Oxygen-supplementing mesoporous polydopamine nanosponges with WS2 QDs-embedded for CT/MSOT/MR imaging and thermoradiotherapy of hypoxic cancer

Fluoride Hafnium/Zirconium-Softened Nanoprobes for Near-Infrared-IIb and CT Dual-Mode Bioimaging

Fluoride-based lanthanide-doped nanoparticles (LDNPs) featuring second near-infrared (NIR-II, 1000-1700 nm) downconversion emission for bioimaging have attracted extensive attention. However, conventional LDNPs cannot be degraded and eliminated from organisms because of an inert lattice, which obstructs bioimaging applications. Herein, the core-shell LDNPs of Na3HfF7:Yb,Er@CaF2:Ce,Zr(Hf) [labeled as Zr(Hf)Ce-HC] with pH-selective and tunable degradability were synthesized for dual-modal bioimaging. Notably, the "softening" lattice of the Na3HfF7 matrix and different Zr4+(Hf4+) doping amounts in the shell enable Zr(Hf)Ce-HC with acidity-dependent and tunable degradability. After coating of an optimized Ce3+-doped CaF2:Zr shell, the near-infrared-IIb (NIR-IIb, 1500-1700 nm) luminescence intensity of ZrCe-HC is enhanced by 5.2 times compared with that of Na3HfF7:Yb,Er. The Hf element with high X-ray attenuation allows ZrCe-HC as the contrast agent for computed tomography (CT) bioimaging. The modification of oxidized sodium alginate endows ZrCe-HC with satisfying biocompatibility for NIR-IIb/CT dual-modal bioimaging. These findings would benefit the bioimaging applications of degradable fluoride-based LDNPs.

Multimodal optoacoustic imaging: methods and contrast materials

Optoacoustic (OA) imaging offers powerful capabilities for interrogating biological tissues with rich optical absorption contrast while maintaining high spatial resolution for deep tissue observations. The spectrally distinct absorption of visible and near-infrared photons by endogenous tissue chromophores facilitates extraction of diverse anatomic, functional, molecular, and metabolic information from living tissues across various scales, from organelles and cells to whole organs and organisms. The primarily blood-related contrast and limited penetration depth of OA imaging have fostered the development of multimodal approaches to fully exploit the unique advantages and complementarity of the method. We review the recent hybridization efforts, including multimodal combinations of OA with ultrasound, fluorescence, optical coherence tomography, Raman scattering microscopy and magnetic resonance imaging as well as ionizing methods, such as X-ray computed tomography, single-photon-emission computed tomography and positron emission tomography. Considering that most molecules absorb light across a broad range of the electromagnetic spectrum, the OA interrogations can be extended to a large number of exogenously administered small molecules, particulate agents, and genetically encoded labels. This unique property further makes contrast moieties used in other imaging modalities amenable for OA sensing.

Unleashing the potential of tungsten disulfide: Current trends in biosensing and nanomedicine applications

The discovery of graphene ignites a great deal of interest in the research and advancement of two-dimensional (2D) layered materials. Within it, semiconducting transition metal dichalcogenides (TMDCs) are highly regarded due to their exceptional electrical and optoelectronic properties. Tungsten disulfide (WS2) is a TMDC with intriguing properties, such as biocompatibility, tunable bandgap, and outstanding photoelectric characteristics. These features make it a potential candidate for chemical sensing, biosensing, and tumor therapy. Despite the numerous reviews on the synthesis and application of TMDCs in the biomedical field, no comprehensive study still summarizes and unifies the research trends of WS2 from synthesis to biomedical applications. Therefore, this review aims to present a complete and thorough analysis of the current research trends in WS2 across several biomedical domains, including biosensing and nanomedicine, covering antibacterial applications, tissue engineering, drug delivery, and anticancer treatments. Finally, this review also discusses the potential opportunities and obstacles associated with WS2 to deliver a new outlook for advancing its progress in biomedical research.

Trends and prospects of 2-D tungsten disulphide (WS2) hybrid nanosystems for environmental and biomedical applications

Recently, 2D layered transition metal dichalcogenides (TMDCs) with their ultrathin sheet nanostructure and diversified electronic structure have drawn attention for various advanced applications to achieve high-performance parameters. Unique 2D TMDCs mainly comprise transition metal and chalcogen element where chalcogen element layers sandwich the transition metal element layer. In such a case, various properties can be enhanced and controlled depending on the targeted application. Among manipulative 2D TMDCs, tungsten disulphide (WS2) is one of the emerging nano-system due to its fascinating properties in terms of direct band gap, higher mobility, strong photoluminescence, good thermal stability, and strong magnetic field interaction. The advancement in characterization techniques, especially scattering techniques, can help in study of opto-electronic properties of 2D TMDCs along with determination of layer variations and investigation of defect. In this review, the fabrication and applications are well summarized to optimize an appropriate WS2-TMDCs assembly according to focused field of research. Here, the scientific investigations on 2D WS2 are studied in terms of its structure, role of scattering techniques to study its properties, and synthesis routes followed by its potential applications for environmental remediation (e.g., photocatalytic degradation of pollutants, gas sensing, and wastewater treatment) and biomedical domain (e.g., drug delivery, photothermal therapy, biomedical imaging, and biosensing). Further, a special emphasis is given to the significance of 2D WS2 as a substrate for surface-enhanced Raman scattering (SERS). The discussion is further extended to commercial and industrial aspects, keeping in view major research gaps in existing research studies.

Therapeutic application of manganese-based nanosystems in cancer radiotherapy

Radiotherapy is an important therapeutic modality in the treatment of cancers. Nevertheless, the characteristics of the tumor microenvironment (TME), such as hypoxia and high glutathione (GSH), limit the efficacy of radiotherapy. Manganese-based (Mn-based) nanomaterials offer a promising prospect for sensitizing radiotherapy due to their good responsiveness to the TME. In this review, we focus on the mechanisms of radiosensitization of Mn-based nanosystems, including alleviating tumor hypoxia, increasing reactive oxygen species production, increasing GSH conversion, and promoting antitumor immunity. We further illustrate the applications of these mechanisms in cancer radiotherapy, including the development and delivery of radiosensitizers, as well as their combination with other therapeutic modalities. Finally, we summarize the application of Mn-based nanosystems as contrast agents in realizing precision therapy. Hopefully, the present review will provide new insights into the biological mechanisms of Mn-based nanosystems, as well as their applications in radiotherapy, in order to address the difficulties and challenges that remain in their clinical application in the future.

