Photothermal Killing Research Articles

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.

Construction of aptamers-modified plasmonic GO/urchin-like Au nanoparticles with enhanced photothermal performance and their efficient capture and elimination of Staphylococcus aureus

Here, aptamers-modified graphene oxide/urchin-like Au nanoparticles (Apt-GUANPs) were developed for efficient capture and photothermal therapy (PTT) of Staphylococcus aureus (S. aureus). Specifically, anisotropic UANPs were first prepared, and the excellent photothermal property was related to the localized surface plasmon resonance (LSPR) in the near infrared (NIR) region caused by sharp branching. Then GO, which was used to enhance the photothermal effect, was added and assembled into GUANPs by electrostatic action. Infrared images showed that GUANPs exhibited a stronger photothermal effect than UANPs. Under the irradiation of 808 nm laser, the photothermal conversion efficiency (η) of GUANPs was as high as 40.5 %, which was attributed to the enhanced optical response of GUANPs at 808 nm and the strong plasmonic coupling effect between tightly packed UANPs loaded on GO surfaces. Aptamers were modified on the surfaces of GUANPs for specific capture of S. aureus, with the capture efficiency of up to 72 %. Utilizing the specific capture ability of aptamers and the excellent photothermal property of GUANPs, Apt-GUANPs exhibited the strong photothermal killing ability against S. aureus. Therefore, Apt-GUANPs will be a promising and efficient photothermal agent, and will have a great application prospect in the treatment of bacterial infections in the future.

Controllable Construction of Aptamer-Modified Fe3O4@SiO2-Au Core-Shell-Satellite Nanocomposites with Surface-Enhanced Raman Scattering and Photothermal Properties and Their Effective Capture, Detection, and Elimination of Staphylococcus aureus.

The early monitoring and inactivation of bacteria are of crucial importance in preventing the further spread of foodborne pathogens. Staphylococcus aureus (S. aureus), a prototypical foodborne pathogen, is widely present in the natural environment and has the capability to trigger a range of diseases at low concentrations. In this work, we designed Fe3O4@SiO2-Au core-shell-satellite nanocomposites (NCs) modified with aptamer for efficient capture, high-sensitivity surface-enhanced Raman scattering (SERS) detection, and photothermal therapy (PTT) against S. aureus. Fe3O4@SiO2-Au NCs with tunable Au nanocrystal nanogaps were prepared. By combining the finite-difference time-domain (FDTD) method and experimental results, we studied the electric field distribution of Fe3O4@SiO2-Au under different Au nanogaps and ultimately obtained the optimal SERS substrate FSA-60. The modification of aptamer on the surfaces of FSA-60 could be used for the specific capture and selective detection of S. aureus, achieving a detection limit of as low as 50 cfu/mL. Furthermore, Apt-FSA-60 possessed excellent photothermal properties, demonstrating the strong photothermal killing ability against S. aureus. Therefore, Apt-FSA-60 is a promising high-sensitivity SERS substrate and efficient photothermal agent and is expected to be widely applied and promoted in future disease prevention and treatment.

NIR-II AIE Luminogen-Based Erythrocyte-Like Nanoparticles with Granuloma-Targeting and Self-Oxygenation Characteristics for Combined Phototherapy of Tuberculosis.

Tuberculosis, a fatal infectious disease caused by Mycobacterium tuberculosis (M.tb), is difficult to treat with antibiotics due to drug resistance and short drug half-life. Phototherapy represents a promising alternative to antibiotics in combating M.tb. Exploring an intelligent material allowing effective tuberculosis treatment is definitely appealing, yet a significantly challenging task. Herein, an all-in-one biomimetic therapeutic nanoparticle featured by aggregation-induced second near-infrared emission, granuloma-targeting, and self-oxygenation is constructed, which can serve for prominent fluorescence imaging-navigated combined phototherapy toward tuberculosis. After camouflaging the biomimetic erythrocyte membrane, the nanoparticles show significantly prolonged blood circulation and increased selective accumulation in tuberculosis granuloma. Upon laser irradiation, the loading photosensitizer of aggregation-induced emission photosensitizer elevates the production of reactive oxygen species (ROS), causing M.tb damage and death. The delivery of oxygen to relieve the hypoxic granuloma microenvironment supports ROS generation during photodynamic therapy. Meanwhile, the photothermal agent, Prussian blue nanoparticles, plays the role of good photothermal killing effect on M.tb. Moreover, the growth and proliferation of granuloma and M.tb colonies are effectively inhibited in the nanoparticle-treated tuberculous granuloma model mice, suggesting the combined therapeutic effects of enhancing photodynamic therapy and photothermal therapy.

