Photothermal Sensitizers Research Articles

Hypoxia-Responsive Covalent Organic Framework Nanoplatform for Breast-Cancer-Targeted Cocktail Immunotherapy via Triple Therapeutic Switch Mechanisms.

Covalent organic frameworks (COFs), known for their exceptional in situ encapsulation and precise release capabilities, are emerging as pioneering drug delivery systems. This study introduces a hypoxia-responsive COF designed to encapsulate the chemotherapy drug gambogic acid (GA) in situ. Bimetallic gold-palladium islands were grown on UiO-66-NH2 (UiO) to form UiO@Au-Pdislands (UAPi), which were encapsulated with GA through COF membrane formation, resulting in a core-shell structure (UAPiGC). Further modification with hyaluronic acid (HA) created UiO@Au-Pdislands@GA-COF@HA (UAPiGCH) for enhanced tumor targeting. In the hypoxic tumor microenvironment, the COF collapses, releasing GA and UAPi, initiating a triple therapeutic response: nanozyme-catalyzed therapy, near-infrared II (NIR-II) mild photothermal therapy (mild-PTT), and chemotherapy. UAPi exhibits catalase (CAT)-like and peroxidase (POD)-like activities, generating oxygen to alleviate hypoxia and reactive oxygen species (ROS) for tumor destruction. GA acts as a chemotherapeutic agent and inhibits heat shock protein 90 (HSP90), enhancing photothermal sensitivity. In vitro and in vivo studies confirm UAPiGCH's ability to induce pyroptosis, stimulate dendritic cell maturation, and boost T cell infiltration, demonstrating its potential as a precise therapeutic nanoplatform. This strategy integrates multiple therapies into a hypoxia-responsive system, offering promising applications in cancer treatment.

Construction and evaluation of a model for efficient identification of photothermal sensitivity of tobacco cultivars based on agronomic traits

The photothermal sensitivity of tobacco refers to the degree to which tobacco responds to changes in light and temperature conditions in its growth environment, which is crucial for determining the planting area of cultivars and improving tobacco yield and quality. In order to accurately and effectively evaluate the photothermal sensitivity of tobacco cultivars, this study selected five cultivars and their hybrid combinations with significant differences planted under different ecological conditions from 2021 to 2022 as materials. The experiment was conducted in two locations with significant differences in temperature and light. We measured the agronomic traits and biomass of the experimental materials, and constructed an effective tobacco photothermal sensitivity evaluation model using principal component analysis, membership function, and regression analysis. The reliability of the model was evaluated by utilizing the photosynthetic characteristics, chlorophyll content, and antioxidant enzyme system activity of the experimental materials. The results showed that tobacco biomass is the most important principal component in agricultural traits, and the comprehensive evaluation model for tobacco photothermal sensitivity is: y = 0.4571y1 + 0.2406y2 + 0.1725y3, where the fitting coefficients R2 of y1, y2, and y3 are 0.945, 0.851, and 0.977, respectively; The photothermal sensitivity of the experimental materials was calculated using this model, and the comprehensive ranking of the 11 experimental materials is: G3 < G5 < G10 < G9 < G11 < G6 < G7 < G2 < G4 < G8 < G1. Conventional identification methods have found that G2, G4, G6, G7, G8, and G11 are sensitive materials, G3, G5, and G10 are insensitive materials, and G1 and G9 are intermediate materials. The consistency rate of the evaluation results of the two methods reached 90.91%. And there is a significant correlation between the agronomic traits selected in the model and the physiological indicators selected by conventional evaluation methods, providing a scientific basis for evaluating the light temperature sensitivity of tobacco cultivars using agronomic traits in this study. The results indicate that the photothermal sensitivity evaluation model established in this study provides an efficient, convenient, and reliable method for evaluating the photothermal sensitivity of tobacco.

MMP-2 Responsive Gold Nanorods Loaded with HSP-70 siRNA for Enhanced Photothermal Tumor Therapy.

