Iron oxide@chlorophyll clustered nanoparticles eliminate bladder cancer by photodynamic immunotherapy-initiated ferroptosis and immunostimulation

The escape of bladder cancer from immunosurveillance causes monotherapy to exhibit poor efficacy; therefore, designing a multifunctional nanoparticle that boosts programmed cell death and immunoactivation has potential as a treatment strategy. Herein, we developed a facile one-pot coprecipitation reaction to fabricate cluster-structured nanoparticles (CNPs) assembled from Fe₃O₄ and iron chlorophyll (Chl/Fe) photosensitizers. This nanoassembled CNP, as a multifunctional theranostic agent, could perform red-NIR fluorescence and change the redox balance by the photoinduction of reactive oxygen species (ROS) and attenuate iron-mediated lipid peroxidation by the induction of a Fenton-like reaction. The intravesical instillation of Fe₃O₄@Chl/Fe CNPs modified with 4-carboxyphenylboronic acid (CPBA) may target the BC wall through glycoproteins in the BC cavity, allowing local killing of cancer cells by photodynamic therapy (PDT)-induced singlet oxygen and causing chemodynamic therapy (CDT)-mediated ferroptosis. An interesting possibility is reprogramming of the tumor microenvironment from immunosuppressive to immunostimulatory after PDT-CDT treatment, which was demonstrated by the reduction of PD-L1 (lower “off” signal to the effector immune cells), IDO-1, TGF-β, and M2-like macrophages and the induction of CD8⁺ T cells on BC sections. Moreover, the intravesical instillation of Fe₃O₄@Chl/Fe CNPs may enhance the large-area distribution on the BC wall, improving antitumor efficacy and increasing survival rates from 0 to 91.7%. Our theranostic CNPs not only demonstrated combined PDT-CDT-induced cytotoxicity, ROS production, and ferroptosis to facilitate treatment efficacy but also opened up new horizons for eliminating the immunosuppressive effect by simultaneous PDT-CDT.

The Current Understanding of Autophagy in Nanomaterial Toxicity and Its Implementation in Safety Assessment-Related Alternative Testing Strategies

Nanotechnology has rapidly promoted the development of a new generation of industrial and commercial products; however, it has also raised some concerns about human health and safety. To evaluate the toxicity of the great diversity of nanomaterials (NMs) in the traditional manner, a tremendous number of safety assessments and a very large number of animals would be required. For this reason, it is necessary to consider the use of alternative testing strategies or methods that reduce, refine, or replace (3Rs) the use of animals for assessing the toxicity of NMs. Autophagy is considered an early indicator of NM interactions with cells and has been recently recognized as an important form of cell death in nanoparticle-induced toxicity. Impairment of autophagy is related to the accelerated pathogenesis of diseases. By using mechanism-based high-throughput screening in vitro, we can predict the NMs that may lead to the generation of disease outcomes in vivo. Thus, a tiered testing strategy is suggested that includes a set of standardized assays in relevant human cell lines followed by critical validation studies carried out in animals or whole organism models such as C. elegans (Caenorhabditis elegans), zebrafish (Danio rerio), and Drosophila (Drosophila melanogaster)for improved screening of NM safety. A thorough understanding of the mechanisms by which NMs perturb biological systems, including autophagy induction, is critical for a more comprehensive elucidation of nanotoxicity. A more profound understanding of toxicity mechanisms will also facilitate the development of prevention and intervention policies against adverse outcomes induced by NMs. The development of a tiered testing strategy for NM hazard assessment not only promotes a more widespread adoption of non-rodent or 3R principles but also makes nanotoxicology testing more ethical, relevant, and cost- and time-efficient.

Encapsulation of Au/Fe3O4 nanoparticles into a polymer nanoarchitecture with combined near infrared-triggered chemo-photothermal therapy based on intracellular secondary protein understanding

