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Original Gold Nanoshell: The Advancing to Fight Against Cancer

Dron P. Modi *1 , Sunita Chaudhary 1, Ragin Shah 1 and Dhrubo Jyoti Sen 2

1Department of Pharmaceutics, Arihant School of Pharmacy & Bio Research Institute, Gujarat Technological University, Uvarsad Square, Sarkhej–Gandhinagar Highway, Post: Adalaj, Dist. Gandhinagar, Gujarat–382421, India 2Department of Pharmaceutical Chemistry, Shri Sarvajanik Pharmacy College, Gujarat Technological University, Arvind Baug, Mehsana– 384001, Gujarat, India

A R T I C L E I N F O A B S T R A C T Received 31 July 2013 Received in revised form 10 July 2013 Accepted 19 Aug 2013 It has been almost 40 years since the “cancer war” had been declared. It is now generally believed that personalized medicine Keywords : Nanoshell, is the future for cancer patient management. Gold , Anti–EGFR, nanospheres, nanorods, nanoshells will be discussed in detail Bio conjugation, OCT, regarding their uses in in–vitro assays, ex–vivo and in–vivo SERS Nanoparticles, imaging, cancer therapy and drug delivery. Multifunctionality is Tissue Welding the key feature of –based agents. Targeting ligands, imaging labels, therapeutic drugs, and other functionalities can all

be integrated to allow for targeted molecular imaging and

molecular therapy of cancer. Gold nanoshells, mainly composed of the silica and gold metal. The antibodies of Anti–Epidermal

Growth Factor Receptor is chief component of Gold Nanoshells therapy used to target the cancer cells and to “guide” the Gold

nanoshells to detect the cancer cells visually by microscope. The future looks brighter than every at many hurdles remain to be

conquered. A multifunctional platform based on gold 1 Corresponding author: Department of nanoparticles, with multiple receptor retargeting, multimodality Pharmaceutics, Arihant School of Pharmacy & Bio Research Institute, imaging and multiple therapeutic entities, holds the promise for a Gujarat Technological University, Uvarsad Square, Sarkhej–Gandhinagar “magic gold bullet” against cancer. In this review, we will Highway, Post: Adalaj, Dist. summarize the current state–of–the–art of gold nanoshells with Gandhinagar, Gujarat–382421, India E-mail address: mechanism in biomedical applications targeting cancer. [email protected] © 2013 British Biomedical Bulletin. All rights reserved

Modi et al______ISSN-2347-5447 Introduction There is a convenient and specific red colour which has been of considerable clinical need for novel methods for detection utility in consumer–related medical products, and treatment of cancer which offer such as home pregnancy tests. In contrast, the improved sensitivity, specificity and cost– optical response of gold nanoshells depends effectiveness. In recent years, a number of dramatically on the relative size of the groups have demonstrated that photonics– nanoparticle core and the thickness of the based technologies are valuable in gold shell. By varying the relative core and addressing this need. Optical technologies shell thicknesses, the colour of gold promise high resolution, non invasive nanoshells can be varied across a broad range functional imaging of tissue at competitive of the optical spectrum that spans the visible costs. However, in many cases, these and the near infrared spectral regions. technologies are limited by the inherently weak optical signals of endogenous Types of Gold Nano Particles chromophores and the subtle spectral There are many subtypes of gold differences of normal and diseased tissue. nanoparticles based on the size, shape and Over the past several years, there has been physical properties (Figure–2). The earliest increasing interest in combining emerging studied gold nanoparticles are gold optical technologies with the development nanospheres (although not exactly spherical of novel exogenous contrast agents, in a strict sense). Subsequently, nanorods, designed to probe the molecular specific nanoshells, and nanocages have all been signatures of cancer, to improve the reported. Another type of gold based detection limits and clinical effectiveness of nanoparticles, with excellent surface– optical imaging. Several scientists has been enhanced Raman scattering properties demonstrated the use and application of gold (termed “SERS nanoparticles”), will also be nanoshells. Recently, interest has developed discussed in this review. 3,4 In the following in the creation of nanotechnology–based text, the term “gold nanoparticle(s)” will refer platform technologies which couple to a collection of all these subtypes and the molecular specific early detection strategies subtype of gold nanoparticles used in each with appropriate therapeutic intervention study will be specified whenever possible. and monitoring capabilities. With continued development in the synthesis The discovery of the nanoshells was techniques over the last two decades, most of made by Professor Naomi J. Halas and her these gold nanoparticles can now be produced team at Rice University in 2003. In 2003 with well controlled size distribution, Halas was awarded for Best Discovery of sometimes with stunning precision (e.g., 2003 by Nanotechnology. nanocages).5

