Facile preparation of hybrid core-shell nanorods for photothermal and radiation combined therapy

Biocompatible Copper-Based Nanocomposites for Combined Cancer Therapy

Copper (Cu) and Cu-based nanomaterials have received tremendous attention in recent years because of their unique physicochemical properties and good biocompatibility in the treatment of various diseases, especially cancer. To date, researchers have designed and fabricated a variety of integrated Cu-based nanocomplexes with distinctive nanostructures and applied them in cancer therapy, mainly including chemotherapy, radiotherapy (RT), photothermal therapy (PTT), chemodynamic therapy (CDT), photodynamic therapy (PDT), cuproptosis-mediated therapy, etc. Due to the limited effect of a single treatment method, the development of composite diagnostic nanosystems that integrate chemotherapy, PTT, CDT, PDT, and other treatments is of great significance and offers great potential for the development of the next generation of anticancer nanomedicines. In view of the rapid development of Cu-based nanocomplexes in the field of cancer therapy, this review focuses on the current state of research on Cu-based nanomaterials, followed by a discussion of Cu-based nanocomplexes for combined cancer therapy. Moreover, the current challenges and future prospects of Cu-based nanocomplexes in clinical translation are proposed to provide some insights into the design of integrated Cu-based nanotherapeutic platforms.

A review of recent advances in the use of complex metal nanostructures for biomedical applications from diagnosis to treatment

Complex metal nanostructures represent an exceptional category of materials characterized by distinct morphologies and physicochemical properties. Nanostructures with shape anisotropies, such as nanorods, nanostars, nanocages, and nanoprisms, are particularly appealing due to their tunable surface plasmon resonances, controllable surface chemistries, and effective targeting capabilities. These complex nanostructures can absorb light in the near-infrared, enabling noteworthy applications in nanomedicine, molecular imaging, and biology. The engineering of targeting abilities through surface modifications involving ligands, antibodies, peptides, and other agents potentiates their effects. Recent years have witnessed the development of innovative structures with diverse compositions, expanding their applications in biomedicine. These applications encompass targeted imaging, surface-enhanced Raman spectroscopy, near-infrared II imaging, catalytic therapy, photothermal therapy, and cancer treatment. This review seeks to provide the nanomedicine community with a thorough and informative overview of the evolving landscape of complex metal nanoparticle research, with a specific emphasis on their roles in imaging, cancer therapy, infectious diseases, and biofilm treatment. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Diagnostic Tools > Diagnostic Nanodevices.

Facile Cu-MOF-derived Co3O4 mesoporous-structure as a cooperative catalyst for the reduction nitroarenes and dyes

The present study describes the environmentally friendly and cost-effective synthesis of magnetic, mesoporous structure-Co3O4 nanoparticles (m-Co3O4) utilizing almond peel as a biotemplate. This straightforward method yields a material with high surface area, as confirmed by various characterization techniques. Subsequently, the utilization of m-Co3O4, graphene oxide (GO), Cu(II)acetate (Cu), and asparagine enabled the successful synthesis of a novel magnetic MOF, namely GO-Cu-ASP-m-Co3O4 MOF. This catalyst revealed remarkable stability that could be easily recovered using a magnet for consecutive use without any significant decline in activity for eight cycles in nitro compound reduction and organic dye degradation reactions. Consequently, GO-Cu-ASP-m-Co3O4 MOF holds immense potential as a catalyst for reduction reactions, particularly in the production of valuable amines with high industrial value, as well as for the elimination of toxic-water pollutants such as organic dyes.

Magnetic-Field-Induced Improvement of Photothermal Sterilization Performance by Fe3O4@SiO2@Au/PDA Nanochains

Due to the abuse of antibiotics, the sensitivity of patients to antibiotics is gradually reduced. This work develops a Fe₃O₄@SiO₂@Au/PDA nanochain which shows an interesting magnetic-field-induced improvement of its photothermal antibacterial property. First, SiO₂ was wrapped on Fe₃O₄ nanospheres assembled in a chain to form a Fe₃O₄@SiO₂ nanocomposite with a chain-like nanostructure. Then, the magnetic Fe₃O₄@SiO₂@Au/PDA nanochains were prepared using in situ redox-oxidization polymerization. Under the irradiation of an 808 nm NIR laser, the temperature rise of the Fe₃O₄@SiO₂@Au/PDA nanochain dispersion was obvious, indicating that they possessed a good photothermal effect. Originating from the Fe₃O₄, the Fe₃O₄@SiO₂@Au/PDA nanochain showed a typical soft magnetic behavior. Both the NIR and magnetic field affected the antimicrobial performance of the Fe₃O₄@SiO₂@Au/PDA nanochains. Escherichia coli and Staphylococcus aureus were used as models to verify the antibacterial properties. The experimental results showed that the Fe₃O₄@SiO₂@Au/PDA nanochains exhibited good antibacterial properties under photothermal conditions. After applying a magnetic field, the bactericidal effect was further significantly enhanced. The above results show that the material has a broad application prospect in inhibiting the growth of bacteria.

Platinum nanoplatforms: classic catalysts claiming a prominent role in cancer therapy

Platinum nanoparticles (Pt NPs) have a well-established role as a classic heterogeneous catalyst. Also, Pt has traditionally been employed as a component of organometallic drug formulations for chemotherapy. However, a new role in cancer therapy is emerging thanks to its outstanding catalytic properties, enabling novel approaches that are surveyed in this review. Herein, we critically discuss results already obtained and attempt to ascertain future perspectives for Pt NPs as catalysts able to modify key processes taking place in the tumour microenvironment (TME). In addition, we explore relevant parameters affecting the cytotoxicity, biodistribution and clearance of Pt nanosystems. We also analyze pros and cons in terms of biocompatibility and potential synergies that emerge from combining the catalytic capabilities of Pt with other agents such as co-catalysts, external energy sources (near-infrared light, X-ray, electric currents) and conventional therapies.

Janus-Nanojet as an efficient asymmetric photothermal source

The combination of materials with radically different physical properties in the same nanostructure gives rise to the so-called Janus effects, allowing phenomena of a contrasting nature to occur in the same architecture. Interesting advantages can be taken from a thermal Janus effect for photoinduced hyperthermia cancer therapies. Such therapies have limitations associated to the heating control in terms of temperature stability and energy management. Single-material plasmonic nanoheaters have been widely used for cancer therapies, however, they are highly homogeneous sources that heat the surrounding biological medium isotropically, thus equally affecting cancerous and healthy cells. Here, we propose a prototype of a Janus-Nanojet heating unit based on toroidal shaped plasmonic nanoparticles able to efficiently generate and release local heat directionally under typical unpolarized illumination. Based on thermoplasmonic numerical calculations, we demonstrate that these Janus-based nanoheaters possess superior photothermal conversion features (up to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Delta T\approx 35$$\end{document}ΔT≈35 K) and unique directional heating capacity, being able to channel up over 90% of the total thermal energy onto a target. We discuss the relevance of these innovative nanoheaters in thermoplasmonics, and hyperthermia cancer therapies, which motivate the development of fabrication techniques for nanomaterials.