The combination of the functions of near infrared-triggered molecule release and chemo-photothermal therapy improved the therapeutic effect, but clarification of the cancer damage pathway in terms of protein molecule levels has yet to be well studied. In this study, we developed a polymer encapsulation synthesis of Au/Fe₃O₄@polymer nanoparticles as a Swiss army knife to integrate near infrared absorption, magnetism, and doxorubicin (DOX) loading ability into a single package. By exposing to near infrared absorption, the Au/Fe₃O₄@polymer nanoparticles possessed photothermal therapy, exhibiting anti-tumor growth suppression of HT-29 tumor-bearing nude mice with less body weight loss. To deeply understand the interactions between the drug-loaded nanocarriers and the protein structures of the treated cells, delivering therapeutic DOX agent combined with photothermal therapy with Au/Fe₃O₄@polymer nanostructures to cancer cells was investigated. Synchrotron-based FTIR imaging and confocal imaging showed direct observation of the efficient photo-chemotherapy impacting MCF7, MCF7/ADR, and HT-29 cells after the near infrared radiation-triggered DOX release. Our demonstration outlines how the cell destruction in the molecular mechanism was initiated by chemo-photothermal combination therapy after the translocation of DOX from the cytosol to the nuclei, leading to altered intracellular secondary proteins. For preclinical application of potential diagnosis to cancer cells, Au/Fe₃O₄@polymer nanoparticles performed integrated computed tomography/magnetic resonance imaging contrast enhancement and near infrared-triggered chemo-photothermal therapy.

Degradable NIR-PTT Nanoagents with a Potential Cu@Cu2O@Polymer Structure

Cu@Cu₂O@PSMA polymer nanoparticles (Cu@Cu₂O@polymer NPs) with near-infrared (NIR) absorption were successfully synthesized in a single-step oxidation reaction of Cu@PSMA polymer NPs at 100 °C for 20 min. The shape, structure, and optical properties of the Cu@Cu₂O@polymer NPs were tailorable by controlling the reaction parameters, for example, using the initial Cu@PSMA polymer NP as a template and varying the halide ion content, heating temperature, and reaction time. The Cu@Cu₂O@polymer NPs exhibited robust NIR absorption between 650 and 710 nm and possessed superior oxidation resistance in water and culture media. In vitro assays demonstrated the low cytotoxicity of the Cu@Cu₂O@PSMA polymer NPs to HeLa cells through an improved cell viability, high IC₅₀, low injury incidence from the supernatant of the partly dissociated Cu@Cu₂O@PSMA polymer NPs, and minor generation of reactive oxygen species. More importantly, we demonstrated that the inorganic Cu-based nanocomposite [+0.34 V vs normal hydrogen electrode (NHE)] was degradable in an endogenous H₂O₂ (+1.78 V vs NHE) environment. Cu ions were detected in the urine of mice, which illustrates the possibility of extraction after the degradation of the Cu-based particles. 'After an treatment of the HeLa cells with the Cu@Cu₂O@polymer NPs and a 660 nm light-emitting diode, the photoablation of 50 and 90% cells was observed at NP doses of 20 and 50 ppm, respectively. These results demonstrate that NIR-functional and moderate redox-active Cu@Cu₂O@polymer NPs are potential next-generation photothermal therapy (PTT) nanoagents because of combined features of degradation resistance in the physiological environment, enabling the delivery of efficient PTT, a possibly improved ability to selectively harm cancer cells by releasing Cu ions under high-H₂O₂ and/or low-pH conditions, and ability to be extracted from the body after biodegradation.

Fabrication of Anisotropic Cu Ferrite-Polymer Core-Shell Nanoparticles for Photodynamic Ablation of Cervical Cancer Cells

In this work we developed methylene blue-immobilized copper-iron nanoparticles (MB-CuFe NPs) through a facile one-step hydrothermal reaction to achieve a better phototherapeutic effect. The Fe/Cu ratio of the CuFe NPs was controllable by merely changing the loading amount of iron precursor concentration. The CuFe NPs could serve as a Fenton catalyst to convert hydrogen peroxide (H2O2) into reactive oxygen species (ROS), while the superparamagnetic properties also suggest magnetic resonance imaging (MRI) potential. Furthermore, the Food and Drug Administration (FDA)-approved MB photosensitizer could strongly adsorb onto the surface of CuFe NPs to facilitate the drug delivery into cells and improve the photodynamic therapy at 660 nm via significant generation of singlet oxygen species, leading to enhanced cancer cell-damaging efficacy. An MTT (thiazolyl blue tetrazolium bromide) assay proved the low cytotoxicity of the CuFe NPs to cervical cancer cells (HeLa cells), namely above 80% at 25 ppm of the sample dose. A slight dissolution of Cu and Fe ions from the CuFe NPs in an acidic environment was obtained, providing direct evidence for CuFe NPs being degradable without the risk of long-term retention in the body. Moreover, the tremendous photo-to-thermal conversion of CuFe NPs was examined, which might be combined with photodynamic therapy (PDT) for promising development in the depletion of cancer cells after a single pulse of deep-red light irradiation at high laser power.

