruiting endogenous stem cells, and facilitating the production of osteogenesis/angiogenesis-related factors. Overall, smart-responsive hydrogel couldenhance the reconstruction of the osteo-vascularization network in bone regeneration.

Catalytic Deprotection of Alkyne Dicobalt Hexacarbonyl Complexes using Near-Infrared Photocatalysis.

Dicobalt hexacarbonyl complexes are well-known for their applications in the Nicholas reaction or simply as a protecting group for alkynes. To recover the alkyne, demetalation is necessary, which usually involves a stoichiometric amount of an oxidizing agent or a strong ligand. This article reports a demetalation methodology based on a photocatalytic process. This approach employs a photocatalyst under aerobic conditions, and the optimal results were achieved using mild near-infrared irradiation. A mechanistic investigation is also presented to elucidate how the photocatalytic system promotes this deprotection. This tool is compatible with the one-pot reaction and orthogonal deprotection of alkynes, offering new perspectives for further applications.

Simultaneous imaging of telomerase activity and protein tyrosine kinase 7 in living cells during epithelial-mesenchymal transformation via a near-infrared light-activatable nanoprobe

Exploring the relationship between key regulation molecules (such as telomerase and protein tyrosine kinase 7) during epithelial-mesenchymal transformation of cells is beneficial for studying malignant tumor metastasis. Fluorescence is usually used for real-time monitoring the distribution and expression of regulatory molecules in living cells. However, the recognition function of these classical nanoprobes is “always active” due to the absence of exogenous control, which leads to the amplification of both the background signal and the response signal, making it difficult to distinguish changes in biomolecule expression levels. To improve the fluorescence ratio between tumor and normal cells, we constructed near-infrared light-activatable nanoprobes by engineering the functional units of catalytic hairpin assembly and integrating upconversion luminescence nanoparticles. Under near-infrared light irradiation, the nanoparticles, serving as a near-infrared-to-ultraviolet light transducer, induced the photolysis of the photo-cleavable linkers sealed in hairpins. The recognition function of the nanoprobes can be controlled by near-infrared light, preventing them from recognizing the targets in non-irradiated regions. By employing the nanoprobes, we realized simultaneous imaging of two regulatory molecules in living cells and observed an increase in telomerase activity and a decrease in protein tyrosine kinase 7 expression during drug-induced epithelial-mesenchymal transformation. This work provides a promising method for revealing changes and relationships of regulatory molecules during tumor metastasis.

Functional and structural construction of photothermal-responsive PEEK composite implants to promote bone regeneration and bone-implant integration

Although poly (ether-ether-ketone) (PEEK) has been widely used in orthopedic surgeries, its clinical efficacy is challenged by ineffective bone regeneration and insufficient osteointegration. Herein, inspired by the Mortise-and-tenon joint in traditional Chinese architectural art, a novel strategy has been developed to construct photothermal-responsive PEEK composite implants, with tapered lock-groove edges as proof of concept, by incorporating graphene oxide (GO) loaded with polydopamine-coated nano-zirconia (PDA@ZrO2) into PEEK (namely PGPZ composite). The PGPZ composite exhibits improved mechanical properties, good cytocompatibility and blood compatibility, excellent antibacterial ability and osteogenic activity remotely controlled by near-infrared irradiation (NIR). The cranial defects experiment on rabbits reveals that repeated NIR treatment on PGPZ composite implant significantly accelerates endogenous bone regeneration. More importantly, abundant newly-formed bone has materialized in the lock grooves, forming interlocked Mortise-and-tenon joints with the implant. This study not only pave the way for further clinical applications of the PEEK composite implants with improved bioactivities to promote bone regeneration and osteointegration, but also providing a novel strategy for structural and functional design of various tissue engineering implants.

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.

