Defect-Repaired g-C3N4 Nanosheets: Elevating the Efficacy of Sonodynamic Cancer Therapy Through Enhanced Charge Carrier Migration.

Sonodynamic therapy (SDT) has garnered growing interest owing to its high tissue penetration depth and minimal side effects. However, the lack of efficient sonosensitizers remains the primary limiting factor for the clinical application of this treatment method. Here, defect-repaired graphene phase carbon nitride (g-C3N4) nanosheets are prepared and utilized for enhanced SDT in anti-tumor treatment. After defect engineering optimization, the bulk defects of g-C3N4 are significantly reduced, resulting in higher crystallinity and exhibiting a polyheptazine imide (PHI) structure. Due to the more extended conjugated structure of PHI, facilitating faster charge transfer on the surface, it exhibits superior SDT performance for inducing apoptosis in tumor cells. This work focuses on introducing a novel carbon nitride nanomaterial as a sonosensitizer and a strategy for optimizing sonosensitizer performance by reducing bulk defects.

Titanium-Based Nanoarchitectures for Sonodynamic Therapy-Involved Multimodal Treatments.

Sonodynamic therapy (SDT) has considerably revolutionized the healthcare sector as a viable noninvasive therapeutic procedure. It employs a combination of low-intensity ultrasound and chemical entities, known as a sonosensitizer, to produce cytotoxic reactive oxygen species (ROS) for cancer and antimicrobial therapies. With nanotechnology, several unique nanoplatforms are introduced as a sonosensitizers, including, titanium-based nanomaterials, thanks to their high biocompatibility, catalytic efficiency, and customizable physicochemical features. Additionally, developing titanium-based sonosensitizers facilitates the integration of SDT with other treatment modalities (for example, chemotherapy, chemodynamic therapy, photodynamic therapy, photothermal therapy, and immunotherapy), hence increasing overall therapeutic results. This review summarizes the most recent developments in cancer therapy and tissue engineering using titanium nanoplatforms mediated SDT. The synthesis strategies and biosafety aspects of Titanium-based nanoplatforms for SDT are also discussed. Finally, various challenges and prospects for its further development and potential clinical translation are highlighted.

Metal Halide Single Crystals RbCdCl3:Sn2+ and Rb3SnCl7 with Blue and White Emission Obtained via a Hydrothermal Process.

Until now, effective blue light-emitting materials are essentially needed for the creation of white light and precise color renderings in real-world applications, but the efficiency of blue light-emitting materials has lagged far behind. Here, we present a hydrothermal method to synthesize tin-based metal halide single crystals (RbCdCl3:Sn2+ and Rb3SnCl7). Two single crystal materials with different shapes and phases can simultaneously be synthesized in the same stoichiometric ratio. Rb3SnCl7 has a bulk shape, while RbCdCl3:Sn2+ has a needle shape. The deep blue emission (436 nm) of RbCdCl3:Sn2+ can be obtained under the optimal excitation wavelength irradiation. However, pure blue emission (460 nm) to white light can be obtained by changing the excitation wavelength in Rb3SnCl7. The refinement spectra of the electronic structures of RbCdCl3:Sn2+ and Rb3SnCl7 are investigated by density functional theory. It is concluded that the difference in the distribution of Cl energy states leads to the existence of Cl local defect states, which is the reason for the rich luminescence of the two single crystals. These findings provide a path for realizing single-phase broadband white-emitting materials.

Multimode Luminescence Tailoring and Improvement of Cs2 NaHoCl6 Cryolite Crystals via Sb3+ /Yb3+ Alloying for Versatile Photoelectric Applications.

Lead-free halide double perovskites are currently gaining significant attention owing to their exceptional environmental friendliness, structural adjustability as well as self-trapped exciton emission. However, stable and efficient double perovskite with multimode luminescence and tunable spectra are still urgently needed for multifunctional photoelectric application. Herein, holmium based cryolite materials (Cs2 NaHoCl6 ) with anti-thermal quenching and multimode photoluminescence were successfully synthesized. By the further alloying of Sb3+ (s-p transitions) and Yb3+ (f-f transitions) ions, its luminescence properties can be well modulated, originating from tailoring band gap structure and enriching electron transition channels. Upon Sb3+ substitution in Cs2 NaHoCl6 , additional absorption peaking at 334 nm results in the tremendous increase of photoluminescence quantum yield (PLQY). Meanwhile, not only the typical NIR emission around 980 nm of Ho3+ is enhanced, but also the red and NIR emissions show a diverse range of anti-thermal quenching photoluminescence behaviors. Furthermore, through designing Yb3+ doping, the up-conversion photoluminescence can be triggered by changing excitation laser power density (yellow-to-orange) and Yb3+ doping concentration (red-to-green). Through a combined experimental-theoretical approach, the related luminescence mechanism is revealed. In general, by alloying Sb3+ /Yb3+ in Cs2 NaHoCl6 , abundant energy level ladders are constructed and more luminescence modes are derived, demonstrating great potential in multifunctional photoelectric applications.

