Exosome-Coated 10B Carbon Dots for Precise Boron Neutron Capture Therapy in a Mouse Model of Glioma In Situ

Novel boron-containing carbon dots (BCDs) are designed and prepared for boron neutron capture therapy (BNCT) with superior water solubility and excellent optical property for tracking ¹⁰B in vitro and in vivo. Encapsulation of BCDs using exosomes (Exos) from macrophages yields BCD–Exos of ≈100 nm. Fluorescent imaging shows that the BCD–Exos are internalized and distributed around the nuclei of U-87-MG glioma cells. BCD–Exos are also verified to cross the blood–brain barrier and significant accumulation in tumor tissue of the orthotopic U-87-MG glioma tumor-bearing mice model 4 h after administration. Using inductively coupled plasma mass spectrometry (ICP-MS), it is detected that ¹⁰B in tumor tissue is 107.07 ± 1.58 ppm, and T/N ratios are enhanced from 2.03 ± 0.08 of boron phenylalanine (BPA) to 5.28 ± 0.29 of the BCD–Exos. In BNCT, the neutron radiation dose is 8.40 ± 0.12 Gy when a 500 mg kg^{−1 10}B dosage is given. Finally, there is a prominent BNCT effect of the BCD–Exos-treated brain glioma in the mice model, and the survival ratio is 100% at the end of the experiment. The excellent curative effect of BNCT using BCD–Exos to brain glioma is achieved through adjusted biodistribution of boron in the cancer cell, enhanced T/N ratios, and the precise match between boron and neutron exposure in the site of the tumor in vivo with fluorescence imaging of BCD–Exos.     

Bioactive Bacteria/MOF Hybrids Can Achieve Targeted Synergistic Chemotherapy and Chemodynamic Therapy against Breast Tumors

The hypoxic tumor microenvironment (TME) significantly affects cancer treatment. Conventional chemotherapeutic agents cannot effectively target hypoxic tumor tissue, which decreases efficacy and results in severe toxic side effects. To alleviate this problem, a self-driving biomotor is developed by functionalizing MCDP nanoparticles containing calcium peroxide and doxorubicin (DOX) loaded onto polydopamine-coated metal–organic frameworks（MOF）, with the anaerobic Bifidobacterium infantis (Bif) for synergistic chemotherapy and chemodynamic therapy (CDT) against breast cancer. The materials of institute Lavoisier (MIL) frameworks + CaO₂ + DOX + polydopamine (MCDP)@Bif biohybrid actively targets hypoxic regions of solid tumors via the inherent targeting ability of Bif. Once it has accumulated in the tumor tissue, MCDP generates hydroxyl radicals through the enhanced Fenton-type reactions between Fe²⁺ and self-generated hydrogen peroxide in the acidic TME. The disruption of Ca²⁺ homeostasis and resulting mitochondrial Ca²⁺ overload triggers apoptosis and enhances oxidative stress, promoting tumor cell death. The results found that the DOX concentration in MCDP@Bif-treated tumors is 3.8 times higher than that in free-DOX-treated tumors, which significantly prolongs the median survival of the tumor-bearing mice to 69 days and reduces the toxic side effects of DOX. Therefore, the novel bacteria-driven drug delivery system is highly effective in achieving synergistic chemotherapy and CDT against solid tumors.     

Size Switchable Nanoclusters Fueled by Extracellular ATP for Promoting Deep Penetration and MRI‐Guided Tumor Photothermal Therapy

Protein‐based theranostic agents (PBTAs) exhibit superior performance in the diagnosis and therapy of cancers. However, the in vivo applications of PBTA are largely limited by undesired accumulation, penetration, or selectivity. Here, an ATP‐supersensitive protein cluster is fabricated for promoting PBTA delivery and enhancing magnetic resonance imaging (MRI)‐guided tumor photothermal therapy. Gd³⁺‐ and CuS‐coloaded small bovine serum albumin nanoparticles (GdCuB) are synthesized as the model protein with a size of 9 nm and are encapsulated into charge switchable polycations (DEP) to form DEP/GdCuB nanoclusters of 120 nm. In blood circulation, DEP/GdCuB significantly extends the half‐lifetime and thereby enhances the tumor accumulation of GdCuB. When the clusters reach the tumor site, the extracellular adenosine triphosphate (ATP) can effectively trigger the release of GdCuB, resulting in tumoral deep penetration as well as the activation of T₁‐weighted MRI (r₁ value switched from 2.8 × 10^?3 to 11.8 × 10^?3 m ^?1 s^?1). Furthermore, this delivery strategy also improves the tumoral photothermal therapy efficacy with the MRI‐guided therapy. The study of ATP‐activated nanoclusters develops a novel strategy for tumor deep penetration and on/off imaging of PBTA by size switchable technology, and reveals the potential for MRI‐guided therapy of cancers.     

