This research was funded by the National Natural Science Foundation of China (31700840); the Key Scientific Research Project of Henan Province (18B430013, 18A150049). This research was supported by the Nanhu Scholars Program for Young Scholars of XYNU. The authors would like to thank bachelor student Zebo Qu from the College of Life Sciences in XYNU for his helpful works. The authors would like to acknowledge the Analysis &#38; Testing Center of XYNU for the use of their equipment.

CAUTION: Make sure to consult all relevant material safety data sheets (MSDS) before using all chemicals. Several of the chemicals used for preparing copolymer and nanoparticles are acutely toxic. Nanoparticles also have potential hazards. Make sure to use all appropriate safety practices and personal protective equipment, including gloves, lab coat, hoods, full-length pants, and close-toed shoes.
1. Synthesis of double-carboxyl polyethylene glycol (CT-PEG)33
<ol>
	<li>Add 1.46 g (14.6 mmol) of succinic anhydride (SA) and 209 mg (1.71 mmol) of 4-dimethylaminopyridine (DMAP) to a 100 mL round bottom flask.</li>
	<li>Add 15 mL of anhydrous tetrahydrofuran (THF) to the flask used in step 1.1 and fit a glass stopper. Keep the flask at 0 &#176;C for 30 min.</li>
	<li>Add 4.28 g (4.28 mmol) of polyethylene glycol (PEG) and 1.8 mL (12.8 mmol) of triethylamine (TEA) to a new flask.</li>
	<li>Add 15 mL of anhydrous THF to the flask used in step 1.3 and fit a glass stopper. Transfer the solution slowly to the flask used in step 1.2, using a syringe under nitrogen atmosphere.</li>
	<li>Stir the solution at 0 &#176;C for 2 h, then continue the reaction at room temperature (RT) overnight.</li>
	<li>Using a rotary evaporator (40 &#176;C, 0.1 MPa), concentrate the reaction solution and remove the THF solvent.</li>
	<li>At RT, dissolve the reaction solution from step 1.6 in 15 mL of 1.325 g/mL dichloromethane (DCM), then add 15 mL of cold diethyl ether (Et2O) to obtain the precipitation product (polyethylene glycol diacid). Remove the solvent via filter paper. 
	NOTE: The precipitation step can be repeated 3x.</li>
	<li>Dry the precipitates under vacuum at RT for 48 h.</li>
</ol>
2. Synthesis of PEI-g-PEG copolymer
<ol>
	<li>Add 305.47 mg of CT-PEG from step 1.8 and 5 mL of dimethyl sulfoxide (DMSO) to a flask and stir at RT to ensure that CT-PEG is fully dissolved in DMSO.</li>
	<li>Dissolve 49.46 mg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) in 5 mL of DMSO, then add the solution to the flask used in step 2.1 and stir for 30 min at RT.</li>
	<li>Dissolve 29.69 mg of N-hydroxysuccinimide (NHS) in 5 mL of DMSO and add the solution to the flask used in step 2.1. Continue to stir at RT for 3 h.</li>
	<li>Dissolve 28.6 &#956;L of polyethyleneimine (PEI) in 10 mL of DMSO and add the solution dropwise to the flask used in step 2.1. Stir for 3 days, at least.</li>
	<li>Transfer the reacted solution from step 2.4 to a dialysis bag (1,000 molecular weight cut-off [MWCO]). Place the dialysis bag into a 1 L beaker with 500 mL of ultrapure water as the dialysate. Change the ultrapure water every 12 h for 3 days.</li>
	<li>Transfer the solution in step 2.5 to another dialysis bag (10,000 MWCO). Place the dialysis bag into a 1 L beaker with 500 mL of ultrapure water as the dialysate. Change the ultrapure water every 12 h for 3 days.</li>
	<li>Concentrate the solution from step 2.6 using a rotary evaporator (40 &#176;C, 0.1 MPa) and freeze-dry the sample to obtain the PEI-g-PEG powder.</li>
</ol>
3. Synthesis of PEI-g-PEG@AuNPs
<ol>
	<li>Dissolve 5 mg of prepared PEI-g-PEG (step 2.7) in 5 mL of ultrapure water in a new flask and fit with a glass stopper.</li>
	<li>Add 100 mL of 0.3 mM HAuCl4 solution to the flask and stir the solution for 3 h at RT. 
	NOTE: The color of the solution should change immediately from yellow to orange.</li>
	<li>Add 1 mL of 1 mg/mL NaBH4 solution to the flask and stir the solution for 3 h at RT. 
	NOTE: The reaction solution should instantly turn burgundy.</li>
	<li>Dialyze the reaction product using a dialysis bag (1,000 MWCO) for 3 days as described in step 2.5 to obtain the PEI-g-PEG@AuNPs solution.</li>
</ol>
4. Synthesis of DOX-g-PEI-g-PEG@AuNPs
<ol>