Keratin-Based Nanoparticles with Tumor-Targeting and Cascade Catalytic Capabilities for the Combinational Oxidation Phototherapy of Breast Cancer

Photodynamic therapy (PDT) holds tantalizing prospects of a prominent cancer treatment strategy. However, its efficacy remains limited by virtue of the hypoxic tumor microenvironment and the inadequate tumor-targeted delivery of photosensitizers, and these can be further exacerbated by the lack of development of a well-controlled nitric oxide (NO) release system at the target site. Inspired by Chinese medicine, we propose a revealing new keratin application. Keratin has garnered attention as an NO generator; however, its oncological use has rarely been investigated. We hypothesized that the incorporation of a phenylboronic acid (PBA) targeting ligand/methylene blue (MB) photosensitizer with a keratin NO donor would facilitate precise tumor delivery, enhancing PDT. Herein, we demonstrated that MB@keratin/PBA/d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) nanoparticles (MB@KPTNPs) specifically targeted breast cancer cells and effectively suppressed their growth. Through MB-mediated biometabolism, the endocytic MB@KPTNPs produced a sufficient amount of intracellular NO that reduced the glutathione level while boosting the efficiency of PDT. A therapeutic combination of NO/PDT was therefore achieved, resulting in significant inhibition of both in vivo tumor growth and lung metastasis. These findings underscore the importance of utilizing keratin-based nanoparticles that simultaneously combine targeting of the tumor and self-generating NO with a cascading catalytic ability as a novel oxidation therapeutic strategy for enhancing PDT.

Development of Folic Acid-Conjugated and Methylene Blue-Adsorbed Au@TNA Nanoparticles for Enhanced Photodynamic Therapy of Bladder Cancer Cells

Photodynamic therapy (PDT) is a promising treatment for malignancy. However, the low molecular solubility of photosensitizers (PSs) with a low accumulation at borderline malignant potential lesions results in the tardy and ineffective management of recurrent urothelial carcinoma. Herein, we used tannic acid (TNA), a green precursor, to reduce HAuCl4 in order to generate Au@TNA core-shell nanoparticles. The photosensitizer methylene blue (MB) was subsequently adsorbed onto the surface of the Au@TNA nanoparticles, leading to the incorporation of a PS within the organic shell of the Au nanoparticle nanosupport, denoted as Au@TNA@MB nanoparticles (NPs). By modifying the surface of the Au@TNA@MB NPs with the ligand folate acid (FA) using NH2-PEG-NH2 as a linker, we demonstrated that the targeted delivery strategy achieved a high accumulation of PSs in cancer cells. The cell viability of T24 cells decreased to 87.1%, 57.1%, and 26.6% upon treatment with 10 ppm[Au] Au@TNA/MB NPs after 45 min, 2 h, and 4 h of incubation, respectively. We also applied the same targeted PDT treatment to normal urothelial SV-HUC-1 cells and observed minor phototoxicity, indicating that this safe photomedicine shows promise for applications aiming to achieve the local depletion of cancer sites without side effects.

Plasmonic metallic nanostructures by direct nanoimprinting of gold nanoparticles

We demonstrated the plasmonic metallic nanostructure fabricated by direct nanoimprinting of gold nanoparticles (AuNPs). This approach combines the patterning and lift-off processes into a simple one-step process without the need for expensive patterning lithographies and the stringent requirement of the lift-off process for nanostructures. Good imprinting integrity was accomplished with a negligible residual layer. The dynamic optical responses of the imprinted gold pillars from AuNPs to the bulk material during the annealing process were investigated. The localized surface plasmon resonance (LSPR) properties of AuNPs or gold pillar arrays can be controlled and tuned during the annealing process. The sensitivity of the gold pillar array in terms of the wavelength shift per refractive index unit (RIU) reached 259 nm/RIU. The size of the imprinted gold pillars is highly scalable in our process. The corresponding resonance wavelengths can be widely tuned from the visible to infrared region by changing the size of the gold pillars, thus providing a wide range of sensing capability.