A novel strategy for specific sensing and inactivation of Escherichia coli: Constructing a targeted sandwich-type biosensor with multiple SERS hotspots to enhance SERS detection sensitivity and near-infrared light-triggered photothermal sterilization performance

Human health is greatly threatened by bacterial infection, which raises the risk of serious illness and death in humans. For early screening and accurate treatment of bacterial infection, there is a strong desire to undertake ultrasensitive detection and effective killing of pathogenic bacteria. Herein, a novel surface-enhanced Raman scattering (SERS) biosensor based on sandwich structure consisting of capture probes/bacteria/SERS tags was established for specific identification, capture and photothermal killing of Escherichia coli (E. coli). Finite-difference time-domain (FDTD) technique was used to simulate the electromagnetic field distribution of capture probes, SERS tags and sandwich-type SERS substrate, and a possible SERS enhancement mechanism based on sandwich structure was presented and discussed. Sandwich-type SERS biosensor successfully achieved distinctive identification and magnetic beneficiation of E. coli. In addition, a single SERS substrate, including capture probes and SERS tags, could also achieve outstanding photothermal effects as a consequence of localized surface plasmon resonance (LSPR) effect. Intriguingly, sandwich-type SERS biosensor demonstrated a higher photothermal conversion efficiency (50.03 %) than the single substrate, which might be attributed to the formation of target bacterial clusters. The superior biocompatibility and the low toxicity of the sandwich-type biosensor were confirmed. Our approach offers a fresh method for constructing sandwich-type biosensor with multiple SERS hotspots based on extremely effective hybrid plasmonic nanoparticles, and has a wide range of potential applications in the recognition and treatment of bacteria.

Polybenzoxazines as new photothermal therapy agents

To make photothermal therapy an attractive alternative to conventional cancer treatments, the development of novel photothermal agents with enhanced properties is demanded. To tackle this challenge, herein we explored the use of polybenzoxazines, a well-known class of phenolic resins. Two different types of polybenzoxazine materials were prepared as potential photothermal agents: water-soluble polybenzoxazines as well as nanoparticles of hydrophobic polybenzoxazines, which can be generated in situ by polymer addition to cell culture medium. For both systems, irradiation with visible light led to significant photothermal effects, whose application to photoinduce human breast cancer cell’s death was investigated in vitro. The best results were obtained for polybenzoxazine nanostructures, which exhibited successful cell internalization, minimal cytotoxicity in the dark and efficient photothermal killing of cancer cells upon illumination with high-penetrating red light. In combination with their low cost and facile preparation, this makes these polymer nanomaterials highly promising for photothermal therapy applications.

Design of Silica@Au Hybrid Nanostars for Enhanced SERS and Photothermal Effect.

Core-shell nanostructures of silicon oxide@noble metal have drawn a lot of interest due to their distinctive characteristics and minimal toxicity with remarkable biocompatibility. Due to the unique property of localized surface plasmon resonance (LSPR), plasmonic nanoparticles are being used as surface-enhanced Raman scattering (SERS) based detection of pollutants and photothermal (PT) agents in cancer therapy. Herein, we demonstrate the synthesis of multifunctional silica core - Au nanostars shell (SiO2 @Au NSs) nanostructures using surfactant free aqueous phase method. The SERS performance of the as-synthesized anisotropic core-shell NSs was examined using Rhodamine B (RhB) dye as a Raman probe and resulted in strong enhancement factor of 1.37×106 . Furthermore, SiO2 @Au NSs were also employed for PT killing of breast cancer cells and they exhibited a concentration-dependent increase in the photothermal effect. The SiO2 @Au NSs show remarkable photothermal conversion efficiency of up to 72 % which is unprecedented. As an outcome, our synthesized NIR active SiO2 @Au NSs are of pivotal importance to have their dual applications in SERS enhancement and PT effect.