Tumor Microenvironment-Responsive Cu/CaCO3 -Based Nanoregulator for Mitochondrial Homeostasis Disruption-Enhanced Chemodynamic/Sonodynamic Therapy.

The efficiency of reactive oxygen species (ROS)-mediated cancer therapy is restrained by intrinsic characteristics in the tumor microenvironment (TME), such as overexpressed glutathione (GSH), hypoxia and limited efficiency of H2 O2 . In this work, intelligent copper-dropped calcium carbonate loading sonosensitizer Ce6 nanoparticles (Cu/CaCO3 @Ce6, CCC NPs) are established to realize TME-responsive self-supply of oxygen and successively Ca2+ -overloading-strengthened chemodynamic therapy/sonodynamic therapy (CDT/SDT). CCC NPs release Ca2+ , Cu2+ , and Ce6 in weakly acid and GSH-excessive TME. Released Cu2+ can not only consume GSH and turn into Cu+ via a redox reaction, but also provide CDT-creating hydroxyl radicals through the Fenton-like reaction. Under ultrasound irradiation, the intracellular oxidative stress is amplified profoundly relying on singlet oxygen outburst from SDT. Moreover, Ca2+ influx aggravates the mitochondrial disruption, which further accelerates the oxidation level. The facile and feasible design of the Cu-dropped CaCO3 -based nanoregulators will be further developed as a paradigm in ROS-contributed cancer therapy.

Biodegradable Upconversion Nanoparticles Induce Pyroptosis for Cancer Immunotherapy.

Pyroptosis, which is a mode of programmed cell death, has proven effective for cancer therapy. However, efficient pyroptosis inducers for tumor treatment are limited. This study proposes biodegradable K3ZrF7:Yb/Er upconversion nanoparticles (ZrNPs) as pyroptosis inducers for cancer immunotherapy. ZrNPs, which are similar to ion reservoirs, can be dissolved inside cancer cells and release high amounts of K+ and [ZrF7]3- ions, resulting a surge in intracellular osmolarity and homeostasis imbalance. This further induces an increase in reactive oxygen species (ROS), caspase-1 protein activation, gasdermin D (GSDMD) cleavage, and interleukin-1ß (IL-1ß) maturity, and results in cytolysis. In vivo tests confirm that ZrNPs-induced pyroptosis exhibits superior antitumor immunity activity confirmed by enhanced dendritic cells (DCs) maturity and frequency of effector-memory T cells, as well as observably inhibiting tumor growth and pulmonary metastasis. This work is believed to extend the biomedical applications of upconversion nanomaterials and deepen the understanding of intrinsic immunomodulatory activity of nanomaterials.

A Robust Oxygen-Carrying Hemoglobin-Based Natural Sonosensitizer for Sonodynamic Cancer Therapy.

The development of novel sonosensitizers with outstanding reactive oxygen (ROS) generation capacity and great biocompatibility poses a significant challenge for the clinical practice of sonodynamic therapy (SDT). In this work, hemoglobin (Hb) with natural metalloporphyrin was first shown to possess great potential as a sonosensitizer. Compared with traditional organic sonosensitizers, Hb had satisfactory sono-sensitizing efficiency because four the porphyrin molecules were separated by four polypeptide chains. This effectively avoided the problem of low ROS quantum yield caused by the stacking of hydrophobic porphyrins. Meanwhile, Hb is an efficient and safe oxygen carrier that may release O2 at hypoxic tumors site, which improved tumor oxygenation and subsequently enhanced SDT efficacy. Therefore, Hb was integrated with zeolitic imidazolate framework 8 (ZIF-8) to form a nanoplatform that demonstrated a potent suppression effect on deep-seated tumors under ultrasound irradiation.

Conferring BiVO4 Nanorods with Oxygen Vacancies to Realize Enhanced Sonodynamic Cancer Therapy.