Mesoporous Polydopamine Carrying Manganese Carbonyl Responds to Tumor Microenvironment for Multimodal Imaging‐Guided Cancer Therapy

Multifunctional nanodrugs integrating multiple therapeutic and imaging functions may find tremendous biomedical applications. However, the development of a simple yet potent theranostic nanosystem with a high payload and microenvironment responsiveness enhancing imaging‐guided cancer therapy is still a great challenge. Herein, a kind of MnCO‐entrapped mesoporous polydopamine nanoparticles are developed, which reach a 1.5 mg payload per gram carrier and exhibit marked theranostic capability through effective CO/Mn²⁺ generation and photothermal conversion inside the H⁺ and H₂O₂‐enriched tumor microenvironment, for a magnetic resonance/photoacoustic bimodal imaging‐guided tumor therapy. The multifunctional nanosystem exhibits a biocompatibility highly desirable for in vivo application and superior performance in inhibiting tumor growth and recurrence via combination CO and photothermal therapy.     

A Laser Synthesis Route to Boron-Doped Gold Nanoparticles Designed for X-Ray Radiotherapy and Boron Neutron Capture Therapy Assisted by CT Imaging

New multifunctional theranostic vectors allow the expansion of cancer therapeutic approaches toward scarcely investigated fields. One example is the combination of boron neutron capture therapy (BNCT) and X-ray radiotherapy (XRT) for treating normal and XRT-resistant hypoxic tumor regions and reduce recurrence. Of great relevance for BNCT is also the support of viable, rapid, safe, and reliable techniques for the localization and quantification of the radiosensitizers in the tissues. To address these challenges, polymer-coated Au-B nanoparticles (NPs) are obtained starting from a laser ablation in liquid process. Despite thermodynamic constraints, the two elements coexist by short-range boron segregation in the gold lattice, as demonstrated experimentally and explained with the support of density functional theory calculations. Thus, the Au-B NPs maintain a marked gold character such as biocompatibility, stability, and straightforward surface chemistry with thiolated compounds, desirable for the integration with agents capable of cell targeting and internalization. Overall, the Au-B NPs exhibit the appropriate features for the investigation of combined BNCT and XRT, supported by the localization and quantification with X-ray computed tomography imaging. Besides, the Au-B nanotechnology tool is achievable without renouncing to reproducibility, environmental sustainability, and cost affordability thanks to the laser-assisted synthetic pathway.     

Ultrasmall Semiconducting Polymer Dots with Rapid Clearance for Second Near‐Infrared Photoacoustic Imaging and Photothermal Cancer Therapy

Phototheranostic agents in the second near‐infrared (NIR‐II) window (1000–1700 nm) are emerging as a promising theranostic platform for precision medicine due to enhanced penetration depth and minimized tissue exposure. The development of metabolizable NIR‐II nanoagents for imaging‐guided therapy are essential for noninvasive disease diagnosis and precise ablation of tumors. Herein, metabolizable highly absorbing NIR‐II conjugated polymer dots (Pdots) are reported for the first time for photoacoustic imaging guided photothermal therapy (PTT). The unique design of low‐bandgap D‐A π‐conjugated polymer (DPP‐BTzTD) together with modified nanoreprecipitation conditions allows to fabricate NIR‐II absorbing Pdots with ultrasmall (4 nm) particle size. Extensive experimental tests demonstrate that the constructed Pdots exhibit good biocompatibility, excellent photostability, bright photoacoustic signals, and high photothermal conversion efficiency (53%). In addition, upon tail‐vein intravenous injection of tumor‐bearing mice, Pdots also show high‐efficient tumor ablation capability with rapid excretion from the body. In particular, both in vitro and in vivo assays indicate that the Pdots possess remarkable PTT performance under irradiation with a 1064 nm laser with 0.5 W cm^?2, which is much lower than its maximum permissible exposure limit of 1 W cm^?2. This pilot study thus paves a novel avenue for the development of organic semiconducting nanoagents for future clinical translation.     