Anti-osteosarcoma trimodal synergistic therapy using NiFe-LDH and MXene nanocomposite for enhanced biocompatibility and efficacy

Osteosarcoma is usually resistant to immunotherapy and, thus primarily relies on surgical resection and high-dosage chemotherapy. Unfortunately, less invasive or toxic therapies such as photothermal therapy (PTT) and chemodynamic therapy (CDT) generally failed to show satisfactory outcomes. Adequate multimodal therapies with proper safety profiles may provide better solutions for osteosarcoma. Herein, a simple nanocomposite that synergistically combines CDT, PTT, and chemotherapy for osteosarcoma treatment was fabricated. In this composite, small 2D NiFe-LDH flakes were processed into 3D hollow nanospheres via template methods to encapsulate 5-Fluorouracil (5-FU) with high loading capacity. The nanospheres were then adsorbed onto larger 2D Ti3C2 MXene monolayers and finally shielded by bovine serum albumin (BSA) to form 5-FU@NiFe-LDH/Ti3C2/BSA nanoplatforms (5NiTiB). Both in vitro and in vivo data demonstrated that the 5-FU induced chemotherapy, NiFe-LDH driven chemodynamic effects, and MXene-based photothermal killing collectively exhibited a synergistic “all-in-one” anti-tumor effect. 5NiTiB improved tumor suppression rate from <5% by 5-FU alone to ∼80.1%. This nanotherapeutic platform achieved higher therapeutic efficacy with a lower agent dose, thereby minimizing side effects. Moreover, the composite is simple to produce, enabling the fine-tuning of dosages to suit different requirements. Thus, the platform is versatile and efficient, with potential for further development.

Reconstituting Low-Density Lipoprotein with NIR-Absorbing Organic Photothermal Agents for Targeted Killing of Cancer Cells.

Photothermal therapy (PTT) systems typically do not possess intrinsic tumor-targeting capability, resulting in indiscriminate thermal damage to both cancer and normal cells. Herein, a low-density lipoprotein (LDL)-based nanosystem (denoted as MTTQ@LDL) is reported for targeted photothermal killing of cancer cells. Such a nanosystem is fabricated by reconstituting the lipophilic core of LDL with an organic photothermal agent MTTQ. The reconstitution process improves the supramolecular photothermal effects of MTTQ assemblies, which contributes to the significantly enhanced photothermal conversion efficiency (41.3%vs. 16.2%). MTTQ@LDL can actively target LDL receptor-overexpressed cancer cells via receptor-mediated endocytosis, enabling the selective killing of cancer cells over normal cells (98%vs. 7%) post-NIR irradiation. Reconstituted LDL can serve as a promising platform for targeted delivery of functional materials, holding great promise in tumor eradication in vivo.

Janus nanoparticles targeting extracellular polymeric substance achieve flexible elimination of drug-resistant biofilms

Safe and efficient antibacterial materials are urgently needed to combat drug-resistant bacteria and biofilm-associated infections. The rational design of nanoparticles for flexible elimination of biofilms remains challenging. Herein, we propose the fabrication of Janus-structured nanoparticles targeting extracellular polymeric substance to achieve dispersion or near-infrared (NIR) light-activated photothermal elimination of drug-resistant biofilms, respectively. Asymmetrical Janus-structured dextran-bismuth selenide (Dex-BSe) nanoparticles are fabricated to exploit synergistic effects of both components. Interestingly, Janus Dex-BSe nanoparticles realize enhanced dispersal of biofilms over time. Alternatively, taking advantage of the preferential accumulation of nanoparticles at infection sites, the self-propelled active motion induced by the unique Janus structure enhances photothermal killing effect. The flexible application of Janus Dex-BSe nanoparticles for biofilm removal or NIR-triggered eradication in vivo is demonstrated by Staphylococcus aureus-infected mouse excisional wound model and abscess model, respectively. The developed Janus nanoplatform holds great promise for the efficient elimination of drug-resistant biofilms in diverse antibacterial scenarios.

Palladium Nanocapsules for Photothermal Therapy in the Near-Infrared II Biological Window.