Owing to the high depth of tissue penetration, non-invasiveness, and controllability, ultrasound (US)-mediated sonodynamic therapy (SDT) has shown broad application prospects for tumor treatment. However, the electron-hole separation inefficiency of sonosensitizers and the tumor hypoxia remain two major challenges limiting the effect of SDT. Here, ultrafine photoetched bismuth vanadate (BiVO4 ) nanorods modified with DSPE-PEG2000 (PEBVO@PEG NRs) were fabricated to achieve in situ self-supply of oxygen (O2 ) and reactive oxygen species (ROS) for hypoxic tumor therapy. The photoetching approach could enhance the charge separation by inducing enriched oxygen vacancies on the surface of BiVO4 , thereby improving the generation efficiency of ROS and O2 . The PEBVO@PEG overcome the main obstacles of traditional sonosensitizers in the SDT process and show promising sonodynamic therapeutic effects, thus providing new strategies for improving the performance of sonosensitizer and hypoxic tumor elimination.

Core-Shell Structured Upconversion/Lead-Free Perovskite Nanoparticles for Anticounterfeiting Applications.

In view of their excellent luminescence properties, nanocrystalline metal halide perovskites have diverse optoelectronic applications, including those related to anticounterfeiting. However, high-quality optical anticounterfeiting typically requires multiple encryptions relying on several optical modes to ensure information security. Herein, an efficient anticounterfeiting strategy based on dual optical encryption is realized by combining up- and downconversion luminescence in a nanocomposite with NaYF4 : Er3+ ,Yb3+ as core and a CsMnCl3 as shell. The emission color of this nanocomposite depends on the penetration depth of incident radiation and can be changed by varying the excitation source (980 nm laser or UV light) to produce different luminescent patterns. This feature allows one to effectively improve the anticounterfeiting index and fabricate professional anticounterfeiting materials.

NIR-Triggered Multi-Mode Antitumor Therapy Based on Bi2 Se3 /Au Heterostructure with Enhanced Efficacy.

Of all the reaction oxygen species (ROS) therapeutic strategies, NIR light-induced photocatalytic therapy (PCT) based on semiconductor nanomaterials has attracted increasing attention. However, the photocatalysts suffer from rapid recombination of electron-hole pairs due to the narrow band gaps, which are greatly restricted in PCT application. Herein, Bi2 Se3 /Au heterostructured photocatalysts are fabricated to solve the problems by introducing Au nanoparticles (NPs) in situ on the surface of the hollow mesoporous structured Bi2 Se3 . Owing to the lower work function of Au NPs, the photo-induced electrons are easier to transfer and assemble on their surfaces, resulting in the increased separation of the electron-hole pairs with efficient ROS generation. Besides, Bi2 Se3 /Au heterostructures also enhance the photothermal efficiency due to the effective orbital overlaps with accelerated electron migrations according to density functional theory calculations. Moreover, the PLGA-PEG and the doxorubicin (DOX) are introduced for photothermal-triggered drug release in the system. The Bi2 Se3 /Au heterostructures also displays excellent infrared thermal (IRT) and computed tomography (CT) dual-modal imaging property for promising cancer diagnosis. Collectively, Bi2 Se3 /Au@PLGA-PEG-DOX exhibits prominent tumor inhibition effect based on synchronous PTT, PCT and chemotherapy triggered by NIR light for efficient antitumor treatment.

Solvatochromic Photoluminescent Effects in All-Inorganic Manganese(II)-Based Perovskites by Highly Selective Solvent-Induced Crystal-to-Crystal Phase Transformations.

The development of lead-free perovskite photoelectric materials has been an extensive focus in the recent years. Herein, a novel one-dimensional (1D) lead-free CsMnCl3 (H2 O)2 single crystal is reported with solvatochromic photoluminescence properties. Interestingly, after contact with N,N-dimethylacetamide (DMAC) or N,N-dimethylformamide (DMF), the crystal structure can transform from 1D CsMnCl3 (H2 O)2 to 0D Cs3 MnCl5 and finally transform into 0D Cs2 MnCl4 (H2 O)2 . The solvent-induced crystal-to-crystal phase transformations are accompanied by loss and regaining of water of crystallization, leading to the change of the coordination number of Mn2+ . Correspondingly, the luminescence changes from red to bright green and finally back to red emission. By fabricating a test-paper containing CsMnCl3 (H2 O)2 , DMAC and DMF can be detected quickly with a response time of less than one minute. These results can expand potential applications for low-dimensional lead-free perovskites.

An overview on enhancing the stability of lead halide perovskite quantum dots and their applications in phosphor-converted LEDs.