	<li>Add 1 mL of 2.2 mg/mL DOX solution and 20 mL of PEI-g-PEG@AuNPs solution to a new flask and fit with a glass stopper.</li>
	<li>Dissolve 0.727 mg of EDC in 1 mL of ultrapure water and add the EDC solution to the flask used in step 4.1.</li>
	<li>Dissolve 0.437 mg of NHS in 1 mL of ultrapure water. Add the NHS solution to the flask and stir at RT for 1 h.</li>
	<li>Dialyze the reaction product by using a dialysis bag (1,000 MWCO) for 3 days as described in step 2.5 to obtain the DOX-g-PEI-g-PEG@AuNPs solution.</li>
</ol>
5. Synthesis of AS1411-g-DOX-g-PEI-g-PEG@AuNPs
<ol>
	<li>Add 20 mL of DOX-g-PEI-g-PEG@AuNPs solution and 4OD of AS1411 (OD = optical density; 1OD &#8776; 33 &#956;g) to a new flask.</li>
	<li>Dissolve 28.76 mg of EDC in 1 mL of ultrapure water and add the EDC solution to the flask used in step 5.1.</li>
	<li>Dissolve 17.27 mg of NHS in 1 mL of ultrapure water. Add the NHS solution to the flask used in step 5.1 and stir the reaction for 1 h at RT.</li>
	<li>Dialyze the reaction product by using a dialysis bag (1,000 MWCO) for 3 days as described in step 2.5 to obtain AS1411-g-DOX-g-PEI-g-PEG@AuNPs.</li>
</ol>
6. Sample characterization
<ol>
	<li>Dissolve the CT-PEG polymer (step 1.8) and PEI-g-PEG copolymer (step 2.7) in chloroform-d in nuclear magnetic resonance (NMR) tubes, respectively. Analyze the samples using a 600 MHz NMR spectrometer equipped with a 14.09 T superconducting magnet and 5.0 mm 600 MHz broadband Z-gradient high resolution probe to confirm the chemical structure34.</li>
	<li>Disperse AuNPs, DOX, and AS1411, and prepared PEI-g-PEG@AuNPs (step 3.4), DOX-g-PEI-g-PEG@AuNPs (step 4.4), and AS1411-g-DOX-g-PEI-g-PEG@AuNPs (step 5.4), respectively in ultrapure water. Then, transfer to cuvettes and record ultraviolet-visible (UV-vis) spectra using a UV-vis spectrophotometer.</li>
	<li>Attach a double-sided adhesive (~2 mm x 2 mm) to the aluminum foil, and dip the sample solution (PEI-g-PEG@AuNPs, DOX-g-PEI-g-PEG@AuNPs, and AS1411-g-DOX-g-PEI-g-PEG@AuNPs) on the whole tape uniformly. Analyze the samples using an X-ray photoelectron spectroscopy analyzer.</li>
	<li>Disperse PEI-g-PEG@AuNPs, DOX-g-PEI-g-PEG@AuNPs, and AS1411-g-DOX-g-PEI-g-PEG@AuNPs solutions, respectively in ultrapure water. Then, transfer to cuvettes and evaluate the size distribution using dynamic light scattering.</li>
	<li>Disperse PEI-g-PEG@AuNPs, DOX-g-PEI-g-PEG@AuNPs, and AS1411-g-DOX-g-PEI-g-PEG@AuNPs solutions in ultrapure water (one drop of sample per 5 mL of ultrapure water for each sample). Sonicate for 2 h. Dip the copper grid into sample solutions and dry under a infrared lamp. Characterize the morphology using a transmission electron microscope.</li>
	<li>Inject 1 mg of AS1411-g-DOX-g-PEI-g-PEG@AuNPs into a 20 kDa MWCO dialysis cassette, then place in 80 mL of phosphate buffered saline (PBS) with 5% bovine serum albumin (BSA). Stir at 37 &#176;C.</li>
	<li>At the predetermined timepoints, collect 100 &#181;L aliquots and replace with fresh PBS. Use a UV-vis spectrophotometer to measure the DOX fluorescence intensity of the aliquots.</li>
</ol>
7. CCK-8 assay of AS1411-g-DOX-g-PEI-g-PEG@AuNPs nanoparticles
<ol>
	<li>Grow A549 cells in Dulbecco&#8217;s modified Eagle&#8217;s medium (DMEM) supplemented with 10% fetal bovine serum, 100 U/mL penicillin, and 100 &#956;g/mL streptomycin under a humidified atmosphere of 95% air and 5% CO2 at 37 &#176;C. Replace the culture medium every 2 days. Use cells at passage 5 for the cell proliferation and cytotoxicity assays to quantitatively evaluate the cytotoxicity of prepared AS1411-g-DOX-g-PEI-g-PEG@AuNPs nanoparticles.</li>
	<li>Add 100 &#956;L of nanoparticle solution into each well containg 1 mL of cell medium. After culturing for 24 h and 48 h, remove the culture media from cell culture plates, then add 300 &#956;L of fresh culture media and 30 &#956;L of cell counting kit-8 (CCK-8) kit solutions immediately to each well. Incubate for 4 h in a CO2 incubator at 37 &#176;C.</li>
	<li>Transfer 200 &#956;L of reaction solutions from step 7.2 into a 96 well plate. Read the optical density (OD) of each well at 570 nm with a microplate reader.</li>
	<li>Observe the morphology of cells at 24 h and 48 h under a microscope.</li>
</ol>

