Double‐Walled Au Nanocage/SiO2 Nanorattles: Integrating SERS Imaging,Drug Delivery and Photothermal Therapy

In this work, a novel type of nanomedical platform, the double‐walled Au nanocage/SiO₂ nanorattle, is successfully fabricated by combining two “hollow‐excavated strategies”—galvanic replacement and “surface‐protected etching”. The rational design of double‐walled nanostructure based on gold nanocages (AuNCs) and hollow SiO₂ shells functionalized respectively with p‐aminothiophenol (pATP) and Tat peptide simultaneously renders the nanoplatforms three functionalities: 1) the whole nanorattle serves as a high efficient drug carrier thanks to the structural characteristics of AuNC and SiO₂ shell with hollow interiors and porous walls; 2) the AuNC with large electromagnetic enhancement acts as a sensitive surface‐enhanced Raman scattering (SERS) substrate to track the internalization process of the nanorattles by human MCF‐7 breast cancer cells, as well as an efficient photothermal transducer for localized hyperthermia cancer therapy due to the strong near‐infrared absorption; 3) Tat‐functionalized SiO₂ shell not only improves biocompatibility and cell uptake efficiency resulting in enhanced anticancer efficacy but also prevents the AuNCs from aggregation and provides the stability of AuNCs so that the SERS signals can be used for cell tracking in high fidelity. The reported chemistry and the designed nanostructures should inspire more interesting nanostructures and applications.     

Dual‐Action Cancer Therapy with Targeted Porous Silicon Nanovectors

There is a pressing need to develop more effective therapeutics to fight cancer. An idyllic chemotherapeutic is expected to overcome drug resistance of tumors and minimize harmful side effects to healthy tissues. Antibody‐functionalized porous silicon nanoparticles loaded with a combination of chemotherapy drug and gold nanoclusters (AuNCs) are developed. These nanocarriers are observed to selectively deliver both payloads, the chemotherapy drug and AuNCs, to human B cells. The accumulation of AuNCs to target cells and subsequent exposure to an external electromagnetic field in the microwave region render them more susceptible to the codelivered drug. This approach represents a targeted two‐stage delivery nanocarrier that benefits from a dual therapeutic action that results in enhanced cytotoxicity.     

Metal-organic framework-based intelligent drug delivery systems for cancer theranostic: A review

The design and development of multifunctional nano-drug delivery systems (NDDSs) is a solution that is expected to solve some intractable problems in traditional cancer treatment. In particular, metal-organic frameworks (MOFs) are novel hybrid porous nanomaterials which are constructed by the coordination of metal cations or clusters and organic bridging ligands. Benefiting from their intrinsic superior properties, MOFs have captivated intensive attentions in drug release and cancer theranostic. Based on what has been achieved about MOF-based DDSs in recent years, this review introduces different stimuli-responsive mechanisms of them and their applications in cancer diagnosis and treatment systematically. Moreover, the existing challenges and future opportunities in this field are summarized. By realizing industrial production and paying attention to biosafety, their clinical applications will be enriched.     

Focused Ultrasound Enabled Trans‐Blood Brain Barrier Delivery of Gold Nanoclusters: Effect of Surface Charges and Quantification Using Positron Emission Tomography

Focused ultrasound (FUS) technology is reported to enhance the delivery of ⁶⁴Cu‐integrated ultrasmall gold nanoclusters (⁶⁴Cu‐AuNCs) across the blood‐brain barrier (BBB) as measured by positron emission tomography (PET). To better define the optimal physical properties for brain delivery, ⁶⁴Cu‐AuNCs with different surface charges are synthesized and characterized. In vivo biodistribution studies are performed to compare the individual organ uptake of each type of ⁶⁴Cu‐AuNCs. Quantitative PET imaging post‐FUS treatment shows site‐targeted brain penetration, retention, and diffusion of the negative, neutral, and positive ⁶⁴Cu‐AuNCs. Autoradiography is performed to compare the intrabrain distribution of these nanoclusters. PET Imaging demonstrates the effective BBB opening and successful delivery of ⁶⁴Cu‐AuNCs into the brain. Of the three ⁶⁴Cu‐AuNCs investigated, the neutrally charged nanostructure performs the best and is the candidate platform for future theranostic applications in neuro‐oncology.     

