Optical properties and biomedical applications of gold nanorods / 国际生物医学工程杂志

In recent years, the research on gold nanoparticles has made great progress. Gold nanoparticles with different morphologies have good application prospects in drug delivery and tumor treatment. Some gold nanoparticles have entered the stage of clinical trials. Gold nanorods have become important research objects due to their special optical properties and photothermal treatment potential. In this paper, the optical properties and main applications of gold nanorods were reviewed. Gold nanorods have good surface modifiable properties and can be modified through surface ligand exchange to improve their biocompatibility. The photothermal properties of gold nanorods can be improved by adjusting the aspect ratio to adjust the surface plasmon resonance (SPR) peak to achieve near-infrared light excitation. These characteristics make gold nanorods show good application prospects in the detection of biological macromolecules, real-time imaging in vivo, and early diagnosis and treatment of tumors. Using gold nanorods as a carrier and modified with different targeting molecules can improve the targeting of its drug delivery system and reduce damage to normal cells, so as to realize the combined application of chemotherapy and photothermal therapy, and finally achieve a better therapeutic effect. Combining gold nanorods with stem cells or certain specific biomolecules can form a hybrid gold nanorod system which provides new ideas for further improving the efficiency of tumor treatment.

Drug Release of Bacterial Cellulose as Antibacterial Nano Wound ‎Dressing

Bacterial cellulose (BC) is a natural polymer that can be utilized for many applications. Because of its renewable nature, goodbiocompatibility and excellent physical features of bacterial cellulose, it can be utilized in pharmaceutical, biomedical fields, andnanotechnology applications. In this study, we prepared antibiotic bacterial cellulose loaded with tetracycline hydrochloride andgentamicin, and its drug release, as well as antibacterial activity, were evaluated separately. The structure and morphology of the loadedbacterial cellulose were determined by scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR).AATCC100 test was used for antibacterial properties against Escherichia coli and Staphylococcus aureus. Ultraviolet spectrophotometrydevice was used to detect absorption and release process of mentioned antibacterial cellulose. By these unique specifications of bacterialcellulose layer loaded with tetracycline hydrochloride and gentamicin, we found that they may successfully serve as a wound dressing andother medical biomaterials.

Surface-enhanced raman scattering technology-based graphene oxide/gold nanorods in detection of circulating tumor cells / 第二军医大学学报

Objective To develop a method combining surface-enhanced Raman scattering (SERS) spectrum and electrostatic adsorption for detecting circulating tumor cells. Methods Graphene oxide was non-covalently functionalized by poly(sodium-p-styrenesulfonate) (PSS), and graphene oxide/gold nanorod (GO/GNR) hybrids were in situ synthesized via gold seeding growth approach. Then, GO/GNR hybrids were non-covalently functionalized by poly dimethyl diallyl ammonium chloride (PDDAC) to make the surface of GO/GNR positively charged. GO/GNR hybrids would target the tumor cells by electrostatic interaction. SERS technology was used to detect the composites of GO/GNR-tumor cells. The blood samples of healthy volunteers were collected, and the tumor cells of different densities were added to the blood samples to make simulated blood samples. The tumor cells in simulated blood samples were detected using the above methods. Results Positively charged GO/GNR hybrids could efficiently target the tumor cells. SERS spectroscopy could detect tumor cells within 50 to 10 000 cells. However, white blood cells might interfere the detection of tumor cells. Conclusion GO/GNR hybrids may serve as SERS probes for detection of circulating tumor cells via Raman spectroscopy.

Biomimetic albumin-modified gold nanorods for photothermo-chemotherapy and macrophage polarization modulation

Nanotechnology-based photothermal therapy has attracted great attention in the past decade. Nevertheless, photothermal therapy has some inherent drawbacks, such as the uneven heat production and limited laser penetration, often leading to insufficient treatment outcomes. Here, we developed a combination strategy to improve cancer therapy. The biomimetic albumin-modified gold nanorods (AuNRs) were prepared with incorporation of paclitaxel (PTX). This therapeutic system was characterized by several features. First, the albumin modification enhanced the biocompatibility and colloidal stability. Second, the surface-coated albumin promoted cellular uptake the albumin-binding protein pathway. Third, PTX was incorporated hydrophobic interaction between PTX and the albumin lipophilic domain. Fourth, the system can be used for combined photothermo-chemotherapy for yielding synergistic effects. The antitumor activity of the system was evaluated both and using the HCT116 colon cancer cell and tumor model. The combination therapy was found with an enhanced treatment efficiency and no obvious side effect. Most importantly, the thermal effect was also discovered with the ability to modulate the tumor microenvironments and suppress the macrophages polarization towards the M2 pro-tumor phenotype. It could be a mechanism for photothermal immunotherapy. The combination strategy and the system provide a potential method for cancer therapy.