Gold nanorods (Au NRs) are a valuable photothermal nanomaterial for tumor therapy. However, when treated with Au NRs for photothermal therapy, the expression of heat shock proteins in tumors will increase, which will induce heat resistance in tumor cells and reduce the photothermal therapeutic effect of Au NRs. By RNA interference, the expression of heat shock proteins would be effectively inhibited to improve the efficasy of tumor photothermal therapy. However, deep and noninvasive tissue penetration remains a great obstacle to applying siRNA successfully. Thus, the nanoplatform AGC/HSP-70 siRNA was designed for enhanced photothermal tumor therapy by RNA interference. In the AGC/HSP-70 siRNA complex, the Au-S bond modified the matrix metalloproteinase-2 (MMP-2)-sensitive peptide GPLGLAG on the surface of gold nanorods. Moreover, the natural basic polysaccharide (chitosan) was reacted with the peptide by an amide bond for delivering heat shock protein 70 silencing siRNA (HSP-70 siRNA). Modifying the MMP-2-sensitive linker could cause more Au NRs to accumulate in tumors to exert a photothermal effect and promote the penetration of HSP-70 siRNA and chitosan complexes into deep tumor tissues. In vitro experiments indicated that the enzymolysis of the MMP-2-sensitive linker for AGC/HSP-70 siRNA could promote the cellular uptake and perinuclear distribution of HSP-70 siRNA in tumor cells, which may be due to the smaller size and positive electricity of the complexes. All of these results ensured the efficient gene silencing effect of HSP-70 siRNA to enhance the photothermal therapeutic effect of Au NRs in tumor tissues, as demonstrated by the gene silencing and cellular apoptotic experiments. In vivo experiments further proved that the AGC/HSP-70 siRNA nanoplatform efficiently improved the photothermal effect of Au NRs. In summary, this work proved that AGC/HSP-70 siRNA is a promising drug delivery strategy for enhancing the photothermal therapy of tumors by regulating the photothermal sensitivity of deep tumor cells as well as retaining more Au NRs in tumor tissues, and also provides a novel strategy for tumor photothermal therapy.

Excessive autophagy-inducing and highly penetrable biomineralized bacteria for multimodal imaging-guided and mild hyperthermia-enhanced immunogenic cell death

The tumor microenvironment, characterized by hypoxia, supports the efficacy of anaerobic bacteria like attenuated S. typhimurium in cancer therapies. These bacteria target and penetrate deep tumor regions, significantly reducing tumor size but often lead to tumor regrowth due to limited long-term efficacy. To enhance the therapeutic impact, a novel biohybrid system, S@UIL, has been developed by coating S. typhimurium with a zirconium-based nanoscale metal–organic framework (UiO-66-NH2) loaded with indocyanine green (ICG) and luteolin (LUT). This system maintains the bacteria’s tumor-targeting ability while increasing the penetration and therapeutic effectiveness through excessive autophagy and mild hyperthermia. In a subcutaneous colon cancer model, the integration of LUT and ICG promotes autophagic cell death and photothermal sensitization, leading to the release of damage-associated molecular patterns (DAMPs). These DAMPs activate immune responses through dendritic cells and T-cells, enhancing immunogenic cell death (ICD) and potentially reducing immune evasion by tumors. This single-administration approach also integrates multimodal imaging capabilities, providing a promising strategy for improved tumor ICD induction and cancer progression inhibition.

Nanoengineered plasmonics-enhanced photothermal tags for sensitive detection of cardiac biomarker troponin I using lateral flow immunoassay

In recent years, photothermal lateral flow immunoassay (LFIA) has gained widespread use as a point-of-care testing (POCT) technique because of its cost-effective portable instrumentation and easy-to-handle procedures. However, developing a highly sensitive photothermal LFIA platform with high photothermal efficiency remains challenging. In this study, we developed a portable smartphone-based plasmonics-enhanced photothermal LFIA (PPh-LFIA) platform to improve the photothermal LFIA sensitivity by engineering plasmonic-active gold nanostars (GNS) having large-sized sharp branches. We investigated the photothermal effect using various GNS engineered to have different sizes and spike lengths of GNSs (GNS-1, GNS-2, GNS-3, and GNS-4) in order to exhibit optimal plasmonics properties. The results showed that the GNS-3 having a broad plasmon band with a plasmon maximum band at 995 nm exhibited the strongest photothermal efficiency (80 %). As a proof-of demonstration, we have employed GNS-3 for the detection of the cardiac biomarker, troponin I (cTnI), used as the model system. The results show high sensitivity with a detection limit (LOD) of 5.5 pg/mL, which was around 1000 times more sensitive than traditional colorimetric LFIA based on gold nanospheres (GNSP). To verify the applicability of the PPh-LFIA platform, cTnI was spiked into human blood serum samples, enabling the detection of cTnI with an LOD of 6.7 pg/mL. Overall, this study offers insights for nanoengineering and fine-tuning the GNS morphology to increase the photothermal efficiency, consequently improving the PPh-LFIA detection sensitivity, which makes it suitable for use as a sensitive and portable POCT tool.