NIR stimulated epigallocatechin gallate loaded polydopamine with enhanced antibacterial and ROS scavenging abilities for improved infectious wound healing

Infectious wound healing is complicated with and limited by infection and oxidative stress at the wound site. In recent years, various evidences suggest that nanozymes with multiple enzymatic activities have enabled the development of novel strategies for infectious wound healing. In this study, epigallocatechin gallate loaded polydopamine (P@E) was developed to act as a potent reactive oxygen species (ROS) scavenger for scavenging ROS, alleviating inflammatory responses, and promoting infectious wound healing. Combining with near infrared (NIR) irradiation, P@E presented excellent antibacterial ability of Escherichia coli (E. coli, 93.6%) and methicillin-resistant Staphylococcus aureus (MRSA, 87.6%). Specifically, P@E+NIR exhibited the most potent antioxidant, anti-inflammatory and cell proliferation behaviors through down-regulating intracellular ROS levels (81.9% and 94.3% for NIH3T3 and RAW264.7 respectively) and inducible nitric oxide synthase (iNOS) expression level (55.7%), and up-regulating the expression levels of arginase-1 (Arg-1, 71.4%), heat shock protein 70 (HSP70, 48.6%) and platelet endothelial cell adhesion molecule (CD31, 35.3%) compared to control group. Meanwhile, it also efficiently induced M2 directional polarization of lipopolysaccharide induced murine macrophages to achieve anti-inflammation, indicated by the down-regulation of CD86 (86.2%), and up-regulation of CD206 (85.6%). Significantly, it was also observed that P@E+NIR presented the excellent behaviors of inhibiting wound infection, alleviating wound inflammation, as well as promoting skin tissue repairing. Altogether, it has developed the strategy of using P@E combining with NIR irradiation for the synergistic enhanced healing of infectious skin wound, which can serve as a promising therapeutic strategy for its clinical treatment.

Molybdenum nanodots act as antioxidants for photothermal therapy osteoarthritis

Osteoarthritis (OA) manifests as the degradation of cartilage and remodeling of subchondral bone. Restoring homeostasis within the joint is imperative for alleviating OA symptoms. Current interventions primarily target singular aspects, such as anti-aging, inflammation inhibition, free radical scavenging, and regeneration of cartilage and subchondral bone. Herein, we developed molybdenum nanodots (MNDs) as bionic photothermal nanomaterials to mimic the antioxidant synthase to concurrently protected cartilage and facilitate subchondral bone regeneration. With near-infrared (NIR) irradiation, MNDs effectively eliminate reactive oxygen and nitrogen species (ROS/RNS) from OA chondrocytes, thereby reversed mitochondrial dysfunction, mitigating chondrocyte senescence, and simultaneously suppresses inflammation, hence preserving the inherent homeostasis between cartilage matrix synthesis and degradation while circumventing safety concerns. RNA sequencing of OA chondrocytes treated with MNDs-NIR revealed the reinstatement of chondrocyte functionality, activation of antioxidant enzymes, anti-aging properties, and regulation of inflammation. NIR irradiation induces thermogenesis and synergistically promotes subchondral bone regeneration via MNDs, as validated through histological assessments and microcomputed tomography (Micro-CT) scans. MNDs-NIR effectively attenuate cellular senescence and inhibit inflammation in vivo, while also remodeling mitochondrial dynamics by upregulating fusion proteins and inhibiting fission proteins, thereby regulating the oxidative stress microenvironment. Additionally, MNDs-NIR exhibited remarkable therapeutic effects in alleviating articular cartilage degeneration in an OA mouse model, evidenced by a 1.67-fold reduction in subchondral bone plate thickness, an 88.57% decrease in OARSI score, a 5.52-fold reduction in MMP13 expression, and a 6.80-fold increase in Col II expression. This novel disease-modifying approach for OA utilizing MNDs-NIR offers insight and a paradigm for improving mitochondrial dysfunction by regulating the accumulation of mitochondrial ROS and ultimately alleviating cellular senescence. Moreover, the dual-pronged therapeutic approach of MNDs-NIR, which addresses both cartilage erosion and subchondral bone lesions in OA, represents a highly promising strategy for managing OA.