Simple control of surface topography of gold nanoshells by a surfactant-less seeded-growth method

Polysaccharide-based gold nanomaterials: Synthesis mechanism, polysaccharide structure-effect, and anticancer activity

Polysaccharide-based gold nanomaterials have attracted great interest in biomedical fields such as cancer therapy and immunomodulation due to their prolonged residence time in vivo and enhanced immune response. This review aims to provide an up-to-date and comprehensive summary of polysaccharide-based Au NMs synthesis, including mechanisms, polysaccharide structure-effects, and anticancer activity. Firstly, research progress on the synthesis mechanism of polysaccharide-based Au NMs was addressed, which included three types based on the variety of polysaccharides and reaction environment: breaking of glycosidic bonds via Au (III) or base-mediated production of highly reduced intermediates, reduction of free hydroxyl groups in polysaccharide molecules, and reduction of free amino groups in polysaccharide molecules. Then, the potential effects of polysaccharide structure characteristics (molecular weight, composition of monosaccharides, functional groups, glycosidic bonds, and chain conformation) and reaction conditions (the reaction temperature, reaction time, pH, concentration of gold precursor and polysaccharides) on the size and shape of Au NMs were explored. Finally, the current status of polysaccharide-based Au NMs cancer therapy was summarized before reaching our conclusions and perspectives.

Cisplatin-loaded gold nanoshells mediate chemo-photothermal therapy against primary and distal lung cancers growth

Lung cancer is the most common cause of cancer mortality worldwide. The advances in surgery, radiotherapy, chemotherapeutic and immunotherapeutic drugs have progressed in the past decades, but the prognosis of lung cancer is still poor. In this study, we developed cisplatin (CDDP)-loaded human serum albumin (HSA)-based gold nanoshells (HCP@GNSs) for synergistic chemo-photothermal therapy (chemo-PTT). The HCP@GNSs not only acted as drug nanocarriers for chemotherapy but also serve as a superior mediator for PTT, which could exhibit a temperature increase upon a near infrared (NIR) laser exposure that was sufficient for photothermal ablation. HCP@GNSs were highly biocompatible and hemocompatible nanocarriers, while the synergistic chemo-PTT resulting from HCP@GNSs plus NIR exposure displayed stronger cytotoxicity effect than HCP@GNSs or PTT alone, especially at a low CDDP concentration. In vivo analysis demonstrated that HCP@GNSs-mediated chemo-PTT increased necrosis in tumors to achieve a high tumor clearance rate with no adverse side effects. Moreover, HCP@GNSs-medicated chemo-PTT induced the recruitment of dendritic cells, B-cells, and natural killer T-cells in distal tumors to inhibit the growth of the tumors. Therefore, the CDDP-loaded HCP@GNSs may be a potential nanomedicine candidate for curative lung cancer treatment in the future.

Sodium Alginate/Chitosan Scaffolds for Cardiac Tissue Engineering: The Influence of Its Three-Dimensional Material Preparation and the Use of Gold Nanoparticles

Natural biopolymer scaffolds and conductive nanomaterials have been widely used in cardiac tissue engineering; however, there are still challenges in the scaffold fabrication, which include enhancing nutrient delivery, biocompatibility and properties that favor the growth, maturation and functionality of the generated tissue for therapeutic application. In the present work, different scaffolds prepared with sodium alginate and chitosan (alginate/chitosan) were fabricated with and without the addition of metal nanoparticles and how their fabrication affects cardiomyocyte growth was evaluated. The scaffolds (hydrogels) were dried by freeze drying using calcium gluconate as a crosslinking agent, and two types of metal nanoparticles were incorporated, gold (AuNp) and gold plus sodium alginate (AuNp+Alg). A physicochemical characterization of the scaffolds was carried out by swelling, degradation, permeability and infrared spectroscopy studies. The results show that the scaffolds obtained were highly porous (>90%) and hydrophilic, with swelling percentages of around 3000% and permeability of the order of 1 × 10−8 m2. In addition, the scaffolds proposed favored adhesion and spheroid formation, with cardiac markers expression such as tropomyosin, troponin I and cardiac myosin. The incorporation of AuNp+Alg increased cardiac protein expression and cell proliferation, thus demonstrating their potential use in cardiac tissue engineering.