Genetically programmable cell membrane-camouflaged nanoparticles for targeted combination therapy of colorectal cancer

Cell membrane-camouflaged nanoparticles possess inherent advantages derived from their membrane structure and surface antigens, including prolonged circulation in the bloodstream, specific cell recognition and targeting capabilities, and potential for immunotherapy. Herein, we introduce a cell membrane biomimetic nanodrug platform termed MPB-3BP@CM NPs. Comprising microporous Prussian blue nanoparticles (MPB NPs) serving as both a photothermal sensitizer and carrier for 3-bromopyruvate (3BP), these nanoparticles are cloaked in a genetically programmable cell membrane displaying variants of signal regulatory protein α (SIRPα) with enhanced affinity to CD47. As a result, MPB-3BP@CM NPs inherit the characteristics of the original cell membrane, exhibiting an extended circulation time in the bloodstream and effectively targeting CD47 on the cytomembrane of colorectal cancer (CRC) cells. Notably, blocking CD47 with MPB-3BP@CM NPs enhances the phagocytosis of CRC cells by macrophages. Additionally, 3BP, an inhibitor of hexokinase II (HK2), suppresses glycolysis, leading to a reduction in adenosine triphosphate (ATP) levels and lactate production. Besides, it promotes the polarization of tumor-associated macrophages (TAMs) towards an anti-tumor M1 phenotype. Furthermore, integration with MPB NPs-mediated photothermal therapy (PTT) enhances the therapeutic efficacy against tumors. These advantages make MPB-3BP@CM NPs an attractive platform for the future development of innovative therapeutic approaches for CRC. Concurrently, it introduces a universal approach for engineering disease-tailored cell membranes for tumor therapy.

Double-Enhanced Photothermal Lateral Flow Biosensor Based on Dual Gold Nanoparticle Conjugates.

Bacterial toxins emerge as the primary triggers of foodborne illnesses, posing a significant threat to human health. To ensure food safety, it is imperative to implement point-of-care testing methods. Lateral flow biosensors (LFBs) based on gold nanoparticles (GNPs) have been commonly used for rapid detection, but their applicationis limited by low sensitivity. Based on the localized surface plasmon resonance and photothermal effect of dual gold nanoparticle conjugates (DGNPs), we developed a smartphone-integrated photothermal LFB (PLFB) with double-enhanced colorimetric and photothermal sensitivity. Through numerical simulations, we verified that DGNPs have significantly enhanced photothermal performance compared to single 15 nm GNPs (SGNPs), and applied DGNPs in PLFB for the detection of staphylococcus enterotoxin A (SEA). The colorimetric and photothermal limits of detection of DGNPs-based PLFB for SEA were 0.091 and 0.0038 ng mL-1, respectively. Compared with the colorimetric detection of the SGNPs-based LFB, the colorimetric detection sensitivity of the DGNPs-based PLFB was increased by 10.7 times, and the photothermal detection sensitivity was further improved by 255.3 times. Moreover, the PLFB exhibits robust reproducibility and exceptional specificity and is applicable for detecting SEA in milk samples. This smartphone-integrated PLFB based on DGNPs allows users to detect toxins simply, conveniently, and quickly and has huge application potential in the field of food safety.

Activation of Piezo1 increases the sensitivity of breast cancer to hyperthermia therapy.

Photothermal therapy (PTT) of nanomaterials is an emerging novel therapeutic strategy for breast cancer. However, there exists an urgent need for appropriate strategies to enhance the antitumor efficacy of PTT and minimize damage to surrounding normal tissues. Piezo1 might be a promising novel photothermal therapeutic target for breast cancer. This study aims to explore the potential role of Piezo1 activation in the hyperthermia therapy of breast cancer cells and investigate the underlying mechanisms. Results showed that the specific agonist of Piezo1 ion channel (Yoda1) aggravated the cell death of breast cancer cells triggered by heat stress in vitro. Reactive oxygen species (ROS) production was significantly increased following heat stress, and Yoda1 exacerbated the rise in ROS release. GSK2795039, an inhibitor of NADPH oxidase 2 (NOX2), reversed the Yoda1-mediated aggravation of cellular injury and ROS generation after heat stress. The in vivo experiments demonstrate the well photothermal conversion efficiency of TiCN under the 1,064 nm laser irradiation, and Yoda1 increases the sensitivity of breast tumors to PTT in the presence of TiCN. Our study reveals that Piezo1 activation might serve as a photothermal sensitizer for PTT, which may develop as a promising therapeutic strategy for breast cancer.

