CuCo2S4 nanocrystals as a nanoplatform for photothermal therapy of arterial inflammation

CoS1.097 nanocrystals as new nanoplatforms for photothermal therapy of arterial inflammation

Cardiovascular diseases caused by atherosclerosis (AS) seriously damage human health. Nano-photothermal technology has been proven to inhibit the development of vascular inflammation by inhibiting the proliferation of inflammatory macrophages. However, photothermal therapy can inhibit the enrichment of AS macrophages in the early stage, but the inhibitory effect is insufficient in the later stage. Herein, we designed and prepared CoS1.097 nanocrystals by a simple hydrothermal method as new nanoplatforms for efficient photothermal therapy of arterial inflammation. CoS1.097 nanocrystals exhibited the degradability to release the cobalt ions, and can inhibit the proliferation of macrophages both in vitro and in vivo resulting from the slowly released cobalt ions. Moreover, CoS1.097 nanocrystals showed intense absorption in the NIR region, thus showing excellent photothermal performance. When irradiated by an 808 nm laser, the photothermal effect of CoS1.097 nanocrystals can more efficiently kill the macrophages which play an important role in the development of atherosclerosis. As far as we know, this is the first work on CoS1.097 nanocrystals for photothermal therapy of arterial inflammation.

Mild phototherapy mediated by IR780-Gd-OPN nanomicelles suppresses atherosclerotic plaque progression through the activation of the HSP27-regulated NF-κB pathway

Reducing plaque lipid content and enhancing plaque stability without causing extensive apoptosis of foam cells are ideal requirements for developing a safe and effective treatment of atherosclerosis. In this study, we synthesized IR780-Gd-OPN nanomicelles by conjugating osteopontin (OPN) and loading a gadolinium-macrocyclic ligand (Gd-DOTA) onto near-infrared dye IR780-polyethylene glycol polymer. The nanomicelles were employed for mild phototherapy of atherosclerotic plaques and dual-mode imaging with near-infrared fluorescence and magnetic resonance. In vitro results reveal that the mild phototherapy mediated by IR780-Gd-OPN nanomicelles not only activates heat shock protein (HSP) 27 to protect foam cells against apoptosis but also inhibits the nuclear factor kappa-B (NF-κB) pathway to regulate lipid metabolism and macrophage polarization, thereby diminishing the inflammatory response. In vivo results further validate that mild phototherapy effectively reduces plaque lipid content and size while simultaneously enhancing plaque stability by regulating the ratio of M1 and M2-type macrophages. In summary, this study presents a promising approach for developing a safe and highly efficient method for the precise therapeutic visualization of atherosclerosis. STATEMENT OF SIGNIFICANCE: The rupture of unstable atherosclerotic plaques is a major cause of high mortality rates in cardiovascular diseases. Therefore, the ideal outcome of atherosclerosis treatment is to reduce plaque size while enhancing plaque stability. To address this challenge, we designed IR780-Gd-OPN nanomicelles for mild phototherapy of atherosclerosis. This treatment can effectively reduce plaque size while significantly improving plaque stability by increasing collagen fiber content and elevating the ratio of M2/M1 macrophages, which is mainly attributed to the inhibition of the NF-κB signaling pathway by mild phototherapy-activated HSP27. In summary, our proposed mild phototherapy strategy provides a promising approach for safe and effective treatment of atherosclerosis.

Progress of nanomaterials in the treatment of thrombus

Thrombus has long been the major contributor of death and disability because it can cause adverse effects to varying degrees on the body, resulting in vascular blockage, embolism, heart valve deformation, widespread bleeding, etc. However, clinically, conventional thrombolytic drug treatments have hemorrhagic complication risks and easy to miss the best time of treatment window. Thus, it is an urgent need to investigate newly alternative treatment strategies that can reduce adverse effects and improve treatment effectiveness. Drugs based on nanomaterials act as a new biomedical strategy and promising tools, and have already been investigated for both diagnostic and therapeutic purposes in thrombus therapy. Recent studies have some encouraging progress. In the present review, we primarily concern with the latest developments in the areas of nanomedicines targeting thrombosis therapy. We present the thrombus' formation, characteristics, and biomarkers for diagnosis, overview recent emerging nanomedicine strategies for thrombus therapy, and focus on the future design directions, challenges, and prospects in the nanomedicine application in thrombus therapy.