Biodegradable Fe(III)@WS2‐PVP Nanocapsules for Redox Reaction and TME‐Enhanced Nanocatalytic,Photothermal, and Chemotherapy

In this study, biocompatible Fe(III) species‐WS₂‐polyvinylpyrrolidone (Fe(III) @ WS₂‐PVP) nanocapsules with enhanced biodegradability and doxorubicin (DOX) loading capacity are one‐pot synthesized. In this nanocapsule, there exists a redox reaction between Fe(III) species and WS₂ to form Fe²⁺ and WO₄^2?. The formed Fe²⁺ could be oxidized to Fe³⁺, which reacts with Fe(III) @ WS₂‐PVP again to continuously produce Fe²⁺ and WO₄^2?. Such a repeated endogenous redox reaction leads to an enhanced biodegradation and DOX release of DOX @ Fe(III) @ WS₂‐PVP. More strikingly, the Fe²⁺ generation and DOX release are further accelerated by the overexpressed H₂O₂ and the mild acidic tumor microenvironment (TME), since H₂O₂ and H⁺ can accelerate the oxidation of Fe²⁺. The continuously generated Fe²⁺ catalyzes a fast Fenton reaction with the innate H₂O₂ in tumor cells and produces abundant highly toxic hydroxyl radicals for nanocatalytic tumor therapy. Together with the high photothermal transforming capability, the DOX @ Fe(III) @WS₂‐PVP nanocapsules successfully achieve the endogenous redox reaction and exogenous TME‐augmented tumor photothermal therapy, chemo and nanocatalytic therapy outcome. The concept of material design can be innovatively extended to the synthesis of biodegradable Fe(III) @ MoS₂‐PVP nanocomposite, thus paving a promising novel way for the rational design of intelligent theranostic agents for highly efficient treatment of cancer.     

Ultralong Circulating Lollipop‐Like Nanoparticles Assembled with Gossypol,Doxorubicin, and Polydopamine via π–π Stacking for Synergistic Tumor Therapy

Long blood circulation in vivo remains a challenge to dual‐drug‐loaded nanocarriers for synergistic chemotherapy. Herein, a novel strategy to prepare lollipop‐like dual‐drug‐loaded nanoparticles (DOX–PDA–gossypol NPs) is developed based on the self‐assembly of gossypol, doxorubicin (DOX), and polydopamine (PDA) via π–π stacking. Dopamine polymerizes to PDA and fills the gaps between the gossypol and DOX molecules to form the super compact long‐circulating nanoparticles. The DOX–PDA–gossypol NPs show a suitable particle size of 59.6 ± 9.6 nm, high drug loading of 91%, superb stability, high maximum‐tolerated dose (MTD) of over 60 mg kg^‐1, and negligible toxicity. These NPs also exhibit pH‐dependent drug release and low combination index (0.23). Notably, they show dramatically ultralong blood circulation (>192 h) with elimination half times 458‐fold and 258‐fold longer than that of free DOX and free gossypol, respectively. These values are markedly higher than most of the reported results. Therefore, the DOX–PDA–gossypol NPs have a high tumor accumulation of 12% remaining on the 8th day postinjection. This characteristic contributes to the excellent tumor comprehensive synergistic therapeutic efficacy (TIR > 90%) with low administration dosage and is benefitted for widening the drug therapeutic window. Thus, the proposed strategy has remarkable potential for tumor synergistic therapy.     