Research Progress of Photothermal Nanomaterials in Multimodal Tumor Therapy

The aggressive growth of cancer cells brings extreme challenges to cancer therapy while triggering the exploration of the application of multimodal therapy methods. Multimodal tumor therapy based on photothermal nanomaterials is a new technology to realize tumor cell thermal ablation through near-infrared light irradiation with a specific wavelength, which has the advantages of high efficiency, less adverse reactions, and effective inhibition of tumor metastasis compared with traditional treatment methods such as surgical resection, chemotherapy, and radiotherapy. Photothermal nanomaterials have gained increasing interest due to their potential applications, remarkable properties, and advantages for tumor therapy. In this review, recent advances and the common applications of photothermal nanomaterials in multimodal tumor therapy are summarized, with a focus on the different types of photothermal nanomaterials and their application in multimodal tumor therapy. Moreover, the challenges and future applications have also been speculated.

Theranostic applications of stimulus-responsive systems based on Fe2O3

According to the interaction of nanoparticles with biological systems, enthusiasm for nanotechnology in biomedical applications has been developed in the past decades. Fe2O3 nanoparticles, as the most stable iron oxide, have special merits that make them useful widely for detecting diseases, therapy, drug delivery, and monitoring the therapeutic process. This review presents the fabrication methods of Fe2O3-based materials and their photocatalytic and magnetic properties. Then, we highlight the application of Fe2O3-based nanoparticles in diagnosis and imaging, different therapy methods, and finally, stimulus-responsive systems, such as pH-responsive, magnetic-responsive, redox-responsive, and enzyme-responsive, with an emphasis on cancer treatment. In addition, the potential of Fe2O3 to combine diagnosis and therapy within a single particle called theranostic agent will be discussed.

Glycol chitosan/iron oxide/polypyrrole nanoclusters for precise chemodynamic/photothermal synergistic therapy

Noninvasive photothermal therapy (PTT) represents a promising direction for more modern and precise medical applications. However, PTT efficacy is still not satisfactory due to the existence of heat shock proteins (HSPs) and poorly targeted delivery. Herein, the design of a nanosystem with improved delivery efficacy for anticancer treatment employing the synergetic effects of reactive oxygen species (ROS)-driven chemodynamic therapy (CDT) to inactivated HSPs with photothermal-hyperthermia was therefore achieved through the development of pH-targeting glycol chitosan/iron oxide enclosed core polypyrrole nanoclusters (GCPI NCs). The designed NCs effectively accumulated toward cancer cells due to their acidic microenvironment, initiating ROS generation via Fenton reaction at the outset and performing site-specific near infrared (NIR)-photothermal effect. A comprehensive analysis of both surface and bulk material properties of the CDT/PTT NCs as well as biointerface properties were ascertained via numerous surface specific analytical techniques by bringing together heightened accumulation of CDT/PTT NCs, which can significantly eradicate cancer cells thus minimizing the side effects of conventional chemotherapies. All of these attributes act in synergy over the cancer cells succeeding in fashioning NC's able to act as competent agents in the MRI-monitored enhanced CDT/PTT synergistic therapy. Findings in this study evoke attention in future oncological therapeutic strategies.

Platinum-crosslinking polymeric nanoparticle for synergetic chemoradiotherapy of nasopharyngeal carcinoma

Despite extensive use of radiotherapy in nasopharyngeal carcinoma (NPC) treatment because of its high radiosensitivity, there have been huge challenges in further improving therapeutic effect, meanwhile obviously reducing radiation damage. To this end, synergistic chemoradiotherapy has emerged as a potential strategy for highly effective NPC therapy. Here, we developed RGD-targeted platinum-based nanoparticles (RGD-PtNPs, denoted as RPNs) to achieve targeted chemoradiotherapy for NPC. Such nanoparticles consist of an RGD-conjugated shell and a cis-platinum (CDDP) crosslinking core. Taking advantage of RGD, the RPNs may effectively accumulate in tumor, penetrate into tumor tissues and be taken by cancer cells, giving rise to a high delivery efficiency of CDDP. When they are fully enriched in tumor sites, the CDDP loaded RPNs can act as radiotherapy sensitizer and chemotherapy agents. By means of X-ray-promoted tumor cell uptake of nanoparticle and CDDP-induced cell cycle arrest in radiation-sensitive G2/M phases, RPNs may offer remarkable therapeutic outcome in the synergistic chemoradiotherapy for NPC.

Folic Acid-Conjugated Gold Nanostars for Computed Tomography Imaging and Photothermal/Radiation Combined Therapy

Fabrication of multifunctional nanoprobes, which integrate tumor targeting, imaging, and effective treatment, has been widely explored in nanomedicine. In the present study, we fabricated tumor-targeting polymer folic acid-terminated polyethylene glycol thiol-modified gold nanostars (GNS-FA), which could realize X-ray computed tomography (CT) imaging and PTT/RT synergistic therapy. The synthesized GNS-FA exhibited good biocompatibility. GNS-FA could be used as a CT imaging contrast agent due to the strong X-ray attenuation of Au. GNS-FA exhibited good near-infrared (NIR) light absorption and excellent photothermal conversion performance, making them promising photothermal transduction agents (PTAs). Furthermore, GNS-FA could be used as an RT sensitizer to enhance the radio-mediated cell death due to the high atomic number (high Z) of gold. Hence, GNS-FA were used as the CT imaging agent, PTA, and radiosensitizer in this work. The in vitro antitumor experiments showed that the PTT/RT combined treatment had enhanced anticancer efficacy compared with the monotherapy (PTT or RT). Our results indicated that the bioconjugated GNS could offer an excellent nanoplatform for CT imaging-guided PTT/RT combined cancer therapy in the future.

Noble Metal Nanomaterials for NIR-Triggered Photothermal Therapy in Cancer

It is of great significance to develop anticancer therapeutic agents or technologies with high degree of specificity and patient compliance, while low toxicity. The emerging photothermal therapy (PTT) has become a new and powerful therapeutic technology due to its noninvasiveness, high specificity, low side effects to normal tissues and strong anticancer efficacy. Noble metal nanomaterials possess strong surface plasmon resonance (SPR) effect and synthetic tunability, which make them facile and effective PTT agents with superior optical and photothermal characteristics, such as high absorption cross-section, incomparable optical-thermal conversion efficiency in the near infrared (NIR) region, as well as the potential of bioimaging. By incorporating with various functional reagents such as antibodies, peptides, biocompatible polymers, chemo-drug and immune factors, noble metal nanomaterials have presented strong potential in multifunctional cancer therapy. Herein, the recent development regarding the application of noble metal nanomaterials for NIR-triggered PTT in cancer treatment is summarized. A variety of studies with good therapeutic effects against cancer from impressive photothermal efficacy of noble metal nanomaterials are concluded. Intelligent nanoplatforms through ingenious fabrication showing potential of multifunctional PTT, combined with chemo-therapy, immunotherapy, photodynamic therapy (PDT), as well as simultaneous imaging modality are also demonstrated.