Nanomedicine for Diagnosis and Treatment of Atherosclerosis

With the changing disease spectrum, atherosclerosis has become increasingly prevalent worldwide and the associated diseases have emerged as the leading cause of death. Due to their fascinating physical, chemical, and biological characteristics, nanomaterials are regarded as a promising tool to tackle enormous challenges in medicine. The emerging discipline of nanomedicine has filled a huge application gap in the atherosclerotic field, ushering a new generation of diagnosis and treatment strategies. Herein, based on the essential pathogenic contributors of atherogenesis, as well as the distinct composition/structural characteristics, synthesis strategies, and surface design of nanoplatforms, the three major application branches (nanodiagnosis, nanotherapy, and nanotheranostic) of nanomedicine in atherosclerosis are elaborated. Then, state-of-art studies containing a sequence of representative and significant achievements are summarized in detail with an emphasis on the intrinsic interaction/relationship between nanomedicines and atherosclerosis. Particularly, attention is paid to the biosafety of nanomedicines, which aims to pave the way for future clinical translation of this burgeoning field. Finally, this comprehensive review is concluded by proposing unresolved key scientific issues and sharing the vision and expectation for the future, fully elucidating the closed loop from atherogenesis to the application paradigm of nanomedicines for advancing the early achievement of clinical applications.

Recent Advances for Dynamic-Based Therapy of Atherosclerosis

Atherosclerosis (AS) is a chronic inflammatory disease, which may lead to high morbidity and mortality. Currently, the clinical treatment strategy for AS is administering drugs and performing surgery. However, advanced therapy strategies are urgently required because of the deficient therapeutic effects of current managements. Increased number of energy conversion-based organic or inorganic materials has been used in cancer and other major disease treatments, bringing hope to patients with the development of nanomedicine and materials. These treatment strategies employ specific nanomaterials with specific own physiochemical properties (external stimuli: light or ultrasound) to promote foam cell apoptosis and cholesterol efflux. Based on the pathological characteristics of vulnerable plaques, energy conversion-based nano-therapy has attracted increasing attention in the field of anti-atherosclerosis. Therefore, this review focuses on recent advances in energy conversion-based treatments. In addition to summarizing the therapeutic effects of various techniques, the regulated pathological processes are highlighted. Finally, the challenges and prospects for further development of dynamic treatment for AS are discussed.

Advances in imaging and treatment of atherosclerosis based on organic nanoparticles

Atherosclerosis, a systemic chronic inflammatory disease, can lead to thrombosis and vascular occlusion, thereby inducing a series of serious vascular diseases. Currently, distinguishing unstable plaques early and achieving more effective treatment are the two main clinical concerns in atherosclerosis. Organic nanoparticles have great potential in atherosclerotic imaging and treatment, showing superior biocompatibility, drug-loading capacity, and synthesis. This article illustrates the process of atherosclerosis onset and the key targeted cells, then systematically summarizes recent progress made in organic nanoparticle-based imaging of different types of targeted cells and therapeutic methods for atherosclerosis, including optical and acoustic-induced therapy, drug delivery, gene therapy, and immunotherapy. Finally, we discuss the major impediments that need to be addressed in future clinical practice. We believe this article will help readers to develop a comprehensive and in-depth understanding of organic nanoparticle-based atherosclerotic imaging and treatment, thus advancing further development of anti-atherosclerosis therapies.