Photothermal Lysis of Engineered Bacteria to Modulate Amino Acid Metabolism against Tumors

Bacterial-mediated synergistic cancer therapy (BMSCT) is used as a promising tumor therapy approach. However, there are some disadvantages of bacterial therapy alone to be resolved, such as low tumor suppression rate in the treatment. In this study, a novel light-controlled engineered bacterial material which synergistically regulates amino acid metabolism to fight tumors is developed. It transcribes l -methionine-γ-lyase (MdeA) into Escherichia coli (E. coli) and loads the approved photothermal agent indocyanine green (ICG), namely E. coli-MdeA@ICG. Using the hypoxic tropism of E. coli, genetically engineered bacteria are first loaded with photothermal agents, then selectively accumulate and replicate in the tumor region. Under laser irradiation, photothermal lysis of E. coli-MdeA is performed to release the MdeA and consume the essential amino acid methionine (Met) in the tumor environment. In vitro cell experiments confirm that the E. coli-MdeA + NIR group can reach 90% of the 4T1 cells killing. In 4T1 tumor-bearing mouse models, E. coli-MdeA@ICG shows enhanced antitumor efficacy, along with 91.8% of the tumor growth inhibited. Apoptosis of tumor cells is induced under the dual action of photothermal therapy (PTT) and amino acid metabolism therapy. This strategy provides new ideas for the combination of synthetic biology and nanotechnology in anti-tumor.     

A Versatile Nanotheranostic Agent for Efficient Dual‐Mode Imaging Guided Synergistic Chemo‐Thermal Tumor Therapy

The integration of efficient imaging for diagnosis and synergistic tumor therapy into a single‐component nanoplatform is much promising for high efficacy tumor treatment but still in a great challenge. Herein, a smart and versatile nanotheranostic platform based on hollow mesoporous Prussian blue nanoparticles (HMPBs) with perfluoropentane (PFP) and doxorubicin (DOX) inside, has been designed, for the first time, to achieve the distinct in vivo synergistic chemo‐thermal tumor therapy and synchronous diagnosis and monitoring by ultrasound (US)/photoacoustic (PA) dual mode imaging. The prepared HMPBs show excellent photothermal conversion properties with large molar extinction coefficient (≈1.2 × 10¹¹m ^?1 cm^?1) and extremely high photothermal conversion efficiency (41.4%). Such a novel theranostic nanoplatform is expected to overcome the inevitable tumor recurrence and metastasis resulting from the inhomogeneous ablation of single thermal therapy, which will find a promising prospect in the application of noninvasive cancer therapy.     

Core–Satellite Mesoporous Silica–Gold Nanotheranostics for Biological Stimuli Triggered Multimodal Cancer Therapy

A core–satellite nanotheranostic agent with pH‐dependent photothermal properties, pH‐triggered drug release, and H₂O₂‐induced catalytic generation of radical medicine is fabricated to give a selective and effective tumor medicine with three modes of action. The nanocomplex (core–satellite mesoporous silica–gold nanocomposite) consists of amino‐group‐functionalized mesoporous silica nanoparticles (MSN‐NH₂) linked to L‐cysteine‐derivatized gold nanoparticles (AuNPs‐Cys) with bridging ferrous iron (Fe²⁺) ions. The AuNPs‐Cys serve as both removable caps that control drug release (doxorubicin) and stimuli‐responsive agents for selective photothermal therapy. Drug release and photothermal therapy are initiated by the cleavage of Fe²⁺ coordination bonds at low pH and the spontaneous aggregation of the dissociated AuNPs‐Cys. In addition, the Fe²⁺ is able to catalyze the decomposition of hydrogen peroxide abundant in cancer cells by a Fenton‐like reaction to generate high‐concentration hydroxyl radicals (·OH), which then causes cell damage. This system requires two tumor microenvironment conditions (low pH and considerable amounts of H₂O₂) to trigger the three therapeutic actions. In vivo data from mouse models show that a tumor can be completely inhibited after two weeks of treatment with the combined chemo‐photothermal method; the data directly demonstrate the efficiency of the MSN–Fe–AuNPs for tumor therapy.     