Meta-Analysis of Nanoparticle Distribution in Tumors and Major Organs in Tumor-Bearing Mice

Low tumor delivery efficiency is a critical barrier in cancer nanomedicine. This study reports an updated version of "Nano-Tumor Database", which increases the number of time-dependent concentration data sets for different nanoparticles (NPs) in tumors from the previous version of 376 data sets with 1732 data points from 200 studies to the current version of 534 data sets with 2345 data points from 297 studies published from 2005 to 2021. Additionally, the current database includes 1972 data sets for five major organs (i.e., liver, spleen, lung, heart, and kidney) with a total of 8461 concentration data points. Tumor delivery and organ distribution are calculated using three pharmacokinetic parameters, including delivery efficiency, maximum concentration, and distribution coefficient. The median tumor delivery efficiency is 0.67% injected dose (ID), which is low but is consistent with previous studies. Employing the best regression model for tumor delivery efficiency, we generate hypothetical scenarios with different combinations of NP factors that may lead to a higher delivery efficiency of >3%ID, which requires further experimentation to confirm. In healthy organs, the highest NP accumulation is in the liver (10.69%ID/g), followed by the spleen 6.93%ID/g and the kidney 3.22%ID/g. Our perspective on how to facilitate NP design and clinical translation is presented. This study reports a substantially expanded "Nano-Tumor Database" and several statistical models that may help nanomedicine design in the future.

Smart Nanozymes for Cancer Therapy: The Next Frontier in Oncology

Nanomaterials that mimic the catalytic activity of natural enzymes in the complex biological environment of the human body are called nanozymes. Recently, nanozyme systems have been reported with diagnostic, imaging, and/or therapeutic capabilities. Smart nanozymes strategically exploit the tumor microenvironment (TME) by the in situ generation of reactive species or by the modulation of the TME itself to result in effective cancer therapy. This topical review focuses on such smart nanozymes for cancer diagnosis, and therapy modalities with enhanced therapeutic effects. The dominant factors that guide the rational design and synthesis of nanozymes for cancer therapy include an understanding of the dynamic TME, structure-activity relationships, surface chemistry for imparting selectivity, and site-specific therapy, and stimulus-responsive modulation of nanozyme activity. This article presents a comprehensive analysis of the subject including the diverse catalytic mechanisms of different types of nanozyme systems, an overview of the TME, cancer diagnosis, and synergistic cancer therapies. The strategic application of nanozymes in cancer treatment can well be a game changer in future oncology. Moreover, recent developments may pave the way for the deployment of nanozyme therapy into other complex healthcare challenges, such as genetic diseases, immune disorders, and ageing.

Mesoporous polydopamine delivery system for intelligent drug release and photothermal-enhanced chemodynamic therapy using MnO2 as gatekeeper

The non-specific leakage of drugs from nanocarriers seriously weakened the safety and efficacy of chemotherapy, and it was very critical of constructing tumor microenvironment (TME)-responsive delivery nanocarriers, achieving the modulation release of drugs. Herein, using manganese dioxide (MnO2) as gatekeeper, an intelligent nanoplatform based on mesoporous polydopamine (MPDA) was developed to deliver doxorubicin (DOX), by which the DOX release was precisely controlled, and simultaneously the photothermal therapy (PTT) and chemodynamic therapy (CDT) were realized. In normal physiological environment, the stable MnO2 shell effectively avoided the leakage of DOX. However, in TME, the overexpressed glutathione (GSH) degraded MnO2 shell, which caused the DOX release. Moreover, the photothermal effect of MPDA and the Fenton-like reaction of the generated Mn2+ further accelerated the cell death. Thus, the developed MPDA-DOX@MnO2 nanoplatform can intelligently modulate the release of DOX, and the combined CDT/PTT/chemotherapy possessed high-safety and high-efficacy against tumors.

Physical Dissolution Combined with Photodynamic Depletion: A Two-Pronged Nanoapproach for Deoxygenation-Driven and Hypoxia-Activated Prodrug Therapy

Hypoxia may enhance the chemoresistance of cancer cells and can significantly compromise the effectiveness of chemotherapy. Many efforts have been made to relieve or reverse hypoxia by introducing more oxygen into the tumor microenvironment (TME). Acting in a diametrically opposite way, in the current study, a novel nanocarrier was designed to further exhaust the oxygen level of the hypoxic TME. By creating such an oxygen depleted TME, the hypoxia-selective cytotoxin can work effectively, and oxygen exhaustion triggered chemotherapy can be achieved. Herein, deoxygenation agent, FDA-approved perfluorocarbon (PFC) and photosensitizer indocyanine green (ICG) for oxygen depletion, along with the hypoxia-activating drug tirapazamine (TPZ), were coincorporated within the poly(lactic-co-glycolic acid) (PLGA) nanoemulsion (ICG/TPZ@PPs) for the treatment of hypoxic tumors. Following hypoxia amplifying through physical oxygen dissolution and photodynamic depletion in tumors, hypoxic chemotherapy could be effectively activated to improve multitreatment synergy. After achieving local tumor enrichment, PFC-mediated oxygen dissolution combined with further ICG-mediated photodynamic therapy (PDT) under near-infrared (NIR) laser irradiation could induce enhanced hypoxia, which would activate the antitumor activity of codelivered TPZ to synergize cytotoxicity. Remarkably, in vivo experimental results exhibited that deoxygenated ICG/TPZ@PPs-based photothermal therapy (PTT), PDT, and hypoxia activated chemotherapy have an excellent synergistic ablation of tumors without obvious side effects, and therefore, a broad prospect of application of this nanocarrier could be expected.

Polydopamine-containing nano-systems for cancer multi-mode diagnoses and therapies: A review

Polydopamine (PDA) has fascinating properties such as inherent biocompatibility, simple preparation, strong near-infrared absorption, high photothermal conversion efficiency, and strong metal ion chelation, which have catalyzed extensive research in PDA-containing multifunctional nano-systems particularly for biomedical applications. Thus, it is imperative to overview synthetic strategies of various PDA-containing nanoparticles (NPs) for state-of-the-art cancer multi-mode diagnoses and therapies applications, and offer a timely and comprehensive summary. In this review, we will focus on the synthetic approaches of PDA NPs, and summarize the construction strategies of PDA-containing NPs with different structure forms. Additionally, the application of PDA-containing NPs in bioimaging such as photoacoustic imaging, fluorescence imaging, magnetic resonance imaging and other imaging modalities will be reviewed. We will especially offer an overview of their therapeutic applications in tumor chemotherapy, photothermal therapy, photodynamic therapy, photocatalytic therapy, sonodynamic therapy, radionuclide therapy, gene therapy, immunotherapy and combination therapy. At the end, the current trends, limitations and future prospects of PDA-containing nano-systems will be discussed. This review aims to provide guidelines for new scientists in the field of how to design PDA-containing NPs and what has been achieved in this area, while offering comprehensive insights into the potential of PDA-containing nano-systems used in cancer diagnosis and treatment.