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) . Furthermore, we proved either the MPEG-AuNR or VER-155008- micelles can be accumulate in the tumor site by photoacoustic imaging and fluorescent imaging. anti-cancer evaluation showed that tumor size remarkably decreased (smaller than 100 mm 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 nm) or normal saline as control (larger than 2000 nm). 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.

Enhanced anti-cancer effect of gambogic acid by gold nanorod-based delivery / 中国药理学与毒理学杂志

OBJECTIVE Nanotechnology provides a novel strategy for the delivery of anticancer drugs. In this study, titanium dioxide coated gold nanorod (GNR/TiO2) nanostructures were used as the drug carrier for gambogic acid in order to improve its anticancer effect. METHODS Biocompatibility and cellular uptake of GNR/TiO2 nanostructures were studied in human glioblastoma U-87 MG cells. Cell viability was evaluated by ATP assay and calcein AM staining. LysoSensor Green DND-189 and Hoechst 33342 were used to analyze the intracellular location of GNR/TiO2 nanostructures. The in vitro anti-cancer effect of gambogic acid loaded nanoparticles was compared with free drug. RESULTS The results showed that GNR/TiO2 nanostructures are biocompatible, and they are localized at the intracel?lular acidic compartments of endosomes and lysosomes. The intracellular drug content delivered via GNR/TiO2 nanostructures was 6 fold higher than the free form, thus dramatically enhancing the anticancer effect of gambogic acid. Furthermore, mild photothermal therapy also showed synergistic effect with the drug. CONCLUSION Our study suggested that GNR/TiO2 nanostructures can be considered as a promising anticancer drug carrier.

Rapid Preparation of Micro-sized Gold Nanorods / 分析化学

The effects of cetyltrimethylammonium bromide ( CTAB) , ascorbic acid, NaBH4 and AgNO3 , as well as the stirring time and reaction time on the preparation of gold nanorods synthesized with seedless growth method were studied. The optimum preparation conditions were obtained in the process of growth of gold nanorods. The gold nanorods prepared under different conditions were characterized by visible absorption spectroscopy and transmission electron microscopy ( TEM ) . Under the optimum conditions such as room temperature, 0. 1 mol/L CTAB, 96 μmol/L AgNO3 , 0. 97 mmol/L ascorbic acid, 1. 5 μmol/L NaBH4 and stirring for 25 s, micro-sized gold nanorods with uniform morphology, good dispersibility, small shaft width and high aspect ratio were prepared within 6 h. The gold nanorods were expected to be applied to the detection of mercury ion in water environment.

Rapid Preparation of Micro-sized Gold Nanorods / 分析化学

The effects of cetyltrimethylammonium bromide ( CTAB) , ascorbic acid, NaBH4 and AgNO3 , as well as the stirring time and reaction time on the preparation of gold nanorods synthesized with seedless growth method were studied. The optimum preparation conditions were obtained in the process of growth of gold nanorods. The gold nanorods prepared under different conditions were characterized by visible absorption spectroscopy and transmission electron microscopy ( TEM ) . Under the optimum conditions such as room temperature, 0. 1 mol/L CTAB, 96 μmol/L AgNO3 , 0. 97 mmol/L ascorbic acid, 1. 5 μmol/L NaBH4 and stirring for 25 s, micro-sized gold nanorods with uniform morphology, good dispersibility, small shaft width and high aspect ratio were prepared within 6 h. The gold nanorods were expected to be applied to the detection of mercury ion in water environment.

Inhibitory effect of gold nanoparticles conjugated with interferon gamma and methionine on breast cancer cell line

Objective: To develop a gold nanoparticles complex conjugated with interferon-gamma (IFN-γ) and methionine along with application of hyperthermia using near-infrared laser beams for the treatment of cancer cells. Methods: Gold nanorods (10 nm) were conjugated with IFN-γ and methionine using carbodiimide family and characterized after purification by dialysis bags. Breast cancer cells were cultured and incubated with gold nanorods at different concentrations followed by irradiation with near-infrared laser beam. Samples were then evaluated for their viability in order to determine the effect of treatment and variables by MTT assy. Results: Zetasizer results confirmed the conjugation of gold nanorods with methionine and IFN-γ. The median percentage of cell viability in 0.30 μg/mL concentration of gold nanorods was 82%. The cell viability reached to 85% at the same concentration of gold nanorods, which existed in the assayed complex. The results of MTT assay showed that the 0.60 μg/mL concentration of gold nanoparticles complex was toxic on tumor cells (P < 0.05). After exposure to hyperthermia, the viability of cells at 6 min decreased to 77% in 0.30 μg/mL concentration of gold nanorods complex. Conclusions: The size and concentration of gold nanorods was not cytotoxic. However, their presence during irradiation near-infrared laser increased the number of dead cells during the treatment of cells.