Multifunctional Magnetic Nanoagents for Bioimaging and Therapy

Multifunctional magnetic nanoagents (MMNs) have drawn increasing attention in cancer precision therapy, attributed to their good biocompatibility and the potential applications for multimodal imaging and multidisciplinary therapy. The noble metal or isotopes contained in MMNs could not only perform superparamagnetism, providing an outstanding magnetic targeting property for drug delivery, but also endow the MMNs with a magnetocaloric effect, photothermal performance, and radiotherapy sensitization, arriving at a multimode combination therapy for cancer. Also, the composite component can endow MMNs with various imaging performance, such as magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), and single-photon emission computed tomography (SPECT), thereby achieving accurate image-guided therapy for cancer. However, the joint function of MMNs is closely correlated with their functional nanocomponents and nanostructures. In this article, we will systematically discuss the design, synthesis, and structure optimization of MMNs, as well as their potential in multimodal diagnosis and therapy, scientifically providing an integrated diagnosis and treatment of nanomedicine for the future cancer therapy.

Palladium Nanosheets as Safe Radiosensitizers for Radiotherapy

Many noble metal-based nanoparticles have emerged for applications in cancer radiotherapy in recent years, but few investigations have been carried out for palladium nanoparticles. Herein, palladium nanosheets (Pd NSs), which possess a sheetlike morphology with a diameter of ∼14 nm and a thickness of ∼2 nm, were utilized as a sensitizer to improve the performance of radiotherapy. It was found that Pd NSs alone did not decrease the cell viability after treatment for as long as 130 h, suggesting the excellent cytocompatibility of the nanoagents. However, the viability of cancer cells treated with X-ray irradiation became lower, and the viability became even lower if the cells were co-treated with X-ray and Pd NSs, indicating the radiosensitization effect of Pd NSs. Additionally, compared with X-ray irradiation, the combined treatment of Pd NSs and X-ray irradiation induced the generation of more DNA double-stranded breaks and reactive oxygen species within cancer cells, which eventually caused elevated cell apoptosis. Moreover, in vivo experiments also verified the radiosensitization effect and the favorable biocompatibility of Pd NSs, indicating their potential for acquiring satisfactory in vivo radiotherapeutic effect at lower X-ray doses. It is believed that the present research will open new avenues for the application of noble metal-based nanoparticles in radiosensitization.

Integration of Fe3O4 with Bi2S3 for Multi-Modality Tumor Theranostics

The combination of reactive oxygen species (ROS)-induced chemodynamic therapy (CDT) and photothermal therapy (PTT) holds a promising application prospect for their superb anticancer efficiency. Herein, we created a novel Fe₃O₄@polydopamine (PDA)@bovine serum albumin (BSA)-Bi₂S₃ composite as a theranostic agent, by chemically linking the Fe₃O₄@PDA with BSA-Bi₂S₃ via the amidation between the carboxyl groups of BSA and the amino groups of PDA. In this formulation, the Fe₃O₄ NPs could not only work as a mimetic peroxidase to trigger Fenton reactions of the innate H₂O₂ in the tumor and generate highly cytotoxic hydroxyl radicals (•OH) to induce tumor apoptosis but also serve as the magnetic resonance imaging (MRI) contrast agent to afford the precise cancer diagnosis. Meanwhile, the PDA could prevent the oxidization of Fe₃O₄, thus supporting the long-term Fenton reactions and the tumor apoptosis in the tumor. The Bi₂S₃ component exhibits excellent photothermal transducing performance and computed tomography (CT) imaging capacity. In addition, the PDA and Bi₂S₃ endow the Fe₃O₄@PDA@BSA-Bi₂S₃ composite with an excellent photothermal transforming ability which could lead to tumor hyperthermia. All of these merits play the synergism with the tumor microenvironment and qualify the Fe₃O₄@PDA@BSA-Bi₂S₃ NPs for a competent agent in the MRI/CT-monitored enhanced PTT/CDT synergistic therapy. Findings in this research will evoke new interests in future cancer therapeutic strategies based on biocompatible nanomaterials.

Nanoplatforms with Remarkably Enhanced Absorption in the Second Biological Window for Effective Tumor Thermoradiotherapy

Thermoradiotherapy acts as an important antitumor modality because heating can increase the blood flow and improve the oxygen level in tumor, thus remission of hypoxia-associated resistance for radiotherapy (RT). However, most agents for thermoradiotherapy are used either in the first near-infrared biological window or low photothermal conversion efficiency. Here, a facile method to prepare Cu_xS/Au nanocomposites via reduction methods from Cu_xS templates in mild synthetic conditions (i.e., aqueous solution and room temperature) is presented. After the growth of Au nanoparticles, the Cu_xS/Au nanocomposites have greater benefits for photothermal efficiency than that of Cu_xS nanoparticles due to the enhanced absorbance in the second near-infrared window. Moreover, biocompatibility and stability of these nanocomposites are greatly improved by lipoic acid poly(ethylene glycol). After the tumors were irradiated with a 1064 nm laser, their oxygenation status is subsequently improved, and the combination of photothermal therapy and RT achieves remarkable synergistic therapeutic effects. This work provides a novel idea to design a new-generation nanomedicine for tumor thermoradiotherapy.

Preparation of Magnetic CuFe2O4@Ag@ZIF-8 Nanocomposites with Highly Catalytic Activity Based on Cellulose Nanocrystals

A facile approach was successfully developed for synthesis of cellulose nanocrystals (CNC)-supported magnetic CuFe2O4@Ag@ZIF-8 nanospheres which consist of a paramagnetic CuFe2O4@Ag core and porous ZIF-8 shell. The CuFe2O4 nanoparticles (NPs) were first prepared in the presence of CNC and dispersant. Ag NPs were then deposited on the CuFe2O4/CNC composites via an in situ reduction directed by dopamine polymerization (PDA). The CuFe2O4/CNC@Ag@ZIF-8 nanocomposite was characterized by TEM, FTIR, XRD, N2 adsorption-desorption isotherms, VSM, and XPS. Catalytic studies showed that the CuFe2O4/CNC@Ag@ZIF-8 catalyst had much higher catalytic activity than CuFe2O4@Ag catalyst with the rate constant of 0.64 min-1. Because of the integration of ZIF-8 with CuFe2O4/CNC@Ag that combines the advantaged of each component, the nanocomposites were demonstrated to have an enhanced catalytic activity in heterogeneous catalysis. Therefore, these results demonstrate a new method for the fabrication of CNC-supported magnetic core-shell catalysts, which display great potential for application in biocatalysis and environmental chemistry.

Manganese Oxide Nanoparticles As MRI Contrast Agents In Tumor Multimodal Imaging And Therapy

Contrast agents (CAs) play a crucial role in high-quality magnetic resonance imaging (MRI) applications. At present, as a result of the Gd-based CAs which are associated with renal fibrosis as well as the inherent dark imaging characteristics of superparamagnetic iron oxide nanoparticles, Mn-based CAs which have a good biocompatibility and bright images are considered ideal for MRI. In addition, manganese oxide nanoparticles (MONs, such as MnO, MnO2, Mn3O4, and MnOx) have attracted attention as T1-weighted magnetic resonance CAs due to the short circulation time of Mn(II) ion chelate and the size-controlled circulation time of colloidal nanoparticles. In this review, recent advances in the use of MONs as MRI contrast agents for tumor detection and diagnosis are reported, as are the advances in in vivo toxicity, distribution and tumor microenvironment-responsive enhanced tumor chemotherapy and radiotherapy as well as photothermal and photodynamic therapies.