Microenvironment Restruction of Emerging 2D Materials and their Roles in Therapeutic and Diagnostic Nano-Bio-Platforms

Engineering advanced therapeutic and diagnostic nano-bio-platforms (NBPFs) have emerged as rapidly-developed pathways against a wide range of challenges in antitumor, antipathogen, tissue regeneration, bioimaging, and biosensing applications. Emerged 2D materials have attracted extensive scientific interest as fundamental building blocks or nanostructures among material scientists, chemists, biologists, and doctors due to their advantageous physicochemical and biological properties. This timely review provides a comprehensive summary of creating advanced NBPFs via emerging 2D materials (2D-NBPFs) with unique insights into the corresponding molecularly restructured microenvironments and biofunctionalities. First, it is focused on an up-to-date overview of the synthetic strategies for designing 2D-NBPFs with a cross-comparison of their advantages and disadvantages. After that, the recent key achievements are summarized in tuning the biofunctionalities of 2D-NBPFs via molecularly programmed microenvironments, including physiological stability, biocompatibility, bio-adhesiveness, specific binding to pathogens, broad-spectrum pathogen inhibitors, stimuli-responsive systems, and enzyme-mimetics. Moreover, the representative therapeutic and diagnostic applications of 2D-NBPFs are also discussed with detailed disclosure of their critical design principles and parameters. Finally, current challenges and future research directions are also discussed. Overall, this review will provide cutting-edge and multidisciplinary guidance for accelerating future developments and therapeutic/diagnostic applications of 2D-NBPFs.

Mesoporous polydopamine delivering 8-gingerol for the target and synergistic treatment to the spinal cord injury

In the treatment of spinal cord injury (SCI), the complex process of secondary injury is mainly responsible for preventing SCI repair or even exacerbating the injury. In this experiment, we constructed the 8-gingerol (8G)-loaded mesoporous polydopamine (M-PDA), M@8G, as the in vivo targeting nano-delivery platform, and investigated the therapeutic effects of M@8G in secondary SCI and its related mechanisms. The results indicated that M@8G could penetrate the blood-spinal cord barrier to enrich the spinal cord injury site. Mechanism research has shown that all of the M-PDA,8G and M@8G displayed the anti-lipid peroxidation effect, and then M@8G can inhibit the secondary SCI by suppressing the ferroptosis and inflammation. In vivo assays showed that M@8G significantly diminished the local injury area, reduced axonal and myelin loss, thus improving the neurological and motor recovery in rats. Based on the analysis of cerebrospinal fluid samples from patients, ferroptosis occurred locally in SCI and continued to progress in patients during the acute phase of SCI as well as the stage after their clinical surgery. This study showcases effective treatment of SCI through the aggregation and synergistic effect of M@8G in focal areas, providing a safe and promising strategy for the clinical treatment of SCI.

Application of nano-radiosensitizers in combination cancer therapy

Radiosensitizers are compounds or nanostructures, which can improve the efficiency of ionizing radiation to kill cells. Radiosensitization increases the susceptibility of cancer cells to radiation-induced killing, while simultaneously reducing the potentially damaging effect on the cellular structure and function of the surrounding healthy tissues. Therefore, radiosensitizers are therapeutic agents used to boost the effectiveness of radiation treatment. The complexity and heterogeneity of cancer, and the multifactorial nature of its pathophysiology has led to many approaches to treatment. The effectiveness of each approach has been proven to some extent, but no definitive treatment to eradicate cancer has been discovered. The current review discusses a broad range of nano-radiosensitizers, summarizing possible combinations of radiosensitizing NPs with several other types of cancer therapy options, focusing on the benefits and drawbacks, challenges, and future prospects.

Piezocatalytic 2D WS2 Nanosheets for Ultrasound-Triggered and Mitochondria-Targeted Piezodynamic Cancer Therapy Synergized with Energy Metabolism-Targeted Chemotherapy

Piezoelectric nanomaterials that can generate reactive oxygen species (ROS) by piezoelectric polarization under an external mechanical force have emerged as an effective platform for cancer therapy. In this study, piezoelectric 2D WS₂ nanosheets are functionalized with mitochondria-targeting triphenylphosphonium (TPP) for ultrasound (US)-triggered, mitochondria-targeted piezodynamic cancer therapy. In addition, a glycolysis inhibitor (FX11) that can inhibit cellular energy metabolism is loaded into TPP- and poly(ethylene glycol) (PEG)-conjugated WS₂ nanosheet (TPEG-WS₂ ) to potentiate its therapeutic efficacy. Upon US irradiation, the sono-excited electrons and holes generated in the WS₂ are efficiently separated by piezoelectric polarization, which subsequently promotes the production of ROS. FX11-loaded TPEG-WS₂ (FX11@TPEG-WS₂ ) selectively accumulates in the mitochondria of human breast cancer cells. In addition, FX11@TPEG-WS₂ effectively inhibits the production of adenosine triphosphate . Thus, FX11@TPEG-WS₂ exhibits outstanding anticancer effects under US irradiation. An in vivo study using tumor-xenograft mice demonstrates that FX11@TPEG-WS₂ effectively accumulated in the tumors. Its tumor accumulation is visualized using in vivo computed tomography . Notably, FX11@TPEG-WS₂ with US irradiation remarkably suppresses the tumor growth of mice without systemic toxicity. This study demonstrates that the combination of piezodynamic therapy and energy metabolism-targeted chemotherapy using mitochondria-targeting 2D WS₂ is a novel strategy for the selective and effective treatment of tumors.

Renal-Clearable Probe with Water Solubility and Photostability for Biomarker-Activatable Detection of Acute Kidney Injuries via NIR-II Fluorescence and Optoacoustic Imaging

Acute kidney injuries (AKI) have serious short-term or long-term complications with high morbidity and mortality rate, thus posing great health threats. Developing high-performance NIR-II probes for noninvasive in situ detection of AKI via NIR-II fluorescent and optoacoustic dual-mode imaging is of great significance. Yet NIR-II chromophores often feature long conjugation and hydrophobicity, which prevent them from being renal clearable, thus limiting their applications in the detection and imaging of kidney diseases. To fully exploit the advantageous features of heptamethine cyanine dye, while overcoming its relatively poor photostability, and to strive to design a NIR-II probe for the detection and imaging of AKI with dual-mode imaging, herein, we have developed the probe PEG3-HC-PB, which is renal clearable, water soluble, and biomarker activatable and has good photostability. As for the probe, its fluorescence (900-1200 nm) is quenched due to the existence of the electron-pulling phenylboronic group (responsive element), and it exhibits weak absorption with a peak at 830 nm. Meanwhile, in the presence of the overexpressed H₂O₂ in the renal region in the case of AKI, the phenylboronic group is converted to the phenylhydroxy group, which enhances NIR-II fluorescent emission (900-1200 nm) and absorption (600-900 nm) and eventually produces conspicuous optoacoustic signals and NIR-II fluorescent emission for imaging. This probe enables detection of contrast-agent-induced and ischemia/reperfusion-induced AKI in mice using real-time 3D-MSOT and NIR-II fluorescent dual-mode imaging via response to the biomarker H₂O₂. Hence, this probe can be used as a practicable tool for detecting AKI; additionally, its design strategy could provide insight into the design of other large-conjugation NIR-II probes with multifarious biological applications.

Biomimetic liposomal nanozymes improve breast cancer chemotherapy with enhanced penetration and alleviated hypoxia

BACKGROUND

Doxorubicin (Dox) has been recommended in clinical guidelines for the standard-of-care treatment of breast cancer. However, Dox therapy faces challenges such as hypoxia, acidosis, H₂O₂-rich conditions and condensed extracellular matrix in TME as well as low targeted ability.