Recent developments in nanomaterials with programmable optical responses and their capacity to modulate the photothermal effect induced by an extrinsic source of light have elevated plasmonic photothermal therapy (PPTT) to the status of a favored treatment for a variety of malignancies. However, the low penetration depth of near-infrared-I (NIR-I) lights and the need to expose the human body to a high laser power density in PPTT have restricted its clinical translation for cancer therapy. Most nanostructures reported to date exhibit limited performance due to (i) activity only in the NIR-I region, (ii) the use of intense laser, (iii) need of large concentration of nanomaterials, or (iv) prolonged exposure times to achieve the optimal hyperthermia state for cancer phototherapy. To overcome these shortcomings in plasmonic nanomaterials, we report a bimetallic palladium nanocapsule (Pd Ncap)─with a solid gold bead as its core and a thin, perforated palladium shell─with extinction both in the NIR-I as well as the NIR-II region for PPTT applications toward cancer therapy. The Pd Ncap demonstrated exceptional photothermal stability with a photothermal conversion efficiency of ∼49% at the NIR-II (1064 nm) wavelength region at a very low laser power density of 0.5 W/cm2. The nanocapsules were further surface-functionalized with Herceptin (Pd Ncap-Her) to target the breast cancer cell line SK-BR-3 and exploited for in vitro PPTT applications using NIR-II light. Pd Ncap-Her caused more than 98% cell death at a concentration of just 50 μg/mL and a laser power density of 0.5 W/cm2 with an output power of only 100 mW. Flow cytometric and microscopic analyses revealed that Pd Ncap-Her-induced apoptosis in the treated cancer cells during PPTT. Additionally, Pd Ncaps were found to have reactive oxygen species (ROS) scavenging ability, which can potentially reduce the damage to cells or tissues from ROS produced during PPTT. Also, Pd Ncap demonstrated excellent in vivo biocompatibility and was highly efficient in photothermally ablating tumors in mice. With a high photothermal conversion and killing efficiency at very low nanoparticle concentrations and laser power densities, the current nanostructure can operate as an effective phototherapeutic agent for the treatment of different cancers with ROS-protecting ability.

Near-Infrared Copper Sulfide Hollow Nanostructures with Enhanced Photothermal and Photocatalytic Performance for Effective Bacterial Sterilization.

The development of nonantibiotic strategies to combat bacterial infection is highly needed, owing to the widespread infectious disease and bacterial resistance becoming a significant health threat to the world's population. In recent years, photoactivated antibacterial therapies including photocatalytic and photothermal therapies have attracted increasing attention due to their high efficiency and low side effect. Herein, we introduce a copper sulfide (Cu2-xS) hollow nanostructure-based near-infrared antibacterial platform with synergy photothermal and photocatalytic properties for effective bacterial sterilization. Compared to traditional Cu2-xS nanoparticles, this unique hollow Cu2-xS nanostructure can generate multiple scattered light, which is conducive to light collection. Moreover, its thin shell can shorten the transmission distance of carrier, thus reducing the charge recombination that usually causes the greatest energy loss. As a result, such a Cu2-xS hollow nanostructure enables enhanced photothermal and photocatalytic bacterial killing activities against both Escherichia coli and Staphylococcus aureus, showing promise for antibiotic-free infection treatment and other bacterial sterilization applications.

Melanin-Based Immunoregulatory Nanohybrids Enhance Antitumor Immune Responses in Breast Cancer Mouse Model.

Natural melanin nanoparticles (MNPs) have demonstrated a potential for eliciting antitumor immune responses through inducing immunogenic cell death (ICD); however, the tumor microenvironment (TME) has been shown to inhibit T cell-mediated antitumor immunity. To address this challenge, we designed TME-responsive biodegradable melanin/MnOx nanohybrids via a biomineralization process. Under near-infrared (NIR) light irradiation, the photothermal property of melanin/MnOx nanohybrids triggers ICD and release of tumor-associated antigens (TAAs), while Mn2+ and TAAs induce dendritic cell (DC) maturation to provoke immune responses. Furthermore, the immunoregulatory properties of the nanohybrids themselves are exploited to reshape immunosuppressive TME and downregulate PD-L1 through alleviation of the hypoxic and acidic TME. Although MNPs demonstrate higher photothermal killing efficiency than the nanohybrids in vitro due to their superior photothermal effect, the melanin/MnOx nanohybrids exhibit significantly enhanced antitumor and antimetastatic effects in vivo, benefiting from their ability to reverse immunosuppression and induce DC maturation. Transcriptomics analysis confirmed the successful activation of immune responses. This work presents a promising approach for immunomodulation-enhanced cancer therapy through the intrinsic properties of melanin/MnOx nanohybrids.

Composite Hydrogel for the Targeted Capture and Photothermal Killing of Bacteria toward Facilitating Wound Healing.