In Situ Immobilized Silver Nanoparticles on Rubia tinctorum Extract-Coated Ultrasmall Iron Oxide Nanoparticles: An Efficient Nanocatalyst with Magnetic Recyclability for Synthesis of Propargylamines by A3 Coupling Reaction

This research suggests a green method for synthesizing hybrid magnetic nanocomposites that can be used as a reductant and a stabilizing agent for immobilizing metal nanoparticles (NPs). The central idea is the modification of magnetic NPs using Rubia tinctorum extract, which consists of numerous carbonyl and phenolic hydroxyl functional groups to increase adsorption of metals and chelate silver ions, and decrease the adsorption of silver ions by Ag NPs, in situ. Thus, the suggested catalyst preparation process does not require toxic reagents, additional reductants, and intricate instruments. To show the effectiveness of the plant extract in reducing and immobilizing Ag NPs, the structural, morphological, and physicochemical features of the particles are studied using Fourier-transform infrared spectroscopy, inductively coupled plasma atomic emission spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, vibrating sample magnetometry, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. One of the advantages of the suggested method is to reduce the size of the magnetic NPs from 15-20 to 2-5 nm, in the presence of the extract. Additionally, the prepared Fe3O4@R. tinctorum/Ag nanocatalyst is demonstrated to exhibit a very high activity in the catalysis of the three-component reaction of aldehydes, amines, and alkynes (A3 coupling) with good to high yields of diverse propargylamines. Moreover, the nanocatalyst can be recovered several times with no considerable leaching or loss of performance.

Biomodal Tumor-Targeted and Redox-Responsive Bi2 Se3 Hollow Nanocubes for MSOT/CT Imaging Guided Synergistic Low-Temperature Photothermal Radiotherapy

Hyperthemia (>50 °C) induced heating damage of nearby normal organs and inflammatory diseases are the main challenges for photothermal therapy (PTT) of cancers. To overcome this limitation, a redox-responsive biomodal tumor-targeted nanoplatform is synthesized, which can achieve multispectral optoacoustic tomography/X-ray computed tomography imaging-guided low-temperature photothermal-radio combined therapy (PTT RT). In this study, Bi₂ Se₃ hollow nanocubes (HNCs) are first fabricated based on a mild cation exchange way and Kirkendall effect and then modified with hyaluronic acid (HA) through redox-cleavable linkage (-s-s-), thus enabling the HNC to target cancer cells overexpressing CD-44 and control the cargo release profile. Finally, gambogic acid (GA), a type of heat-shock protein (HSP) inhibitor, which is vital to cells resisting heating-caused damage is loaded, into Bi₂ Se₃ HNC. Such HNC-s-s-HA/GA under a mild NIR laser irradiation can induce efficient cancer cell apoptosis, achieving PTT under relatively low temperature (≈43 °C) with remarkable cancer cell damage efficiency. Furthermore, enhanced radiotherapy (RT) can also be experienced without depth limitation based on RT sensitizer Bi₂ Se₃ HNC. This research designs a facile way to synthesize Bi₂ Se₃ HNC-s-s-HA/GA possessing theranostic functionality and cancer cells-specific GSH, but also shows a low-temperature PTT RT method to cure tumors in a minimally invasive and highly efficient way.

Synthesis of magnetite hybrid nanocomplexes to eliminate bacteria and enhance biofilm disruption

Bacteria can increase drug resistance by forming bacterial biofilms. Once the biofilm is formed, it becomes difficult to remove or kill the related bacteria completely by antibiotics and other antibacterial agents because these antibacterial agents cannot easily break through the biofilm matrix barrier and reach the internal bacteria. Therefore, we synthesized magnetite hybrid nanocomplexes that can penetrate and disrupt bacterial biofilms. The obtained nanocomposites are composed of multinucleated iron oxides and Ag seeds. The outer iron oxides can help the internal Ag nanoparticles penetrate the bacterial biofilms, hence killing the internal bacteria and disrupting the biofilms. We took advantage of E. coli and P. aeruginosa bacteria to test the antibacterial properties of the magnetite hybrid nanocomplexes. When planktonic E. coli and P. aeruginosa bacteria were incubated with 100 μg mL-1 magnetite hybrid nanocomplexes for 30 min, almost all the bacteria were killed. When the obtained biofilms of E. coli and P. aeruginosa were treated with magnetite hybrid nanocomplexes (10 μg mL-1 and 100 μg mL-1), the survival of E. coli and P. aeruginosa biofilms with a magnetic field showed a big decrease compared with that without a magnetic field. Therefore, the as-synthesized nanocomposites have promising potential as antimicrobial agents for killing bacteria and disrupting biofilms in the presence of a magnetic field, and thus should be further studied for a wide range of antibacterial applications.

Cobalt nanowire-based multifunctional platform for targeted chemo-photothermal synergistic cancer therapy

Cobalt nanowires (CoNWs) simultaneously possessing advantages in photothermal effect, targeting drug delivery and photoacoustic imaging property are hopefully promising strategies to further improve the treatment efficiency and reduce the side effects of cancer chemotherapy. Herein, a unique cobalt-based structure decorated with graphene oxide (GO) and polyethylene glycol (PEG) is fabricated through a facile approach. The resultant nanohybrids show relatively low cytotoxicity, favorable biocompatibility as well as inherit the outstanding properties of cobalt. Moreover, CoNWs decorated with GO and PEG (CoNWs-GO-PEG) can load therapeutic drug molecules (e.g., doxorubicin, DOX) with a high drug loading capacity (992.91 mg/g), and simultaneously they are responsive to pH, NIR (near-infrared) irradiation and magnetism stimulation. Accordingly, CoNWs-GO-PEG-DOX shows the satisfactory effect of eliminating cancer cells with synergistic chemo-photothermal therapy in vitro. Current work provides a solid demonstration of the potential of CoNWs-GO-PEG for serving as a targeted antitumor agent in synergistic chemo-photothermal therapy.

In situ redox-oxidation polymerization for magnetic core-shell nanostructure with polydopamine-encapsulated-Au hybrid shell

This work reports a facile one-step method for the fabricating Fe₃O₄@Au/polydopamine sandwich-like core-shell nanostructure, in which the Au/polydopamine (Au/PDA) hybrid shell is obtained via an in situ redox-oxidation polymerization between the HAuCl₄ and dopamine. The content of Au nanocrystals, shell thickness, and particle sizes are tunable by varying the experimental parameters. Intriguingly, this general method can be applied for different functional nanostructures such as the β-FeOOH@Au/PDA, SiO₂@Au/PDA, and CNT@Au/PDA nanocomposites. A possible formation mechanism is proposed and it is found that the surface interaction plays a key role in determining the final nanostructure. The as-prepared Fe₃O₄@Au/PDA exhibited eminent catalytic activity on the reduction of 4-nitrophenol. Since the external PDA shell prevents the Au nanocrystals from leaching during the reduction, the cycling activity has been maintained as high as 95% after seven times of catalytic reaction.