Selective enhanced cytotoxicity of amino acid deprivation for cancer therapy using thermozyme functionalized nanocatalyst

BackgroundEnzyme therapy based on differential metabolism of cancer cells has demonstrated promising potential as a treatment strategy. Nevertheless, the therapeutic benefit of reported enzyme drugs is compromised by their uncontrollable activity and weak stability. Additionally, thermozymes with high thermal-stability suffer from low catalytic activity at body temperature, preventing them from functioning independently.ResultsHerein, we have developed a novel thermo-enzymatic regulation strategy for near-infrared (NIR)-triggered precise-catalyzed photothermal treatment of breast cancer. Our strategy enables efficient loading and delivery of thermozymes (newly screened therapeutic enzymes from thermophilic bacteria) via hyaluronic acid (HA)-coupled gold nanorods (GNRs). These nanocatalysts exhibit enhanced cellular endocytosis and rapid enzyme activity enhancement, while also providing biosafety with minimized toxic effects on untargeted sites due to temperature-isolated thermozyme activity. Locally-focused NIR lasers ensure effective activation of thermozymes to promote on-demand amino acid deprivation and photothermal therapy (PTT) of superficial tumors, triggering apoptosis, G1 phase cell cycle arrest, inhibiting migration and invasion, and potentiating photothermal sensitivity of malignancies.ConclusionsThis work establishes a precise, remotely controlled, non-invasive, efficient, and biosafe nanoplatform for accurate enzyme therapy, providing a rationale for promising personalized therapeutic strategies and offering new prospects for high-precision development of enzyme drugs.Graphical

MoS2 nanoflower-Indocyanine green composite for enhanced optical imaging capabilities

ABSTRACT To enhance the efficiency of painless targeted nanotherapies, integrating optical imaging capabilities into nanoplatforms is gaining momentum. Our study presents a cost-effective synthesis of MoS2 nanoflower (MNF) and Indocyanine green (ICG) composites (MNF-ICG) using a physical method based on van der Waals interactions. MNF, prepared via the hydrothermal method, underwent characterization through UV-vis, FTIR, and fluorescence spectroscopy, while FESEM and XRD techniques were employed to analyse morphology and structural phase. Through electrostatic interaction, ICG was absorbed onto the MNF surface. The resulting MNF-ICG demonstrated exceptionally high optical absorbance across a broad NIR spectra, facilitating longer-wavelength photothermic imaging with increased penetration depth. In comparison to MNF alone, the composite significantly enhanced the photothermal imaging sensitivity of nanoplatforms, exhibiting notable bathochromic and hyperchromic shifts in fluorescence intensity. This innovative approach holds promise for advancing nanotherapeutics with improved optical imaging capabilities.

An autocatalytic multicomponent DNAzyme nanomachine for tumor-specific photothermal therapy sensitization in pancreatic cancer

Multicomponent deoxyribozymes (MNAzymes) have great potential in gene therapy, but their ability to recognize disease tissue and further achieve synergistic gene regulation has rarely been studied. Herein, Arginylglycylaspartic acid (RGD)-modified Distearyl acylphosphatidyl ethanolamine (DSPE)-polyethylene glycol (PEG) (DSPE-PEG-RGD) micelle is prepared with a DSPE hydrophobic core to load the photothermal therapy (PTT) dye IR780 and the calcium efflux pump inhibitor curcumin. Then, the MNAzyme is distributed into the hydrophilic PEG layer and sealed with calcium phosphate through biomineralization. Moreover, RGD is attached to the outer tail of PEG for tumor targeting. The constructed nanomachine can release MNAzyme and the cofactor Ca2+ under acidic conditions and self-assemble into an active mode to cleave heat shock protein (HSP) mRNA by consuming the oncogene miRNA-21. Silencing miRNA-21 enhances the expression of the tumor suppressor gene PTEN, leading to PTT sensitization. Meanwhile, curcumin maintains high intracellular Ca2+ to further suppress HSP-chaperone ATP by disrupting mitochondrial Ca2+ homeostasis. Therefore, pancreatic cancer is triple-sensitized to IR780-mediated PTT. The in vitro and in vivo results show that the MNAzyme-based nanomachine can strongly regulate HSP and PTEN expression and lead to significant pancreatic tumor inhibition under laser irradiation.