Efficient Radioisotope Energy Transfer by Gold Nanoclusters for Molecular Imaging

Beta‐emitting isotopes Fluorine‐18 and Yttrium‐90 are tested for their potential to stimulate gold nanoclusters conjugated with blood serum proteins (AuNCs). AuNCs excited by either medical radioisotope are found to be highly effective ionizing radiation energy transfer mediators, suitable for in vivo optical imaging. AuNCs synthesized with protein templates convert beta‐decaying radioisotope energy into tissue‐penetrating optical signals between 620 and 800 nm. Optical signals are not detected from AuNCs incubated with Technetium‐99m, a pure gamma emitter that is used as a control. Optical emission from AuNCs is not proportional to Cerenkov radiation, indicating that the energy transfer between the radionuclide and AuNC is only partially mediated by Cerenkov photons. A direct Coulombic interaction is proposed as a novel and significant mechanism of energy transfer between decaying radionuclides and AuNCs.     

A NIR-II-emitting gold nanocluster-based drug delivery system for smartphone-triggered photodynamic theranostics with rapid body clearance

Nanomedicine has grown structurally complex in order to perform multiple tasks at a time. However, their unsatisfied reliability, uniformity and reproducibility account for the high rates of attrition in translational research. So far, most studies have been one-sidedly focused on the treatment efficacy of inorganic nanoparticles as cancer therapeutics, but overlook their elimination from the body – a key factor in getting regulatory approval. Instead of developing a new drug nanocarrier with uncertain future in medical practice, we therefore choose to leverage the utility of promising and translatable gold nanoclusters (AuNCs) for designing a simple but robust “all-in-one” nanocluster drug delivery system, where the AuNCs not only strengthen the renal clearance of neutral red (NR) as a model drug, but also aid its passive tumor targeting via the enhanced permeability and retention (EPR) effect. More interestingly, NR can stimulate the production of reactive oxygen species (ROS) to suppress tumor growth under ultralow-level radiation with a smartphone’s torch (fluence rate: 8 mW/cm²). This finding is especially valuable to low- and middle-income countries lacking resources in healthcare settings. By means of first-principles simulations, we also study in-depth the energies, structural and electronic properties of the AuNCs emitting in the second near-infrared window (NIR-II, 1000–1700 nm). In brief, our model fulfills safety, effectiveness and cost-effectiveness requirements for translational development.     

Self‐Supplying O2 through the Catalase‐Like Activity of Gold Nanoclusters for Photodynamic Therapy against Hypoxic Cancer Cells

Photodynamic therapy (PDT) typically involves oxygen (O₂) consumption and therefore suffers from greatly limited anticancer therapeutic efficacy in tumor hypoxia. Here, it is reported for the first time that amine‐terminated, PAMAM dendrimer‐encapsulated gold nanoclusters (AuNCs‐NH₂) can produce O₂ for PDT via their intrinsic catalase‐like activity. The AuNCs‐NH₂ not only show optimum H₂O₂ consumption via the catalase‐like activity over the physiological pH range (i.e., pH 4.8–7.4), but also extend such activity to acidic conditions. The possible mechanism is deduced from that the enriched tertiary amines of dendrimers are easily protonated in acidic solutions to facilitate the preadsorption of OH on the metal surface, thereby favorably triggering the catalase‐like reaction. By taking advantage of the exciting feature on AuNCs‐NH₂, the possibility to supply O₂ via the catalase‐like activity of AuNCs‐NH₂ for PDT against hypoxia of cancer cells was further studied. This proof‐of‐concept study provides a simple way to combine current O₂‐dependent cancer therapy of PDT to overcome cancer cell hypoxia, thus achieving more effective anticancer treatments.     