Pathogenic infections pose a significant risk to public health and are regarded as one of the most difficult clinical treatment obstacles. A reliable and safe photothermal antibacterial platform is a promising technique for the treatment of bacterial infections. Given the damage that high temperatures cause in normal tissues and cells, a multifunctional hydrogel driven by photothermal energy is created by trapping bacteria to reduce heat transfer loss and conduct low-temperature photothermal sterilization efficiently. The 3-aminobenzene boronic acid (ABA)-modified graphene oxide is combined with carboxymethyl chitosan (CMCS) and cellulose nanocrystalline (CNC) networks to create the ABA-GO/CNC/CMCS composite hydrogel (composite gel). The obtained composite gel displays a uniform three-dimensional network structure, which can be rapidly heated to 48 °C under infrared light irradiation and is beneficial for killing wound infection bacteria and promoting wound healing. The results of animal experiments show that the composite gel significantly reduces inflammation by killing >99.99% of bacteria under near-infrared light irradiation. The result also demonstrates that it increases the granulation tissue thickness and collagen distribution and promotes wound healing. After treatment for 14 days, compared with the remaining 27.73% of the remaining wound area in the control group, the wound area in the composite gel with NIR group is only 0.91%. It significantly accelerates the wound healing process of Staphylococcus aureus infection and shows great potential for clinical application.

Preparation of polydopamine-based concave nanoparticles and mild photothermal-anti-inflammatory combination therapy for breast cancer guided by magnetic resonance imaging

Photothermal therapy (PTT) has been widely investigated as a regimen for superficial tumors. However, conventional PTT strategies usually require photothermal temperatures above 50 °C to achieve significant therapeutic efficacy, which in effect would lead to injury to adjacent normal tissues and meanwhile, the heat generated by the photothermal effect would induce inflammation owing to the damage to cytoplasmic components. In order to reduce the toxicity of photothermal therapy and increase the efficiency of photothermal tumor destruction, novel strategies are prerequisite for targeted regimen and surveillance of photothermal therapy in real time. In this paper, we reported a concave mesoporous polydopamine-targeting nanotherapeutic agent. We employed B-MPDA as the carrier and encapsulated CQ and ASP to yield B-MPDA/CQ/ASP which was loaded with autophagy inhibitors and anti-inflammatory agents and coated uniformly with MnO2 Nanosheet. With HA functionalizing MnO2 Nanosheet, B-MPDA/CQ/ASP@MnO2-HA was constituted. The yielded nanoparticles were identified to be advantageous for good biocompatibility, potent targeting and low toxicity. In anti-tumor regimens, the nanoparticles can be applied to hyaluronic acid targeting, mesoporous polydopamine thermotherapy, and autophagy inhibitor sensitization thermotherapy, and simultaneously eliminate the inflammatory effects induced by photothermal therapy. Furthermore, in combination with the anti-inflammatory effect of targeting tumor, this agent can effectively induce apoptosis of cancer cells and significantly improve the efficiency of mild photothermal killing of cancer cells, which provides insight into the development of nanoparticles and application to mild photothermal therapy in the clinical scenario.

Bacteria-based multiplex system eradicates recurrent infections with drug-resistant bacteria via photothermal killing and protective immunity elicitation

BackgroundThe high mortality associated with drug-resistant bacterial infections is an intractable clinical problem resulting from the low susceptibility of these bacteria to antibiotics and the high incidence of recurrent infections.MethodsHerein, a photosynthetic bacteria-based multiplex system (Rp@Al) composed of natural Rhodopseudomonas palustris (Rp) and Food and Drug Administration-approved aluminum (Al) adjuvant, was developed to combat drug-resistant bacterial infections and prevent their recurrence. We examined its photothermal performance and in vitro and in vivo antibacterial ability; revealed its protective immunomodulatory effect; verified its preventative effect on recurrent infections; and demonstrated the system’s safety.ResultsRp@Al exhibits excellent photothermal properties with an effective elimination of methicillin-resistant Staphylococcus aureus (MRSA). In addition, Rp@Al enhances dendritic cell activation and further triggers a T helper 1 (TH1)/TH2 immune response, resulting in pathogen-specific immunological memory against recurrent MRSA infection. Upon second infection, Rp@Al-treated mice show significantly lower bacterial burden, faster abscess recovery, and higher survival under near-lethal infection doses than control mice.ConclusionsThis innovative multiplex system, with superior photothermal and immunomodulatory effects, presents great potential for the treatment and prevention of drug-resistant bacterial infections.Graphical

Stimulus-responsive tumor supramolecular nanotherapeutic system based on indocyanine green

Indocyanine green (ICG), a clinical near-infrared fluorescent probe, has the potential to be used as an integrated diagnostic and therapeutic agent for tumors. In this study, ICG-COOH-TK was obtained by connecting ICG molecules through stimulus-responsive thioketone (TK) bond, which can self-assemble into nanoparticles in water. Under 808 nm near-infrared light irradiation, the molecule exhibited excellent photothermal conversion efficiency, as well as better photostability and in vivo circulation stability than free ICG. The nanoparticle can respond to reactive oxygen species (ROS) overexpression in the tumor microenvironment and release ICG upon disassembly, resulting in significantly enhanced fluorescence emission at the tumor. In vitro cell experiments demonstrated excellent biocompatibility and photothermal killing effect on cancer cells, indicating that this molecule can serve as a diagnostic and therapeutic agent for fluorescence-guided tumor photothermal therapy.