Copper Oxide Nanoparticles Induce Enhanced Radiosensitizing Effect via Destructive Autophagy

Emerging nanotechnologies for radiotherapy are attracting increasing interest from researchers in recent years. To improve the radiotherapeutic performance, developing nanoparticles that can efficiently generate toxic reactive oxygen species (ROS) under X-ray irradiation are highly desirable. Here, we investigate the potential of copper oxide nanoparticles (CuO NPs) as nanoradiosensitizers. Increased cancer cell inhibition is observed in colony formation assay and real-time cell analysis after the combined treatment with CuO NPs and X-ray irradiation, whereas the CuO NPs alone do not have any negative influence on cell viability, indicating the radiosensitization effect of CuO NPs. Importantly, the significantly increased ROS level in cells contributes to the enhanced damage to cancer cells under the combined treatment. Besides, the cell cycle is regulated to the X-ray-sensitive phase (G₂/M phase) by CuO NPs, which may also account for the inhibited proliferation of cancer cells. Furthermore, results from Western blot analysis and colony formation assay reveal that the increased cell death may be mainly attributed to the excessive autophagy induced by both CuO NPs and X-ray irradiation. Moreover, in vivo experiments verify the radiosensitization of CuO NPs and their favorable biosafety. The current study suggests that CuO NPs can be utilized as nanoradiosensitizers for increasing the efficiency of cancer radiotherapy.

Biofunctional magnetic hybrid nanomaterials for theranostic applications

Cancer is a major disease that seriously threatens human health and is a leading cause of human death. At present, the commonly used cancer treatment methods are surgical therapy, chemical drug therapy and radiation therapy (RT). However, these treatments all have their own shortcomings and cannot perfectly meet the needs of clinical diagnosis and treatment. It is of great significance to improve the diagnosis and treatment level, so that the curative effect and quality of life of tumor patients can be improved. The rapid development of nanotechnology has brought hope to the diagnosis and treatment of cancer and the appearance of biofunctional magnetic hybrid nanomaterials (MHNs) has provided a new possibilities for the integration of cancer diagnosis and treatment. As a promising research direction, the multifunctional nanoplatform integrates imaging diagnosis, drug therapy and drug delivery. Better treatment effects and fewer side effects can be achieved by optimizing materials to build stable, efficient, and safe MHNs with combined functions of multimodal imaging and various treatments. This review focuses on not only the research progress of MHNs but also their applications and development trend in the integration of cancer diagnosis and treatment. A description of the applications of MHN structure optimization for both magnetic resonance imaging-based multimodal diagnosis and cancer therapy is given. Furthermore, RT is introduced and the development of MHNs for diagnosis and treatment system is investigated.

Magnetic-Plasmonic Heterodimer Nanoparticles: Designing Contemporarily Features for Emerging Biomedical Diagnosis and Treatments

Magnetic-plasmonic heterodimer nanostructures synergistically present excellent magnetic and plasmonic characteristics in a unique platform as a multipurpose medium for recently invented biomedical applications, such as magnetic hyperthermia, photothermal therapy, drug delivery, bioimaging, and biosensing. In this review, we briefly outline the less-known aspects of heterodimers, including electronic composition, interfacial morphology, critical properties, and present concrete examples of recent progress in synthesis and applications. With a focus on emerging features and performance of heterodimers in biomedical applications, this review provides a comprehensive perspective of novel achievements and suggests a fruitful framework for future research.

Fe-N-C Artificial Enzyme: Activation of Oxygen for Dehydrogenation and Monoxygenation of Organic Substrates under Mild Condition and Cancer Therapeutic Application

Developing highly efficient biomimetic catalysts that directly use O₂ as the terminal oxidant to dehydrogenate and monoxygenate substrates with high selectivity under mild conditions has long been pursued but rarely achieved yet. Herein, we report that heterogeneous Fe-N-C, which is commonly used as an electrocatalyst for oxygen reduction reaction, had unusual biomimetic catalytic activity in both dehydrogenation and monoxygenation of a series of organic molecules (∼100% selectivity) by directly using O₂. The Fe-N _x center was verified to be the active site that reductively activated O₂ by spontaneously generating specific reactive oxygen species (ROS) (¹O₂, O₂^•-, and H₂O₂). Aided by these ROS, under physiological conditions, the Fe-N-C was further successfully exampled to kill proliferative lung cancer cells. Fe-N-C had several striking superior features with respect to natural enzymes, classical heterogeneous nanozymes, and homogeneous artificial enzymes incapable of working under harsh conditions (extreme pH and high temperature), ease of separation and recycling, and direct use of O₂. It would open up a new vista of Fe-N-C as an artificial enzyme in biomimetic catalysis, ranging from fundamental simulation of oxidase/oxygenase metabolism to industrial oxidation processes and to disease treatment.

Fabrication of Multifoliate PtRu Bimetallic Nanocomplexes for Computed Tomography Imaging and Enhanced Synergistic Thermoradiotherapy

To improve the efficiency of cancer therapy, we developed multifoliate PEGylated PtRu bimetallic nanocomplexes (PtRu-PEG BNCs) as multifunctional theranostic nanoagents for computed tomography (CT) imaging and synergistic thermoradiotherapy. The synthesized PtRu-PEG BNCs with uniform size and morphology exhibit excellent stability, notable photothermal effect, and good biocompatibility. As compared with other platinum nanomaterials, the PtRu-PEG BNCs are able to absorb near-infrared laser energy and present excellent photothermal conversion efficiency (44.5%). Multifoliate PtRu-PEG BNCs can be applied to CT imaging and radiotherapy (RT) because of the presence of platinum. Unlike a single therapy method, the integration of photothermal therapy with RT can effectively induce cell apoptosis and generate an obvious synergistic effect. Hence, the as-prepared nanocomplexes can be used as multifunctional theranostic nanoagents.

Selective Growth Synthesis of Ternary Janus Nanoparticles for Imaging-Guided Synergistic Chemo- and Photothermal Therapy in the Second NIR Window

Multifunctional therapeutic agents in the second near-infrared (NIR-II) window have attracted wide attention on account of their synergetic properties for effective cancer therapy. Here, we construct a selective growth strategy for the first time to fabricate ternary Janus nanoparticles (JNPs) containing hemispherical MnO₂ at one side and Au core covered with CuS shell at opposite side. The obtained ternary JNPs are further modified with poly(ethylene glycol)thiol to enhance the stability and biocompatibility (designated as PEG-CuS-Au-MnO₂ ternary JNPs). The MnO₂ domain with mesoporous structures can serve as hydrophobic drug carriers and magnetic resonance (MR) imaging contrast agents. Meanwhile, the Au segment is used for X-ray computed tomography (CT) imaging. Moreover, the PEG-CuS-Au-MnO₂ ternary JNPs can conduct hyperthermia at 1064 nm in NIR-II window to ablate tumors in deep tissue, which is ascribed to the localized surface plasmon resonance coupling effect of the Au core and CuS domain. All of the results reveal that PEG-CuS-Au-MnO₂ ternary JNPs not only exhibit pre-eminent CT/MR imaging capabilities, but also provide high chemo-photothermal antitumor efficacy under the guidance of CT/MR imaging. Taking together, the PEG-CuS-Au-MnO₂ ternary JNPs can be regarded as a prospective therapeutic nanoplatform for dual-modal imaging-guided synergistic chemo-photothermal cancer therapy in the NIR-II window.