Composition of Gold Nanoshells Gold Nanoshells Metal nanoshells (Figure–1) area new Optical imaging, include those that type of nanoparticle composed of a dielectric uses gold nanoparticles as the contrast agents, core such as silica coated with an ultrathin has very limited applications in human metallic layer, which is typically gold. 1,2 Gold studies. However, in the near–infrared region nanoshells possess physical properties similar (NIR; 700–900 nm), the absorbance of all bio to gold colloid, in particular, a strong optical molecules reaches minimum which provides a absorption due to the collective electronic relatively clear window for optical imaging. 6 response of the metal to light. The optical By varying the composition and dimensions absorption of gold colloid yields a brilliant of the layers, gold nanoshells can be designed

BBB[1][1][2013]023-034 Modi et al______ISSN-2347-5447 and fabricated with surface II. Attach very small (1–2 nm) metal “seed” resonance (SPR) peaks ranging from the colloid to the surface of the nanoparticles via visible to the NIR region. 7 For a given molecular linkages; these seed colloids cover composition of gold nanoshell, the SPR peak the dielectric nanoparticle surfaces with a can be tuned by changing the ratio of the core discontinuous metal colloid layer, size to its shell thickness. III. Grow additional metal onto the “seed” Gold nanoshells with SPR peaks in metal colloid adsorbates via chemical the NIR region can be prepared by coating reduction in solution. silica or polymer beads with gold shells of This approach has been successfully used to variable thickness. 8,9 Silica cores are grown grow both gold and silver metallic shells onto using the Stöber process, the basic reduction silica nanoparticles. Various stages in the of tetraethyl orthosilicate in ethanol. To coat growth of a gold metallic shell onto a the silica nanoparticles with gold in an functionalized silica nanoparticle are shown aqueous environment, a seeded growth in Figure–5. technique is typically used. Small gold nanospheres (2–4 nm in diameter) can be Type–1. Synthesis of Gold nano Particles attached to the silica core using an amine– The original synthesis is a four–step terminated silane as a liner molecule, process in which first, mono dispersed silica allowing additional gold to be reduced until nanoparticles are grown using the Stober the seed particles coalesced into a complete method to produce the spherical dielectric shell. 10 The diameter of the gold nanoshell is cores. The Stober method produces spherical largely determined by the diameter of the silica particles by means of hydrolysis of silica core and the shell thickness can be alkyl silicates and subsequent condensation of controlled through the amount of gold silicic acid in alcoholic solution with an deposited on the surface of the core. ammonia catalyst. In the second step, the Gold nanoshells have also been surface of the silica nanoparticles is synthesized via in–situ gold nanoparticle functionalized by the adsorption of an formation using thermo sensitive core–shell organosilane (3–amino propyl particles as the template. 11,12 The use of triethoxysilane), with its amine tails microgel as the core offers significantly protruding from the surface. In the third step a reduced particle aggregation, as well as solution of gold colloid (1–2 nm in diameter) thickness control of the gold nanoshells using is added to the solution. The gold colloid is electro less gold plating. In one study, a virus produced separately from reduction of scaffold has been used to assemble gold HAuCl 4 by alkaline tetrakis nanoshells. 13 This approach may potentially (hydroxymethyl)–phosphonium chloride, provide cores with a narrower size according to the method of Duff. 15 The gold distribution and smaller diameters (80 nm) particles bond to the organosilane linker via than those of silica. (Figure–3 & 4). the amine group, producing silica nanoparticles with a smattered, uneven gold Synthesis and Bioconjugation coating. 16 A final reduction process is used to The synthetic protocol developed for produce silica nanoparticles with a uniform the fabrication of gold nanoshells is very layer of gold that is, a gold nanoshells. In the simple in concept: 14 reduction process, the 'seeded' gold particles I. Grow or obtain silica nanoparticles which are covalently bonded to the silica core dispersed in solution, serve as nucleation sites where an aged mixture of chloroauric acid and potassium