Photoluminescence enhancement with all-dielectric coherent metasurfaces

Mie resonances have recently attracted much attention in research on dielectric metasurfaces, owning to their enriched multipole resonances, negligible optical loss, and efficient light emitter integration. Although there is a rapid advancement in this field, some fundamental developments are still required to provide a simpler and more versatile paradigm for photoluminescence (PL) control. In this work, we proposed that an all-dielectric coherent metasurface can engineer the PL response by tuning the array size. Such PL manipulation is attributed to the collective Mie resonances that mediate the inter-unit interactions between unit elements and alter the PL intensity. Metasurfaces with different chip sizes are utilized to explore the array size effect on the collective Mie resonances, field enhancement, and Q-factor in TiO2 metasurfaces. Incorporating the all-dielectric coherent metasurface with fluorescent photon emitters, we performed the dependence of PL enhancement on array size, which achieves an enhancement factor of ∼10 at the central area of a 90 × 90 μm2 TiO2 metasurface array. These findings provide an additional degree of freedom to engineer the near-field confinement and enhancement, allowing one to manipulate incoherent photon emission and tune light-matter interaction at the nanoscale.

Sb(2)O(3) nanobelt networks for excellent visible-light-range photodetectors

Excellent photoconductive properties have been found in Sb(2)O(3) nanobelts synthesized by a surfactant-assisted solvothermal method. Visible-light photodetectors have been designed from Sb(2)O(3) nanobelt networks using micrometer-wide gold wires as masks. Photodetectors show high sensitivity to visible light, high stability, and reproducibility. Fast response and decay times (<0.3 s) are comparable or even better than these parameters in many other metal oxide nanoscale photodetectors. The dominant mechanism of excellent photoconductivity is attributed to the barrier height modulations in the nanobelt-to-nanobelt contact regions. These results demonstrate that Sb(2)O(3) nanobelt networks can indeed serve as high-performance photodetectors in the visible light range.

Providing instrumental social support is more beneficial to reduce mortality risk among the elderly with low educational level in Taiwan: a 12-year follow-up national longitudinal study

BACKGROUND

To evaluate whether the effects of providing or receiving social support are more beneficial to reduce mortality risk among the elderly with different educational levels.

METHODS

In this long-term prospective cohort study, data were retrieved from the Taiwan Longitudinal Study on Aging. This study was initiated from 1996 until 2007. The complete data from 1492 males and 1177 females aged ≥67 years were retrieved. Participants received financial, instrumental, and emotional support, and they actively provided instrumental and emotional support to others and involved in social engagement. Education attainment was divided into two levels: high and low. The low education level included illiterate and elementary school. The high education level included junior high school to senior high school and above college. Cox regression analysis was used to examine the association between providing or receiving social support on mortality with different educational levels.

RESULTS

The average age of the participants in 1996 was 73.0 (IQR=8.0) years, and the median survival following years (1996-2007) of participants was 10.3 (IQR=6.7) years. Most participants were low educational level including illiterate (39.3%) and elementary school (41.2%). Participants with high educational level tend to be younger and more male significantly. On the contrary, participants with low educational level tend to have significant more poor income, more depression, more cognition impairment, more with IADL and ADL disability than high educational level. Most participants received instrumental support from others (95.5%) and also provided emotional support to others (97.7%). Providing instrumental support can reduce 17% of mortality risk among the elderly with a low level of education after adjusting several covariates [Hazard ratio (HR) = 0.83; 95% confidence interval (CI) = 0.70-0.99; p = 0.036].

CONCLUSIONS

Providing instrumental social support to others confer benefits to the giver and prolong life expectancy among the elderly with low educational levels.