Light-activated gold nanorods for effective therapy of venous malformation

Gold nanorods have been studied extensively in the field of tumor therapy but have not been explored in the treatment of venous malformation (VM), which is a common vascular disease in clinic practice lacking an effective therapeutic approach. Herein we reported a nanoplatform of CD31 antibody-conjugated gold nanorods for the photothermal therapy of venous malformation. We immobilized CD31 antibodies on gold nanorods using standard 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysulfosuccinimide sodium (NHS) amine coupling strategies. Besides, a VM xenograft model suitable for testing therapeutic efficacy was established by isolating and culturing VM patient endothelial cells. In vitro experiments indicated that anti-CD31 gold nanorods (GNRs) combined with photothermal therapy (PTT) contributed to the suppression of proliferation and activation of the apoptosis pathway. For in vivo experiments, anti-CD31 GNRs were locally injected into VM xenograft models followed by near infrared (NIR) 808 ​nm laser irradiation. Notably, VM on the mice was destroyed and absorbed. The anti-CD31 GNRs nanoplatform may serve as a new strategy for the treatment of VM which is of good biosafety and high value of applications.

Self-Assembled CuCo2S4 Nanoparticles for Efficient Chemo-Photothermal Therapy of Arterial Inflammation

Cardiovascular disease caused by atherosclerosis (AS) seriously affects human health. Photothermal therapy (PTT) brings hope to the diagnosis and treatment of AS, with the development of nanotechnology. To improve treatment efficiency, self-assembled CuCo₂S₄ nanocrystals (NCs) were developed as a drug-delivery nanocarrier, triggered by near-infrared (NIR) light for efficient chemophotothermal therapy of arterial inflammation. The as-prepared self-assembled CuCo₂S₄ NCs exhibited excellent biocompatibility and a very high chloroquine (CL)-loading content. In addition, the self-assembled CuCo₂S₄ NCs/CL nanocomposites showed good photothermal performance, due to strong absorption in the NIR region, and the release of CL from the NCs/CL nanocomposites was driven by NIR light. When illuminated by NIR light, both PTT from the NCs and chemotherapy from the CL were simultaneously triggered, resulting in killing macrophages with a synergistic effect. Moreover, chemo-photothermal therapy with CuCo₂S₄ NCs/CL nanocomposites showed an effective therapeutic effect for arterial inflammation, in vivo. Our work demonstrated that chemo-photothermal therapy could be a promising strategy for the treatment of arterial inflammation against atherosclerosis.

Macrophage-Targeted Sonodynamic/Photothermal Synergistic Therapy for Preventing Atherosclerotic Plaque Progression Using CuS/TiO2 Heterostructured Nanosheets

Sonodynamic therapy (SDT) and photothermal therapy (PTT) are two effective strategies for the treatment of atherosclerotic plaques. However, the low yield of reactive oxygen species (ROS) of conventional organic sonosensitizers and the low biosafety of hyperthermia limit the therapeutic efficacy of SDT and PTT. Herein, we report copper sulfide/titanium oxide heterostructure nanosheets modified with hyaluronic acid (HA) and PEG (HA-HNSs) for low-intensity sonodynamic and mild-photothermal synergistic therapy for early atherosclerotic plaques. CuS/TiO₂ heterostructure nanosheets (HNSs) show high electron-hole separation efficiency and superior sonodynamic performance, because it has high surface energy crystal facets as well as a narrow band. Moreover, HNSs exhibit intense absorbance in the NIR-II region, which endows the nanosheets with excellent photothermal performance. With a further modification of HA, HA-HNSs can selectively target intraplaque proinflammatory macrophages through CD44-HA interaction. Because SDT reduces the expression of heat shock protein 90 and PTT facilitates the sonocatalytic process, the combination of SDT and PTT based on HA-HNSs could synergistically induce proinflammatory macrophage apoptosis. More importantly, the synergistic therapy prevents the progression of early atherosclerotic plaque by removing lesional macrophages and mitigating inflammation. Taken together, this work provides a macrophage-targeting sonodynamic/photothermal synergistic therapy, which is an effective translational clinical intervention for early atherosclerotic plaques.