<ol>
	<li>Abad, J. M., Bravo, I., Pariente, F., Lorenzo, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-tasking+base+ligand:+a+new+concept+of+AuNPs+synthesis.">Multi-tasking base ligand: a new concept of AuNPs synthesis.</a> Analytical and Bioanalytical Chemistry. 408 (9), 2329-2338 (2016).</li><li>Siegel, R. L., Miller, K. D., Jemal, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cancer+statistics,+2019.">Cancer statistics, 2019.</a> CA-A Cancer Journal for Clinicians. 69 (1), 7-34 (2019).</li><li>Jang, B., Kwon, H., Katila, P., Lee, S. J., Lee, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dual+delivery+of+biological+therapeutics+for+multimodal+and+synergistic+cancer+therapies.">Dual delivery of biological therapeutics for multimodal and synergistic cancer therapies.</a> Advanced Drug Delivery Reviews. 98, 113-133 (2016).</li><li>Gansler, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sixty+years+of+CA:+a+cancer+journal+for+clinicians.">Sixty years of CA: a cancer journal for clinicians.</a> CA-A Cancer Journal for Clinicians. 60 (6), 345-350 (2010).</li><li>Li, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+Mechanism+for+Selective+Cytotoxicity+towards+Cancer+Cells+of+Diselenide-Containing+Paclitaxel+Nanoparticles.">Molecular Mechanism for Selective Cytotoxicity towards Cancer Cells of Diselenide-Containing Paclitaxel Nanoparticles.</a> International Journal of Biological Sciences. 15 (8), 1755-1770 (2019).</li><li>Zhao, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Precise+ratiometric+loading+of+PTX+and+DOX+based+on+redox-sensitive+mixed+micelles+for+cancer+therapy.">Precise ratiometric loading of PTX and DOX based on redox-sensitive mixed micelles for cancer therapy.</a> Colloids Surfaces B: Biointerfaces. 155, 51-60 (2017).</li><li>Blum, R. H., Carter, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adriamycin.+A+new+anticancer+drug+with+significant+clinical+activity.">Adriamycin. A new anticancer drug with significant clinical activity.</a> Annals of Internal Medicine. 80 (2), 249-259 (1974).</li><li>de Lima, R. D. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-level+laser+therapy+alleviates+the+deleterious+effect+of+doxorubicin+on+rat+adipose+tissue-derived+mesenchymal+stem+cells.">Low-level laser therapy alleviates the deleterious effect of doxorubicin on rat adipose tissue-derived mesenchymal stem cells.</a> Journal of Photochemistry Photobiology B. 196, 111512 (2019).</li><li>Markowska, A., Kaysiewicz, J., Markowska, J., Huczynski, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doxycycline,+salinomycin,+monensin+and+ivermectin+repositioned+as+cancer+drugs.">Doxycycline, salinomycin, monensin and ivermectin repositioned as cancer drugs.</a> Bioorganic &amp; Medicinal Chemistry Letters. 29 (13), 1549-1554 (2019).</li><li>Songbo, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidative+stress+injury+in+doxorubicin-induced+cardiotoxicity.">Oxidative stress injury in doxorubicin-induced cardiotoxicity.</a> Toxicology Letters. 307, 41-48 (2019).</li><li>Ewer, M. S., Ewer, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiotoxicity+of+anticancer+treatments.">Cardiotoxicity of anticancer treatments.</a> Nature Reviews Cardiology. 12 (9), 547-558 (2015).</li><li>Gabizon, A., Shmeeda, H., Barenholz, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharmacokinetics+of+pegylated+liposomal+Doxorubicin:+review+of+animal+and+human+studies.">Pharmacokinetics of pegylated liposomal Doxorubicin: review of animal and human studies.</a> Clinical Pharmacokinetics. 42 (5), 419-436 (2003).</li><li>Xu, X., Ho, W., Zhang, X., Bertrand, N., Farokhzad, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cancer+nanomedicine:+from+targeted+delivery+to+combination+therapy.">Cancer nanomedicine: from targeted delivery to combination therapy.</a> Trends in Molecular Medicine. 21 (4), 223-232 (2015).</li><li>Feng, S., Nie, L., Zou, P., Suo, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+drug+and+polymer+molecular+weight+on+drug+release+from+PLGA-mPEG+microspheres.">Effects of drug and polymer molecular weight on drug release from PLGA-mPEG microspheres.</a> Journal of Applied Polymer Science. 132 (6), 41431 (2015).</li><li>Chen, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Injectable+Temperature-sensitive+Hydrogel+with+VEGF+Loaded+Microspheres+for+Vascularization+and+Bone+Regeneration+of+Femoral+Head+Necrosis.">Injectable Temperature-sensitive Hydrogel with VEGF Loaded Microspheres for Vascularization and Bone Regeneration of Femoral Head Necrosis.</a> Materials Letters. 229, 138-141 (2018).</li><li>Abadeer, N. S., Murphy, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+Progress+in+Cancer+Thermal+Therapy+Using+Gold+Nanoparticles.">Recent Progress in Cancer Thermal Therapy Using Gold Nanoparticles.</a> The Journal of Physical Chemistry C. 120 (9), 4691-4716 (2016).</li><li>Riley, R. S., Day, E. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gold+nanoparticle-mediated+photothermal+therapy:+applications+and+opportunities+for+multimodal+cancer+treatment.">Gold nanoparticle-mediated photothermal therapy: applications and opportunities for multimodal cancer treatment.</a> WIREs Nanomedicine and Nanobiotechnology. 9 (4), 1449 (2017).</li><li>Fratoddi, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+Hydrophilic+Gold+Nanoparticles+as+Carrier+for+Anticancer+Copper(I)+Complexes:+Loading+and+Release+Studies+for+Biomedical+Applications.">Highly Hydrophilic Gold Nanoparticles as Carrier for Anticancer Copper(I) Complexes: Loading and Release Studies for Biomedical Applications.</a> Nanomaterials (Basel). 9 (5), 772 (2019).</li><li>Lee, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drug-loaded+gold+plasmonic+nanoparticles+for+treatment+of+multidrug+resistance+in+cancer.">Drug-loaded gold plasmonic nanoparticles for treatment of multidrug resistance in cancer.</a> Biomaterials. 35 (7), 2272-2282 (2014).