A dual-responsive "Yin-Yang" photothermal delivery system to accelerate Parthenolide anti-tumor efficacy

Parthenolide (PTL), a germacrane sesquiterpene lactone extracted from the "Yin" Chinese traditional herb feverfew, has gained interest due to its lethal effects on tumor cells and its pharmacological effects within traditional Chinese medicine theory. To overcome low, non-targeted accumulation and uncontrolled release of PTL administration, a dual-responsive PTL-liposomes@chitosan@gold nanoshells (PTL-Lips@CS@GNS) system was fabricated. Hyperthermia generated under light irradiation in the near-infrared region via local surface plasmon resonance of gold nanoshells induced photothermal therapy, which also stimulated PTL release due to the liposomes gel-to-liquid crystalline phase transition. Additionally, PTL-Lips@CS@GNS exhibited a pH-responsive release in the acidic tumor microenvironment. Collectively, this study provides a realistic strategy for an effective combination of traditional Chinese medicine and current nanotechnology for tumor therapy.

The synergistic effect of chemo-photothermal therapies in SN-38-loaded gold-nanoshell-based colorectal cancer treatment

Aim: 7-Ethyl-10-hydroxycamptothecin (SN-38)-loaded gold nanoshells nanoparticles (HSP@Au NPs) were developed for combined chemo-photothermal therapy to treat colorectal cancer. Materials & methods: SN-38-loaded nanoparticles (HSP NPs) were prepared by the lyophilization-hydration method, and then developed into gold nanoshells. The nanoparticles were characterized and assessed for photothermal properties, cytotoxicity and hemocompatibility in vitro. In vivo anticancer activity was tested in a tumor mouse model. Results: The HSP@Au NPs (diameter 186.9 nm, zeta potential 33.4 mV) led to significant cytotoxicity in cancer cells exposed to a near-infrared laser. Moreover, the HSP@Au NP-mediated chemo-photothermal therapy displayed significant tumor growth suppression and disappearance (25% of tumor clearance rate) without adverse side effects in vivo. Conclusion: HSP@Au NPs may be promising in the treatment of colorectal cancer in the future.

Cisplatin-loaded PLGA nanoparticles for HER2 targeted ovarian cancer therapy

The conventional treatment (cytoreduction combined with cisplatin/carboplatin and taxane drugs) of ovarian cancer has a high rate of failure and recurrence despite a favorable initial response. This lack of success is usually attributed to the development of multidrug resistance mechanisms by cancer cells and avoidance of the anti-growth effects of monoclonal targeted therapeutic antibodies. The disease, like other cancers, is characterized by the overexpression of molecular markers, including HER2 receptors. Preclinical and clinical studies with trastuzumab, a HER2-targeted therapeutic antibody, reveal a low improvement of the outcomes of HER2 positive ovarian cancer patients. Therefore, here, we propose a cisplatin-loaded, HER2 targeted poly(lactic-co-glycolic) nanoplatform, a system capable to escape the drug-efflux effect and to take advantage of the overexpressed HER2 receptors, using them as docks for targeted chemotherapy. The NP/trastuzumab ratio was determined after fluorescein labeling of antibodies and quantification of fluorescence in NPs. The system was also characterized in terms of size, zeta potential, drug release kinetics, cytotoxicity and cellular internalization in the epithelial ovarian cancer cell line SKOV-3, and compared with the HER2 negative breast cancer cell line HCC70. Our results show an increased cytotoxicity of NPs as compared to free cisplatin, and moreover, an enhanced internalization and cytotoxicity due to the bionfunctionalization of NPs with the monoclonal antibody.