Adhesive hydrogel wrap loaded with Netrin-1-modified adipose-derived stem cells: An effective approach against periarterial inflammation after endovascular intervention

Endovascular interventions, such as balloon dilation and stent implantation, are currently recommended as the primary treatment for patients with peripheral artery disease (PAD), greatly improving patient prognosis. However, the consequent lumen restenosis that occurs after endovascular interventions has become an important clinical problem. Inflammation has been proven to be crucial to postoperative restenosis. In previous studies we have identified that Netrin-1-modified adipose-derived stem cells (N-ADSCs) transplantation is an effective anti-inflammatory strategy to repair vascular damage. Nevertheless, it remained to be explored how one could constantly deliver N-ADSCs onto damaged arteries. Therefore, we developed an adhesive double network (DN) hydrogel wrap loaded with N-ADSCs for sustained perivascular delivery. Inspired by the adhesion mechanism of mussels, we developed an adhesive and tough polyacrylamide/calcium-alginate/reduced graphene oxide/polydopamine (PAM/CA/rGO/PDA) hydrogel. Dopamine was attached to graphene sheets and limitedly oxidized to generate free catechol groups. The hydrogel could wrap damaged arteries and induce anti-inflammatory effects through N-ADSCs. In vitro experiments demonstrated that N-ADSCs significantly promoted the M2 polarization of macrophages to anti-inflammatory phenotypes and reduced the expression of inflammatory factors. In vivo experiments in a rat carotid artery guidewire injury model showed that the adhesive hydrogel wrap loaded with N-ADSCs could significantly reduce arterial inflammation, inhibit intimal hyperplasia and improve re-endothelialization. Altogether, this newly developed N-ADSCs-loaded hydrogel wrap provides an effective slow-releasing system, which may be a promising way to prevent and treat restenosis after endovascular interventions.

Gram-Scale Production of Photothermally Active Tetrahedrite Nanoparticles for Solar-Driven Water Evaporation

Pristine and substituted tetrahedrite nanoparticles have shown immense potential as low-cost and sustainable materials for energy conversion applications. However, the commonly used synthetic methods for their production are cumbersome and are not easily scalable. In this work, we report a facile colloidal synthetic protocol for the preparation of phase-pure samples of pristine (Cu₁₂ Sb₄ S₁₃ ) and Zn-substituted (Cu₁₁ ZnSb₄ S₁₃ ) tetrahedrite nanoparticles on the gram scale. Both tetrahedrite compositions were found to be photothermally responsive, enabling their use in solar-driven water evaporation.

A Near-Infrared Light Triggered Composite Nanoplatform for Synergetic Therapy and Multimodal Tumor Imaging

Transition-metal chalcogenide compounds with facile preparation and multifunctional elements act as ideal photothermal agents for cancer theranostics. This work synthesizes Cu_7.2S₄/5MoS₂ composite nanoflowers and investigates the crystal growth mechanism to optimize the synthesis strategy and obtain excellent photothermal therapy agents. Cu_7.2S₄/5MoS₂ exhibits a high photothermal conversion efficiency of 58.7% and acts as a theranostic nanoplatform and demonstrated an effective photothermal–chemodynamic–photodynamic synergetic therapeutic effect in both in vitro and in vivo tests. Moreover, Cu_7.2S₄/5MoS₂ shows strong photoacoustic signal amplitudes and computed tomographic contrast enhancement in vivo. These results suggest a potential application of Cu_7.2S₄/5MoS₂ composite nanoflowers as photo/H₂O₂-responsive therapeutic agents against tumors.

Ferrite-encapsulated nanoparticles with stable photothermal performance for multimodal imaging-guided atherosclerotic plaque neovascularization therapy