Beyond the unprecedented success achieved in photovoltaics (PVs), lead halide perovskites (LHPs) have shown great potential in other optoelectronic devices. Among them, nanometer-scale perovskite quantum dots (PQDs) with fascinating optical properties including high brightness, tunable emission wavelength, high color purity, and high defect tolerance have been regarded as promising alternative down-conversion materials in phosphor-converted light-emitting diodes (pc-LEDs) for lighting and next-generation of display technology. Despite the promising applications of perovskite materials in various fields, they have received strong criticism for the lack of stability. The poor stability has also attracted much attention. Within a few years, numerous strategies towards enhancing the stability have been developed. This review summarizes the mechanisms of intrinsic- and extrinsic-environment-induced decomposition of PQDs. Simultaneously, the strategies for improving the stability of PQDs are reviewed in detail, which can be classified into four types: (1) compositional engineering; (2) surface engineering; (3) matrix encapsulation; (4) device encapsulation. Finally, the challenges for applying PQDs in pc-LEDs are highlighted, and some possible solutions to improve the stability of PQDs together with suggestions for further improving the performance of pc-LEDs as well as the device lifetime are provided.

Correction: An overview on enhancing the stability of lead halide perovskite quantum dots and their applications in phosphor-converted LEDs.

Correction for 'An overview on enhancing the stability of lead halide perovskite quantum dots and their applications in phosphor-converted LEDs' by Yi Wei et al., Chem. Soc. Rev., 2019, DOI: 10.1039/c8cs00740c.

Yolk-Shell Structured Au Nanostar@Metal-Organic Framework for Synergistic Chemo-photothermal Therapy in the Second Near-Infrared Window.

Light-sensitive yolk-shell nanoparticles (YSNs) as remote-controlled and stimuli-responsive theranostic platforms provide an attractive method for synergistic cancer therapy. Herein, a kind of novel stimuli-responsive multifunctional YSNs has been successfully constructed by integrating star-shaped gold (Au star) nanoparticles as the second near-infrared (NIR-II) photothermal yolks and biodegradable crystalline zeolitic imidazolate framework-8 (ZIF-8) as the shells. In this platform, a chemotherapeutic drug (doxorubicin hydrochloride, DOX) was encapsulated into the cavity, which can show the behavior of controlled release due to the degradation process of ZIF-8 in the mildly acidic tumor microenvironment. Upon the 1064 nm (NIR-II biowindow) laser irradiation, gold nanostar@ZIF-8 (Au@MOF) nanoparticles exhibited outstanding synergistic anticancer effect based on their photothermal and promoted cargo release properties. Moreover, the strong NIR region absorbance endows the Au@MOF of NIR thermal imaging and photoacoustic (PA) imaging properties. This work contributes to design a stimuli-responsive "all-in-one" nanocarrier that realizes bimodal imaging diagnosis and chemo-photothermal synergistic therapy.

Intelligent Hollow Pt-CuS Janus Architecture for Synergistic Catalysis-Enhanced Sonodynamic and Photothermal Cancer Therapy.

As a noninvasive treatment modality, ultrasound (US)-triggered sonodynamic therapy (SDT) shows broad and promising applications to overcome the drawbacks of traditional photodynamic therapy (PDT) in combating cancer. However, the SDT efficacy is still not satisfactory without oxygen (O2) assistance. In addition, there is also much space to explore the SDT-based synergistic therapeutic modalities. Herein, a novel Pt-CuS Janus composed of hollow semiconductor CuS and noble metallic Pt was rationally designed and successfully synthesized. The hollow CuS shows a large inner cavity for loading sonosensitizer molecules (tetra-(4-aminophenyl) porphyrin, TAPP) to implement SDT. Moreover, the deposition of Pt not only enhances photothermal performance compared with those of CuS nanoparticles (NPs) due to the effect of the local electric field enhancement but also possesses nanozyme activity for catalyzing decomposition of endogenous overexpressed hydrogen peroxide (H2O2) to produce O2 that can overcome tumor hypoxia and augment the SDT-induced highly toxic reactive oxygen species (ROS) production for efficient cancer cell apoptosis. Importantly, the generated heat of Pt-CuS by 808 nm laser irradiation can accelerate the catalytic activity of Pt and elevate the O2 level that further facilitates SDT efficacy. Interestingly, the thermally sensitive copolymer coated around the Janus can act as a smart switch to regulate the catalytic ability of Pt and control TAPP release that has a significant effect on modulating the therapeutic effect. The synergistic catalysis-enhanced SDT efficiency and highly photothermal effect almost realized complete tumor resection without obvious reoccurrence and simultaneously displayed a highly therapeutic biosafety. Furthermore, the high optical absorbance allows the as-synthesized Pt-CuS Janus for photoacoustic (PA) imaging and NIR thermal imaging. This work develops a versatile nanoplatform for a multifunctional theranostic strategy and broadens the biological applications by rationally designing their structure.