</li><li>Dreaden, E. C., Alkilany, A. M., Huang, X., Murphy, C. J., El-Sayed, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+golden+age:+gold+nanoparticles+for+biomedicine.">The golden age: gold nanoparticles for biomedicine.</a> Chemical Society Reviews. 41 (7), 2740-2779 (2012).</li><li>Wei, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anticancer+drug+nanomicelles+formed+by+self-assembling+amphiphilic+dendrimer+to+combat+cancer+drug+resistance.">Anticancer drug nanomicelles formed by self-assembling amphiphilic dendrimer to combat cancer drug resistance.</a> Proceedings of the National Academy of Sciences of the United States of America. 112 (10), 2978-2983 (2015).</li><li>Galluzzi, L., Buque, A., Kepp, O., Zitvogel, L., Kroemer, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunological+Effects+of+Conventional+Chemotherapy+and+Targeted+Anticancer+Agents.">Immunological Effects of Conventional Chemotherapy and Targeted Anticancer Agents.</a> Cancer Cell. 28 (6), 690-714 (2015).</li><li>Muddineti, O. S., Ghosh, B., Biswas, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+trends+in+using+polymer+coated+gold+nanoparticles+for+cancer+therapy.">Current trends in using polymer coated gold nanoparticles for cancer therapy.</a> International Journal of Pharmaceutics. 484 (1-2), 252-267 (2015).</li><li>Hu, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methyl+Orange+removal+by+a+novel+PEI-AuNPs-hemin+nanocomposite.">Methyl Orange removal by a novel PEI-AuNPs-hemin nanocomposite.</a> Journal of Environmental Sciences. 53, 278-283 (2017).</li><li>Gu, F. X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeted+nanoparticles+for+cancer+therapy.">Targeted nanoparticles for cancer therapy.</a> Nano Today. 2 (3), 14-21 (2007).</li><li>Srinivasarao, M., Galliford, C. V., Low, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Principles+in+the+design+of+ligand-targeted+cancer+therapeutics+and+imaging+agents.">Principles in the design of ligand-targeted cancer therapeutics and imaging agents.</a> Nature Reviews Drug Discovery. 14 (3), 203-219 (2015).</li><li>Liu, Z., Shi, Y., Chen, Z., Duan, L., Wang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+progress+towards+the+use+of+aptamers+in+targeted+cancer+therapy.">Current progress towards the use of aptamers in targeted cancer therapy.</a> Chinese Science Bulletin (Chinese Version). 59 (14), 1267 (2014).</li><li>Ghosh, P., Han, G., De, M., Kim, C. K., Rotello, V. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gold+nanoparticles+in+delivery+applications.">Gold nanoparticles in delivery applications.</a> Advanced Drug Delivery Reviews. 60 (11), 1307-1315 (2008).</li><li>Vandghanooni, S., Eskandani, M., Barar, J., Omidi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antisense+LNA-loaded+nanoparticles+of+star-shaped+glucose-core+PCL-PEG+copolymer+for+enhanced+inhibition+of+oncomiR-214+and+nucleolin-mediated+therapy+of+cisplatin-resistant+ovarian+cancer+cells.">Antisense LNA-loaded nanoparticles of star-shaped glucose-core PCL-PEG copolymer for enhanced inhibition of oncomiR-214 and nucleolin-mediated therapy of cisplatin-resistant ovarian cancer cells.</a> International Journal of Pharmaceutics. 573, 118729 (2020).</li><li>Andghanooni, S., Eskandani, M., Barar, J., Omidi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=AS1411+aptamer-decorated+cisplatin-loaded+poly(lactic-co-glycolic+acid)+nanoparticles+for+targeted+therapy+of+miR-21-inhibited+ovarian+cancer+cells.">AS1411 aptamer-decorated cisplatin-loaded poly(lactic-co-glycolic acid) nanoparticles for targeted therapy of miR-21-inhibited ovarian cancer cells.</a> Nanomedicine. 13 (21), 2729-2758 (2018).</li><li>Palmieri, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+anti-nucleolin+recombinant+immunoagent+for+cancer+therapy.">Human anti-nucleolin recombinant immunoagent for cancer therapy.</a> Proceedings of the National Academy of Sciences of the United States of America. 112 (30), 9418-9423 (2015).</li><li>Pichiorri, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+NCL+targeting+affects+breast+cancer+aggressiveness+through+miRNA+regulation.">In vivo NCL targeting affects breast cancer aggressiveness through miRNA regulation.</a> Journal of Experimental Medicine. 210 (5), 951-968 (2013).</li><li>Hou, S., McCauley, L. K., Ma, P. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+erosion+properties+of+PEG-containing+polyanhydrides.">Synthesis and erosion properties of PEG-containing polyanhydrides.</a> Macromolecular Bioscience. 7 (5), 620-628 (2007).</li><li>Nie, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Injectable+Vaginal+Hydrogels+as+a+Multi-Drug+Carrier+for+Contraception.">Injectable Vaginal Hydrogels as a Multi-Drug Carrier for Contraception.</a> Applied Sciences. 9 (8), 1638 (2019).</li><li>Zou, P., Suo, J., Nie, L., Feng, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature-responsive+biodegradable+star-shaped+block+copolymers+for+vaginal+gels.">Temperature-responsive biodegradable star-shaped block copolymers for vaginal gels.</a> Journal of Materials Chemistry. 22 (13), 6316-6326 (2012).</li><li>Etrych, T., &#352;ubr, V., Laga, R., &#344;&#237;hov&#225;, B., Ulbrich, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymer+conjugates+of+doxorubicin+bound+through+an+amide+and+hydrazone+bond:+Impact+of+the+carrier+structure+onto+synergistic+action+in+the+treatment+of+solid+tumours.">Polymer conjugates of doxorubicin bound through an amide and hydrazone bond: Impact of the carrier structure onto synergistic action in the treatment of solid tumours.</a> European Journal of Pharmaceutical Sciences. 58, 1-12 (2014).</li><li>Safari, F., Tamaddon, A. M., Zarghami, N., Abolmali, S., Akbarzadeh, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polyelectrolyte+complexes+of+hTERT+siRNA+and+polyethyleneimine:+Effect+of+degree+of+PEG+grafting+on+biological+and+cellular+activity.">Polyelectrolyte complexes of hTERT siRNA and polyethyleneimine: Effect of degree of PEG grafting on biological and cellular activity.</a> Artificial Cells, Nanomedicine, and Biotechnology. 44 (6), 1561-1568 (2016).</li></ol>