Emerging Porous Two-Dimensional Materials: Current Status,Existing Challenges,and Applications

Two-Dimensional (2D) materials have attracted immense attention in recent years. These materials have found their applications in various fields, such as catalysis, adsorption, energy storage, and sensing, as they exhibit excellent physical, chemical, electronic, photonic, and biological properties. Recently, researchers have focused on constructing porous structures on 2D materials. Various strategies, such as chemical etching and template-based methods, for the development of surface pores are reported, and the porous 2D materials fabricated over the years are used to develop supercapacitors and energy storage devices. Moreover, the lattice structure of the 2D materials can be modulated during the construction of porous structures to develop 2D materials that can be used in various fields such as lattice defects in 2D nanomaterials for enhancing biomedical performances. This review focuses on the recently developed chemical etching, solvent thermal synthesis, microwave combustion, and template methods that are used to fabricate porous 2D materials. The application prospects of the porous 2D materials are summarized. Finally, the key scientific challenges associated with developing porous 2D materials are presented to provide a platform for developing porous 2D materials.     

Facile and Scalable Synthesis of Novel Spherical Au Nanocluster Assemblies@Polyacrylic Acid/Calcium Phosphate Nanoparticles for Dual‐Modal Imaging‐Guided Cancer Chemotherapy

Engineering novel theranostic agents with both imaging and therapeutic functions have profound impact on molecular diagnostics, imaging, and therapeutics. In this paper, we develop for the first time a simple, scalable, and reproducible route to synthesize novel multifunctional spherical Au nanoclusters assemblies encapsulated by a polyacylic acid (PAA)/calcium phosphate (CaP) shell with aggregation enhanced fluorescence property (designated as AuNCs‐A@PAA/CaP). Furthermore, the resulting AuNCs‐A@PAA/CaP nanoparticles (NPs) possess a high payload of doxorubicin as synergetic pH‐sensitive drug delivery vehicles to employ for dual‐modal computed tomography (CT) and fluorescence imaging‐guided liver cancer chemotherapy in vivo. The results reveal that AuNCs‐A@PAA/CaP NPs not only provide excellent bimodal CT and fluorescence contrast imaging but also present efficient tumor ablation under the guidance of CT and fluorescence imaging, to achieve excellent chemotherapeutic efficacy to the hepatocarcinoma cell line (H‐22) bearing mice through intravenous injection. Comprehensive blood tests and careful histological examinations reveal no apparent toxicity of AuNCs‐A@PAA/CaP NPs. Our work highlights the great promise of AuNCs‐A@PAA/CaP NPs for guiding and monitoring the chemotherapeutic process using simultaneous dual‐modality CT and fluorescence imaging through a single theranostic agent.     

Recent Advances of Porous Graphene: Synthesis,Functionalization, and Electrochemical Applications

Graphene is a 2D sheet of sp² bonded carbon atoms and tends to aggregate together, due to the strong π–π stacking and van der Waals attraction between different layers. Its unique properties such as a high specific surface area and a fast mass transport rate are severely blocked. To address these issues, various kinds of 2D holey graphene and 3D porous graphene are either self‐assembled from graphene layers or fabricated using graphene related materials such as graphene oxide and reduced graphene oxide. Porous graphene not only possesses unique pore structures, but also introduces abundant exposed edges and accelerates mass transfer. The properties and applications of these porous graphenes and their composites/hybrids have been extensively studied in recent years. Herein, recent progress and achievements in synthesis and functionalization of various 2D holey graphene and 3D porous graphene are reviewed. Of special interest, electrochemical applications of porous graphene and its hybrids in the fields of electrochemical sensing, electrocatalysis, and electrochemical energy storage, are highlighted. As the closing remarks, the challenges and opportunities for the future research of porous graphene and its composites are discussed and outlined.     