Gold nanorods together with HSP inhibitor-VER-155008 micelles for colon cancer mild-temperature photothermal therapy

Enhancing the heat-sensitivity of tumor cells provides an alternative solution to maintaining the therapeutic outcome of photothermal therapy (PTT). In this study, we constructed a therapeutic system, which was composed of methoxy-polyethylene-glycol-coated-gold-nanorods (MPEG-AuNR) and VER-155008-micelles, to evaluate the effect of VER-155008 on the sensitivity of tumor cells to heat, and further investigate the therapeutic outcome of MPEG-AuNR mediated PTT combined with VER-155008- micelles. VER-155008- micelles down-regulate the expression of heat shock proteins and attenuate the heat-resistance of tumor cell. The survival of HCT116 cells treated with VER-155008- micelles under 45 °C is equal to that treated with high temperature hyperthermia (55 °C) in vitro. Furthermore, we proved either the MPEG-AuNR or VER-155008- micelles can be accumulate in the tumor site by photoacoustic imaging and fluorescent imaging. In vivo anti-cancer evaluation showed that tumor size remarkably decreased (smaller than 100 mm³ or vanished) when treated with combing 45 °C mild PTT system, which contrasted to the tumor size when treated with individual 45 °C mild PTT (around 500 nm³) or normal saline as control (larger than 2000 nm³). These results proved that the VER-155008- micelles can attenuate the heat-resistance of tumor cells and enhance the therapeutic outcome of mild-temperature photothermal therapy.

Magnetically Separable Nanocatalyst with the Fe3O4 Core and Polydopamine-Sandwiched Au Nanocrystal Shell

This work reports a novel Fe₃O₄@polydopamine/Au/polydopamine core/shell nanocomposite toward a magnetically separable nanocatalyst. Because the polydopamine (PDA) layer-sandwiched Au nanocrystals were prepared by a layer-by-layer method, the content of Au could be controlled by varying the Au shell number (such as burger-like Fe₃O₄@PDA/Au/PDA/Au/PDA). Fe₃O₄@PDA/Au/PDA exhibited excellent catalytic activity in reducing p-nitrophenol because the substrate could penetrate the PDA shell. Owing to the protection of the PDA shell, Fe₃O₄@PDA/Au/PDA presented higher cyclability than Fe₃O₄@PDA/Au. The activity of Fe₃O₄@PDA/Au/PDA maintained 95% after 7 cycles, while that of Fe₃O₄@PDA/Au was only 61%. The detailed cycling catalytic mechanism was investigated, and it was found that the catalytic rate of Fe₃O₄@PDA/Au/PDA/Au/PDA was faster than that of Fe₃O₄@PDA/Au/PDA because of the higher Au content. Interestingly, this method could be extended for other magnetic nanocomposites with two different kinds of noble metal nanocrystals integrated within one particle, such as Fe₃O₄@PDA/Au/PDA/Ag/PDA and Fe₃O₄@PDA/Au/PDA/Pd/PDA.

Engineered contrast agents in a single structure for T1-T2 dual magnetic resonance imaging

The development of contrast agents (CAs) for Magnetic Resonance Imaging (MRI) with T1-T2 dual-mode relaxivity requires the accurate assembly of T1 and T2 magnetic centers in a single structure. In this context, we have synthesized a novel hybrid material by monitoring the formation of Prussian Blue analogue Gd(H2O)4[Fe(CN)6] nanoparticles with tailored shape (from nanocrosses to nanorods) and size, and further protection with a thin and homogeneous silica coating through hydrolysis and polymerization of silicate at neutral pH. The resulting Gd(H2O)4[Fe(CN)6]@SiO2 magnetic nanoparticles are very stable in biological fluids. Interestingly, this combination of Gd and Fe magnetic centers closely packed in the crystalline network promotes a magnetic synergistic effect, which results in significant improvement of longitudinal relaxivity with regards to soluble Gd3+ chelates, whilst keeping the high transversal relaxivity inherent to the iron component. As a consequence, this material shows excellent activity as MRI CA, improving positive and negative contrasts in T1- and T2-weighted MR images, both in in vitro (e.g., phantom) and in vivo (e.g., Sprague-Dawley rats) models. In addition, this hybrid shows a high biosafety profile and has strong ability to incorporate organic molecules on the surface with variable functionality, displaying great potential for further clinical application.

Significant Suppression of Non-small-cell Lung Cancer by Hydrophobic Poly(ester amide) Nanoparticles with High Docetaxel Loading

Non-small-cell lung cancer (NSCLC) accounts for over 85% of clinical lung cancer cases, which is the leading cause of cancer-related death. To develop new therapeutic strategy for NSCLC, a library of L-phenylalanine-based poly(ester amide) (Phe-PEA) polymers was synthesized and assembled with docetaxel (Dtxl) to form Dtxl-loaded Phe-PEA nanoparticles (NPs). The hydrophobic Phe-PEA polymers were able to form NPs by nanoprecipitation method and the characterization results showed that the screened Dtxl-8P4 NPs have small particle size (∼100 nm) and high Dtxl loading (∼20 wt%). In vitro experiments showed that Dtxl-8P4 NPs were rapidly trafficked into cancer cells, then effectively escaped from lysosomal degradation and achieved significant tumor cell inhibition. In vivo results demonstrated that Dtxl-8P4 NPs with prolonged blood circulation could efficiently deliver Dtxl to A549 tumor sites, leading to reduced cell proliferation, block metastasis, and increase apoptosis, then persistent inhibition of tumor growth. Therefore, Phe-PEA NPs are able to load high amount of hydrophobic drugs and could be a promising therapeutic approach for NSCLC and other cancer treatments.

Multifunctional Porous Iron Oxide Nanoagents for MRI and Photothermal/Chemo Synergistic Therapy

Nanoagents of integrating multiple imaging and therapeutic modalities have attracted tremendous attention for biomedical applications. Herein, we synthesize porous hollow Fe₃O₄ as a theranostic agent for MRI and combined photothermal/chemo cancer therapy. The as-prepared porous iron oxide nanoagents allow for T₂-weighted MR imaging. Interestingly, we demonstrate that the porous structure endows the nanoagents an outstanding photothermal property for cancer cell killing, in comparison with other types of iron oxide nanomaterials. Under the exposure of an NIR laser, the heat produced by porous Fe₃O₄ can accelerate the release of the loaded drug (e.g., DOX) to enhance chemotherapeutic efficacy, promoting the ablation of cancer cells with synergistic photothermal/chemotherapy.

Metal-based NanoEnhancers for Future Radiotherapy: Radiosensitizing and Synergistic Effects on Tumor Cells

Radiotherapy is one of the major therapeutic strategies for cancer treatment. In the past decade, there has been growing interest in using high Z (atomic number) elements (materials) as radiosensitizers. New strategies in nanomedicine could help to improve cancer diagnosis and therapy at cellular and molecular levels. Metal-based nanoparticles usually exhibit chemical inertness in cellular and subcellular systems and may play a role in radiosensitization and synergistic cell-killing effects for radiation therapy. This review summarizes the efficacy of metal-based NanoEnhancers against cancers in both in vitro and in vivo systems for a range of ionizing radiations including gamma-rays, X-rays, and charged particles. The potential of translating preclinical studies on metal-based nanoparticles-enhanced radiation therapy into clinical practice is also discussed using examples of several metal-based NanoEnhancers (such as CYT-6091, AGuIX, and NBTXR3). Also, a few general examples of theranostic multimetallic nanocomposites are presented, and the related biological mechanisms are discussed.