BBB[1][1][2013]023-034 Modi et al______ISSN-2347-5447 carbonate is reduced in solution in the Human epidermal growth factor presence of sodium borohydride. This process receptor 2 (HER2) is a frequently used breast forms a highly crystallized gold shell through cancer biomarker, and Loo et al. have Oswald ripening. 17 Transmission electron successfully bio conjugated gold nanoshells microscopy (TEM) images of the nanoshells with HER2 antibodies to target human during different phases of growth are shown mammary adeno carcinoma cells in– in Figure–6. 18 vitro .19,20,24 In the synthesis, orthopyridyl– disulfide–n–hydroxysuccinimide–PEG Type–2: Bioconjugation: Smarter polymer (OPSS) is used to tether the Nanoshells antibodies on the surface after which, using The biologically inert gold surface of NaHCO 3 (100 mm, pH 8.5), the OPSS is nanoshells facilitates bio conjugation with resuspended in a volume equal to that of the antibodies and other biomarkers, rendering HER2 antibodies. The reaction bonding nanoshells capable of selectively binding to OPSS to anti–HER2 proceeds on ice for about in–vivo targets. 19–21 The following examples 12 h, after which any excess OPSS is of successful bioconjugation schemes should removed via membrane dialysis. The provide a general idea of the chemistry antibody complex (0.67 mg/ml) is then involved in the production of bio conjugated allowed to interact with added gold nanoparticles. nanoshells for 1 h and any unbound antibody Sokolov et al . have synthesized is then removed by centrifugation. The bioconjugates of gold nanospheres with functionalized gold nanoshells pellet is then monoclonal antibodies against epidermal re–suspended in potassium carbonate solution growth factor receptor (EGFR), a (2 mm). Following antibody conjugation, the transmembrane glycoprotein (Mr 170000) nano shell surfaces are further modified with which is over expressed in cancers originating PEG–thiol to prevent any nonspecific from epithelial cells. 20 Colloidal gold of adsorption and improve biocompatibility. various sizes is prepared using a citrate reduction of HAuCl 4. Materials and Methods Used in To prepare the bioconjugates, the gold Preparation of Gold Nanoshells colloid is diluted with 20mm HEPES buffer and anti–EGFR monoclonal antibodies are 1. Gold Nanoshell Fabrication reconstituted in the same buffer at 100g/ml Cores of silica nanoparticles are and mixed at a 1:1 volume ratio and allowed fabricated as described by Stober et al. in to interact for 20 min at room temperature. In which tetraethyl orthosilicate is reduced in this environment, gold Nano spheres bind NH 4OH in ethanol particles are sized with a noncovalently with anti–EGFR antibodies at scanning electron microscope. 14,22 their isoelectric point to form stable bio Polydispersity of <10% is considered conjugates. Polyethylene glycol (PEG) is acceptable. Next, the silica surface is added to the solution up to a final aminated by reaction with concentration of 0.2mg/ml, after which the aminopropyltriethoxysilane in ethanol. Gold solution is centrifuged to remove any shells are grown using the method of Duff et unbound antibody. After a second wash, the al. 15,23 Briefly, small gold colloid (1–3nm) anti–EGFR gold nanoparticle pellet is re- was adsorbed onto the aminated silica suspended in phosphate–buffered saline nanoparticle surface. More gold is then (PBS). reduced onto these colloid nucleation sites using potassium carbonate and HAuCl 4 in the