Pathological angiogenesis is a critical contributor to atherosclerotic plaque rupture. However, there are few effective theranostic strategies to stabilize plaques by suppressing neovascularization. In this study, we fabricated a polymeric nanosystem using 3 nm manganese ferrite (MnFe₂O₄) and perfluorohexane (PFH) stabilized by polylactic acid-glycolic acid (PLGA) shells and conjugated to the surface of an anti-vascular endothelial growth factor receptor 2 (VEGFR2) antibody [ramucirumab (Ram)]. The PFH@PLGA/MnFe₂O₄-Ram nanoparticles (NPs) were used as atherosclerotic plaque angiogenesis theranostics for multimodal imaging-guided photothermal therapy (PTT). Three-nanometer MnFe₂O₄ is an excellent magnetic resonance imaging T1 and photoacoustic imaging contrast agent. Upon exposure to near-infrared (NIR) light, MnFe₂O₄ in the NPs could transform NIR light into thermal energy for the photothermal elimination of plaque angiogenesis. Additionally, optical droplet vaporization of PFH in the NPs triggered by the thermal effect to form gas bubbles enhanced ultrasound imaging. Our in vitro experiments revealed that PFH@PLGA/MnFe₂O₄-Ram NPs actively accumulated in rabbit aortic endothelial cells, and NP-mediated PTT promoted endothelial cell apoptosis while inhibiting their proliferation, migration, and tubulogenesis. Notably, the PFH@PLGA/MnFe₂O₄-Ram NPs possessed excellent photostability and biocompatibility. In the rabbit advanced atherosclerotic plaque model, PFH@PLGA/MnFe₂O₄-Ram NP-guided PTT significantly induced apoptosis of neovascular endothelial cells and improved the hypoxia status in the plaque 3 days after treatment. On day 28, PTT significantly reduced the density of neovessels and subsequently stabilized rabbit plaques by inhibiting plaque hemorrhage and macrophage infiltration. Collectively, these results suggest that PFH@PLGA/MnFe₂O₄-Ram NP-guided PTT is a safe and effective theranostic strategy for inhibiting atherosclerotic plaque angiogenesis.

Near-Infrared Light-Driven Multifunctional Tubular Micromotors for Treatment of Atherosclerosis

One of the difficulties in atherosclerosis treatment is that the ablation of inflammatory macrophages, repair of vascular endothelial injury, and anti-tissue proliferation should be considered. However, there are few studies that can solve the abovementioned problems simultaneously. Herein, we present a kind of near-infrared (NIR) light-driven multifunctional mesoporous/macroporous tubular micromotor which can rapidly target the damaged blood vessels and release different drugs. Their motion effect can promote themselves to penetrate into the plaque site, and the generated heat effect caused by NIR irradiation can realize the photothermal ablation of inflammatory macrophages. Furthermore, these micromotors can rapidly release the vascular endothelial growth factor for endothelialization and slowly release paclitaxel for antiproliferation to achieve synergistic treatment of atherosclerosis. In vivo results demonstrated that the micromotors can achieve a good therapeutic effect for atherosclerosis. This kind of micro/nanomotor technology with a complex porous structure for drug loading will bring a more potential treatment platform for the disease.

SR-A-Targeted Nanoplatform for Sequential Photothermal/Photodynamic Ablation of Activated Macrophages to Alleviate Atherosclerosis

Cardiovascular and cerebrovascular diseases induced by atherosclerosis (AS) have become the dominant cause of disability and mortality throughout the world. The typical early pathological process of AS involves the activation of inflammatory macrophages in the vulnerable plaque. In this work, we first employed chitosan-coated carbon nanocages (CS-CNCs) as nanocarriers to load Chlorin e6 (Ce6) and then linked dextran sulfate (DS) to the outermost layer by electrostatic adsorption to create a multifunctional therapeutic nanoplatform, CS-CNCs@Ce6/DS. The DS of the nanoplatform can recognize and bind to the type A scavenger receptor (SR-A), which is expressed only on the activated macrophages of the arterial plaque, so the proposed nanoplatform selectively targets these macrophages and accumulates there. Furthermore, DS can competitively inhibit cellular endocytosis of oxidized low-density lipoproteins via blocking of SR-A. The rapid photothermal conversion capability of CS-CNCs enables efficient therapeutic delivery during photothermal therapy (PTT). Interestingly, near-infrared-accelerated drug release induced by initial 808-nm laser irradiation was observed, thus enhancing the Ce6 concentration in the atherosclerotic plaque area and the efficiency of photodynamic therapy (PDT). Sequential photothermal/photodynamic ablation of the activated macrophages reduced pro-inflammatory cytokine secretion and alleviated the proliferation and migration of smooth muscle cells. These finally resulted in the stabilization and shrinkage of atherosclerotic plaques, further inhibiting the development and exacerbation of AS. Therefore, this work achieved a "1 + 1 greater than 2" effect by providing a novel approach to the treatment of atherosclerotic plaques, which is promising for the prevention of AS-related diseases.