The authors have nothing to disclose.

The 1H NMR spectrum (Figure 2) confirm the successful synthesis of CT-PEG copolymer and PEI-g-PEG copolymer. The molecular weights of PEG and PEI were 1,000 and 1,200, respectively. Additionally, the EDC/NHS catalytic system was used to synthesize PEI-g-PEG copolymer via amide reactions. It should be noted that if the molecular weights of PEG and PEI changed for synthesizing PEI-g-PEG copolymer, then the reaction time and catalytic system needs to be reevaluated. Also, the reactio...

Being the major public health problem worldwide, cancer is widely characterized as having a low cure rate, high recurrence rate, and high mortality rate1,2. Current conventional anti-cancer methods include surgery, chemotherapy, and radiotherapy3, among which chemotherapy is the primary treatment for cancer patients in the clinic4. Clinical used anticancer drugs mainly include paclitaxel (PTX)5 and doxorubicin (DOX)6,7. DOX, an antineoplastic drug, has been broadly applied in clinical chemotherapy, due to the advantages of cancer cytotoxicity and inhibition of cancer cell proliferation8,9. However, DOX causes cardiotoxicity10,11, and the short half-life of DOX restricts its application in the clinic12. Therefore, degradable drug carriers are needed to load DOX and subequently release in a controlled fashion to a targeted area.
Nanoparticles have been widely used in targeted drug delivery systems and have several advantages in cancer treatment (i.e., sizeable surface-to-volume ratio, small size, ability to encapsulate various drugs, and tunable surface chemistry, etc.)13,14,15. In particular, gold nanoparticles (AuNPs) have been widely used in biological and biomedical applications, such as photothermal cancer therapy16,17. The unique properties of AuNPs, such as facile synthesis and general surface functionalization, have excellent prospects in the clinical field of cancer therapy18. Also, AuNPs have been used to identify drug delivery strategies, diagnose tumors, and overcome resistance in many studies19,20.
Notwithstanding, AuNPs need to be further tailored to overcome drug resistance via high local release at tumor lesions through enhanced permeation and retention (EPR), such as the targeting and accessibility properties. Polymer functionalized AuNPs have exhibited unique advantages, such as improved water solubility of hydrophobic anticancer drugs and prolonged circulation time21,22. Various biocompatible polymers have been used for AuNP coatings, such as polyethylene glycol (PEG), polyethyleneimine (PEI), hyaluronic acid, heparin, and xanthan gum. Then the stability, as well as the payload, of AuNPs is improved well23. Specifically, PEI is a highly branched polymer that is composed of many repeating units of primary, secondary, and tertiary amines24. PEI has excellent solubility, low viscosity, and a high degree of functionality, which is suitable for coating on AuNPs.
On the other hand, anti-cancer drugs need to be delivered to cancer cells directly with improved loading efficiency, and with lower toxicity for treating primary and advanced metastatic tumors25. Targeted ligands have great potential for anti-cancer drug targeted delivery systems26. Its selectivity for target molecule binding confers anti-cancer drug targeting specificity and increases drug enrichment in diseased tissues27. More ligands include antibodies, polypeptides, and small molecules. Compared to other ligands, nucleic acid aptamers can be synthesized in vitro and are easy to modify. AS1411 is an unmodified 26 bp phosphodiester oligonucleotide that forms a stable dimeric G-tetramer structure to specifically bind to an overexpressed target nuclear protein receptor on cancer cells28,29,30. AS1411 inhibits the proliferation of many cancer cells but does not affect the growth of healthy cells31,32. As a result, AS1411 has been used to fabricate an ideal targeted drug delivery system.
In this study, a PEI-g-PEG copolymer is synthesized via an amide reaction, then PEI-g-PEG copolymer coated gold nanoparticles (PEI-g-PEG@AuNPs) are fabricated. Additionally, DOX and AS1411 are sequentially linked to the prepared PEI-g-PEG@AuNPs, as shown in Figure 1. This detailed protocol is intended to help researchers avoid many of the common pitfalls associated with the fabrication of new PEI-g-PEG@AuNPs loaded with DOX and AS1411.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>4-Dimethylaminopyridine</td>
			<td>Macklin</td>
			<td>D807273</td>
			<td></td>
		</tr>
		<tr>
			<td>A549 cell</td>
			<td></td>
			<td>ATCC CCL-185TM</td>
			<td></td>
		</tr>
		<tr>
			<td>AS1411</td>
			<td>BBI Life Sciences Corporation</td>
			<td></td>
			<td>5&#39;-d (TTTGGTGGTGGTGGTTGTGGTGGTGGTGG) FL-AS1411 (fluorophore-labeled AS1411)</td>
		</tr>
		<tr>
			<td>Anhydrous Tetrahydrofuran (THF)</td>
			<td>SinoPharm Chemical Reagent Co., Ltd</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cell counting kit-8 (CCK-8)</td>
			<td>Sigma Aldrich</td>
			<td>96992-500TESTS-F</td>
			<td></td>
		</tr>
		<tr>
			<td>Dichloromethane</td>
			<td>Traditional Chinese medicine</td>
			<td>80047318</td>
			<td></td>
		</tr>
		<tr>
			<td>Diethyl ether (Et2O)</td>
			<td>SinoPharm Chemical Reagent Co., Ltd</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dimethyl sulfoxide</td>
			<td>Macklin</td>
			<td>D806645</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s modified Eagle&#39;s medium (DMEM)</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Doxorubicin hydrochloride</td>
			<td>Rhawn</td>
			<td>R017518</td>
			<td></td>
		</tr>
		<tr>
			<td>Ether absolute</td>
			<td>Traditional Chinese medicine</td>
			<td>80059618</td>
			<td></td>
		</tr>
		<tr>
			<td>Field Emission Transmission Electron Microscope</td>
			<td>FEI Company</td>
			<td>Tecnai G2 F 20</td>
			<td></td>
		</tr>
		<tr>
			<td>Gold(III) chloride trihydrate</td>
			<td>Rhawn</td>
			<td>R016035</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser Particle-size Instrument</td>
			<td>Malvern Instruments Ltd</td>
			<td>ZetasizerNanoZS/Masterszer3000E</td>
			<td></td>
		</tr>
		<tr>
			<td>Microplate Reader</td>
			<td>Molecular Devices</td>
			<td>SpectraMax 190</td>
			<td></td>
		</tr>
		<tr>
			<td>N-(3-Dimethylaminopropyl)-N&#39;-ethylcarbodiimide hydrochloride</td>
			<td>Macklin</td>
			<td>N808856</td>
			<td></td>
		</tr>
		<tr>
			<td>N-Hydroxysuccinimide</td>
			<td>Macklin</td>
			<td>H6231</td>
			<td></td>
		</tr>
		<tr>
			<td>NMR software</td>
			<td>Delta 5.2.1</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Nuclear Magnetic Resonance Spectrometer</td>
			<td>JEOL</td>
			<td>JNM-ECZ600R/S3</td>
			<td></td>
		</tr>
		<tr>
			<td>Origin 8.5</td>
			<td>OriginLab</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin</td>
			<td>Sigma Aldrich</td>
			<td>V900929-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate-buffered saline</td>
			<td>Sigma Aldrich</td>
			<td>P4417-100TAB</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly(ethylene glycol)</td>
			<td>Sigma Aldrich</td>
			<td>81188</td>
			<td>BioUltra, average Mn ~ 1000</td>
		</tr>
		<tr>
			<td>Poly (ethyleneimine) solution</td>
			<td>Sigma Aldrich</td>
			<td>482595</td>
			<td>average Mn ~ 1200, 50 wt.% in H2O</td>
		</tr>
		<tr>
			<td>Sodium borohydride, powder</td>
			<td>Acros</td>
			<td>C18930</td>
			<td></td>
		</tr>
		<tr>
			<td>Streptomycin</td>
			<td>Sigma Aldrich</td>
			<td>85886-10ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Succinic anhydride</td>
			<td>Traditional Chinese medicine</td>
			<td>30171826</td>
			<td></td>
		</tr>
		<tr>
			<td>Tetrahydrofuran</td>
			<td>Traditional Chinese medicine</td>
			<td>40058161</td>
			<td></td>
		</tr>
		<tr>
			<td>Triethylamine</td>
			<td>Traditional Chinese medicine</td>
			<td>80134318</td>
			<td></td>
		</tr>
		<tr>
			<td>UV/VIS/NIR Spectrometer</td>
			<td>Lambda950</td>
			<td>Lambda950</td>
			<td></td>
		</tr>
		<tr>
			<td>X-ray Photoelectron Spectrometer</td>
			<td>Thermo&#8194;Fisher&#8194;Scientific</td>
			<td>K-ALPHA 0.5EV</td>
			<td></td>
		</tr>
	</tbody>
</table>