Precise classification and regional delineation of maturity groups in soybean cultivars across China

The maturity group (MG) system is a widely recognized and effective approach for assessing the photothermal sensitivity of soybean cultivars and determining their optimal adaptation zones. In China, soybean have been cultivated extensively for thousands of years, evolving into various ecotypes through natural and artificial selection. In this study, the relative maturity groups (RMGs) of a total of 766 soybean cultivars collected from the Northeast Spring Planting Sub-region (NE), Huang-Huai-Hai Summer Planting Region (HH), Northwest Spring Planting Sub-region (NW,), and South Multiple Cropping Region (SC) of China were evaluated using linear regression models at 36 sites nationwide. The results show that the RMGs of Chinese soybean cultivars range from MG m1.6 to MG 9.5. Among all the identified soybean cultivars, MG III cultivars account for the largest proportion of 22.19 %, followed by MG II (21.67 %) and MG I (18.54 %). Conversely, MG IX has the fewest number of cultivars, representing only 0.26 % of all cultivars. The MG ranges for spring- and summer-sowing cultivars are MG 000-V and MG II-IX, respectively. The adaptive soybean MG zones across China were mapped using the method of Kriging interpolation based on the soybean RMGs data from 816 sites of 29 soybean-producing provinces. Cultivars of MG 0 and earlier groups are primarily distributed in the NE, and MG III and MG IV are the major MGs in HH and NW. The cultivars in MG V and later groups mainly distribute in SC. This study realizes the unification and normalization of the MG system between China and other major soybean- producing countries worldwide. Such unification and standardization will facilitate global germplasm exchanges and assist soybean producers in making more informed decisions when selecting cultivars.

Bio-inspired self-assembled bacteriochlorin nanoparticles for superior visualization and photothermal ablation of tumors

BackgroundAlthough hyperthermia-based photothermal therapy (PTT) has achieved great success in the battle against malignant tumors, various commonly used photothermal sensitizers still suffer from non-selective tumor accumulation, limited photothermal conversion efficiency, potential toxicity and side effects, as well as complex and low cost-effective preparation process. Therefore, novel photothermal sensitizers are urgently required. The well-organized self-assembling of natural bacteriochlorophylls with superior photothermal property may provide an interesting option for the engineering of ideal PTS. MethodsInspired by the self-assembly peripheral light-harvesting antennas of natural bacteriochlorin in microorganisms, a biomimetic light-harvesting nanosystem (Nano-Bc) was developed via bacteriochlorophylls self-arranging in aqueous phase. The characterization of Nano-Bc were measured using DLS, TEM, UV−vis−near-infrared spectroscopy and preclinical PA imaging system. The cytotoxicity of Nano-Bc was quantitatively evaluated via a standard MTT assay using mouse breast cancer 4T1 cells, and the in vivo photothermal eradication of tumor was investigated in the 4T1 breast tumor-bearing mouse model. ResultsThe obtained bacteriochlorin nanoparticles (Nano-Bc) exhibited ultra-high photothermal performance within the biological transparent window, showing superior heating capacity compared to commonly used photothermal sensitizers of organic dye indocyanine green and inorganic gold nanorods. Guiding by the inherent photoacoustic imaging of Nano-Bc, complete tumor elimination in vitro and vivo was evidenced upon laser irradiation. ConclusionThe green and facile preparation, ultra-high photothermal effect in the transparent window, excellent photoacoustic imaging capacity, and great biosafety prompt, the bio-inspired Nano-Bc as a promising theranostic platform against cancer in the areas of healthcare.

High-Affinity DNA Nanomatrix: A Platform Technology for Synergistic Drug Delivery and Photothermal Therapy.

With the advent of nucleosome/nucleotide intercalating drugs, DNA-based nanocarriers have recently gained impetus. However, most of the newly proposed DNA nanosystems are rather complex, thereby having low scalability and translatability. In this study, we propose a simple DNA nanomatrix core encapsulated within a chitosan shell, which is expected to enhance the encapsulation efficiency of intercalating drugs. This has been demonstrated using proflavine hemisulfate (PfHS), a model intercalating agent that shows improved ROS generation, among other anticancerous properties. The release of the drug from the nanomatrix is triggered by providing a heat trigger using IR-792 perchlorate, a known NIR photothermal sensitizer.