Activatable ultrasmall gold nanorods for theranostics in breast cancer cells / 国际生物医学工程杂志

Objective To develop a fluorescence signal activatable multifunctional molecular probe with theranostics function through combining ultrasmall gold nanorods(UGNRs) with fluorescein,and to evaluate its therapeutic effect on photothermal therapy (PTT) in breast cancer cells.Methods The UGNRs were synthesized by the one-pot seedless method,then the functionalized modification of UGNRs were conducted using cysteamine.Finally,the activatable ultrasmall gold nanorods (AUGNRs) were synthesized by amide condensation of —NH2 of cysteamine and —COOH of carboxylated fluorescein CyS.The cell uptake ability and GSH-mediated imaging ability of AUGNRs were studied using breast cancer 4T1 cells.4T1 cells co-cultured with AUGNRs were irradiated with 808 nm excitation light,and the PTT effects were assessed by MTT colorimetric staining and calcein-AM/PI staining.Results The AUGNRs were synthesized successfully,which could be uptaken by 4T1 cells quickly and efficiently,and could achieve intracellular glutathione (GSH) triggered fluorescence recovery.No obvious cytotoxicity of AUGNRs to 4T1 cells was observed in the co-cultivation.Moreover,obvious PTT effects could be induced by 808 nm laser,which could effectively kill 4T1 cancer cells.Conclusion The fluorescence signals of AUGNRs can be induced by intracellular GSH,and tumor cell destruction can be achieved by 808 laser-excitated PTT effects.

Preparation and characterization of self-assembled thiolated chitosan derivatives and gold nanoparticles / 国际生物医学工程杂志

Objective To prepare self-assembled thiolated chitosan derivatives gold nanoparticles (CS-GNRs) and carry out the feature tests.Methods CS-GNRs was prepared by chitosan derivatives and GNRs through strong metal sulfur chemical bond between thiols and gold on GNRs surface.Morphology features was tested by transmission electron microscope,dynamic light scattering was adopted to observe the size of nanoparticles.Ultraviolet-visible spectrophotometer was used to detect the optical properties and the property change.Meanwhile,the surface-enhanced Raman scattering (SERS) activity of CS-GNRs was investigated by using crystal violet (CV) as a probe molecular.Results CS-GNRs were in good shape,uniform particle size and good dispersion.The SERS of CV was enhanced,and the enhancement factor of CV adsorbed on CS-GNRs was up to 2×103.Conclusions The nanoparticles have potential application in molecular detection and Raman spectra detection.

An Analysis of the Diversification of Cell Temperature of Photothermal Effects of Gold Nanorods Coated with mAb-EGFR on FADU Human Pharyngeal Squamous Cell Lines and Non-tumor Cells 293 T Cell Line / 听力学及言语疾病杂志

Objective To study the cell temperature on photothermal effects of gold nanorods coated with mAb-EGFR targeted on FADU human pharyngeal squamous cell lines and non- tumor cells(293T cell line) .Meth‐ods CTAB gold nanorods were synthesized to complete the functional modifications of EGFR monoclonal antibody , with a UV spectrophotometer and electron microscopy characterization .The cultured FADU hypopharyngeal cells and non-tumor cells 293 T cell lines were expressed by western blot EGFR statutory comparison of two cell lines , cells to swallow the gold nanorods were observed .Cell apoptosis was observed by Annexin-V -FLUOS and pro‐pidium iodide .Then we set different doses of gold nanoparticles concentration (15% ,25 % ,and 35% ) .After 6 minutes'near-infrared laser irradiation (λ=808 nm) ,the temperature was recorded once every minute ,and cell viability was detected by XTT assay .Results After six minutes'near -infrared laser irradiation ,the cell tempera‐ture was 41 ℃ ~43 ℃ ,with 15% ~25 % of gold nanorods .The cell killing effects on hypopharyngeal were signifi‐cant .The 293T cells did not show any damaging effects (P<0 .05) ,whereas the concentration of gold nanoparticles in 35% of hypopharyngeal FADU cells and 293T cells had significant cytotoxicity (P<0 .05) .Conclusion There were significant cell killing effects with 15% ~25% gold nanorods coated with mAb-EGFR in the near -infrared laser irradiation six minutes (Cell temperatures of both cell lines were 41 ℃ ~43 ℃)on hypopharyngeal FADU cell but not on non-tumor cells .

Optical Properties and Biomedical Application of Gold Nanorods / 生物化学与生物物理进展

Gold nanorods is a capsule-shaped gold nanoparticles. Gold nanorods give rise to two absorption peaks corresponding to their plasmonic modes, transverse mode and longitudinal mode, corresponding to light absorption and scattering along the short and long axis, respectively. The longitudinal surface plasmon resonance can be tuned by adjusting their aspect ratio from the visible to the NIR region and extremely sensitive to changes in the dielectric properties of the surroundings including solvents, adsorbates, and the interparticle distance of the gold nanorods. This unique optical property of gold nanorods opens up fascinating applications in biological and chemical sensors. Optical properties and biomedical application of gold nanorods are introduced, and its future research prospects are discussed.