Combination of Bacterial‐Photothermal Therapy with an Anti‐PD‐1 Peptide Depot for Enhanced Immunity against Advanced Cancer

Photothermal therapy (PTT) is a promising cancer treatment, but it has so far proven successful only with relatively small subcutaneous tumors in animal models. Treating larger tumors (≈200 mm³) is challenging because most PTT materials do not efficiently reach the hypoxic, avascular center of tumors, and the immunosuppressive tumor microenvironment prevents T cells from fighting against residual tumor cells, thereby allowing recurrence and metastasis. Here, the widely used PTT material polydopamine is coated on the surface of the facultative anaerobe Salmonella VNP20009, which can penetrate deep into larger tumors. The coated bacteria are intravenously injected followed by near‐infrared laser irradiation at the tumor site, combined with a local inoculation of phospholipid‐based phase separation gel containing the anti‐programmed cell death‐1 peptide AUNP‐12. The gel releases AUNP‐12 sustainably during 42 days, maintaining the tumor microenvironment as immunopermissive. Using a mouse model of melanoma, this triple combination of biotherapy, PTT, and sustainable programmed cell death‐1 (PD‐1) blockade shows high efficiency on eliciting robust antitumor immune responses and eliminating relatively large tumors in 50% of animals within 80 days. Thus, the results shed new light on a previously unrecognized immunological facet of bacteria‐mediated therapy, and this innovative triple therapy may be a powerful cancer immunotherapy tool.     

Intracellular Mutual Promotion of Redox Homeostasis Regulation and Iron Metabolism Disruption for Enduring Chemodynamic Therapy

Intracellular redox homeostasis and the iron metabolism system in tumor cells are closely associated with the limited efficacy of chemodynamic therapy (CDT). Despite extensive attempts, maintaining high levels of intracellular catalysts (free iron) and reactants (H₂O₂) while decreasing the content of reactive oxygen species (ROS) scavengers (especially glutathione (GSH)) for enduring CDT still remains great challenges. Herein, S S bond-rich dendritic mesoporous organic silica nanoparticles (DMON) are utilized as GSH-depleting agents. After co-loading Fe⁰ and a catalase inhibitor (3-amino-1,2,4-triazole (AT)), a novel biodegradable nanocarrier is constructed as DMON@Fe⁰/AT. In the mildly acidic tumor microenvironment, on-demand ferrous ions and AT are intelligently released. AT suppresses the activity of catalase for H₂O₂ hoarding, and the exposed DMON weakens ROS scavenging systems by persistently depleting intracellular GSH. The highly efficient •OH production by DMON@Fe⁰/AT can effectively attack mitochondria and downregulate the expression of ferroportin 1, which can disrupt the cellular iron metabolism system, leading to the desired retention of iron in the cytoplasm. More importantly, DMON@Fe⁰/AT exhibits a much more efficient CDT killing effect on 4T1 tumor cells than plain Fe⁰ nanoparticles, benefiting from their synergistic redox regulation and iron metabolism disruption. Overall, the as-prepared intelligent, degradable DMON@Fe⁰/AT provides an innovative strategy for enduring CDT.     

Enhanced Photocatalytic Activity using Layer‐by‐Layer Electrospun Constructs for Water Remediation

Endocrine disruptors such as bisphenol A (BPA) are environmental pollutants that interfere with the body's endocrine system because of their structural similarity to natural and synthetic hormones. Due to their strong oxidizing potential to decompose such organic pollutants, colloidal metal oxide photocatalysts have attracted increasing attention for water detoxification. However, achieving both long‐term physical stability and high efficiency simultaneously with such photocatalytic systems poses many challenges. Here a layer‐by‐layer (LbL) deposition approach is reported for immobilizing TiO₂ nanoparticles (NPs) on a porous support while maintaining a high catalytic efficiency for photochemical decomposition of BPA. Anatase TiO₂ NPs ≈7 nm in diameter self‐assemble in consecutive layers with positively charged polyhedral oligomeric silsesquioxanes on a high surface area, porous electrospun polymer fiber mesh. The TiO₂ LbL nanofibers decompose approximately 2.2 mg BPA per mg of TiO₂ in 40 h of illumination (AM 1.5G illumination), maintaining first‐order kinetics with a rate constant (k) of 0.15 h^?1 for over 40 h. Although the colloidal TiO₂ NPs initially show significantly higher photocatalytic activity (k ≈ 0.84 h^?1), the rate constant drops to k ≈ 0.07 h^?1 after 4 h of operation, seemingly due to particle agglomeration. In the BPA solution treated with the multilayered TiO₂ nanofibers for 40 h, the estrogenic activity, based on human breast cancer cell proliferation, is significantly lower than that in the BPA solution treated with colloidal TiO₂ NPs under the same conditions. This study demonstrates that water‐based, electrostatic LbL deposition effectively immobilizes and stabilizes TiO₂ NPs on electrospun polymer nanofibers for efficient extended photochemical water remediation.     

