{"id":231,"date":"2021-01-06T01:39:32","date_gmt":"2021-01-06T06:39:32","guid":{"rendered":"https:\/\/www.cd-bioparticles.com\/blog\/?p=231"},"modified":"2021-01-06T01:39:32","modified_gmt":"2021-01-06T06:39:32","slug":"what-role-does-gold-nanorod-play-in-cancer-treatment","status":"publish","type":"post","link":"https:\/\/www.cd-bioparticles.com\/blog\/nanoparticles\/what-role-does-gold-nanorod-play-in-cancer-treatment\/","title":{"rendered":"What Role Does Gold Nanorod Play in Cancer Treatment?"},"content":{"rendered":"\n

Gold nanorods\n(AuNRs) are gold nanoparticles with a specific morphology in the range of 1 to\n100 nm. They present two distinct SPRs on the transversal axis and the\nlongitudinal axis. Longitudinal plasmon resonance can provide absorption of\nwavelength radiation in the near-infrared region (NIR), which is very important\nin medical applications because the absorption rate of such radiation by living\ntissue is relatively small. This feature also distinguishes gold nanorods from\nspherical nanoparticles, making the former suitable for analysis, structural\nand medical research, and also suitable for metal sol dispersion research. Of\ncourse, SPR depends on physical properties such as the size, shape, and thermal\nstability of nanoparticles. Under the excitation of different laser radiation,\nthe thermal constant decreases significantly, and the particle size ratio\nincreases. The size adjustment can be done by increasing the longitudinal\ndiameter while the absorption spectrum of the NIR region will be enhanced as\nwell. In addition, gold nanorods are very sensitive to the dielectric constant\nof the surrounding environment, so they can be used as a colorimetric agent.<\/p>\n\n\n\n

Gold nanorods\nare often used in photothermal therapy due to their properties. Among them,\ncombination therapy is considered to be a promising strategy to improve the\nefficiency of tumor treatment. Therefore, Sim et al.<\/em> used pH-sensitive\npolymer, poly(aspartic acid-graft-imidazole)-PEG, to encapsulate gold nanorods\nand doxorubicin (DOX) to prepare an on-demand pH-sensitive nanocluster (NC)\nsystem to improve the efficacy of chemotherapy and photothermal therapy. The\nresults were published in Pharmaceutics<\/em><\/a>.\nThe following are some background introductions and experimental results.<\/p>\n\n\n\n

Chemotherapy is\na drug therapy that uses powerful chemicals to kill fast-growing cells in the\nbody. It is most commonly used to treat cancer because cancer cells grow and\nmultiply much faster than most cells in the body. There are many different\nchemotherapy drugs to choose from. Chemotherapy drugs can be used alone or in\ncombination to treat a variety of cancers.<\/p>\n\n\n\n

Although\nchemotherapy is an effective way to treat many types of cancer, chemotherapy\nalso carries the risk of side effects. Some chemotherapy has mild side effects\n(such as nausea, vomiting, diarrhea, hair loss, etc.) and can be treated, while\nothers may cause serious complications (such as lung tissue damage, heart\nproblems, infertility, etc.).<\/p>\n\n\n\n

Photothermal\ntherapy<\/p>\n\n\n\n

Compared\nwith ultraviolet light and visible light, near-infrared (NIR) light has photons\nwith longer wavelengths and less energy. This feature helps NIR light go deeper\ninto biological tissues, but if there is not enough energy, NIR photons cannot\nperform many photochemical reactions. Photosensitive nanomaterials can convert\nNIR light into heat, which can be applied to specific areas for hyperthermia.\nWhen nanomaterials are used as nanocarriers in drug delivery systems, the\nthermally activated nanostructure changes to release the drug. As photothermal\nagents, the heat produced by these nanomaterials can directly damage or ablate\ntumor cells. In order to design a qualified PTT system, the photothermal agent\nneeds to meet the conditions of absorption of NIR light, efficient conversion\nof light and heat, biocompatibility and biodegradability. Examples of these\nnanomaterials include AuNRs, carbon nanomaterials, and upconversion\nnanoparticles.<\/p>\n\n\n\n

Combination\ntherapies<\/p>\n\n\n\n

In\nrecent years, tumor-targeted combination therapy has received more and more\nattention from researchers, especially in the field of nanomedicine. The\ncombination of multiple therapies is more effective than monotherapy, because\nit produces a synergistic anti-cancer effect through different mechanisms,\nreduces drug-related toxicity, and inhibits multidrug resistance. Therefore,\nusing two methods or multiple comprehensive treatment methods or one method to\nassist another treatment method has become a new trend in cancer treatment. In\ncombination therapy, especially co-chemotherapy and phototherapy, both\nanticancer drugs and photosensitizers lack tumor selectivity, which increases\nthe potential toxicity to normal tissues. The use of nano-targeted delivery\nsystems to deliver photosensitizers and chemotherapeutic drugs can increase the\nconcentration of drugs at the target, significantly reduce side effects, and\nimprove the effects of phototherapy and chemotherapy.<\/p>\n\n\n\n