Nanoparticles Interacting with Proteins and Cells: A Systematic Study of Protein Surface Charge Effects

Despite intense research on biological and biomedical applications of nanoparticles, our understanding of their basic interactions with the biological environment is still incomplete. Systematic variation of the physicochemical properties of the nanoparticles is widely seen as a promising strategy to obtain further insights. In view of the key role of the protein adsorption layer forming on nanoparticles in contact with biofluids, we systematically varied the surface charge of proteins adsorbing onto nanoparticles by chemical modification so as to examine the effect of Coulomb forces in modulating nano‐bio interactions. We chose human serum albumin (HSA) as a model protein and ultra‐small, negatively charged fluorescent gold nanoclusters (AuNCs) as model nanoparticles. By using fluorescence and CD spectroscopies, we measured binding affinities and structural changes upon binding of the HSA variants. The strengths of the protein‐nanoparticle interactions were found to change substantially upon modifying the surface charge of HSA. Furthermore, by using inductively coupled plasma optical emission spectroscopy, confocal fluorescence microscopy, scanning transmission electron microscopy and cell viability assays, we observed that cellular interactions of the AuNCs, including their adherence to cell membranes, uptake efficiency and cytotoxicity, depended markedly on the different surface charges of the HSA variants adsorbed onto the nanoparticles. These results illustrate vividly that the cellular responses to nanoparticle exposure depend on the specific properties of the proteins that adsorb onto nanoparticles from biofluids.     

Yolk–Shell Nanostructures: Design,Synthesis, and Biomedical Applications

Yolk–shell nanostructures (YSNs) composed of a core within a hollow cavity surrounded by a porous outer shell have received tremendous research interest owing to their unique structural features, fascinating physicochemical properties, and widespread potential applications. Here, a comprehensive overview of the design, synthesis, and biomedical applications of YSNs is presented. The synthetic strategies toward YSNs are divided into four categories, including hard‐templating, soft‐templating, self‐templating, and multimethod combination synthesis. For the hard‐ or soft‐templating strategies, different types of rigid or vesicle templates are used for making YSNs. For the self‐templating strategy, a number of unconventional synthetic methods without additional templates are introduced. For the multimethod combination strategy, various methods are applied together to produce YSNs that cannot be obtained directly by only a single method. The biomedical applications of YSNs including biosensing, bioimaging, drug/gene delivery, and cancer therapy are discussed in detail. Moreover, the potential superiority of YSNs for these applications is also highlighted. Finally, some perspectives on the future research and development of YSNs are provided.     

Base-selective adsorption of nucleosides to pore-engineered nanocarbon, carbon nanocage

Selective molecular recognition is an important subject in supramolecular science as well as in practical applications such as sensing, drug delivery, and biomedical processes. In this research we have investigated adsorption behavior of nucleosides (adenosine, guanosine, and thymidine) onto various porous supports. When compared with mesoporous silica, porous carbons exhibit superior adsorptive performance. We serendipitously observed a pronounced selectivity between purine-base and pyrimidine-base nucleosides by carbon naonocage. These findings are useful for design of materials for applications in adsorption-based separations and as column stationary phases for separation of costly and important biomolecules.     

Zirconia toughened alumina ceramic foams for potential bone graft applications: fabrication,bioactivation, and cellular responses

Zirconia toughened alumina (ZTA) has been regarded as the next generation orthopedic graft material due to its excellent mechanical properties and biocompatibility. Porous ZTA ceramics with good interconnectivity can potentially be used as bone grafts for load-bearing applications. In this work, three-dimensional (3D) interconnected porous ZTA ceramics were fabricated using a direct foaming method with egg white protein as binder and foaming agent. The results showed that the porous ZTA ceramics possessed a bimodal pore size distribution. Their mechanical properties were comparable to those of cancellous bone. Due to the bio-inertness of alumina and zirconia ceramics, surface bioactivation of the ZTA foams was carried out in order to improve their bioactivity. A simple NaOH soaking method was employed to change the surface chemistry of ZTA through hydroxylation. Treated samples were tested by conducting osteoblast-like cell culture in vitro. Improvement on cells response was observed and the strength of porous ZTA has not been deteriorated after the NaOH treatment. The porous 'bioactivated' ZTA ceramics produced here could be potentially used as non-degradable bone grafts for load-bearing applications.     