synthesis of aptamer-pei-g-peg modified gold nanoparticles loaded with doxorubicin for targeted drug delivery

Due to drug resistance and toxicity in healthy cells, use of doxorubicin (DOX) has been limited in clinical cancer therapy. This protocol describes the designing of poly(ethylenimine) grafted with polyethylene glycol (PEI-g-PEG) copolymer functionalized gold nanoparticles (AuNPs) with loaded aptamer (AS1411) and DOX through amide reactions. AS1411 is specifically bonded with targeted nucleolin receptors on cancer cells so that DOX targets cancer cells instead of healthy cells. First, PEG is carboxylated, then grafted to branched PEI to obtain a PEI-g-PEG copolymer, which is confirmed by 1H NMR analysis. Next, PEI-g-PEG copolymer coated gold nanoparticles (PEI-g-PEG@AuNPs) are synthesized, and DOX and AS1411 are covalently bonded to AuNPs gradually via amide reactions. The diameter of the prepared AS1411-g-DOX-g-PEI-g-PEG@AuNPs is ~39.9 nm, with a zeta potential of -29.3 mV, indicating that the nanoparticles are stable in water and cell medium. Cell cytotoxicity assays show that the newly designed DOX loaded AuNPs are able to kill cancer cells (A549). This synthesis demonstrates the delicate arrangement of PEI-g-PEG copolymers, aptamers, and DOX on AuNPs that are achieved by sequential amide reactions. Such aptamer-PEI-g-PEG functionalized AuNPs provide a promising platform for targeted drug delivery in cancer therapy.

1H NMR spectroscopy was used to confirm the successful synthesis of CT-PEG polymer and PEI-g-PEG copolymers (Figure 2). Figure 2a shows that the methylene proton signal at &#948; = 3.61 ppm and carboxyl proton signal at &#948; = 2.57 ppm confirm the successful synthesis of CT-PEG polymers. Figure 2b shows that the methylene proton signal of PEG at &#948; = 2.6 ppm and proton signal of PEI at <em...

Watch this Scientific Journal Video about Synthesis of Aptamer-PEI-g-PEG Modified Gold Nanoparticles Loaded with Doxorubicin for Targeted Drug Delivery at JoVE.com

Synthesis of Aptamer-PEI-g-PEG Modified Gold Nanoparticles Loaded with Doxorubicin for Targeted Drug Delivery

In this protocol, doxorubicin-loaded AS1411-g-PEI-g-PEG modified gold nanoparticles are synthesized via three-step amide reactions. Then, doxorubicin is loaded and delivered to target cancer cells for cancer therapy.

Due to drug resistance and toxicity in healthy cells, use of doxorubicin (DOX) has been limited in clinical cancer therapy. This protocol describes the ...

synthesis-aptamer-pei-g-peg-modified-gold-nanoparticles-loaded-with

Research

JoVE Journal

Chemistry

5.8K Views.  Xinyang Normal University. In this protocol, doxorubicin-loaded AS1411-g-PEI-g-PEG modified gold nanoparticles are synthesized via three-step amide reactions. Then, doxorubicin is loaded and delivered to target cancer cells for cancer therapy.

Video: Synthesis of Aptamer-PEI-g-PEG Modified Gold Nanoparticles Loaded with Doxorubicin for Targeted Drug Delivery

Template Directed Synthesis of Plasmonic Gold Nanotubes with Tunable IR Absorbance

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) membranes have been under development since the 1990's and have become a common method to template the synthesis of high aspect ratio nanostructures, mostly by electrochemical growth or pore-wetting. Recently, these membranes have become commercially available in a wide range of pore sizes and densities, leading to an extensive library of functional nanostructures being synthesized from AAO membranes. These include composite nanorods, nanowires and nanotubes made of metals, inorganic materials or polymers 3-10. Nanoporous membranes have been used to synthesize nanoparticle and nanotube arrays that perform well as refractive index sensors, plasmonic biosensors, or surface enhanced Raman spectroscopy (SERS) substrates 11-16, as well as a wide range of other fields such as photo-thermal heating 17, permselective transport 18, 19, catalysis 20, microfluidics 21, and electrochemical sensing 22, 23. Here, we report a novel procedure to prepare gold nanotubes in AAO membranes. Hollow nanostructures have potential application in plasmonic and SERS sensing, and we anticipate these gold nanotubes will allow for high sensitivity and strong plasmon signals, arising from decreased material dampening 15.

Solution-suspendable gold nanotubes with controlled dimensions can be synthesized by electrochemical deposition in porous anodic aluminum oxide (AAO) membranes using a hydrophobic polymer core. Gold nanotubes and nanotube arrays hold promise for applications in plasmonic biosensing, surface-enhanced Raman spectroscopy, photo-thermal heating, ionic and molecular transport, microfluidics, catalysis and electrochemical sensing.

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) ...