Polydopamine as a Biocompatible Multifunctional Nanocarrier for Combined Radioisotope Therapy and Chemotherapy of Cancer

Development of biodegradable nanomaterials for drug delivery and cancer theranostics has attracted great attention in recent years. In this work, polydopamine (PDA), a biocompatible polymer, is developed as a promising carrier for loading of both radionuclides and an anticancer drug to realize nuclear‐imaging‐guided combined radioisotope therapy (RIT) and chemotherapy of cancer in one system. It is found that PDA nanoparticles after modification with poly(ethylene glycol) (PEG) can successfully load several different radionuclides such as ^99mTc and ¹³¹I, as well as an anticancer drug doxorubicin (DOX). While labeling PDA‐PEG with ^99mTc (^99mTc‐PDA‐PEG) enables in vivo single photon emission computed tomography imaging, nanoparticles co‐loaded with ¹³¹I and DOX (¹³¹I‐PDA‐PEG/DOX) can be utilized for combined RIT and chemotherapy, which offers effective cancer treatment efficacy in a remarkably synergistic manner, without rendering significant toxicity to the treated animals. Therefore, this study presents an interesting class of biocompatible nanocarriers, which allow the combination of RIT and chemotherapy, the two extensively applied cancer therapeutic strategies, promising for future clinic translations in cancer treatment.     

Nanoscintillator-Mediated X-Ray-Triggered Boosting Transformation of Fe3+ into Fe2+ for Enhancing Tumor Ferroptosis/Immunotherapy

Ferroptosis therapy induced by iron-catalyzed Fenton reaction has offered enormous opportunities for tumor therapy. Unfortunately, high catalytic activity ferrous (Fe²⁺)-based therapeutic agent has remained challenging due to the instability of Fe²⁺. Herein, an X-ray-activated Fe²⁺ supply platform, termed “PFCN”, containing the core of CaWO₄ nanoscintillator to emit ultraviolet (UV) light and Fe₃O₄ decorated on the surface to deliver excessive Fe²⁺ is proposed. Under X-ray excitation, the UV light emitted by CaWO₄ can catalyze ferric (Fe³⁺) to generate Fe²⁺, which further cascades the Fenton reaction to induce highly toxic hydroxyl radicals generation. More importantly, immunogenic cell death-associated immunotherapy is simultaneously triggered during this process. Experiments conducted in vitro and in vivo revealed that X-ray-triggered PFCN shows superior tumor therapeutic efficacy, contributing i) enhanced radiotherapy; ii) X-ray-activated ferroptosis therapy; and iii) ferroptosis/radiotherapy-induced immunotherapy. Besides, PFCN can be utilized as an MR/CT dual-mode imaging contrast agent for tumor diagnosis and treatment monitoring. The study provides a novel example of an X-ray-activated ferrous-regeneration platform for imaging-guided augmenting tumor ferroptosis/immunotherapy     

Remarkable NIR Enhancement of Multifunctional Nanoprobes for In Vivo Trimodal Bioimaging and Upconversion Optical/T2‐Weighted MRI‐Guided Small Tumor Diagnosis

Effective nanoprobes and contrast agents are urgently sought for early‐stage cancer diagnosis. Upconversion nanoparticles (UCNPs) are considerable alternatives for bioimaging, cancer diagnosis, and therapy. Yb³⁺/Tm³⁺ co‐doping brings both emission and excitation wavelengths into the near‐infrared (NIR) region, which is known as “optical transmission window” and ideally suitable for bioimaging. Here, NIR emission intensity is remarkably enhanced by 113 times with the increase of Yb³⁺ concentration from 20% to 98% in polyethylene glycol (PEG) modified NaYF₄:Yb³⁺/Tm³⁺ UCNPs. PEG‐UCNPs‐5 (98% Yb³⁺) can act as excellent nanoprobes and contrast agents for trimodal upconversion (UC) optical/CT/T₂‐weighted magnetic resonance imaging (MRI). In addition, the enhanced detection of lung in vivo long‐lasting tracking, as well as possible clearance mechanism and excretion routes of PEG‐UCNPs‐5 have been demonstrated. More significantly, a small tumor down to 4 mm is detected in vivo via intravenous injection of these nanoprobes under both UC optical and T₂‐weighted MRI modalities. PEG‐UCNPs‐5 can emerge as bioprobes for multi‐modal bioimaging, disease diagnosis, and therapy, especially the early‐stage tumor diagnosis.     