Architecting functionalized carbon microtube/carrollite nanocomposite demonstrating significant microwave characteristics

Biomass-derived materials have recently received considerable attention as lightweight, low-cost, and green microwave absorbers. On the other hand, sulfide nanostructures due to their narrow band gaps have demonstrated significant microwave characteristics. In this research, carbon microtubes were fabricated using a biowaste and then functionalized by a novel complementary solvothermal and sonochemistry method. The functionalized carbon microtubes (FCMT) were ornamented by CuCo2S4 nanoparticles as a novel spinel sulfide microwave absorber. The prepared structures illustrated narrow energy band gap and deposition of the sulfide structures augmented the polarizability, desirable for dielectric loss and microwave attenuation. Eventually, the architected structures were blended by polyacrylonitrile (PAN) to estimate their microwave absorbing and antibacterial characteristics. The antibacterial properties against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) were scrupulously assessed. Noteworthy, the maximum reflection loss (RL) of the CuCo2S4/PAN with a thickness of 1.75 mm was 61.88 dB at 11.60 GHz, while the architected FCMT/PAN composite gained a broadband efficient bandwidth as wide as 7.91 GHz (RL > 10 dB) and 3.25 GHz (RL > 20 dB) with a thickness of 2.00 mm. More significantly, FCMT/CuCo2S4/PAN demonstrated an efficient bandwidth of 2.04 GHz (RL > 20 dB) with only 1.75 mm in thickness. Interestingly, FCMT/CuCo2S4/PAN and CuCo2S4/PAN composites demonstrated an electromagnetic interference shielding efficiency of more than 90 and 97% at the entire x and ku-band frequencies, respectively.

Thrombolysis Combined Therapy Using CuS@SiO2-PEG/uPA Nanoparticles

Massive hemorrhage caused by the uncontrolled release of thrombolysis drugs is a key issue of thrombolysis therapy in clinical practice. In this study, we report a near-infrared (NIR) light-triggered drug delivery system, i.e., CuS@mSiO₂-PEG (CSP) nanoparticles, for the loading of a thrombolytic drug (urokinase plasminogen activators, uPA). CSP nanoparticles with the CuS nanoparticles as photothermal agents and mesoporous SiO₂ for the loading of uPA were synthesized using a facile hydrothermal method. The CSP core-shell nanoparticles were demonstrated to possess excellent photothermal performance, exhibiting a photothermal conversion efficiency of up to 52.8%. Due to the mesoporous SiO₂ coating, the CSP core-shell nanoparticles exhibited appropriate pore size, high pore volume, and large surface area; thus, they showed great potential to be used as drug carriers. Importantly, the release of uPA from CuS@mSiO₂-PEG/uPA (CSPA) carriers can be promoted by the NIR laser irradiation. The drug loading content of uPA for the as-prepared NIR-triggered drug delivery system was calculated to be 8.2%, and the loading efficiency can be determined to be as high as 89.6%. Due to the excellent photothermal effect of CSP nanocarriers, the NIR-triggered drug delivery system can be used for infrared thermal imaging in vivo. The in vivo thrombolysis assessment demonstrated that the NIR-triggered drug delivery system showed excellent thrombolytic ability under the irradiation of an 808 nm laser, showing the combined therapy for thrombolysis. As far as we know, the CSPA core-shell nanoparticles used as NIR-triggered drug delivery systems for thrombolysis have not been reported.

Recent advances in nanomaterials for therapy and diagnosis for atherosclerosis

Atherosclerosis is a chronic inflammatory disease driven by lipid accumulation in arteries, leading to narrowing and thrombosis. It affects the heart, brain, and peripheral vessels and is the leading cause of mortality in the United States. Researchers have strived to design nanomaterials of various functions, ranging from non-invasive imaging contrast agents, targeted therapeutic delivery systems to multifunctional nanoagents able to target, diagnose, and treat atherosclerosis. Therefore, this review aims to summarize recent progress (2017-now) in the development of nanomaterials and their applications to improve atherosclerosis diagnosis and therapy during the preclinical and clinical stages of the disease.