Tailoring Enzyme‐Like Activities of Gold Nanoclusters by Polymeric Tertiary Amines for Protecting Neurons Against Oxidative Stress

The cytotoxicity of nanozymes has drawn much attention recently because their peroxidase‐like activity can decompose hydrogen peroxide (H₂O₂) to produce highly toxic hydroxyl radicals (?OH) under acidic conditions. Although catalytic activities of nanozymes are highly associated with their surface properties, little is known about the mechanism underlying the surface coating‐mediated enzyme‐like activities. Herein, it is reported for the first time that amine‐terminated PAMAM dendrimer‐entrapped gold nanoclusters (AuNCs‐NH₂) unexpectedly lose their peroxidase‐like activity while still retaining their catalase‐like activity in physiological conditions. Surprisingly, the methylated form of AuNCs‐NH₂ (i.e., MAuNCs‐N⁺R₃, where R = H or CH₃) results in a dramatic recovery of the intrinsic peroxidase‐like activity while blocking most primary and tertiary amines (1°‐ and 3°‐amines) of dendrimers to form quaternary ammonium ions (4°‐amines). However, the hidden peroxidase‐like activity is also found in hydroxyl‐terminated dendrimer‐encapsulated AuNCs (AuNCs‐OH, inside backbone with 3°‐amines), indicating that 3°‐amines are dominant in mediating the peroxidase‐like activity. The possible mechanism is further confirmed that the enrichment of polymeric 3°‐amines on the surface of dendrimer‐encapsulated AuNCs provides sufficient suppression of the critical mediator ?OH for the peroxidase‐like activity. Finally, it is demonstrated that AuNCs‐NH₂ with diminished cytotoxicity have great potential for use in primary neuronal protection against oxidative damage.     

多孔钽植入物在骨缺损中的应用进展EI北大核心CSCD

多孔金属钽具有良好的生物相容性与骨传导能力,相比于传统的金属植入物材料有较低的弹性模量与高的摩擦因数,可以避免发生应力遮挡效应且具有与人类松质骨类似的多孔结构。多孔钽的力学性能优势与优秀的生物学性能,在骨修复材料领域受到越来越多的关注,且已研发并应用于多种部位的骨缺损修复中。随着多孔钽材料制备方法的更新与多种改性方法的提出,多孔钽进一步展示了在临床应用中的广阔前景。本文从多孔钽材料的制备工艺、细胞毒性、与骨结合特性以及目前在临床的应用情况等方面,介绍多孔钽植入物在骨缺损中的应用进展,并提出了多孔钽在表面改性建立复合体系、优化制备工艺及个性化制备技术的发展方向,为多孔钽植入物在治疗骨缺损的临床应用提供参考。     

Using Functional Nanomaterials to Target and Regulate the Tumor Microenvironment: Diagnostic and Therapeutic Applications

Malignant tumors remain a major health burden throughout the world and effective therapeutic strategies are urgently needed. Cancer nanotechnology, as an integrated platform, has the potential to dramatically improve cancer diagnosis, imaging, and therapy, while reducing the toxicity associated with the current approaches. Tumor microenvironment is an ensemble performance of various stromal cells and extracellular matrix. The recent progress in understanding the critical roles and the underlying mechanisms of the tumor microenvironment on tumor progression has resulted in emerging diagnostic and therapeutic nanomaterials designed and engineered specifically targeting the microenvironment components. Meanwhile, the bio‐physicochemical differences between tumor and normal tissues have recently been exploited to achieve specific tumor‐targeting for cancer diagnosis and treatment. Here, the major players in the tumor microenvironment and their biochemical properties, which can be utilized for the design of multifunctional nanomaterials with the potential to target and regulate this niche, are summarized. The recent progress in engineering intelligent and versatile nanomaterials for targeting and regulating the tumor microenvironment is emphasized. Although further investigations are required to develop robust methods for more specific tumor‐targeting and well‐controlled nanomaterials, the applications of tumor microenvironment regulation‐based nanotechnology for safer and more effective anticancer nanomedicines have been proven successful and will eventually revolutionize the current landscape of cancer therapy.     