METHODS

We developed a nanosystem H-MnO₂-Dox-Col NPs based on mesoporous manganese dioxide (H-MnO₂) in which Dox was loaded in the core and collagenase (Col) was wrapped in the surface. Further the H-MnO₂-Dox-Col NPs were covered by a fusion membrane (MP) of inflammation-targeted RAW264.7 cell membrane and pH-sensitive liposomes to form biomimetic MP@H-MnO₂-Dox-Col for in vitro and in vivo study.

RESULTS

Our results shows that MP@H-MnO₂-Dox-Col can increase the Dox effect with low cardiotoxicity based on multi-functions of effective penetration in tumor tissue, alleviating hypoxia in TME, pH sensitive drug release as well as targeted delivery of Dox.

CONCLUSIONS

This multifunctional biomimetic nanodelivery system exhibited antitumor efficacy in vivo and in vitro, thus having potential for the treatment of breast cancer.

Oxygen switches: Refueling for cancer radiotherapy

Radiotherapy remains the major therapeutic intervention for tumor patients. However, the hypoxic tumor microenvironment leads to treatment resistance. Recently, a burgeoning number of nano-radiosensitizers designed to increase the oxygen concentration in tumors were reported. These nano radiosensitizers served as oxygen carriers, oxygen generators, and even sustained oxygen pumps, attracting increased research interest. In this review, we focus on the novel oxygen-enrich nano radiosensitizers, which we call oxygen switches, and highlight their influence in radiotherapy through different strategies. Physical strategies-based oxygen switches carried O2 into the tumor via their high oxygen capacity. The chemical reactions to generate O2 in situ were triggered by chemical strategies-based oxygen switches. Biological strategies-based oxygen switches regulated tumor metabolism, remodeled tumor vasculature, and even introduced microorganisms-mediated photosynthesis for long-lasting hypoxia alleviating. Moreover, the challenges and perspectives of oxygen switches-mediated oxygen-enrich radiotherapy were discussed.

A pH-Responsive Charge-Convertible Drug Delivery Nanocarrier for Precise Starvation and Chemo Synergistic Oncotherapy

A pH-responsive charge-convertible drug delivery nanocarrier (MSN-TPZ-GOx@ZnO@PAH-PEG-DMMA, abbreviated as MTGZ@PPD) was prepared, which could specifically release hypoxia-activated chemotherapeutic Tirapazamine (TPZ) and glucose oxidase (GOx) in the tumor site for precise starvation and chemo synergistic oncotherapy. Acid-responsive Schiff base structure modified mesoporous silica nanoparticles (MSN) co-load with GOx and TPZ, then link with ZnO quantum dots (QDs). PAH-PEG-DMMA (PPD) polymer makes MTGZ@PPD with biocompatibility and charge-convertible feature. MTGZ@PPD is negatively charged at physiological pH, and the charge reversal of PPD and acidolysis of the Schiff base structure under the acidic tumor microenvironment (TME) induce a positively charged surface, which could potentiate the cell internalization. ZnO QDs could decompose at acidic TME, achieving controllable drug release. GOx could starve the tumor cells and enhance hypoxia level, thus initiates the activation of TPZ to realize synergistic starvation therapy and chemotherapy. This intelligent MTGZ@PPD has shown great potential for starvation and chemo synergistic oncotherapy.

Smart Chemical Oxidative Polymerization Strategy To Construct Au@PPy Core-Shell Nanoparticles for Cancer Diagnosis and Imaging-Guided Photothermal Therapy

Imaging-guided photothermal therapy (PTT) in a single nanoscale platform has aroused extensive research interest in precision medicine, yet only a few methods have gained wide acceptance. Thus, it remained an urgent need to facilely develop biocompatible and green probes with excellent theranostic capacity for superior biomedical applications. In this study, a smart chemical oxidative polymerization strategy was successfully developed for the synthesis of Au@PPy core-shell nanoparticles with polyvinyl alcohol (PVA) as the hydrophile. In the reaction, the reactant tetrachloroauric acid (HAuCl₄) was reduced by pyrrole to fabricate a gold (Au) core, and pyrrole was oxidized to deposit around the Au core to form a polypyrrole (PPy) shell. The as-synthesized Au@PPy nanoparticles showed a regular core-shell morphology and good colloidal stability. Relying on the high X-ray attenuation of Au and strong near-infrared (NIR) absorbance of PPy and Au, Au@PPy nanoparticles exhibited excellent performance in blood pool/tumor imaging and PTT treatment by a series of in vivo experiments, in which tumor could be precisely positioned and thoroughly eradicated. Hence, the facile chemical oxidative polymerization strategy for constructing monodisperse Au@PPy core-shell nanoparticles with potential for cancer diagnosis and imaging-guided photothermal therapy shed light on an innovative design concept for the facile fabrication of biomedical materials.

Copolymerized carbon nitride nanoparticles for near-infrared II photoacoustic-guided synergistic photothermal/radiotherapy

Nanotheranostic agents that integrate diagnosis and treatment are promising for precision medicine, but they encounter some obstacles such as penetration depth and efficiency. In this study, novel carbon nitride-rose bengal nanoparticles (CN-RB NPs) with a graphite carbon nitride skeleton were synthesized by one-step thermal copolymerization. The enhanced absorption in the near-infrared-II region (NIR-II) endows CN-RB NPs with an excellent photothermal effect under 1064 nm laser irradiation, as well as an obvious photoacoustic signal for imaging in vivo. Interestingly, due to the introduced iodine element, CN-RB NPs exhibit enhanced radiation therapy, indicating that CN-RB NPs can achieve ideal therapeutic outcome through collaborative photothermal/radiation therapy under the guidance of NIR-II photoacoustic imaging. Moreover, CN-RB NPs demonstrate minimal side effects and long-term biological stability after 14 days. Therefore, the proposed new multifunctional nano-platform CN-RB NPs hold great potential in the application of deep therapeutics.

Prospects for hypoxia-based drug delivery platforms for the elimination of advanced metastatic tumors: From 3D modeling to clinical concepts

Hypoxia is a unique characteristic of the solid tumor microenvironment. Hypoxia contributes to multi-drug resistance, metastasis and cancer relapse through numerous molecular pathways, but at the same time provides an opportunity for the development of novel drugs or modalities specifically targeting hypoxic tumor regions. Given the high significance of tumor hypoxia in therapeutic results, we here discuss a variety of hypoxia-adopted strategies, and their potential and utility in the treatment of deep-seated hypoxic tumor cells. We discuss the merits and demerits of these approaches, as well as their combination with other approaches such as photodynamic therapy. We also survey the currently available 3D hypoxia modeling systems, in particular organoid-based microfluidics. Finally, we discuss the potential and the current status of preclinical tumor hypoxia approaches in clinical trials for advanced cancer. We believe that multi-modal imaging and therapeutic hypoxia adopted drug delivery platforms could provide better efficacy and safety profiles, and more importantly personalized therapy. Determining the hypoxia status of tumors could offer a second chance for the clinical translation of hypoxia-based agents, such as hypoxia activated prodrugs (HAPs) from bench to bedside.