CuGeO3 Nanoparticles: An Efficient Photothermal Theragnosis Agent for CT Imaging-Guided Photothermal Therapy of Cancers

The photothermal agents have been widely developed due to the minimally invasive treatment for targeted tumor photothermal therapy, which is considered to have great potential for antitumor bioapplications. The development of multifunctional photothermal agents is extremely challenging. This work presents a novel photothermal theragnosis agent, i.e., CuGeO3 nanoparticles (CGO NPs), showing intense absorption in the near-infrared (NIR) window and excellent ability of CT imaging. Due to the strong NIR absorption, CGO NPs exhibit excellent photothermal effect with a photothermal conversion efficiency of 59.4%. Moreover, because of the high X-ray attenuation coefficient of germanium, the CGO NPs have a great potential of CT imaging diagnosis in clinical application. Additionally, the CGO NPs show negligible cytotoxicity in vitro and in vivo, indicating that it can be served as an outstanding contrast and anticancer agent in a biosafe way. Our work opens the way for the development of bimetallic copper-based oxides used in photothermal diagnostic agents for cancer treatment.

Greigite (Fe3S4) is thermodynamically stable: Implications for its terrestrial and planetary occurrence

Iron sulfide minerals are widespread on Earth and likely in planetary bodies in and beyond our solar system. Using measured enthalpies of formation for three magnetic iron sulfide phases: bulk and nanophase Fe₃S₄ spinel (greigite), and its high-pressure monoclinic phase, we show that greigite is a stable phase in the Fe-S phase diagram at ambient temperature. The thermodynamic stability and low surface energy of greigite supports the common occurrence of fine-grained Fe₃S₄ in many anoxic terrestrial settings. The high-pressure monoclinic phase, thermodynamically metastable below about 3 GPa, shows a calculated negative P-T slope for its formation from the spinel. The stability of these three phases suggests their potential existence on Mercury and their magnetism may contribute to its present magnetic field.

Multifunctional CuBiS2 Nanoparticles for Computed Tomography Guided Photothermal Therapy in Preventing Arterial Restenosis After Endovascular Treatment

Chronic inflammation mediated by artery infiltrated macrophages plays critical role in artery restenosis after endovascular therapy. Evidence has demonstrated the potential ability of photothermal therapy (PTT) in eliminating chronic inflammation by targeting inflammatory cells including macrophages. Recently, increasing attention has been payed to copper chalcogenide nanocrystals doped of radiocontrast agent, e.g., bismuth (Bi) for computed tomography (CT) guided PTT. However, the application of imaging guided PTT in preventing artery restenosis is lacking and limited. Herein, a novel multifunctional CuBiS₂ nanoparticles (CuBiS₂ NPs) were synthesized for CT imaging guided PTT in artery re-stenosis prevention. The optimum amount and other conditions of CuBiS₂ NPs were optimized to exert the maximum ablation effect on macrophages with good biocompatibility. In vivo carotid injury model revealed that CuBiS₂ NPs exhibited promising therapeutic effect on inhibition of artery stenosis by eliminating macrophages with excellent CT imaging ability. The recent study highlights a new cost-effective metal nanostructures-based nanotechnology in prevention of artery restenosis after endovascular therapy.

Cu3BiS3 Nanocrystals as Efficient Nanoplatforms for CT Imaging Guided Photothermal Therapy of Arterial Inflammation

Cardio-cerebrovascular diseases caused by chronic inflammatory atherosclerosis seriously damage human health. Nano-photothermal technology has been proven to inhibit the development of vascular inflammation, but the currently reported photothermal agents cannot efficient monitor it during the development of the disease. Herein, we designed and prepared an efficient bifunctional nanoplatform for CT imaging guided photothermal therapy of arterial inflammation. Cu₃BiS₃ nanocrystals with a size of about 12 nm were synthesized by a simple hydrothermal method. The as-prepared Cu₃BiS₃ nanocrystals showed intense absorption in the NIR region, thus exhibited amazing photothermal effect. The photothermal conversion efficiency of Cu₃BiS₃ nanocrystals was reach up to 58.6% under the excitation of an 808 nm laser with a power density of 0.4 W cm^–2. Cu₃BiS₃ nanocrystals can efficiently kill the macrophages both in vitro and in vivo, which plays an important role in the development of atherosclerosis, thus can be used as an effective way to inhibit the occurrence of hypertension. Importantly, Cu₃BiS₃ nanocrystals can be used as an efficient CT contrast agent to monitor carotid inflammation. Our work provides an insight for imaging guided photothermal therapy of arterial inflammation.