Fabrication of Hollow Microporous Carbon Spheres from Hyper‐Crosslinked Microporous Polymers

Porous carbon materials prepared from the porous organic polymers are currently the subject of extensive investigation. On the basis of their interesting applications, it is highly desirable to develop new synthetic methodologies to obtain carbon materials with controllable pore size and morphology. Herein, a facile synthesis of hollow microporous carbon spheres (HCSs) from hollow microporous organic capsules (HMOCs) with a good control over the pore morphology, hollow cavity, and the shell thickness is reported. The highly porous hollow carbon spheres are prepared by the pyrolysis of HMOCs‐based microporous polymers. The synthetic parameters, such as hypercrosslinking and pyrolysis conditions, are optimized to modify the porous structures and the properties. The morphology and porosity as well as energy storage applications of the microporous structures HCSs, derived through a combination of divinylbenzene‐crosslinking and micropore‐generating hypercrosslinking, are discussed. These findings provide a new benchmark for fabricating well‐defined HCSs with great promise for various applications.     

Porous Polymers as Multifunctional Material Platforms toward Task‐Specific Applications

Exploring advanced porous materials is of critical importance in the development of science and technology. Porous polymers, being famous for their all‐organic components, tailored pore structures, and adjustable chemical components, have attracted an increasing level of research interest in a large number of applications, including gas adsorption/storage, separation, catalysis, environmental remediation, energy, optoelectronics, and health. Recent years have witnessed tremendous research breakthroughs in these fields thanks to the unique pore structures and versatile skeletons of porous polymers. Here, recent milestones in the diverse applications of porous polymers are presented, with an emphasis on the structural requirements or parameters that dominate their properties and functionalities. The Review covers the following applications: i) gas adsorption, ii) water treatment, iii) separation, iv) heterogeneous catalysis, v) electrochemical energy storage, vi) precursors for porous carbons, and vii) other applications (e.g., intelligent temperature control textiles, sensing, proton conduction, biomedicine, optoelectronics, and actuators). The key requirements for each application are discussed and an in‐depth understanding of the structure–property relationships of these advanced materials is provided. Finally, a perspective on the future research directions and challenges in this field is presented for further studies.     

Fabrication of antibacterial sponge cleaner using gold nanoclusters

From the dinner table to the office, many surfaces contain bacteria and the threat to human health. In this work, cost‐effective antimicrobial foams were developed by the adsorption of lysozyme protected gold nanoclusters (AuNCs) in sponges. Antibacterial activities of the prepared antibacterial AuNCs were evaluated using typical Gram‐negative bacteria (Escherichia coli) and Gram‐positive bacteria (Staphylococcus aureus). The antibacterial foams were further fabricated by the absorption of the positively charged AuNCs in the negatively charged sponges. The inhibitions of bacteria on random surfaces, such as mobile phones, tables, doorknobs, and cabinet handles, were exhibited by cleaning them with the antibacterial foams.Inspec keywords: molecular biophysics, gold, microorganisms, nanomedicine, nanofabrication, adsorption, antibacterial activity, enzymes, metal clusters, nanostructured materials, porous materials, foamsOther keywords: antibacterial sponge cleaner, human health, cost‐effective antimicrobial foams, antibacterial activity, Gram‐negative bacteria, Escherichia coli, Gram‐positive bacteria, Staphylococcus aureus, random surfaces, antibacterial gold nanoclusters, adsorption, positively charged gold nanoclusters, negatively charged sponges, lysozyme protected gold nanoclusters, Au