Effect of Alkylamines on Morphology Control of Silver Nanoshells for Highly Enhanced Raman Scattering

Morphology control of the surface of a nanostructure is a key issue in modulating its surface plasmon resonance and scattering properties. Here, we studied the effect of alkylamines on morphology control during the one-step fabrication of silver nanoshells (NSs) for highly enhanced Raman scattering. Various types of alkylamines were used to study the effects of chain length, existence of hydroxyl groups, and degree of alkyl chains on the surface morphology of silver NSs. The alkylamines influenced the silver ion reduction and the growth of silver domains, resulting in distinctive morphology changes. The optical properties of the silver NSs of different surface morphologies were characterized by surface-enhanced Raman spectra. Especially, when long alkylamines were used, intense and uniform surface-enhanced Raman scattering signals were obtained at the visible and near-infrared (NIR) region, and their enhancement factor was ∼10⁷. To detect cancer biomarkers in vivo, as a feasibility test, silver NSs were modified to highly NIR-active nanoprobes and successfully applied to detect colon cancer without causing nonspecific interactions. Our one-step fabrication method of silver NSs is simple and can overcome various hurdles of morphology control and can be extended to other metal nanostructures of controlled surface morphologies or shape.

Synthetic Methodologies to Gold Nanoshells: An Overview

Gold nanostructures that can be synthetically articulated to adapt diverse morphologies, offer a versatile platform and tunable properties for applications in a variety of areas, including biomedicine and diagnostics. Among several conformational architectures, gold nanoshells provide a highly advantageous combination of properties that can be fine-tuned in designing single or multi-purpose nanomaterials, especially for applications in biology. One of the important parameters for evaluating the efficacy of gold nano-architectures is their reproducible synthesis and surface functionalization with desired moieties. A variety of methods now exist that allow fabrication and chemical manipulation of their structure and resulting properties. This review article provides an overview and a discussion of synthetic methodologies to a diverse range of gold nanoshells, and a brief summary of surface functionalization and characterization methods employed to evaluate their overall composition.

Gold-nanobranched-shell based drug vehicles with ultrahigh photothermal efficiency for chemo-photothermal therapy

Development of combined chemo-photothermal nanoplatform is of great interest for enhancing antitumor efficacy. Herein, a multifunctional drug delivery system was synthesized based on gold-nanobranched coated betulinic acid liposomes (GNBS-BA-Lips) for chemo-photothermal synergistic therapy. In this system, GNBS-BA-Lips exhibited broad near-infrared (NIR) absorption, preferable photothermal response and good photostability under NIR irradiation. Importantly, the gold-nanobranched nanostructure possessed high photothermal conversion efficiency (η = 55.7%), and the temperature change (ΔT) reached 43.2 °C after laser irradiation for 5 min. Upon NIR irradiation, the nanocarriers apparently endowed higher cell uptake, resulting in an enhanced intracellular drug accumulation. Furthermore, the tumor growth inhibition ratio achieved from chemo-photothermal therapy of GNBS-BA-Lips was 86.9 ± 1.1%, which was higher than that of the chemotherapy or photothermal therapy alone, showing an outstanding synergistic anticancer effect. Our data suggested that the nanoplatform should be considered as a critical platform in the development of cancer multi-mode therapies.

Designed synthesis of ultrafine NiO nanocrystals bonded on a three dimensional graphene framework for high-capacity lithium-ion batteries

NiO nanocrystals/3D-GF nanohybrids are fabricated in situ and used for high-capacity lithium-ion batteries.

Gold nanoshell coated thermo-pH dual responsive liposomes for resveratrol delivery and chemo-photothermal synergistic cancer therapy

Stimuli-responsive drug delivery and release have a great significance in cancer therapy. Herein, a multifunctional responsive drug carrier was designed and developed by loading resveratrol (Res) in chitosan (CTS) modified liposomes, and coated by gold nanoshells (GNS@CTS@Res-lips). The resultant GNS@CTS@Res-lips possess broad near-infrared (NIR) absorbance, high capability, stability, and also high photothermal conversion ability for efficient photothermal therapy (PTT) applications. In addition, the GNS@CTS@Res-lips exhibit the on-demand pH/photothermal-sensitive drug release, and a high loading capacity of Res. Under NIR laser irradiation, the drug delivery system could significantly enhance the cellular uptake of drugs. More importantly, compared to the single chemotherapy or PTT, the carriers with NIR irradiation displayed a higher therapeutic effect for HeLa cells. Therefore, the GNS@CTS@Res-lips with a combination of chemotherapy and PTT will show great potential for application in cancer therapy.