Tungsten-based Nanomaterials in the Biomedical Field: A Bibliometric Analysis of Research Progress and Prospects

Tungsten-based nanomaterials (TNMs) with diverse nanostructures and unique physicochemical properties have been widely applied in the biomedical field. Although various reviews have described the application of TNMs in specific biomedical fields, there are still no comprehensive studies that summarize and analyze research trends of the field as a whole. To identify and further promote the development of biomedical TNMs, a bibliometric analysis method is used to analyze all relevant literature on this topic. First, general bibliometric distributions of the dataset by year, country, institute, referenced source, and research hotspots are recognized. Next, a comprehensive review of the subjectively recognized research hotspots in various biomedical fields, including biological sensing, anticancer treatments, antibacterials, and toxicity evaluation, is provided. Finally, the prospects and challenges of TNMs are discussed to provide a new perspective for further promoting their development in biomedical research.

Frontiers in Preparations and Promising Applications of Mesoporous Polydopamine for Cancer Diagnosis and Treatment

Polydopamine (PDA) is a natural melanin derived from marine mussels that has good biocompatibility, biodegradability, and photothermal conversion ability. As a new coating material, it offers a novel way to modify the surface of various substances. The drug loading capacity and encapsulation efficiency of PDA are greatly improved via the use of mesoporous materials. The abundant pore canals on mesoporous polydopamine (MPDA) exhibit a uniquely large surface area, which provides a structural basis for drug delivery. In this review, we systematically summarized the characteristics and manufacturing process of MPDA, introduced its application in the diagnosis and treatment of cancer, and discussed the existing problems in its development and clinical application. This comprehensive review will facilitate further research on MPDA in the fields of medicine including cancer therapy, materials science, and biology.

Thrombus Inhibition and Neuroprotection for Ischemic Stroke Treatment through Platelet Regulation and ROS Scavenging

Ischemic stroke is caused by cerebrovascular stenosis or occlusion. Excessive reactive oxygen species (ROS) are the focus-triggering factor of irreversible injury in ischemic regions, which result in harmful cascading effects to brain tissue, such as inflammation and microthrombus formation. In the present work, we designed nanodelivery systems (NDSs) based on MnO₂ loaded with Ginkgolide B (GB) for restoring the intracerebral microenvironment in ischemic stroke, such as ROS scavenging, O₂ elevation, thrombus inhibition and damage repair. GB can activate the endogenous antioxidant defense of cells by enhancing the nuclear factor-E2-related factor 2 (Nrf2) signalling pathway, thus protecting brain tissue from oxidative damage. However, the blood-brain barrier (BBB) is also a therapeutic obstacle for the delivery of these agents to ischemic regions. MnO₂ nanoparticles have an inherent BBB penetration effect, which enhances the delivery of therapeutic agents within brain tissue. MnO₂ , with mimicking enzymatic activity, can catalyze the decomposition of overproduced H₂ O₂ in the ischemic microenvironment to O₂ , meanwhile releasing platelet-antagonizing GB molecules, thus alleviating cerebral hypoxia, oxidative stress damage, and microthrombus generation. This study may provide a promising therapeutic route for regulating the microenvironment of ischemic stroke through a combined function of ROS scavenging, microthrombus inhibition, and BBB penetration.

Ultrasmall Gold-Coated Mesoporous Polydopamine Nanoprobe to Enhance Chemodynamic Therapy by Self-Supplying H2O2 and Photothermal Stimulation

Tumor microenvironment (TME) responsive chemodynamic therapy (CDT) showed an important application in inhibiting tumor growth by producing the highly toxic hydroxyl radical (·OH), but insufficient hydrogen peroxide (H₂O₂) and overexpressed glutathione (GSH) limited its application. Herein, by integrating photothermal therapy (PTT) and CDT, a new kind of mesoporous polydopamine (MPDA)-based cascade-reaction nanoplatform (MPDA@AuNPs-Cu) was designed for enhanced antitumor therapy, in which ultrasmall gold nanoparticles (AuNPs) with glucose oxidase (GOx)-like activity were deposited on MPDA for providing H₂O₂, and Cu²⁺ was chelated for GSH-responsive Fenton-like reaction. It was demonstrated that the MPDA@AuNPs-Cu nanoprobe showed high photothermal conversion efficiency and excellent biocompatibility. Moreover, the MPDA@AuNPs-Cu nanoprobe exhibited strong ·OH generation because of H₂O₂ self-generation and photothermal stimulation. Importantly, compared with MPDA-Cu, MPDA@AuNPs-Cu exhibited enhanced in vitro and in vivo CDT/PTT performance, by which the tumor growth was completely inhibited, achieving TME-responsive antitumor efficacy.

Targeted Wolfram-Doped Polypyrrole for Photonic Hyperthermia-Synergized Radiotherapy

Single ionizing radiation at a tolerable dose is ineffectual in eliminating malignancies but readily generates harmful effects on surrounding normal tissues. Herein, we intelligently fabricated novel wolfram-doped polypyrrole (WPPy) through a simple oxidative polymerization method with WCl₆ as an oxidizing catalyst, which possessed good biocompatibility, high photothermal conversion, and intensive radiosensitivity capacities to concurrently serve as a photothermal reagent and a radiosensitizer for hyperthermia-synergized radiotherapy (RT) against a malignant tumor. In comparison with traditional polypyrrole without noble metal doping, the innovative introduction of WCl₆ not only successfully launched the polymerization of a pyrrole monomer but also endowed WPPy with additional radiosensitization. More importantly, after further decoration with an active targeted component (SP94 polypeptide), the obtained WPPy@SP94 significantly increased tumor internalization and accumulation in vitro and in vivo and induced obvious DNA damage as well as robust ROS generation under X-ray irradiation, which meanwhile synergized with strong photonic hyperthermia to effectively inhibit tumor growth by single drug injection. Moreover, such biocompatible WPPy@SP94 showed negligible adverse effects on normal cells and tissues. WPPy@SP94 developed in this study not only expands the category of polypyrrole chemical syntheses but also sheds light on WPPy@SP94-based radiosensitizers for cancer RT.

New anti-cancer explorations based on metal ions

Due to the urgent demand for more anti-cancer methods, the new applications of metal ions in cancer have attracted increasing attention. Especially the three kinds of the new mode of cell death, including ferroptosis, calcicoptosis, and cuproptosis, are of great concern. Meanwhile, many metal ions have been found to induce cell death through different approaches, such as interfering with osmotic pressure, triggering biocatalysis, activating immune pathways, and generating the prooxidant effect. Therefore, varieties of new strategies based on the above approaches have been studied and applied for anti-cancer applications. Moreover, many contrast agents based on metal ions have gradually become the core components of the bioimaging technologies, such as MRI, CT, and fluorescence imaging, which exhibit guiding significance for cancer diagnosis. Besides, the new nano-theranostic platforms based on metal ions have experimentally shown efficient response to endogenous and exogenous stimuli, which realizes simultaneous cancer therapy and diagnosis through a more controlled nano-system. However, most metal-based agents have still been in the early stages, and controlled clinical trials are necessary to confirm or not the current expectations. This article will focus on these new explorations based on metal ions, hoping to provide some theoretical support for more anti-cancer ideas.