Silicon nanowire-based multifunctional platform for chemo-photothermal synergistic cancer therapy

The new type of silicon nanowire-based pH/NIR/magnetism triple-responsive system shows high-efficacy synergistic photothermal-chemotherapy on cancer cells.

Octopod PtCu Nanoframe for Dual-Modal Imaging-Guided Synergistic Photothermal Radiotherapy

Heavy atom nanoparticles have high X-ray absorption capacity and near infrared (NIR) photothermal conversion efficiency, which could be used as radio-sensitizers. We hypothesized that concave PtCu octopod nanoframes (OPCNs) would be an efficient nanoplatform for synergistic radio-photothermal tumor ablation.

Methods: In this study, we newly exploited a folic acid-receptor (FR) mediated photothermal radiotherapy nanoagent base on OPCNs. OPCNs were synthesized with a hydrothermal method and then modified with polyethylene glycol (PEG) and folic acid (FA). A series of physical and chemical characterizations, cytotoxicity, targeting potential, endocytosis mechanism, biodistribution, systematic toxicological evaluation, pharmacokinetics, applications of OPCNs-PEG-FA for in vitro and in vivo infrared thermal imaging (ITI)/photoacoustic imaging (PAI) dual-modal imaging and synergistic photothermal radiotherapy against tumor were carried out.

Results: The OPCNs-PEG-FA demonstrated good biocompatibility, strong NIR absorption and X-ray radio-sensitization, which enabling it to track and visualize tumor in vivo via ITI/PAI dual-modal imaging. Moreover, the as-synthesized OPCNs-PEG-FA exhibited remarkable photothermal therapy (PTT) and radiotherapy (RT) synergistic tumor inhibition when treated with NIR laser and X-ray.

Conclusion: A novel multifunctional theranostic nanoplatform based on OPCNs was designed and developed for dual-modal image-guided synergistic tumor photothermal radiotherapy.

Platinum nanoworms for imaging-guided combined cancer therapy in the second near-infrared window

Cancer imaging and therapy in the second near-infrared (NIR II) window have gained increasing interest owing to the high light penetration depth and minimal optical scattering in the NIR II region (1000–1350 nm).

A highly sensitive gold nanoparticle-based electrochemical aptasensor for theophylline detection

Theophylline is a common bronchodilator for the treatment of diseases like asthma, bronchitis and emphysema. However, it should be strictly used and monitored due to its toxicity when the concentration is above certain levels. In this work, an electrochemical biosensor for theophylline detection is proposed by recognition of RNA aptamer and gold nanoparticle (AuNP)-based amplification technique. First, RNA aptamer is splitted into two single-stranded RNA probes. One is hybridized with DNA tetrahedron and the resulted nanostructure is then immobilized onto a gold electrode; the other is modified on the surface of AuNPs which is also labeled with methylene blue (MB) as electrochemical species. The recognition process between the two RNA probes and theophylline causes the localization of AuNPs and the enrichment of MB on the electrode interface. A significant electrochemical response is thus generated which is related to the concentration of initial theophylline. This proposed aptasensor shows excellent sensitivity and selectivity which could also be applied in quantitatively detection of theophylline in serums samples.

Action of Gold Nanospikes-Based Nanoradiosensitizers: Cellular Internalization, Radiotherapy, and Autophagy

A major challenge to achieve effective X-ray radiation therapy is to use a relatively low and safe radiation dose. Various radiosensitizers, which can significantly enhance the radiotherapeutic performance, have been developed. Gold-based nanomaterials, as a new type of nanoparticle-based radiosensitizers, have been extensively used in researches involving cancer radiotherapy. However, the cancer therapeutic effect using the gold nanoparticle-based radiotherapy is usually not significant because of the low cellular uptake efficiency and the autophagy-inducing ability of these gold nanomaterials. Herein, using gold nanospikes (GNSs) as an example, we prepared a series of thiol-poly(ethylene glycol)-modified GNSs terminated with methoxyl (GNSs), amine (NH₂-GNSs), folic acid (FA) (FA-GNSs), and the cell-penetrating peptide TAT (TAT-GNSs), and evaluated their effects on X-ray radiotherapy. For the in vitro study, it was found that the ionizing radiation effects of these GNSs were well correlated with their cellular uptake amounts, with the same order of GNSs < NH₂-GNSs < FA-GNSs < TAT-GNSs. The sensitization enhancement ratio (SER), which is commonly used to evaluate how effectively radiosensitizers decrease cell proliferation, reaches 2.30 for TAT-GNSs. The extremely high SER value for TAT-GNSs indicates the superior radiosensitization effect of this nanomaterial. The radiation enhancement mechanisms of these GNSs involved the increased reactive oxygen species (ROS), mitochondrial depolarization, and cell cycle redistribution. Western blotting assays confirmed that the surface-modified GNSs could induce the up-regulation of autophagy-related protein (LC3-II) and apoptosis-related protein (active caspase-3) in cancer cells. By monitoring the degradation of the autophagy substrate p62 protein, GNSs caused impairment of autolysosome degradation capacity and autophagosome accumulation. Our data demonstrated that autophagy played a protective role against caner radiotherapy, and the inhibition of protective autophagy with inhibitors would result in the increase of cell apoptosis. Besides the above in vitro experiments, the in vivo tumor growth study also indicated that X-ray + TAT-GNSs treatment had the best tumor growth inhibitory effect, which confirmed the highest radiation sensitizing effect of TAT-GNSs. This work furthered our understanding on the interaction mechanism between gold nanomaterials and cancer cells and should be able to promote the development of nanoradiosensitizers for clinical applications.

Enhanced Radiotherapy using Bismuth Sulfide Nanoagents Combined with Photo-thermal Treatment

Nanotechniques that can improve the effectiveness of radiotherapy (RT) by integrating it with multimodal imaging are highly desirable. Results In this study, we fabricated Bi2S3 nanorods that have attractive features such as their ability to function as contrast agents for X-ray computed tomography (CT) and photoacoustic (PA) imaging as well as good biocompatibility. Both in vitro and in vivo studies confirmed that the Bi2S3 nanoagents could potentiate the lethal effects of radiation via amplifying the local radiation dose and enhancing the anti-tumor efficacy of RT by augmenting the photo-thermal effect. Furthermore, the nanoagent-mediated hyperthermia could effectively increase the oxygen concentration in hypoxic regions thereby inhibiting the expression of hypoxia-inducible factor (HIF-1α). This, in turn, interfered with DNA repair via decreasing the expression of DNA repair-related proteins to overcome radio-resistance. Also, RT combined with nanoagent-mediated hyperthermia could substantially suppress tumor metastasis via down-regulating angiogenic factors. Conclusion In summary, we constructed a single-component powerful nanoagent for CT/PA imaging-guided tumor radiotherapy and, most importantly, explored the potential mechanisms of nanoagent-mediated photo-thermal treatment for enhancing the efficacy of RT in a synergistic manner.