BBB[1][1][2013]023-034 Modi et al______ISSN-2347-5447 presence of formaldehyde. Gold nanoshell presence of gold on cell surfaces, is used to formation and dimensions are assessed with a assess cellular nanoshell binding. Cells UV–VIS spectrophotometer and scanning incubated with targeted nanoshells are fixed electron microscopy (SEM). with 2.5% glutaraldehyde, and exposed to silver stain for 15 minutes. Silver growth is 2. Antibody Conjugation monitored under phase–contrast, with further Ortho–pyridyl–disulfide–n–hydroxyl silver enhancement blocked by immersion in succinimide polyethylene glycol polymer 2.5% sodium thiosulfate. (OPSS–PEG–NHS, MW=2000) is used to tether antibodies onto the surfaces of gold 5. Optical Coherence Tomography (OCT ) nanoshells. Using NaHCO 3 (100mM, pH 8.5) Optical coherent tomography (OCT) OPSS–PEG– NHS is re–suspended to a is a state–of–the–art imaging technique which volume equal to that of either HER 2 (specific) produces high resolution (typically 10–15 or IgG (non–specific) antibodies. At this µm), real–time, cross–sectional images concentration, the concentration of polymer is through biological tissues. The method is in molar excess to the amount of HER2 or often described as an optical analog to IgG antibody used. The reaction is allowed to ultrasound. OCT detects the reflections of a proceed on ice overnight. Unbound antibody low coherence light source directed into a is removed by centrifugation at 650 G, tissue and determines at what depth the supernatant removal and resuspension in reflections occurred. By employing a potassium carbonate (2mM). Following heterodyne optical detection scheme, OCT is antibody conjugation, nanoshells surfaces able to detect very faint reflections relative to were further modified with PEG–thiol the incident power delivered to the tissue. In (MW=5000, 1µM) to block non–specific OCT imaging out of focus light is strongly adsorption sites and to enhance rejected due to the coherence grating inherent biocompatibility. 24 to the approach. This permits deeper imaging using OCT than is possible using alternative 3. Cell Culture methods such as reflectance confocal HER2–positive SKBr 3 human microscopy where the out of focus rejection mammary adenocarcinoma cells are cultured achievable is far lower. Each image required in McCoy’s 5A modified medium approximately 20 seconds to acquire. System supplemented with 10% FBS and antibiotics. parameters remained the same throughout the 25 Cells were maintained at 37ºC and 5% CO 2. experiment.

4. Molecular Imaging, Cytotoxicity and Silver 6. In–vitro Photo Thermal Nano Shell Staining Therapy SKBR 3 cells are exposed to 8µg/mL The SKBr 3 breast cancer cells were of bio conjugated nanoshells for 1 hr, washed cultured in 24–well plates until fully with phosphate–buffered saline and observed confluent. Cells were then divided into two under darkfield microscopy, a form of treatment groups: nanoshells + NIR–laser and microscopy sensitive only to scattered light. NIR–laser alone. Cells exposed to nanoshells The calcein–AM live stain (Molecular alone or cells receiving neither nanoshells nor Probes, 1 µM) is used to assess cell viability laser were used as controls. Nanoshells were after nanoshell targeting. A silver prepared in FBS–free medium (2×10 9 enhancement stain (Amersham Pharmacia), a Nanoshells/mL). Cells were then irradiated qualitative stain capable of detecting the under a laser emitting light at 820 nm at a