Surfactant-Free Green Synthesis of Au@Chlorophyll Nanorods for NIR PDT-Elicited CDT in Bladder Cancer Therapy

The facile and straightforward fabrication of NIR-responsive theranostic materials with high biocompatibility is still an unmet need for nanomedicine applications. Here, we used a natural photosensitizer, iron chlorophyll (Chl/Fe), for the J-aggregate template-assisted synthesis of Au@Chl/Fe nanorods with high stability. The assembly of a high amount of Chl/Fe J-aggregate onto the Au surface enabled red-NIR fluorescence for monitoring and tracking residential tumor lesions. The Chl/Fe moieties condensed on the nanorods could change the redox balance by the photon induction of reactive oxygen species and attenuate iron-mediated lipid peroxidation by inducing a Fenton-like reaction. After conjugation with carboxyphenylboronic acid (CPBA) to target the glycoprotein receptor on T24 bladder cancer (BC) cells, the enhanced delivery of Au@Chl/Fe-CPBA nanorods could induce over 85% cell death at extremely low concentrations of 0.16 ppm_[Au] at 660 nm and 1.6 ppm_[Au] at 785 nm. High lipid peroxidation, as shown by BODIPY staining and GSH depletion, was observed when treated T24 cells were exposed to laser irradiation, suggesting that preliminary photodynamic therapy (PDT) can revitalize Fenton-like reaction-mediated chemodynamic ferroptosis in T24 cells. We also manipulated the localized administration of Au@Chl-Fe combined with PDT at restricted regions in orthotopic tumor-bearing mice to cure malignant BC successfully without recurrence. By intravesical instillation of the Au@Chl/Fe-CPBA nanorods, this localized treatment could prevent the material from entering the systemic circulation, thus minimizing systemic toxicity. Upon activating NIR-PDT-elicited chemodynamic therapy, ultrasound imaging revealed almost complete tumor remission. Anti-tumor efficacy and survival benefit were achieved with a green photosensitizer.

In Situ Creation of Surface-Enhanced Raman Scattering Active Au-AuO x Nanostructures through Electrochemical Process for Pigment Detection

Roughing the metallic surface via oxidation-reduction cycles (ORC) to integrate the surface plasmon resonance and surface-enhanced Raman scattering (SERS) is predominant in developing sensor systems because of the facile preparation and uniform distribution of nanostructures. Herein, we proposed a distinctive ORC process: the forward potential passed through the oxidation of Au and reached the oxygen evolution reaction, and once the potential briefly remained at the vertex, the various reverse rates were employed to control the reduction state. The created hybrid Au-AuO _x possessed electromagnetic and chemical enhancements concurrently, wherein the rough surface provided the strong local electromagnetic fields and significant interaction between AuO _x and molecule to improve the charge transfer. The synergistic effects significantly amplified the intensity of Raman signal with an enhancement factor of 5.5 × 10⁶ under the optimal conditions. Furthermore, the prepared SERS substrate can simultaneously identify and quantify the mixed edible pigments, Brilliant Blue FCF and Indigo Carmine, individually. This result suggested that the development of SERS sensor based on the proposed SERS-activated methodology is feasible and reliable.

Nanoparticles augment the therapeutic window of RT and immunotherapy for treating cancers: pivotal role of autophagy

Immunotherapies are now emerging as an efficient anticancer therapeutic strategy. Cancer immunotherapy utilizes the host's immune system to fight against cancer cells and has gained increasing interest due to its durable efficacy and low toxicity compared to traditional antitumor treatments, such as chemotherapy and radiotherapy (RT). Although the combination of RT and immunotherapy has drawn extensive attention in the clinical setting, the overall response rates are still low. Therefore, strategies for further improvement are urgently needed. Nanotechnology has been used in cancer immunotherapy and RT to target not only cancer cells but also the tumor microenvironment (TME), thereby helping to generate a long-term immune response. Nanomaterials can be an effective delivery system and a strong autophagy inducer, with the ability to elevate autophagy to very high levels. Interestingly, autophagy could play a critical role in optimal immune function, mediating cell-extrinsic homeostatic effects through the regulation of danger signaling in neoplastic cells under immunogenic chemotherapy and/or RT. In this review, we summarize the preclinical and clinical development of the combination of immunotherapy and RT in cancer therapy and highlight the latest progress in nanotechnology for augmenting the anticancer effects of immunotherapy and RT. The underlying mechanisms of nanomaterial-triggered autophagy in tumor cells and the TME are discussed in depth. Finally, we suggest the implications of these three strategies combined together to achieve the goal of maximizing the therapeutic advantages of cancer therapy and show recent advances in biomarkers for tumor response in the evaluation of those therapies.