Black phosphorous nanomaterials as a new paradigm for postoperative tumor treatment regimens

Surgery is currently a mainstream treatment modality for various solid tumor indications. However, aggressive resection of tumor tissues frequently causes postoperative complications, which severely undermine the well-being of patients. Moreover, the residue tumor cells may substantially increase the risk of local and distant tumor relapse. The recent development in black phosphorus (BP)-based nanomaterials offers a promising opportunity to address these clinical challenges. BP is an emerging nanomaterial with excellent biocompatibility and versatile functionality, which has already demonstrated great potential for a variety of biomedical applications including tumor therapy and tissue engineering. In this review, the recent advances in BP-based nanobiomaterials for the post-surgery treatment of solid tumor have been summarized, while specific emphasis was placed on their capability to continuously inhibit residue tumor growth at the surgery site as well as stimulating various healing mechanisms, aiming to preventing tumor relapse while promoting the healing of surgery-induced traumatic soft/hard tissue injuries. It is anticipated that the nanoengineered BP-based materials may open new avenues to tackle those clinical challenges in surgical treatment of solid tumors.

Dual-Mode Tumor Imaging Using Probes That Are Responsive to Hypoxia-Induced Pathological Conditions

Hypoxia in solid tumors is associated with poor prognosis, increased aggressiveness, and strong resistance to therapeutics, making accurate monitoring of hypoxia important. Several imaging modalities have been used to study hypoxia, but each modality has inherent limitations. The use of a second modality can compensate for the limitations and validate the results of any single imaging modality. In this review, we describe dual-mode imaging systems for the detection of hypoxia that have been reported since the start of the 21st century. First, we provide a brief overview of the hallmarks of hypoxia used for imaging and the imaging modalities used to detect hypoxia, including optical imaging, ultrasound imaging, photoacoustic imaging, single-photon emission tomography, X-ray computed tomography, positron emission tomography, Cerenkov radiation energy transfer imaging, magnetic resonance imaging, electron paramagnetic resonance imaging, magnetic particle imaging, and surface-enhanced Raman spectroscopy, and mass spectrometric imaging. These overviews are followed by examples of hypoxia-relevant imaging using a mixture of probes for complementary single-mode imaging techniques. Then, we describe dual-mode molecular switches that are responsive in multiple imaging modalities to at least one hypoxia-induced pathological change. Finally, we offer future perspectives toward dual-mode imaging of hypoxia and hypoxia-induced pathophysiological changes in tumor microenvironments.

Vascular bursts-mediated tumor accumulation and deep penetration of spherical nucleic acids for synergistic radio-immunotherapy

While nanomedicines have attracted great interests for tumor therapy, their targeting and intra-tumoral penetrating efficiencies have been questioned. Here, we report a two-step low-dose radiotherapy (RT) strategy to realize significant accumulation and deep penetration of spherical nucleic acids (SNAs)-based nanomedicine for synergistic radio-immunotherapy. The first step RT was employed to recruit large amounts of macrophages into tumor. The tumor infiltrated macrophages not only served as nanoparticles drug depots, but also elicited dynamic bursts extravasation to enhance nanoparticles accumulation. We optimized the spatiotemporal combination of RT and SNAs administration for higher level of SNAs delivery, and the delivered SNAs promote M2-to-M1 phenotype switch of macrophages to increase phagocytosis of nanoparticles by 6-fold, resulting in positive feedback with even higher accumulation and intra-tumor penetration of SNAs. Through vascular bursts and macrophage repolarization, as high as 25-fold enhancement of nanoparticles accumulation was achieved as compared to passive targeting of nanoparticles, and the nanoparticles were eventually distributed throughout the tumor tissue with efficient deep penetration. Finally, SNAs in tumor simultaneously sensitized the second dose of RT and remodeled tumor immune microenvironment, resulting in a synergistic anticancer therapy in combination of anti-PD-L1 antibody (αPD-L1) with no noticeable side effects caused by either RT or αPD-L1.

Mild phototherapy mediated by manganese dioxide-loaded mesoporous polydopamine enhances immunotherapy against colorectal cancer

One of the main challenges in applying the immune checkpoint blockade to treat colorectal cancer (CRC) is the immunosuppressive tumor microenvironment. Owing to its excellent cancer cell killing ability and immune activation, mild photothermal therapy (PTT) has shown bright promise to sensitize tumors to immune checkpoint inhibition through turning the immunologically "cold" tumors into "hot" ones. Herein, a mild photothermal effect-assisted theragnostic nanodrug (MnO₂@MPDA-PEG NPs) is developed by incorporating MnO₂ into PEGylated-mesoporous polydopamine nanoparticles (MPDA-PEG NPs). The presence of PEG endows the theragnostic nanodrug with high biostability. After accumulation in colorectal tumor, the theragnostic nanodrug responds to the tumor microenvironment, leading to the simultaneous release of Mn²⁺ which serves as a magnetic resonance imaging (MRI) contrast agent for tumor imaging. The released Mn²⁺ could also promote mild photothermal treatment-induced immune response, including the maturation of BMDC cells. In vivo antitumor studies on a CT26 model demonstrate that MnO₂@MPDA-PEG NPs could be a promising dual-imaging theragnostic nanodrug to potentiate the systemic antitumor immunities.

A multi-hit therapeutic nanoplatform for hepatocellular carcinoma: Dual stimuli-responsive drug release, dual-modal imaging, and in situ oxygen supply to enhance synergistic therapy

Nanomedicine has been widely studied for the diagnosis and treatment of hepatocellular carcinoma (HCC). How to synthesize a nanoplatform possessing a high synergistic therapeutic efficacy remains a challenge in this emerging research field. In this study, a convenient all-in-one therapeutic nanoplatform (FTY720@AM/T7-TL) is designed for HCC. This advanced nanoplatform consists of multiple functional elements, including gold-manganese dioxide nanoparticles (AM), tetraphenylethylene (T), fingolimod (FTY720), hybrid-liposome (L), and T7 peptides (T7). The nanoplatform is negatively charged at physiological pH and can transit to a positively charged state once moving to acidic pH environments. The specially designed pH-responsive charge-reversal nanocarrier prolongs the half-life of nanodrugs in blood and improves cellular uptake efficiency. The platform achieves a sustained and controllable drug release through dual stimulus-response, with pH as the endogenous stimulus and near-infrared as the exogenous stimulus. Furthermore, the nanoplatform realizes in situ O₂ generation by catalyzing tumor over-expressed H₂O₂, which alleviates tumor microenvironment hypoxia and improves photodynamic therapy. Both in vitro and in vivo studies show the prepared nanoplatform has good photothermal conversion, cellular uptake efficiency, fluorescence/magnetic resonance imaging capabilities, and synergistic anti-tumor effects. These results suggest that the prepared all-in-one nanoplatform has great potential for dual-modal imaging-guided synergistic therapy of HCC.