Controllable Gold Nanocluster-Emulsion Interface for Direct Cell Penetration and Photothermal Killing.

In the view of their ability to be uptaken by cells, colloidal particles can exert diverse physiological effects and are promising vehicles for the intracellular delivery of biologically active substances. Given that the modulation of biomaterial interfaces greatly facilitates the prediction and control of the corresponding cellular responses, the interfacial behavior of hydrophobic dye-modified gold (Au) nanoclusters (Au NCs) is rationally designed to develop Au NC-containing emulsions and control their biointerfacial interactions with cell membranes. The observed biological performance is indicative of a physical penetration mechanism. The amphiphilic Au NCs decrease the interfacial energy of two immiscible liquids and hinder droplet coalescence to facilitate the formation of emulsions thermodynamically stabilized by dipole-dipole and hydrophobic interactions. Moreover, the amphiphilic Au NCs are localized on the emulsion droplet surface and form segregated interfacial microdomains that adapt to the membrane structure and facilitate the traverse of the emulsions across the cell membrane via direct penetration. Fast penetration coupled with excellent photophysical performance endows the emulsions with multifluorescence tracing and efficient photothermal killing capabilities. The successful change of the interaction mode between NCs and biological objects and the provision of a universal formulation to modulate biointerfacial interactions are expected to inspire new bioapplications.

Bimetallic Au–Pd nanoparticles/RGO as theranostic nanoplatform for photothermal therapy of throat cancer - an in vitro approach

The current work showed the fabrication of bimetallic Au–Pd-NPs on reduced graphene oxide (RGO) sheets functionalized with plant polyphenols of Ziziphus ziziphus leaf extract for enhanced aqueous dispersibility using a simple green method. The synthesized Au–Pd/RGO nanocomposite was effectively employed for the in-vitro photothermal killing of HNE-1 cells. Applying the 808 nm laser (1 W cm−2) and maintaining the concentration of Au–Pd/RGO at 75 μg mL−1, the solution temperature was brought to 58 °C, which is adequate for the eradication of cancer cells. Later, the solution temperature was brought to 80 °C by increasing the concentrations to 90 μg mL−1. Ultimately, the near total photoablation (≈97%) of HNE-1 cells was obtained by maintaining the concentration of Au–Pd–RGO nanocomposites at ≈20 μg mL−1, a laser power of 1 W cm−1 and a LC50 value of 7 μg mL−1. This exceptional efficiency was attributed mostly to the synergistic effect of Au–Pd NPs, and RGO. The current study might lead the way for the synthesis of advanced materials that could be used as prospective photothermal candidates for the ablation of various unregulated cells.

Enhanced Tumor Accumulation of Multimodal Magneto-Plasmonic Nanoparticles via an Implanted Micromagnet-Assisted Delivery Strategy.

One of the major shortcomings of nano carriers-assisted cancer therapeutic strategies continues to be the inadequate tumor penetration and retention of systemically administered nanoformulations and its off-target toxicity. Stromal parameters-related heterogeneity in enhanced permeability and retention effect and physicochemical properties of the nanoformulations immensely contributes to their poor tumor extravasation. Herein, a novel tumor targeting strategy, where an intratumorally implanted micromagnet can significantly enhance accumulation of magneto-plasmonic nanoparticles (NPs) at the micromagnet-implanted tumor in bilateral colorectal tumor models while limiting their off-target accumulation, is demonstrated. To this end, novel multimodal gold/iron oxide NPs comprised of an array of multifunctional moieties with high therapeutic, sensing, and imaging potential are developed. It is also discovered that cancer cell targeted NPs in combination with static magnetic field can selectively induce cancer cell death. A multimodal caspase-3 nanosensor is also developed for real-time visualization of selective induction of apoptosis in cancer cells. In addition, the photothermal killing capability of these NPs in vitro is evaluated, and their potential for enhanced photothermal ablation in tissue samples is demonstrated. Building on current uses of implantable devices for therapeutic purposes, this study envisions the proposed micromagnet-assisted NPs delivery approach may be used to accelerate the clinical translation of various nanoformulations.