Postnatal development of 11beta-hydroxysteroid dehydrogenase type 1 in the rat hippocampus

Glucocorticoids (GCs) have important actions in the hippocampus of the brain, where their access to glucocorticoid receptor (GR) is increased by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). 11beta-HSD1 converts biologically inactive 11-dehydrocorticosterone into active corticosterone. However, the postnatal development of 11beta-HSD1 in the hippocampus is not properly understood. In this study, the postnatal distribution and development of 11beta-HSD1 in the hippocampus of the rat brain was studied with immunohistochemistry and Western blot analysis. Results showed that abundant 11beta-HSD1 immunoreactive substance (ir-11beta-HSD1) was present in the hippocampus. There were homogeneous distributions of 11beta-HSD1 in the hippocampal CA1, CA2, CA3, CA4 regions and the dentate gyrus at postnatal days 1, 3, and 7. Interestingly, the developmental distribution of GR in the hippocampus followed the same pattern as 11beta-HSD1. Western blot analysis demonstrated that a higher level of expression of 11beta-HSD1 in the hippocampus was found in the first 2 weeks of life. The expressions of 11beta-HSD1 started to drop to adult levels at about postnatal day 15 both in the hippocampus and in other brain areas. These results suggest that the higher expression of 11beta-HSD1 in the neonatal hippocampus may be important for the maturation of the central nervous system mediated by GCs through GR.

Theranostic doxorubicin encapsulated FeAu alloy@metal-organic framework nanostructures enable magnetic hyperthermia and medical imaging in oral carcinoma

Metal-organic frameworks (MOFs) have emerged as attractive candidates in cancer theranostics due to their ability to envelop magnetic nanoparticles, resulting in reduced cytotoxicity and high porosity, enabling chemodrug encapsulation. Here, FeAu alloy nanoparticles (FeAu NPs) are synthesized and coated with MIL-100(Fe) MOFs to fabricate FeAu@MOF nanostructures. We encapsulated Doxorubicin within the nanostructures and evaluated the suitability of this platform for medical imaging and cancer theranostics. FeAu@MOF nanostructures (FeAu@MIL-100(Fe)) exhibited superparamagnetism, magnetic hyperthermia behavior and displayed DOX encapsulation and release efficiency of 69.95 % and 97.19 %, respectively, when stimulated with alternating magnetic field (AMF). In-vitro experiments showed that AMF-induced hyperthermia resulted in 90 % HSC-3 oral squamous carcinoma cell death, indicating application in cancer theranostics. Finally, in an in-vivo mouse model, FeAu@MOF nanostructures improved image contrast, reduced tumor volume by 30-fold and tumor weight by 10-fold, which translated to enhancement in cumulative survival, highlighting the prospect of this platform for oral cancer treatment.

Lung radiodensity along the needle passage is a quantitative predictor of pneumothorax after CT-guided percutaneous core needle biopsy

AIM

To analyse whether the lowest value of lung radiodensity along the passage of the biopsy needle is a quantitative predictor of pneumothorax.

MATERIALS AND METHODS

CT-guided percutaneous core needle biopsy (PCNB) procedures performed at Zhongnan Hospital were analysed retrospectively. Age, gender, lesion size, lesion depth, lesion location, patient position, number of passages, needle pleural angle, pulmonary bleeding, and lung radiodensity along the needle passage were collected and classified by the extent of pneumothorax. Univariate analysis and multiple logistic regression analysis were assessed to explore the independent risk factors for pneumothorax.

RESULTS

Six hundred and seventy-seven cases were included in the study, including 456 males and 221 females. Pneumothorax occurred in 40.18% of cases, of which 82.4% were mild, 14% were moderate, and 3.7% were severe. Univariate and multivariate analysis showed that lesion size ≤2 cm (p=0.002), two or more passages (p=0.033), and lung radiodensity of -850 HU or less (p≤0.001) were independent risk factors for pneumothorax; bleeding (p<0.001) was a protective factor for pneumothorax.

CONCLUSIONS

The lowest value of lung radiodensity along the needle passage was a quantitative predictor of pneumothorax. A value of -850 HU or less was an independent risk factor for pneumothorax. As the value decreased, there was a higher risk of occurrence of more severe pneumothorax.