Full Color Luminescence Tuning in Bi3+/Eu3+-Doped LiCa3MgV3O12 Garnet Phosphors Based on Local Lattice Distortion and Multiple Energy Transfers.

In the pursuit of high-quality W-LED lighting, the precise control of emission color of phosphor materials is indispensable. Herein we report a series of single-composition Bi3+-doped LiCa3MgV3O12 garnet-structure phosphors, whose emission colors under n-UV excitation could be tuned from bluish green (480 nm) to yellow (562 nm) on the basis of local lattice distortion and VO43- → Bi3+ energy transfer. Furthermore, full-color luminescence tuning from bluish green to orangish red across the warm white light region was successfully achieved by designing VO43- → Bi3+ → Eu3+ energy transfers. More interestingly, the thermal stabilities of as-prepared samples were gradually enhanced through designing VO43-/Bi3+ → Eu3+ energy transfers. This work provides a new perspective for color tuning originating from simultaneous local lattice distortion and multiple energy transfers.

Enhanced Cisplatin Chemotherapy by Iron Oxide Nanocarrier-Mediated Generation of Highly Toxic Reactive Oxygen Species.

Reactive oxygen species (ROS) plays a key role in therapeutic effects as well as side effects of platinum drugs. Cisplatin mediates activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX), which triggers oxygen (O2) to superoxide radical (O2•-) and its downstream H2O2. Through the Fenton's reaction, H2O2 could be catalyzed by Fe2+/Fe3+ to the toxic hydroxyl radicals (•OH), which cause oxidative damages to lipids, proteins, and DNA. By taking the full advantage of Fenton's chemistry, we herein demonstrated tumor site-specific conversion of ROS generation induced by released cisplatin and Fe2+/Fe3+ from iron-oxide nanocarriers with cisplatin(IV) prodrugs for enhanced anticancer activity but minimized systemic toxicity.

Stimuli-responsive nanocomposites for magnetic targeting synergistic multimodal therapy and T1/T2-weighted dual-mode imaging.

Anticancer drug doxorubicin hydrochloride (DOX)-loaded photothermal nanocomposite MnFe2O4@mSiO2 with magnetic targeting and T1/T2-weighted dual-mode magnetic resonance imaging of MnFe2O4 core and NIR/pH-coupling sensitive mesoporous silica shell nanocarriers was designed and synthesized successfully. The anticancer drug DOX can be absorbed into mesoporous layer of MnFe2O4@mSiO2 nanocomposite, which shows obvious photothermal/chemo dual-modal synergistic therapies triggered by NIR/pH. Under 808 nm irradiation, MnFe2O4 can transform light into thermo, which can not only ablate tumor cells directly but also promote chemotherapy drugs releasing from mesoporous layer to kill tumor cells. The lower pH can also promote DOX releasing from mesoporous layer to enhance tumor inhibitory effect. It is confirmed that biocompatible DOX-MnFe2O4@mSiO2 nanocomposites can act as a potential multifunctional platform for effective magnetic targeting photothermal/chemo dual-modal synergistic therapies with enhanced anti-tumor efficacy and T1/T2-weighted dual-mode magnetic resonance imaging (MRI) applications in vivo.

Current advances in lanthanide ion (Ln(3+))-based upconversion nanomaterials for drug delivery.

Lanthanide ion (Ln(3+))-based upconversion nano/micromaterials that emit higher-energy visible light when excited by low-energy NIR light have aroused considerable attention in the forefront of materials science and biomedical fields, which stems from their unique optical and chemical properties including minimum photodamage to living organisms, low autofluorescence, high signal-to-noise ratio and detection sensitivity, and high penetration depth in biological or environmental samples. Thus, Ln(3+)-based upconversion materials are rising new stars and are quickly emerging as potential candidates to revolutionize novel biomedical applications. In this review article, we mainly focus on the recent progress in various chemical syntheses of Ln(3+)-based upconversion nanomaterials, with special emphasis on their application in stimuli-response controlled drug release and subsequent therapy. Functional groups that are introduced into the stimuli-responsive system can respond to external triggers, such as pH, temperature, light, and even magnetic fields, which can regulate the movement of the pharmaceutical cargo and release the drug at a desired time and in a desired area. This is crucial to boost drug efficacy in cancer treatment while minimizing the side effects of cytotoxic drugs. Many multifunctional (magnetic/upconversion luminescence and porous) composite materials based on Ln(3+) have been designed for controlled drug delivery and multimodal bioimaging. Finally, the challenges and future opportunities for Ln(3+)-based upconversion materials are discussed.