Preparation and Characterization of SDF-1&#945;-Chitosan-Dextran Sulfate Nanoparticles

Chitosan (CS) and dextran sulfate (DS) are charged polysaccharides (glycans), which form polyelectrolyte complex-based nanoparticles when mixed under appropriate conditions. The glycan nanoparticles are useful carriers for protein factors, which facilitate the in vivo delivery of the proteins and sustain their retention in the targeted tissue. The glycan polyelectrolyte complexes are also ideal for protein delivery, as the incorporation is carried out in aqueous solution, which reduces the likelihood of inactivation of the proteins. Proteins with a heparin-binding site adhere to dextran sulfate readily, and are, in turn, stabilized by the binding. These particles are also less inflammatory and toxic when delivered in vivo. In the protocol described below, SDF-1&#945; (Stromal cell-derived factor-1&#945;), a stem cell homing factor, is first mixed and incubated with dextran sulfate. Chitosan is added to the mixture to form polyelectrolyte complexes, followed by zinc sulfate to stabilize the complexes with zinc bridges. The resultant SDF-1&#945;-DS-CS particles are measured for size (diameter) and surface charge (zeta potential). The amount of the incorporated SDF-1&#945; is determined, followed by measurements of its in vitro release rate and its chemotactic activity in a particle-bound form.

Preparation and Characterization of SDF-1&amp;#945;-Chitosan-Dextran Sulfate Nanoparticles

The objective of this protocol is to incorporate SDF-1&#945;, a stem cell homing factor, into dextran sulfate-chitosan nanoparticles. The resultant particles are measured for their size and zeta potential, as well as the content, activity, and in vitro release rate of SDF-1&#945; from the nanoparticles.

Chitosan (CS) and dextran sulfate (DS) are charged polysaccharides (glycans), which form polyelectrolyte complex-based nanoparticles when mixed under ...

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

Hydroquinone Based Synthesis of Gold Nanorods

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the synthetic methods for the preparation of gold nanorods are still not fully optimized. In this paper we describe a new, highly efficient, two-step protocol based on the use of hydroquinone as a mild reducing agent. Our approach allows the preparation of nanorods with a good control of size and aspect ratio (AR) simply by varying the amount of hexadecyl trimethylammonium bromide (CTAB) and silver ions (Ag+) present in the "growth solution". By using this method, it is possible to markedly reduce the amount of CTAB, an expensive and cytotoxic reagent, necessary to obtain the elongated shape. Gold nanorods with an aspect ratio of about 3 can be obtained in the presence of just 50 mM of CTAB (versus 100 mM used in the standard protocol based on the use of ascorbic acid), while shorter gold nanorods are obtained using a concentration as low as 10 mM.

This paper describes a protocol for the synthesis of gold nanorods, based on the use of hydroquinone as reducing agent, plus the different mechanisms for controlling their size and aspect ratio.

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the ...

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area

We demonstrate a method for the synthesis of NixNb1-xO catalysts with sponge-like and fold-like nanostructures. By varying the Nb:Ni ratio, a series of NixNb1-xO nanoparticles with different atomic compositions (x = 0.03, 0.08, 0.15, and 0.20) have been prepared by chemical precipitation. These NixNb1-xO catalysts are characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The study revealed the sponge-like and fold-like appearance of Ni0.97Nb0.03O and Ni0.92Nb0.08O on the NiO surface, and the larger surface area of these NixNb1-xO catalysts, compared with the bulk NiO. Maximum surface area of 173 m2/g can be obtained for Ni0.92Nb0.08O catalysts. In addition, the catalytic hydroconversion of lignin-derived compounds using the synthesized Ni0.92Nb0.08O catalysts have been investigated.

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area

A protocol for the synthesis of sponge-like and fold-like Ni1-xNbxO nanoparticles by chemical precipitation is presented.

We demonstrate a method for the synthesis of NixNb1-xO catalysts with sponge-like and fold-like nanostructures. By varying the Nb:Ni ratio, a series of ...

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity and convenient colorimetric readout. However, high densities of nanoparticles are typically needed for detection. The available synthesis-based enhancement protocols are either limited to gold and silver nanoparticles or rely on precise enzymatic control and optimization. Here, we present a protocol to enhance the colorimetric readout of gold, silver, silica, and iron oxide nanoprobes. It was observed that the colorimetric signal can be improved by up to a 10000-fold factor. The basis for such signal enhancement strategies is the chemical reduction of Au3+ to Au0. There are several chemical reactions that enable the reduction of Au3+ to Au0. In the protocol, Good&#39;s buffers and H2O2 are used and it is possible to favor the deposition of Au0 onto the surface of existing nanoprobes, in detriment of the formation of new gold nanoparticles. The protocol consists of the incubation of the microarray with a solution consisting of chloroauric acid and H2O2 in 2-(N-morpholino)ethanesulfonic acid pH 6 buffer following the nanoprobe-based detection assay. The enhancement solution can be applied to paper and glass-based sensors. Moreover, it can be used in commercially available immunoassays as demonstrated by the application of the method to a commercial allergen microarray. The signal development requires less than 5 min of incubation with the enhancement solution and the readout can be assessed by naked eye or low-end image acquisition devices such as a table-top scanner or a digital camera.

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

In this work, a protocol for signal enhancement of nanoprobe-based biosensing is presented. The protocol is based on the reduction of chloroauric acid onto the surface of existing nanoprobes that consist of gold, silver, silica or iron-oxide nanoparticles.

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity ...

Methionine Functionalized Biocompatible Block Copolymers for Targeted Plasmid DNA Delivery

