Stanene-Based Nanosheets for ß-Elemene Delivery and Ultrasound-Mediated Combination Cancer Therapy.

Ultrasound (US)-mediated sonodynamic therapy (SDT) has emerged as a superior modality for cancer treatment owing to the non-invasiveness and high tissue-penetrating depth. However, developing biocompatible nanomaterial-based sonosensitizers with efficient SDT capability remains challenging. Here, we employed a liquid-phase exfoliation strategy to obtain a new type of two-dimensional (2D) stanene-based nanosheets (SnNSs) with a band gap of 2.3 eV, which is narrower than those of the most extensively studied nano-sonosensitizers, allowing a more efficient US-triggered separation of electron (e- )-hole (h+ ) pairs for reactive oxygen species (ROS) generation. In addition, we discovered that such SnNSs could also serve as robust near-infrared (NIR)-mediated photothermal therapy (PTT) agents owing to their efficient photothermal conversion, and serve as nanocarriers for anticancer drug delivery owing to the inherent 2D layered structure. This study not only presents general nanoplatforms for SDT-enhanced combination cancer therapy, but also highlights the utility of 2D SnNSs to the field of nanomedicine.

In situ sprayed NIR-responsive, analgesic black phosphorus-based gel for diabetic ulcer treatment.

The treatment of diabetic ulcer (DU) remains a major clinical challenge due to the complex wound-healing milieu that features chronic wounds, impaired angiogenesis, persistent pain, bacterial infection, and exacerbated inflammation. A strategy that effectively targets all these issues has proven elusive. Herein, we use a smart black phosphorus (BP)-based gel with the characteristics of rapid formation and near-infrared light (NIR) responsiveness to address these problems. The in situ sprayed BP-based gel could act as 1) a temporary, biomimetic "skin" to temporarily shield the tissue from the external environment and accelerate chronic wound healing by promoting the proliferation of endothelial cells, vascularization, and angiogenesis and 2) a drug "reservoir" to store therapeutic BP and pain-relieving lidocaine hydrochloride (Lid). Within several minutes of NIR laser irradiation, the BP-based gel generates local heat to accelerate microcirculatory blood flow, mediate the release of loaded Lid for "on-demand" pain relief, eliminate bacteria, and reduce inflammation. Therefore, our study not only introduces a concept of in situ sprayed, NIR-responsive pain relief gel targeting the challenging wound-healing milieu in diabetes but also provides a proof-of-concept application of BP-based materials in DU treatment.

Marriage of black phosphorus and Cu2+ as effective photothermal agents for PET-guided combination cancer therapy.

The use of photothermal agents (PTAs) in cancer photothermal therapy (PTT) has shown promising results in clinical studies. The rapid degradation of PTAs may address safety concerns but usually limits the photothermal stability required for efficacious treatment. Conversely, PTAs with high photothermal stability usually degrade slowly. The solutions that address the balance between the high photothermal stability and rapid degradation of PTAs are rare. Here, we report that the inherent Cu2+-capturing ability of black phosphorus (BP) can accelerate the degradation of BP, while also enhancing photothermal stability. The incorporation of Cu2+ into BP@Cu nanostructures further enables chemodynamic therapy (CDT)-enhanced PTT. Moreover, by employing 64Cu2+, positron emission tomography (PET) imaging can be achieved for in vivo real-time and quantitative tracking. Therefore, our study not only introduces an "ideal" PTA that bypasses the limitations of PTAs, but also provides the proof-of-concept application of BP-based materials in PET-guided, CDT-enhanced combination cancer therapy.

Engineering H2O2 Self-Supplying Nanotheranostic Platform for Targeted and Imaging-Guided Chemodynamic Therapy.

Developing highly efficient chemodynamic therapy (CDT)-based theranostic technology for cancer treatment is highly desired but still challenging. A novel nanotheranostic platform is constructed for enhanced CDT by engineering hybrid CaO2 and Fe3O4 nanoparticles with a hyaluronate acid (HA) stabilizer and NIR fluorophore label. This design not only enables the nanotheranostic agent to afford highly efficient CDT against tumor cells but also confers NIR fluorescence (NIRF) and magnetic resonance (MR) bimodal imaging for in vivo visualization of CDT. Moreover, the use of the HA stabilizer allows for the facile synthesis of the nanotheranostic agent with excellent biocompatibility and active targetability. The nanotheranaostic agent possesses a high capacity of self-supplying H2O2 and producing •OH in acidic conditions, while retaining the desired stability under physiological conditions. It also demonstrates high selectivity to tumor cells via CDT with minimized toxicity to normal cells. In vivo studies reveal that our nanotheranaostic agent exhibits efficacious tumor growth inhibition via a CDT mechanism with favorable biosafety. Moreover, in vivo visualization of the CDT progress via NIRF and MR bimodal imaging demonstrates specific targeting and treatment of tumors. The developed H2O2 self-supplying, active targeting, and bimodal imaging nanotheranostic platform holds the potential as a highly efficient strategy for CDT of cancer.

2D Monoelemental Germanene Quantum Dots: Synthesis as Robust Photothermal Agents for Photonic Cancer Nanomedicine.