Using nanomaterials to enhance the additive manufacturing of polymeric resins

Additive manufacturing (AM) technologies, also called 3D printing, have dramatically developed over the past decade to allow new capabilities in materials processing with printed resolution comparable to that of traditional manufacturing techniques. Sequential layer deposition can lead to the creation of complex parts with minimized material waste, high manufacturing throughput, and increased prototyping ability, while also meeting the demand for mid- and low-volume production. The AM of polymer nanocomposites is a growing area of research because nanomaterial additives can enhance the mechanical, electrical, and other properties for end-use applications. However, the use of nanomaterial inclusions can also enhance the AM processes themselves. Here, we discuss works where nanomaterials are employed as local heaters for fused deposition modeling, as viscosifiers for direct ink writing, and as photothermal sensitizers for selective laser sintering and vat polymerization. We also note the disconnect between the researched AM capabilities and current industrial manufacturing; nanomaterials can bridge the technological gap and lead to new common practices in industrial manufacturing spaces.

Nanotechnology-Based Strategies for Treatment of Obesity, Cancer and Anti-microbial Resistance: Highlights of the Department of Science and Innovation/Mintek Nanotechnology Innovation Centre Biolabels Research Node at the University of the Western Cape

Nanotechnology has recently received much interest in various fields, including medicine. South Africa (SA) was the first country in Africa to adopt the technology with the aim of enhancing the national bio-economy and global competitiveness by using innovative nanotechnology-based solutions. Since its inception in 2005 in SA, researchers have seized opportunities to increase and develop niche areas for its application in the health, energy, food, agriculture, and water sectors. We ventured into this field and have performed pioneering work on nanotechnology-based treatment strategies over the years. This perspective highlights the journey, with associated successes over the years, in order to display the impact of our nanotechnology research in health. The focus is on the nanotechnology outputs that have emanated from the Department of Science and Innovation (DSI)/Mintek Nanotechnology Innovation Centre (NIC) Biolabels Research Node (BRN) at the University of the Western Cape (UWC). BRN’s research interests were on nano-enabled materials for developing therapeutic agents, photothermal sensitizers, and targeted drug-delivery systems for treatment of chronic diseases and antimicrobial resistance.

Sheet-like 2D Manganese(IV) Complex with High Photothermal Conversion Efficiency.

We report a stable, water-soluble, mononuclear manganese(IV) complex [MnIV(H2L)]·5H2O (Mn-HDCL) that acts as an efficient photothermal material. This system is based on a hexahydrazide clathrochelate ligand (L/HDCL) and is obtained via an efficient one-pot templated synthesis that avoids the need for harsh reaction conditions. Scanning tunneling microscopy images reveal that Mn-HDCL exists as a 2D sheet-like structure. In Mn-HDCL, the manganese(IV) ion is trapped within the cavity of the cage-like ligand. This effectively shields the Mn(IV) ion from the external environment while providing adequate water solubility. As a result of orbital transitions involving the coordinated manganese(IV) ion, as well as metal-to-ligand charge transfer effects, Mn-HDCL possesses a large extinction coefficient and displays a photothermal performance comparable to single-wall carbon nanotubes in the solid state. A high photothermal conversion efficiency (ca. 71%) was achieved in aqueous solution when subjected to near-infrared 730 nm laser photo-irradiation. Mn-HDCL is paramagnetic and provides a modest increase in the T1-weighted contrast of magnetic resonance images both in vitro and in vivo. Mn-HDCL was found to target tumors passively and allow tumor margins to be distinguished in vivo in a mouse model. In addition, it also exhibited an efficient laser-triggered photothermal therapy effect in vitro and in vivo. We thus propose that Mn-HDCL could have a role to play as a tumor-targeting photothermal sensitizer.