Reversible addition-fragmentation chain transfer (RAFT) polymerization integrates the advantages of radical polymerization and living polymerization. This work presents the preparation of methionine functionalized biocompatible block copolymers via RAFT polymerization. Firstly, N,N-bis(2-hydroxyethyl)methacrylamide-b-N-(3-aminopropyl)methacrylamide (BNHEMA-b-APMA, BA) was synthesized via RAFT polymerization using 4,4&#8217;-azobis(4-cyanovaleric acid) (ACVA) as an initiating agent and 4-cyanopentanoic acid dithiobenzoate (CTP) as the chain transfer agent. Subsequently, N,N-bis(2-hydroxyethyl)methacrylamide-b-N-(3-guanidinopropyl)methacrylamide (methionine grafted BNHEMA-b-GPMA, mBG) was prepared by modifying amine groups in APMA with methionine and guanidine groups. Three kinds of block polymers, mBG1, mBG2, and mBG3, were synthesized for comparison. A ninhydrin reaction was used to quantify the APMA content; mBG1, mBG2, and mBG3 had 21%, 37%, and 52% of APMA, respectively. Gel permeation chromatography (GPC) results showed that BA copolymers possess molecular weights of 16,200 (BA1), 20,900(BA2), and 27,200(BA3) g/mol. The plasmid DNA (pDNA) complexing ability of the obtained block copolymer gene carriers was also investigated. The charge ratios (N/P) were 8, 16, and 4 when pDNA was complexed completely with mBG1, mBG2, mBG3, respectively. When the N/P ratio of mBG/pDNA polyplexes was higher than 1, the Zeta potential of mBG was positive. At an N/P ratio between 16 and 32, the average particle size of mBG/pDNA polyplexes was between 100-200 nm. Overall, this work illustrates a simple and convenient protocol for the block copolymer carrier synthesis.

This work presents the preparation of methionine functionalized biocompatible block copolymers (mBG) via the reversible addition-fragmentation chain transfer (RAFT) method. The plasmid DNA complexing ability of the obtained mBG and their transfection efficiency were also investigated. The RAFT method is very beneficial for polymerizing monomers containing special functional groups.

Reversible addition-fragmentation chain transfer (RAFT) polymerization integrates the advantages of radical polymerization and living polymerization. This ...

Synthesis and Characterization of Amphiphilic Gold Nanoparticles

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of their interactions with cell membranes, lipid bilayers, and viruses. The hydrophilic ligands make these particles colloidally stable in aqueous solutions and the combination with hydrophobic ligands creates an amphiphilic particle that can be loaded with hydrophobic drugs, fuse with the lipid membranes, and resist nonspecific protein adsorption. Many of these properties depend on nanoparticle size and the composition of the ligand shell. It is, therefore, crucial to have a reproducible synthetic method and reliable characterization techniques that allow the determination of nanoparticle properties and the ligand shell composition. Here, a one-phase chemical reduction, followed by a thorough purification to synthesize these nanoparticles with diameters below 5 nm, is presented. The ratio between the two ligands on the surface of the nanoparticle can be tuned through their stoichiometric ratio used during synthesis. We demonstrate how various routine techniques, such as transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and ultraviolet-visible (UV-Vis) spectrometry, are combined to comprehensively characterize the physicochemical parameters of the nanoparticles.

Amphiphilic gold nanoparticles can be used in many biological applications. A protocol to synthesize gold nanoparticles coated by a binary mixture of ligands and a detailed characterization of these particles is presented.

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of ...

Gold Nanoparticle Modified Carbon Fiber Microelectrodes for Enhanced Neurochemical Detection

For over 30 years, carbon-fiber microelectrodes (CFMEs) have been the standard for neurotransmitter detection. Generally, carbon fibers are aspirated into glass capillaries, pulled to a fine taper, and then sealed using an epoxy to create electrode materials that are used for fast scan cyclic voltammetry testing. The use of bare CFMEs has several limitations, though. First and foremost, the carbon fiber contains mostly basal plane carbon, which has a relatively low surface area and yields lower sensitivities than other nanomaterials. Furthermore, the graphitic carbon is limited by its temporal resolution, and its relatively low conductivity. Lastly, neurochemicals and macromolecules have been known to foul at the surface of carbon electrodes where they form non-conductive polymers that block further neurotransmitter adsorption. For this study, we modify CFMEs with gold nanoparticles to enhance neurochemical testing with fast scan cyclic voltammetry. Au3+ was electrodeposited or dipcoated from a colloidal solution onto the surface of CFMEs. Since gold is a stable and relatively inert metal, it is an ideal electrode material for analytical measurements of neurochemicals. Gold nanoparticle modified (AuNP-CFMEs) had a stability to dopamine response for over 4 h. Moreover, AuNP-CFMEs exhibit an increased sensitivity (higher peak oxidative current of the cyclic voltammograms) and faster electron transfer kinetics (lower &#916;EP or peak separation) than bare unmodified CFMEs. The development of AuNP-CFMEs provides the creation of novel electrochemical sensors for detecting fast changes in dopamine concentration and other neurochemicals at lower limits of detection. This work has vast applications for the enhancement of neurochemical measurements. The generation of gold nanoparticle modified CFMEs will be vitally important for the development of novel electrode sensors to detect neurotransmitters in vivo in rodent and other models to study neurochemical effects of drug abuse, depression, stroke, ischemia, and other behavioral and disease states.

In this study, we modify carbon-fiber microelectrodes with gold nanoparticles to enhance the sensitivity of neurotransmitter detection.

For over 30 years, carbon-fiber microelectrodes (CFMEs) have been the standard for neurotransmitter detection. Generally, carbon fibers are aspirated into ...

Gold Nanoparticle Synthesis

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of tetrachloroauric acid in 3.0 g (3.7 mmol, 3.6 mL) of oleylamine (technical grade) and 3.0 mL of toluene into a boiling solution of 5.1 g (6.4 mmol, 8.7 mL) of oleylamine in 147 mL of toluene. While boiling and mixing the reaction solution for 2 hours, the color of the reaction mixture changed from clear, to light yellow, to light pink, and then slowly to dark red. The heat was then turned off, and the solution was allowed to gradually cool down to room temperature for 1 hour. The gold nanoparticles were then collected and separated from the solution using a centrifuge and washed three times; by vortexing and dispersing the gold nanoparticles in 10 mL portions of toluene, and then precipitating the gold nanoparticles by adding 40 mL portions of methanol and spinning them in a centrifuge. The solution was then decanted to remove any remaining byproducts and unreacted starting materials. Drying the gold nanoparticles in a vacuum environment produced a solid black pellet; which could be stored for long periods of time (up to one year) for later use, and then redissolved in organic solvents such as toluene.

A protocol for synthesizing ~12 nm diameter gold nanoparticles (Au nanoparticles) in an organic solvent is presented. The gold nanoparticles are capped with oleylamine ligands to prevent agglomeration. The gold nanoparticles are soluble in organic solvents such as toluene.