As a new family member of the emerging two-dimensional (2D) monoelemental materials (Xenes), germanene has shown promising advantages over the prototypical 2D Xenes, such as black phosphorus (BP) and graphene. However, efficient manufacture of novel germanene nanostructures is still a challenge. Herein, a simple top-down approach for the liquid-exfoliation of ultra-small germanene quantum dots (GeQDs) is presented. The prepared GeQDs possess an average lateral size of about 4.5 nm and thickness of about 2.2 nm. The functionalized GeQDs were demonstrated to be robust photothermal agents (PTAs) with outstanding photothermal conversion efficacy (higher than those of graphene and BPQDs), superior stability, and excellent biocompatibility. As a proof-of-principle, 2D GeQDs-based PTAs were used in fluorescence/photoacoustic/photothermal-imaging-guided hyperpyrexia ablation of tumors. This work could expand the application of 2D germanene to the field of photonic cancer nanomedicine.

A NIR-II light responsive hydrogel based on 2D engineered tungsten nitride nanosheets for multimode chemo/photothermal therapy.

A hydrogel drug cargo based on 2D tungsten nitride nanosheets was fabricated. It exhibits stable NIR-II responsive photothermal properties and drug release behaviour. Moreover, this hydrogel shows excellent tumour ablation efficiency in vivo via NIR-II triggered multiple chemo/photothermal therapy.

Emerging Two-Dimensional Nanomaterials for Cancer Therapy.

Two-dimensional (2D) nanomaterials have drawn tremendous attention due to their unique physicochemical properties and promising applications in the fields of electronics, energy storage, and catalysis. Recently, the biomedicine community has gradually started to recognize the great potential of these nanostructured materials for biomedical applications - in particular those related to cancer therapy. In this review, we provide a brief overview of a few representative 2D nanomaterials, discuss their preparation strategies and physicochemical properties, and highlight their applications in cancer nanomedicine. We expect that this review will shed some light on the new opportunities associated with 2D nanomaterials for biomedical research.

Multifunctional two dimensional Bi2Se3 nanodiscs for combined antibacterial and anti-inflammatory therapy for bacterial infections.

A multifunctional platform based on two-dimensional nanomaterials for combined antibacterial and anti-inflammatory therapy is developed. Bi2Se3 nanodiscs selectively eradicate Gram-positive bacteria with a low risk of drug resistance. Moreover, Bi2Se3 nanodiscs with antioxidant activity relieve intracellular oxidative stress of macrophages to suppress inflammation caused by bacterial infections.

Coordination Nanosheets of Phthalocyanine as Multifunctional Platform for Imaging-Guided Synergistic Therapy of Cancer.

"All-in-one" nanodrugs integrating various functionalities into one nanosystem are highly desired for cancer treatment. Coordination nanosheets as one type of two dimensional (2D) nanomaterials offer great opportunities, but there is lack of enough candidates. Here, a new kind of coordination nanosheets based on phthalocyanine are constructed. Manganese phthalocyanine (MnPc) tetracarboxylic acid is employed as photoactive ligand to form MnPc nanosheets; meanwhile, hyaluronic acid (HA) is coated on their surface. The obtained MnPc@HA nanosheets exhibit superior near-infrared (NIR) photothermal effect with photothermal conversion efficiency of 72.3%, much higher than those of the previously reported photothermal agents. Due to their 2D nanostructures, MnPc@HA nanosheets possess superhigh drug-loading capacity for chemotherapy drug curcumin. With HA as a targeting group, the nanosheets selectively accumulated in CD44 overexpressed tumors, followed by drug release under the control of NIR light. Moreover, MnPc@HA nanosheets with intrinsic paramagnetism can serve as T1 contrast agent for magnetic resonance imaging. The synergistic effect of phototherapy and chemotherapy endows curcumin-loaded MnPc@HA nanosheets with superior tumor-eradicating efficacy. Besides, MnPc@HA nanosheets are biocompatible and safe for biomedical applications. This work provides novel insight for developing new multifunctional platforms based on 2D coordination nanosheets to synergistically combat cancer.

Black Phosphorus Nanosheets as a Neuroprotective Nanomedicine for Neurodegenerative Disorder Therapy.

Transition-metal dyshomeostasis is recognized as a critical pathogenic factor at the onset and progression of neurodegenerative disorder (ND). Excess transition-metal ions such as Cu2+ can catalyze the generation of cytotoxic reactive oxygen species and thereafter induce neuronal cell apoptosis. Exploring new chelating agents, which are not only capable of capturing excess redox-active metal, but can also cross the blood-brain barrier (BBB), are highly desired for ND therapy. Herein, it is demonstrated that 2D black phosphorus (BP) nanosheets can capture Cu2+ efficiently and selectively to protect neuronal cells from Cu2+ -induced neurotoxicity. Moreover, both in vitro and in vivo studies show that the BBB permeability of BP nanosheets is significantly improved under near-infrared laser irradiation due to their strong photothermal effect, which overcomes the drawback of conventional chelating agents. Furthermore, the excellent biocompatibility and stability guarantee the biosafety of BP in future clinical applications. Therefore, these features make BP nanosheets have the great potential to work as an efficient neuroprotective nanodrug for ND therapy.

Black Phosphorus Nanosheet-Based Drug Delivery System for Synergistic Photodynamic/Photothermal/Chemotherapy of Cancer.

A black phosphorus (BP)-based drug delivery system for synergistic photodynamic/photothermal/chemotherapy of cancer is constructed. As a 2D nanosheet, BP shows super high drug loading capacity and pH-/photoresponsive drug release. The intrinsic photothermal and photodynamic effects of BP enhance the antitumor activities. The synergistic photodynamic/photothermal/chemotherapy makes BP-based drug delivery system a multifunctional nanomedicine platform.