Self-Assemblies of Fe3O4 Nanocrystals: Toward Nanoscale Precision of Photothermal Effects in the Tumor Microenvironment

Fe₃O₄ nanocrystals are self-assembled into two different conformations: colloidosome and supraball that confer them with distinct properties determining their photo-induced heating capacities. These self-assemblies are assessed for photothermal therapy, an adjuvant strategy for tumor therapy. The tumor microenvironment is a heterogeneous ecosystem including immune cells and the extracellular matrix. The interactions between photothermal therapy agents and the different components of the tumor microenvironment determine the outcome of this therapy. In this study, the fate of both colloidosomes and supraballs within the tumor microenvironment in comparison to their Fe₃O₄ nanocrystal building blocks is revealed. This study highlights how these two hybrid self-assemblies target different compartments of the tumor microenvironment and trigger local photothermal damages that are inaccessible for isolated nanocrystals and not predicted by global temperature measurements.     

GSH-Depleted Nanozymes with Dual-Radicals Enzyme Activities for Tumor Synergic Therapy

Although inspiring progress has been achieved in tumor nanocatalytic therapies based on tailor-made nanozymes for converting hydrogen peroxide into reactive oxygen species (ROS) efficiently, most cytotoxic hydroxyl radicals do not spread far enough within a cell to damage the primary organelles for effective tumor therapy due to their short half-life time (≈1 µs). Developing a novel nanocatalyst platform involving longer half-life time ROS is desired. To this end, Fe₃O₄-Schwertmannite nanocomposites (Fe₃O₄-Sch) with triple-effect tumor therapy are constructed through a facile method. The Schwertmannite shell converts the ^•OH produced by Fe₃O₄ via the Fenton reaction into sulfate radicals with a longer half-life time (30 µs). Combination of dual radicals exhibits overwhelming tumor inhibition efficacy. The nanocomposites also show the multifunctionality of good photothermal efficiency (33.2%) and synergistic oxidative stress amplification upon glutathione biosynthesis (GSH) depletion by the l -buthionine sulfoximine (BSO) molecules loaded in the hollow Fe₃O₄ cores. The comprehensive properties of the nanoplatform including the dual-radical production, Fe₃O₄ nanocrystal mediated PTT, and the BSO mediated GSH depletion result in remarkable tumor inhibition both in vitro and in vivo, which may pave a way to constructing a synergic catalytic nanoplatform for efficient tumor therapy.     

Construction of Tri-Functional HOFs Material for Efficient Selective Adsorption and Photodegradation of Bisphenol A and Hydrogen Production

This study proposes the construction of porous nanomaterial (HOFs@Fe³⁺) which anchors non-noble metal ions Fe³⁺ onto nanoscale rod-like hydrogen-bonded organic frameworks (HOFs) by electrostatic and coordination interactions. The high specific surface area and the abundance of hydrogen-bond adsorption active sites in pore structure of HOFs@Fe³⁺ facilitate strong interactions with the double  OH in bisphenol A (BPA), resulting in the highest saturation adsorption of BPA that has been reported so far (452 mg g^-1). In addition, the ordered conjugate stacking framework structure and hydrogen bond of HOFs@Fe³⁺ and the variable valence properties of Fe³⁺ create new pathways for efficient separation of photogenerated carriers. The results show that HOFs@Fe³⁺ can completely adsorb and photodegrade 50 ppm BPA within 20 min, owing to the abundant hydrogen bond that acts both as adsorption sites to accelerate the mass transfer process and as catalytic sites to ensure adsorption and photodegradation can be matched synergistically. Meanwhile, the efficiency of photocatalytic H₂ production by HOFs@Fe³⁺ reaches 21.55 mmol g^-1 h^-1 with non-noble metal Fe³⁺ as co-catalyst. This tri-functional material with high adsorption capacity, high photodegradation efficiency, and high photocatalytic H₂ production activity can be successfully used to solve the long-standing conflict between environment and energy.