Rapid mineralization of graphene-based 3D porous scaffolds by semi-dry electrodeposition for photothermal treatment of tumor-induced bone defects

Graphene-based three-dimensional (3D) porous scaffolds have been extensively investigated in the photothermal treatment of tumor-induced bone defects due to their photothermal and osteogenic capacity. However, scaffold processing destroys conjugated graphene structure and reduces its photothermal conversion efficiency. In this study, a graphene-based 3D scaffold (GS) with intact conjugated structure was prepared by chemical vapor deposition (CVD). GS was rapidly mineralized biomimetically by a newly developed semi-dry electrochemical deposition method to form a hydroxyapatite (HA) incorporated graphene scaffold (HA-GS). The simulation of the charged particle dynamics provides a better understanding of the mechanism of semi-dry electrodeposition. This scaffold exhibits high photothermal sensitivity that generates sufficient thermal energy for photothermal therapy even under near-infrared irradiation (980 nm) with extremely low power density (0.2 W/cm2). Moreover, osteogenic activity was improved by HA-GS compared with GS. Compared with the blank GS, the HA-GS scaffold deposited with HA also showed regulation of macrophage-derived chemokine (MDC) and remodeled the immune microenvironment of the wound after photothermal therapy. In vivo experiments further verified that HA-GS can ablate osteosarcoma through a photothermal effect. These results suggest that the as-prepared HA-GS may be adopted as a promising multifunctional bone scaffold against tumor-induced bone defect. Statement of significanceThe hydroxyapatite (HA) incorporated graphene scaffold (HA-GS) scaffold was prepared by semi-dry electrodeposition first time. The prepared HA-GS has a high photothermal conversion efficiency (it can rise to 48 °C under the 5 min irradiation of 980 nm near-infrared laser at 0.2 W/cm2). The mineralized layer prepared by semi-dry electrodeposition is not only osteoinductive, but also reduces the inflammatory response after photothermal therapy. This modulates the immune microenvironment at the bone tumor invasion site, thereby promoting defect repair.

Epithelial Cell Adhesion Molecule-Functionalized Fe3O4@Au Nanoparticles for Coregistered Optoacoustic and Magnetic Resonance Imaging and Photothermal Therapy of Hepatocellular Carcinoma

Early diagnosis and management of hepatocellular carcinoma (HCC) is important for improving the 5-year survival rate. Multimodal imaging is of great significance for obtaining complementary information, improving the efficacy of tumor detection, and monitoring HCC recurrence. The rational development of targeted nanoprobes with excellent performance is of great significance for the accurate diagnosis of HCC and image-guided photothermal therapy (PTT). In the present study, we synthesized a hybrid nanoprobe containing epithelial cell adhesion molecule-functionalized Fe3O4@Au nanoparticles as an HCC-targeted nanoprobe, which served as a dual-modal contrast agent for optoacoustic tomography (OAT) and magnetic resonance imaging (MRI) and as a photothermal sensitizer for PTT. Using this nanoprobe, we evaluated the application of coregistered OAT–MRI for the diagnosis and therapy of HCC to resolve an image alignment problem. Body-position variation in OAT and MRI was minimized using a specially designed 3D-printed dual-modality animal imaging bed constructed from polylactic acid. The registration accuracy of OAT–MRI data was further improved by a robust image registration protocol. Dual-modality coregistered imaging was performed for the early diagnosis of HCC and monitoring of curative effects. To our knowledge, this is the first study to apply a combination of a targeted nanoprobe and coregistration of OAT–MRI for the diagnosis and management of abdominal diseases.

Melanin-Binding Colorants: Updating Molecular Modeling, Staining and Labeling Mechanisms, and Biomedical Perspectives

Melanin and melanoma tumors are two fields of increasing interest in biomedical research. Melanins are ubiquitous biopigments with adaptive value and multiple functions, and occur in the malignant melanoma. Although several chemical structures have been proposed for eumelanin, molecular modeling and orbitals indicate that a planar or spiral benzoquinone-porphycene polymer would be the model that better explains the broad-band light and ultrasound absorption, electric conductivity, and graphite-like organization shown by X-ray crystallography and electron microscopy. Lysosomes and melanosomes are selectively labeled by vital probes, and melanin also binds to metal cations, colorants, and drugs, with important consequences in pharmacology, pathology, and melanoma therapy. In addition to traditional and recent oncologic treatments, photodynamic, photothermal, and ultrasound protocols represent novel modalities for melanoma therapy. Since eumelanin is practically the ideal photothermal and ultrasound sensitizer, the vibrational decay from photo-excited electrons after NIR irradiation, or the electrochemical production of ROS and radicals after ultrasound absorption, induce an efficient heating or oxidative response, resulting in the damage and death of tumor cells. This allows repetitive treatments due to the remaining melanin contained in tumoral melanophages. Given that evolution and prognosis of the advanced melanoma is still a concern, new biophysical procedures based on melanin properties can now be developed and applied.