Functional magnetic hybrid nanomaterials for biomedical diagnosis and treatment

Magnetic nanomaterials integrating supplemental functional materials are called magnetic hybrid nanomaterials (MHNs). Such MHNs have drawn increasing attention due to their biocompatibility and the potential applications either as alternative contrast enhancing agents or effective heat nanomediators in hyperthermia therapy. The joint function comes from the hybrid nanostructures. Hybrid nanostructures of different modification can be easily achieved owing to the large surface-area-to-volume ratio and sophisticated surface characteristic. In this focus article, we mainly discussed the design and synthesis of MHNs and their applications as multimodal imaging probes and therapy agents in biomedicine. These MHNs consisting magnetic nanomaterials with functional nanocomponents such as noble metal or isotopes could perform not only superparamagnetism but also features that can be adapted in, for example, enhancing computed tomography contrast modalities, positron emission tomography, and single-photon emission computed tomography. The combination of several techniques provides more comprehensive information by both synergizing the advantages, such as quantitative evaluation, higher sensitivity and spatial resolution, and mitigating the disadvantages. Such hybrid nanostructures could also provide a unique nanoplatform for enhanced medical tracing, magnetic field, and light-triggered hyperthermia. Moreover, potential advantages and opportunities will be achieved via a combination of diagnostic and therapeutic agents within a single platform, which is so-called 'theranostics.' We expect the combination of unique structural characteristics and integrated functions of multicomponent magnetic hybrid nanomaterials will attract increasing research interest and could lead to new opportunities in nanomedicine and nanobiotechnology. WIREs Nanomed Nanobiotechnol 2018, 10:e1476. doi: 10.1002/wnan.1476 This article is categorized under: Diagnostic Tools > Diagnostic Nanodevices.

Shape-Dependent Radiosensitization Effect of Gold Nanostructures in Cancer Radiotherapy: Comparison of Gold Nanoparticles, Nanospikes, and Nanorods

The shape effect of gold (Au) nanomaterials on the efficiency of cancer radiotherapy has not been fully elucidated. To address this issue, Au nanomaterials with different shapes but similar average size (∼50 nm) including spherical gold nanoparticles (GNPs), gold nanospikes (GNSs), and gold nanorods (GNRs) were synthesized and functionalized with poly(ethylene glycol) (PEG) molecules. Although all of these Au nanostructures were coated with the same PEG molecules, their cellular uptake behavior differed significantly. The GNPs showed the highest cellular responses as compared to the GNSs and the GNRs (based on the same gold mass) after incubation with KB cancer cells for 24 h. The cellular uptake in cells increased in the order of GNPs > GNSs > GNRs. Our comparative studies indicated that all of these PEGylated Au nanostructures could induce enhanced cancer cell-killing rates more or less upon X-ray irradiation. The sensitization enhancement ratios (SERs) calculated by a multitarget single-hit model were 1.62, 1.37, and 1.21 corresponding to the treatments of GNPs, GNSs, and GNRs, respectively, demonstrating that the GNPs showed a higher anticancer efficiency than both GNSs and GNRs upon X-ray irradiation. Almost the same values were obtained by dividing the SERs of the three types of Au nanomaterials by their corresponding cellular uptake amounts, indicating that the higher SER of GNPs was due to their much higher cellular uptake efficiency. The above results indicated that the radiation enhancement effects were determined by the amount of the internalized gold atoms. Therefore, to achieve a strong radiosensitization effect in cancer radiotherapy, it is necessary to use Au-based nanomaterials with a high cellular internalization. Further studies on the radiosensitization mechanisms demonstrated that ROS generation and cell cycle redistribution induced by Au nanostructures played essential roles in enhancing radiosensitization. Taken together, our results indicated that the shape of Au-based nanomaterials had a significant influence on cancer radiotherapy. The present work may provide important guidance for the design and use of Au nanostructures in cancer radiotherapy.

DNA Modified Fe3O4@Au Magnetic Nanoparticles as Selective Probes for Simultaneous Detection of Heavy Metal Ions

Driven by the urgent need to detect trace heavy metal ions in various real water samples, this article demonstrates for the first time an electrochemical biosensor based on DNA modified Fe₃O₄@Au magnetic nanoparticles (NPs). Three DNA probes are designed to contain certain mismatched base pairs. One is thiolated and modified on the surface of Fe₃O₄@Au NPs (DNA 1). The other two probes (DNA 2 and 3) are labeled with two independent electrochemical species. Stable structures of cytosine-Ag⁺-cytosine and thymine-Hg²⁺-thymine formed in the presence of Ag⁺ and Hg²⁺ can assist the hybridization of DNA 1/DNA 2 and DNA 1/DNA 3, which locate corresponding electrochemical species onto the surface of the magnetic NPs. The achieved nanocomposites are then used as selective electrochemical probes for the detection of heavy metal ions by recording the square wave voltammetry signals. Simultaneous detection of Ag⁺ and Hg²⁺ is demonstrated without significant interference, and their individual high sensitivities are fundamentally preserved, which meet the requirements of U.S. Environmental Protection Agency (USEPA). Furthermore, the proposed method has been challenged by various real water samples. The results confirm the DNA modified magnetic NPs based sensing method may have potential applications for the monitoring of heavy metal ions in real sample analysis.

Anisotropic noble metal nanoparticles: Synthesis, surface functionalization and applications in biosensing, bioimaging, drug delivery and theranostics

Anisotropic nanoparticles have fascinated scientists and engineering communities for over a century because of their unique physical and chemical properties. In recent years, continuous advances in design and fabrication of anisotropic nanoparticles have opened new avenues for application in various areas of biology, chemistry and physics. Anisotropic nanoparticles have the plasmon absorption in the visible as well as near-infrared (NIR) region, which enables them to be used for crucial applications such as biological imaging, medical diagnostics and therapy ("theranostics"). Here, we describe the progress in anisotropic nanoparticles achieved since the millennium in the area of preparation including various shapes and modification of the particle surface, and in areas of application by providing examples of applications in biosensing, bio-imaging, drug delivery and theranostics. Furthermore, we also explain various mechanisms involved in cellular uptake of anisotropic nanoparticles, and conclude with our opinion on various obstacles that limit their applications in biomedical field.

STATEMENT OF SIGNIFICANCE

Anisotropy at the molecular level has always fascinated scientists and engineering communities for over a century, however, the research on novel methods through which shape and size of nanoparticles can be precisely controlled has opened new avenues for anisotropic nanoparticles in various areas of biology, chemistry and physics. In this manuscript, we describe progress achieved since the millennium in the areas of preparation of various shapes of anisotropic nanoparticles, investigate various methods involved in modifying the surface of these NPs, and provide examples of applications in biosensing and bio-imaging, drug delivery and theranostics. We also present mechanisms involved in cellular uptake of nanoparticles, describe different methods of preparation of anisotropic nanoparticles including biomimetic and photochemical synthesis, and conclude with our opinion on various obstacles that limit their applications in biomedical field.