Their\nresults<\/p>\n\n\n\n

In\nSim’s research, AuNRs (RFA-10-808<\/a>,\nCD Bioparticles) and DOX were encapsulated by a pH-sensitive polymer\nPAIM-PEG, which improves the efficacy of chemotherapy and photothermal therapy\nthrough targeted tumor drug delivery and controlled drug release.<\/p>\n\n\n\n

Zeta potential measurement\nconfirmed the pH sensitivity of the NC systems (Figure 1). At pH7.4, the Zeta\npotentials of AuNR, NC1, NC2, and NC3 were approximately \u22120.8, \u22125.0, \u22124.7, and\n\u22125.6 mV, respectively. When the pH was further reduced to 6.5, the Zeta\npotentials of AuNR and NC systems increased to about +1.9, +1.3, +1.9, and +1.6\nmV, respectively.<\/li><\/ul>\n\n\n\n
$\"\"$
Figure 1. Zeta potential at pH 7.4 and 6.5 of AuNR and NC systems. <\/figcaption><\/figure><\/div>\n\n\n\n
The NC2, AuNR, and DOX in PBS\nwere irradiated with 808 nm laser with a power density of 2.0 W\/cm^{2<\/sup>\nfor 5 min, respectively. An infrared camera was used to record the temperature\nchange of the solution (Figure 2b). In order to study drug release, NC2 was\nexposed to different pH conditions (pH 7.4 and 6.5) (Figure 2c). At pH 7.4, the\nDOX release profile from the NC system similarly showed less than ca. 40%\nmaximum cumulative release over 24 h, while pH 6.5 caused a significant\nincrease in the DOX release of NC2.<\/li><\/ul>\n\n\n\n}
$\"\"$
Figure 2. (b) heat generation by NIR laser, and (c) DOX release at different pH conditions. <\/figcaption><\/figure><\/div>\n\n\n\n
The cell viabilities of NC2 were\nevaluated for the synergistic effect of DOX and AuNR. AuNR exhibits the\ntoxicity of the photothermal effect induced by 808 nm laser (Figure 3a), while\nDOX exhibits similar cytotoxicity regardless of light radiation. Flow cytometry\nwas used to detect the uptake of DOX by live KB cells under different pH\nconditions to evaluate its synergy. Treating KB cells with NC2 at pH 6.5, the\nfluorescence intensity was 1.24 times that at pH 7.4 (Figure 3b).\nLysoTracker\u00aeGreen DND-26 shows green fluorescence in the endosome and lysosome compartments\n(Figure 3c).<\/li><\/ul>\n\n\n\n
$\"\"$
Figure 3. In vitro<\/em> study of NC: (a) Cell viability of KB cells treated with PAIM-PEG, AuNR, DOX, and NC2 with or without a NIR laser; Nanocluster effect on cellular uptake of doxorubicin determined by (b) flow cytometry and (c) confocal microscope. <\/figcaption><\/figure><\/div>\n\n\n\n
High-resolution fluorescence\nimaging was used to study the tumor targeting of NC2 in tumor-bearing nude mice\n(Figure 4). The results showed that NC2 gradually accumulated in the tumor site\nafter 48h. Representative fluorescence images of various organs showed that NC2\nmainly accumulated in the tumor site and the kidney. These results were\nconsistent with the results of in vitro experiments, suggesting that NC2 can\ninhibit tumor growth in vivo and in vitro.<\/li><\/ul>\n\n\n\n
$\"\"$
Figure 4. Non-invasive in vivo fluorescent imaging of Cy5.5-tagged NC2 after intravenous injection into tail veins of single KB tumor-bearing nude mice. <\/figcaption><\/figure><\/div>\n\n\n\n
CD Bioparticles offers a wide range of Functional Gold Nanorods<\/a> with different active groups including carboxyl, amine, methyl, as well as NHS-activated gold nanorods. These particles are available in different aspect ratios and LSPR absorbance. The carboxyl and amine functional gold nanorods are suitable for covalent conjugation of antibodies, proteins, nucleic acids, and other ligands by using standard EDC\/NHS activation. We also provide NHS-activated gold nanorods to enables fast and convenient one-step conjugation of your desired antibody to gold nanorods by a simple mixing process. <\/p>\n\n\n\n
Reference:
Sim, T., Lim, C., Hoang, N. H., Shin, Y., Kim, J. C., Park, J. Y., … & Oh, K. T. (2020). An on-demand pH-sensitive nanocluster for cancer treatment by combining photothermal therapy and chemotherapy. Pharmaceutics<\/em>, 12(9), 839. <\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"
Gold nanorods (AuNRs) are gold nanoparticles with a specific morphology in the range of 1 to 100 nm. They present<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,2],"tags":[62,28],"class_list":["post-231","post","type-post","status-publish","format-standard","hentry","category-applications","category-nanoparticles","tag-cancer-treatment","tag-gold-nanorods"],"_links":{"self":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/231","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/comments?post=231"}],"version-history":[{"count":1,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/231\/revisions"}],"predecessor-version":[{"id":236,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/231\/revisions\/236"}],"wp:attachment":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/media?parent=231"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/categories?post=231"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/tags?post=231"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}