Fabrication of gold nanocages and nanoshells using lanreotide acetate and a comparison study of their photothermal antitumor therapy

Functional gold nanoshells and nanocages were synthesized via self-assembly of lanreotide acetate.

Biologically inspired self-assembly of bacitracin-based platinum nanoparticles with anti-tumor effects

The green synthesis of bacitracin-based platinum nanoparticles with excellent antitumor efficacyin vitroandin vivo.

Combined Near Infrared Photothermal Therapy and Chemotherapy Using Gold Nanoshells Coated Liposomes to Enhance Antitumor Effect

Novel antitumor system based on the targeting photothermal and pH-responsive nanocarriers, gold nanoshells coated oleanolic acid liposomes mediating by chitosan (GNOLs), is designed and synthesized for the first time. The GNOLs present spherical and uniform size (172.03 nm) with zeta potential (20.7 ± 0.4 mV), which are more easily accumulated in tumor. Meanwhile, the GNOLs exhibit a slow and controlled release of oleanolic acid at pH 7.4, as well as a rapid release at pH 5.5, which is beneficial for tumor-targeting drug release. Under near infrared (NIR) irradiation, hyperthermia can be generated by activated gold nanoshells to perform photothermal therapy effect, which triggers drug release from the carriers by activating the gel to liquid crystalline phase transition of the liposomes. Moreover, the NIR assisting drug release can be easily and selectively activated locally due to the spatially and real-timely controllable property of light. The experimental results also verify that the GNOLs with NIR irradiation achieve more ideal antitumor effects than other oleanolic acid formulations in vitro and in vivo. Hence, the drug delivery system exhibits a great potential in chemo-photothermal antitumor therapy.

Development of ordered metal nanoparticle arrangements on solid supports by combining a green nanoparticle synthetic method and polymer templating for sensing applications

One step, simple, robust and "green" methodology to fabricate high-density ordered arrays of uniform gold nanoparticles and gold nanoparticles clusters at room temperature over large areas which are suitable for high-performance SERS.

Preparation of Anisotropic and Oriented Particles on a Flexible Substrate

Elongated plasmonic nanoparticles show superior optical properties when compared to spherical ones. Facile, versatile and cost-effective bottom-up approaches for fabrication of anisotropic nanoparticles in solution have been developed. However, fabrication of 2-D plasmonic templates from elongated nanoparticles with spatial arrangement at the surface is still a challenge. We used controlled seed-mediated growth in the presence of porous and functionalized surface of flexible polydimethylsiloxane (PDMS) templates to provide directional growth and formation of elongated gold nanoparticles (AuNPs). Atomic force microscopy (AFM) and spectroscopy revealed embedding of the particles within the functionalized porous surface of PDMS. Nanoparticles shapes were observed with transmission electron microscope (TEM), UV-Vis spectroscopy, and X-ray powder diffraction (XRPD) measurements, which revealed an overall orientation of particles at the surface. Anisotropic and oriented particles on a flexible substrate are of interest for sensing applications.

Effects of Size, Shape, Surface Charge and Functionalization on Cytotoxicity of Gold Nanoparticles

Gold nanoparticles ( Au NPs) are emerging as promising nanomaterials from which we construct diagnostic and therapeutic nanosystems. For understanding the fundamental behaviors of Au NPs with biological systems, interactions of Au NPs and cells should be considered first. In this review, we present a detailed analysis of data on the cytotoxicity of most popular Au NPs including gold nanoclusters ( Au NCs), spherical Au NPs, gold nanoshells ( Au NSs) and gold nanorods ( Au NRs). Relationships correlating the cell models, physicochemical properties (size, shape, chemical functionality and surface charge) of Au NPs and cytotoxicity are discussed on the basis of data analysis. Some general conclusions, current challenges and future prospects/solutions on the issue have been provided.

Achieving plasmon reproducibility from surfactant free gold nanostar synthesis

The novelty and significance lies in the low temperature synthesis to improve reproducibility of the plasmonic response by a factor of at least two compared to current approaches.