Biodegradation Mn-CoS@carbon di-shell nanoheterostructure with enhanced nanozyme-mediated phototherapy

The efficacy of phototherapy is dependent on intracellular O₂ concentration and NIR harvest. Here, a simple nanoplatform with nanoenzyme mediated phototherapy enhances anticancer capacity. Mn-CoS@carbon (CMS/C) di-shell hollow nanospheres (50 nm) are synthesized successfully through two-step consecutive Kirkendall process. The nanoheterostructure reveals the higher near-infrared (NIR) light absorption and photothermal conversion rate of 66.3% than pure CoS (45.5%), owing to the decreased band gap and multi-reflection of incident light in the hollow structure. And CMS/C reveals the reactive oxygen species (ROS) production and nanoenzyme activities (mimic peroxidase and catalase) that are 6 and 2 times than those of pure CoS. Furthermore, the nanoenzyme exhibits NIR-enhanced abilities to produce more OH and O₂ facilitating anticancer. In addition, it also depletes glutathione (mimicking glutathione oxidase), to disturb intracellular redox-homeostasis, boosting the increase of oxidative stress. With grafting bovine serum albumin (BSA) and drug loading, CMS/C@BSA-Dox integrated multi-therapy make the great anticancer effect in vitro and vivo. After that, the nanocomposite could be biodegraded and eliminated via urinary and feces within 14 days. Based on this work, the efficient charge-separation can be designed to reveal high performance nanoenzymes as well as photosensitizers for anticancer.

Recent Advances in Transition-Metal Based Nanomaterials for Noninvasive Oncology Thermal Ablation and Imaging Diagnosis

With the developments of nanobiotechnology and nanomedicine, non-invasive thermal ablation with fewer side effects than traditional tumor treatment methods has received extensive attention in tumor treatment. Non-invasive thermal ablation has the advantages of non-invasiveness and fewer side effects compared with traditional treatment methods. However, the clinical efficiency and biological safety are low, which limits their clinical application. Transition-metal based nanomaterials as contrast agents have aroused increasing interest due to its unique optical properties, low toxicity, and high potentials in tumor diagnosis. Transition-metal based nanomaterials have high conversion efficiency of converting light energy into heat energy, good near-infrared absorption characteristics, which also can targetedly deliver those loaded drugs to tumor tissue, thereby improving the therapeutic effect and reducing the damage to the surrounding normal tissues and organs. This article mainly reviews the synthesis of transition-metal based nanomaterials in recent years, and discussed their applications in tumor thermal ablation and diagnosis, hopefully guiding the development of new transition metal-based nanomaterials in enhancing thermal ablation.

BSA-templated Ultrasmall Ag/Gd2O3 as A Self-enabled Nanotheranostics for MR/CT/PA tri-modality Imaging and Photothermal Therapy

It is becoming more and more important to effectively integrate multiple complementary diagnostic imaging and synergistic therapy into a nano-platform, but it is still challenging. Here, we used bovine serum...

Biodegradable and Excretable 2D W1.33 C i-MXene with Vacancy Ordering for Theory-Oriented Cancer Nanotheranostics in Near-Infrared Biowindow

MXenes, a new class of two-dimensional (2D) nanomaterials, have shown enormous potential for biological applications. Notably, the development of 2D MXenes in nanomedicine is still in its infancy. Herein, a distinct W1.33 C i-MXene with multiple theranostic functionalities, fast biodegradation, and satisfactory biocompatibility is explored. By designing a parent bulk laminate in-plane ordered (W2/3 Y1/3 )2 AlC ceramic and optionally etching aluminum (Al) and yttrium (Y) elements, 2D W1.33 C i-MXene nanosheets with ordered divacancies are efficiently fabricated. Especially, theoretical simulations reveal that W1.33 C i-MXene possesses a strong predominance of near-infrared (NIR) absorbance. The constructed ultrathin W1.33 C nanosheets feature excellent photothermal-conversion effectiveness (32.5% at NIR I and 49.3% at NIR II) with desirable biocompatibility and fast degradation in normal tissue rather than in tumor tissue. Importantly, the multimodal-imaging properties and photothermal-ablation performance of W1.33 C-BSA nanosheets are systematically revealed and demonstrated both in vitro and in vivo. The underlying mechanism and regulation factors for the W1.33 C-BSA nanosheets-induced hyperthermia ablation are also revealed by transcriptome and proteome sequencing. This work offers a paradigm that i-MXenes achieve the tailoring biomedical applications through composition and structure design on the atomic scale.

Tumor Diagnosis and Therapy Mediated by Metal Phosphorus-Based Nanomaterials

Metal phosphorus-based nanomaterials (Metal-P NMs) including metal phosphate nanomaterials, metal phosphide nanomaterials, and metal-black phosphorus (Metal-BP) nanocomposite are widely used in the field of biomedicine owing to their excellent physical and chemical properties, biocompatibility, and biodegradability. In recent years, metal phosphate nanomaterials and Metal-BP nanocomposite acted as medicine delivery system have made breakthroughs in tumor diagnosis including magnetic resonance imaging, fluorescence imaging, photoacoustic imaging, nuclear imaging, and therapies including chemotherapy, gene therapy, photothermal therapy, photodynamic therapy, and radiation therapy. Metal phosphate nanomaterials have good biodegradability, especially calcium-based metal phosphate nanomaterials can be dissolved into nontoxic ions and participate in the metabolisms of normal organs. Compared with metal phosphate nanomaterials, metal phosphide nanomaterials have excellent optical, magnetic, and catalytic properties, which can be used as multifunctional diagnostic nanoplatforms and therapeutic agents for chemodynamic therapy, photothermal therapy, or immunotherapy. The latest developments in Metal-P NMs, covering the range of preparation methods and biological applications, such as serving as drug carriers, tumor diagnosis, and therapy, are focused. All in all, the current trends, key issues, future prospects and challenges of Metal-P NMs are concluded and discussed, which are important for the development of this research field and shining more lights on this direction.

Plasmonic Oxygen Defects in MO3- x (M = W or Mo) Nanomaterials: Synthesis, Modifications, and Biomedical Applications

Nanomedicine is a promising technology with many advantages and provides exciting opportunities for cancer diagnosis and therapy. During recent years, the newly developed oxygen-deficiency transition metal oxides MO_{3- x} (M = W or Mo) have received significant attention due to the unique optical properties, such as strong localized surface plasmon resonance (LSPR) , tunable and broad near-IR absorption, high photothermal conversion efficiency, and large X-ray attenuation coefficient. This review presents an overview of recent advances in the development of MO_{3- x} nanomaterials for biomedical applications. First, the fundamentals of the LSPR effect are introduced. Then, the preparation and modification methods of MO_{3- x} nanomaterials are summarized. In addition, the biological effects of MO_{3- x} nanomaterials are highlighted and their applications in the biomedical field are outlined. This includes imaging modalities, cancer treatment, and antibacterial capability. Finally, the prospects and challenges of MO_{3- x} and MO_{3- x} -based nanomaterial for fundamental studies and clinical applications are also discussed.