Applications of inorganic nanoparticles in the diagnosis and therapy of atherosclerosis

Atherosclerosis is a chronic progressive disease, which may result in serious clinical outcomes, such as acute heart events or stroke with high mortality. At present, the clinical problems of atherosclerosis mainly consist of the difficulty in confirming the plaques or identifying the stability of the plaques in the early phase and the shortage of valid treatments. Fortunately, with the development of nanotechnology, various inorganic nanoparticles with imaging enhancement and noninvasive therapy functions have been studied in the imaging and treatment of atherosclerosis, which has brought new hope to patients. This review focuses on the recent progress in the use of inorganic nanoparticles in the diagnosis and therapy of atherosclerosis, including the key processes in the development of atherosclerosis and the mainly involved cells, inorganic nanoparticle-based dual-mode imaging methods classified by the types of targeting cells, and inorganic nanoparticle-based therapeutic approaches, such as photothermal therapy (PTT), photodynamic therapy (PDT), sonodynamic therapy (SDT), drug delivery, gene therapy and imaging-guided therapy for atherosclerosis. Finally, this review discusses the challenges and directions of inorganic nanoparticles in potential clinical translation of anti-atherosclerosis in future. We believe this review will enable readers to systematically understand the progress of the inorganic nanoparticle-based imaging and therapy of atherosclerosis and therefore promote the further development of anti-atherosclerosis.

AgFeS2 nanoparticles as a novel photothermal platform for effective artery stenosis therapy

Ternary I-III-VI2 semiconductors usually have narrow band gaps and large absorption coefficients arising from the unique characteristics of their outer-d valence electrons, which are intimately connected with the photothermal conversion properties. AgFeS2 is known as one such material that has the potential to absorb near-infrared light. In this work, we utilized density functional theory (DFT) calculations to evaluate the electronic structure and optical absorption properties of AgFeS2. Strong absorptions were predicted over a wide Vis-NIR region due to the localized 3d electron of Fe atoms, which agree quite well with the UV-Vis-NIR spectra measured by experiment. The as-prepared AgFeS2 nanoparticles were then modified with mPEG-DSPE, an efficient photothermal agent for artery stenosis therapy. Its photothermal conversion effect has been systematically studied, indicating the potential for causing the hyperthermia of macrophages, an essential part of the artery inflammation response. More importantly, both in vitro cell experiments and in vivo mouse-model studies show that the induction of hyperthermia in artery stenosis by using AgFeS2 nanoparticles is safe and effective when injected at a very low concentration. This study provides a novel photothermal platform derived from the inheritability of bandgap structure and also promotes the process of artery inflammation and stenosis therapy.

Fluorescent Silicon Nanorods-Based Nanotheranostic Agents for Multimodal Imaging-Guided Photothermal Therapy

The utilization of diagnosis to guide/aid therapy procedures has shown great prospects in the era of personalized medicine along with the recognition of tumor heterogeneity and complexity. Herein, a kind of multifunctional silicon-based nanostructure, i.e., gold nanoparticles-decorated fluorescent silicon nanorods (Au@SiNRs), is fabricated and exploited for tumor-targeted multimodal imaging-guided photothermal therapy. In particular, the prepared Au@SiNRs feature high photothermal conversion efficiency (~ 43.9%) and strong photothermal stability (photothermal performance stays constant after five-cycle NIR laser irradiation), making them high-performance agents for simultaneously photoacoustic and infrared thermal imaging. The Au@SiNRs are readily modified with targeting peptide ligands, enabling an enhanced tumor accumulation with a high value of ~ 8.74% ID g-1. Taking advantages of these unique merits, the Au@SiNRs are superbly suitable for specifically ablating tumors in vivo without appreciable toxicity under the guidance of multimodal imaging. Typically, all the mice treated with the Au@SiNRs remain alive, and no distinct tumor recurrence is observed during 60-day investigation.