AI-Assisted Fusion of Scanning Electrochemical Microscopy Images Using Novel Soft Probe

Scanning electrochemical microscopy (SECM) is one of the scanning probe techniques that has attracted considerable attention because of its ability to interrogate surface morphology or electrochemical reactivity. However, the quality of SECM images generally depends on the sizes of the electrodes and many uncontrollable factors. Furthermore, manipulating fragile glass ultramicroelectrodes and blurred images sometimes frustrate researchers. To overcome the challenges of modern SECM, we developed novel soft gold probes and then established the AI-assisted methodology for image fusion. A novel gold microelectrode probe with high softness was developed to scan fragile samples. The distribution of EGFR (protein biomarker) in oral cancer was investigated. Then, we fused the optical microscopic and SECM images to enhance the image quality using Matlab software. However, thousands of fused images were generated by changing the parameters for image fusion, which is annoying for researchers. Thus, a deep learning model was built to select the best-fused images according to the contrast and clarity of the fused images. Therefore, the quality of the SECM images was improved using a novel soft probe and combining the image fusion technique. In the future, a new scanning probe with AI-assisted fused SECM image processing may be interpreted more preciously and contribute to the early detection of cancers.

Charge Carrier Dynamics of CsPbBr3/g-C3N4 Nanoheterostructures in Visible-Light-Driven CO2-to-CO Conversion

The photon energy-dependent selectivity of photocatalytic CO₂-to-CO conversion by CsPbBr₃ nanocrystals (NCs) and CsPbBr₃/g-C₃N₄ nanoheterostructures (NHSs) was demonstrated for the first time. The surficial capping ligands of CsPbBr₃ NCs would adsorb CO₂, resulting in the carboxyl intermediate to process the CO₂-to-CO conversion via carbene pathways. The type-II energy band structure at the heterojunction of CsPbBr₃/g-C₃N₄ NHSs would separate the charge carriers, promoting the efficiency in photocatalytic CO₂-to-CO conversion. The electron consumption rate of CO₂-to-CO conversion for CsPbBr₃/g-C₃N₄ NHSs was found to intensively depend on the rate constant of interfacial hole transfer from CsPbBr₃ to g-C₃N₄. An in situ transient absorption spectroscopy investigation revealed that the half-life time of photoexcited electrons in optimized CsPbBr₃/g-C₃N₄ NHS was extended two times more than that in the CsPbBr₃ NCs, resulting in the higher probability of charge carriers to carry out the CO₂-to-CO conversion. The current work presents important and novel insights of semiconductor NHSs for solar energy-driven CO₂ conversion.

Discontinuity-Enhanced Thin Film Electrocatalytic Oxygen Evolution

Thin film electrocatalysts allow strong binding and intimate electrical contact with electrodes, rapid mass transfer during reaction, and are generally more durable than powder electrocatalysts, which is particularly beneficial for gas evolution reactions. In this work, using cobalt manganese oxyhydroxide, an oxygen evolution reaction (OER) electrocatalyst that can be grown directly on various electrodes as a model system, it is demonstrated that breaking a continuous film into discontinuous patches can significantly enhance the overall OER performance without sacrificing long-term stability even under elevated electrocatalytic stress. Discontinuous films with higher edge-to-area ratios exhibits reduced overpotentials, increased turnover frequency, and more pronounced current increase after electrochemical conditioning. Operando Raman spectroscopy studies during electrocatalysis reveal that the film edges require lower potential barrier for activation. Introducing discontinuity into thin film electrocatalysis can thus lead to the realization of high performance yet highly robust systems for harsh gas evolution reactions.

In situ probing the dynamic reconstruction of copper-zinc electrocatalysts for CO2 reduction

Unravelling the dynamic characterization of electrocatalysts during the electrochemical CO₂ reduction reaction (CO₂RR) is a critical factor to improve the production efficiency and selectivity, since most pre-electrocatalysts undergo structural reconstruction and surface rearrangement under working conditions. Herein, a series of pre-electrocatalysts including CuO, ZnO and two different ratios of CuO/ZnO were systematically designed by a sputtering process to clarify the correlation of the dynamic characterization of Cu sites in the presence of Zn/ZnO and the product profile. The evidence provided by in situ X-ray absorption spectroscopy (XAS) indicated that appropriate Zn/ZnO levels could induce a variation in the coordination number of Cu sites via reversing Ostwald ripening. Specifically, the recrystallized Cu site with a lower coordination number exhibited a preferential production of methane (CH₄). More importantly, our findings provide a promising approach for the efficient production of CH₄ by in situ reconstructing Cu-based binary electrocatalysts.