Recent developments in mesoporous polydopamine-derived nanoplatforms for cancer theranostics

Polydopamine (PDA), which is derived from marine mussels, has excellent potential in early diagnosis of diseases and targeted drug delivery owing to its good biocompatibility, biodegradability, and photothermal conversion. However, when used as a solid nanoparticle, the application of traditional PDA is restricted because of the low drug-loading and encapsulation efficiencies of hydrophobic drugs. Nevertheless, the emergence of mesoporous materials broaden our horizon. Mesoporous polydopamine (MPDA) has the characteristics of a porous structure, simple preparation process, low cost, high specific surface area, high light-to-heat conversion efficiency, and excellent biocompatibility, and therefore has gained considerable interest. This review provides an overview of the preparation methods and the latest applications of MPDA-based nanodrug delivery systems (chemotherapy combined with radiotherapy, photothermal therapy combined with chemotherapy, photothermal therapy combined with immunotherapy, photothermal therapy combined with photodynamic/chemodynamic therapy, and cancer theranostics). This review is expected to shed light on the multi-strategy antitumor therapy applications of MPDA-based nanodrug delivery systems.

A multifunctional nanoamplifier with self-enhanced acidity and hypoxia relief for combined photothermal/photodynamic/starvation therapy

Phototherapies, including photothermal therapy (PTT) and photodynamic therapy (PDT) have been potential noninvasive therapeutic modality with high efficiency, however, there still exist some intrinsic limitations that impede their clinical applications. Herein, taking the advantages of the synergistic effect and high reactivity of manganese dioxide (MnO₂) nanosheets and glucose oxidase (GOx), multifunctional MPDA@MnO₂-MB-GOx nanoamplifier was constructed for enhanced PTT, PDT, and starvation therapy. In tumor microenvironment (TME), MnO₂ nanosheets on the surface of mesoporous polydopamine (MPDA) could react with endogenous hydrogen peroxide (H₂O₂) and generate oxygen (O₂) to relieve tumor hypoxia, thus enhancing the efficacy of PDT and GOx catalysis. Glucose consumption under the catalysis of GOx will enhance the acidity of TME and increase intracellular H₂O₂ concentration, which in turn promotes the production of O₂ by MnO₂ nanosheets, thus forming efficient cascade reaction and maximizing the efficacy of the functional agents. Furthermore, the heat generated by MPDA under the irradiation of 808 nm laser can accelerate chemical reactions, thus further enhancing synergistic therapeutic efficacy. In vitro/vivo results emphasize that enhanced cancer cell death and tumor inhibition are gained by modulating unfavorable TME with the functional nanosystem, which highlights the promise of the synthesized MPDA@MnO₂-MB-GOx nanomaterial to overcome the limitations of phototherapy.

Multifunctional nanoreactors-integrated microneedles for cascade reaction-enhanced cancer therapy

Starvation therapy based on glucose oxidase (GOx) has attracted considerable attention in tumor treatment. However, several shortcomings severely hinder its further applications, including limited therapeutic efficacy, poor enzyme stability, and potential side effects. Herein, a strategy of cascade reaction-enhanced combined therapy based on the oxygen-evolving multifunctional nanoreactors is proposed for tumor therapy. The GOx and catalase (CAT) are immobilized in metal-organic frameworks by biomimetic mineralization to improve their stability via spatial confinement. The GOx can consume glucose, reduce ATP levels, and down-regulate the expression of heat shock proteins, which consequently sensitize tumor cells to indocyanine green-based photothermal therapy. Furthermore, the hydrogen peroxide generated by GOx as well as overexpressed in tumor can be decomposed by CAT and continuously generate oxygen, which further enhance the efficacy of oxygen-dependent starvation therapy and photodynamic therapy. The nanoreactors are directly delivered to the superficial tumor by microneedles, achieving efficient tumor accumulation and dramatically strengthened antitumor efficacy without obvious side effects, which provides a valuable paradigm for the application of cascade reaction-based combined therapy.

An intelligent tumor microenvironment responsive nanotheranostic agent for T1/T2 dual-modal magnetic resonance imaging-guided and self-augmented photothermal therapy

Photothermal therapy (PTT), as a promising antineoplastic therapeutic strategy, has been harnessed to restrain tumor growth through near-infrared (NIR) irradiation mediated thermal ablation. Nevertheless, its biological applications are hampered by thermal diffusion and up-regulated heat shock proteins (HSPs). Herein, a versatile nanotheranostic agent is developed via integrating Zn_0.2Fe_2.8O₄ nanoparticles (NPs), polydopamine (PDA), and MnO₂ NPs for T1/T2 dual-modal magnetic resonance (MR) imaging-guided and self-augmented PTT. The as-designed Zn_0.2Fe_2.8O₄@PDA@MnO₂ NPs adequately serve as a PTT agent to realize effective photothermal conversion and obtain local hyperthermia. Additionally, the Zn_0.2Fe_2.8O₄@PDA@MnO₂ NPs can significantly consume overexpressed glutathione (GSH) and generate Mn²⁺ in the tumor microenvironment (TME), thus destroying redox homeostasis and catalytically generating hydroxyl radicals (˙OH) for HSP suppression and PTT enhancement. Meanwhile, Mn²⁺ and Zn_0.2Fe_2.8O₄ NPs significantly strengthen T1- and T2-weighted MR contrast for tumor imaging and PTT guidance. Hence, this study offers proof of concept for self-augmented PTT and T1/T2 dual-modal MR imaging for tumor elimination.

Mesoporous polydopamine nanoparticles carrying peptide RL-QN15 show potential for skin wound therapy

BACKGROUND

Skin wound healing remains a considerable clinical challenge, thus stressing the urgent need for the development of new interventions to promote repair. Recent researches indicate that both peptides and nanoparticles may be potential therapies for the treatment of skin wounds.

METHODS

In the current study, the mesoporous polydopamine (MPDA) nanoparticles were prepared and the peptide RL-QN15 that was previously identified from amphibian skin secretions and exhibited significant potential as a novel prohealing agent was successfully loaded onto the MPDA nanoparticles, which was confirmed by results of analysis of scanning electron microscopy and fourier transform infrared spectroscopy. The encapsulation efficiency and sustained release rate of RL-QN15 from the nanocomposites were determined. The prohealing potency of nanocomposites were evaluated by full-thickness injured wounds in both mice and swine and burn wounds in mice.

RESULTS

Our results indicated that, compared with RL-QN15 alone, the prohealing potency of nanocomposites of MPDA and RL-QN15 in the full-thickness injured wounds and burn wounds in mice was increased by up to 50 times through the slow release of RL-QN15. Moreover, the load on the MPDA obviously increased the prohealing activities of RL-QN15 in full-thickness injured wounds in swine. In addition, the obvious increase in the prohealing potency of nanocomposites of MPDA and RL-QN15 was also proved by the results from histological analysis.

CONCLUSIONS

Based on our knowledge, this is the first research to report that the load of MPDA nanoparticles could significantly increase the prohealing potency of peptide and hence highlighted the promising potential of MPDA nanoparticles-carrying peptide RL-QN15 for skin wound therapy.