BBB[1][1][2013]023-034 Modi et al______ISSN-2347-5447 power density of ~35W/cm 2 for 7 minutes no any antibodies of EGFR nor gold shells. with or without Nanoshells. After NIR–light So, it is safe. (Figure–10) exposure, cells were replenished with FBS– containing media and were incubated for an Other Useful Applications of Gold additional hour at 37ºC. Cells were then Nanoparticles exposed to the calcein–AM live stain for 45 Due to their unique physical minutes in order to measure cell viability. The characteristics and benign toxicity profile, calcein dye causes viable cells to fluoresce gold nanoshells have been at the forefront of a green. Fluorescence was visualized with a growing number of biomedical applications. Zeiss Axiovert 135 fluorescence microscope They have shown potential as integrated equipped with a filter set specific for cancer targeting, imaging and therapy agents. excitation and emission wavelengths at 480 As contrast agents, nanoshell bioconjugates and 535 nm, respectively. Membrane damage have been used to detect and image individual was assessed using an aldehyde–fixable cancer cells in–vitro and in solid tumours in– fluorescein dextran dye. Cells were incubated vivo . As Photo thermal agents, nanoshells for 30 min with the fluorescent dextran, have successfully been used in animal studies rinsed and immediately fixed with 5% to induce thermal necrosis of tumors. On the glutaraldehyde. Photothermal destruction of laboratory bench, they have been used to cells was attributed to hyperthermia induced potentiate thermal drug delivery in via Nanoshell absorption of NIR light. 26 temperature–sensitive hydrogels. Outside the realm of cancer treatment, nanoshells have Mechanism of Gold Nanoshells on Cancer proven their worth in a number of novel Cells applications; for example, as biosensors they have been used for the sensitive detection of STEP 1: Gold nanoshells and Antibodies of biomarkers at the ng ml –l level. EGFR (Epidermal Growth Factor Receptor) solution treated with IR Radiation. So, 1. Cell and Phantom Imaging: Now a days, antibodies of EGFR joined with gold the most imaging studies using gold nanoshells with the help of amine group. nanoparticles were carried out in cell culture. Here, amine group works as a catalyst. The versatile optical properties of gold (Figure–7) nanoparticles have enabled optical imaging of STEP 2: Now, antibodies of EGFR are the cells and phantoms with a wide variety of keys to unlock the cancer cells for target. So it contrast mechanisms. Functional cellular matches with cancer cells’ specific receptor imaging around single molecules has been sites. (Figure–8) reported, taking advantage of the enhanced STEP 3: Then, nanoshells are already in IR second harmonic signal by antibody region, heated up. At that time pass laser light conjugated gold nanospheres. 27 Subsequently, for specific time. (It depends on size of cancer many other studies have been reported which tumour) which melts the gold nanoshells employed Photo thermal interference which are already present around cancer contrast. 28 tumour. (Figure–9) STEP 4: It is the final process, in which laser 2. In–vitro cancer detection and Imaging: light melts all gold nanoshells, it burns the all Detecting cancer in its earliest stages is targeted cancer cells by the heat and it doesn’t strongly associated with positive patient affect on normal body cells because there are outcomes, including reduced morbidity and improved five–year survival rates. 29 As many

BBB[1][1][2013]023-034 Modi et al______ISSN-2347-5447 cancers originate from a small number of Notably, the healing results were similar to malignant epithelial cells, the ability to detect the suture treat control group until day 5, after low numbers of malignant or precancerous which healing was shown to be better in the epithelial cells. 30 In–vivo would represent a suture group. giant leap forward in the fight against cancer. Notably, it would facilitate the detection of 5. Biosensors: Nanoshells have several cancer in its earliest stages, before any unique properties that are ideal for biosensing significant pathogenesis, tumour formation applications. The position of the plasmon and metastasis. resonance peak and absorbance depended heavily on the refractive index (dielectric 3. Cancer Therapy: Conventional strategies constant) of the surrounding medium. for cancer intervention include surgery, chemotherapy, and radiation therapy. Taking 6. Drug Delivery: Several studies have advantage of their unique properties, most reported the use of gold nanoparticle as drug studies of gold nanoparticle–based cancer delivery vehicles. Tumour necrosis factor– therapy have used photothermal therapy for alpha (TNF–α), a cytokine with excellent the destruction of cancer cells or tumour anticancer efficacy, is systemically toxic tissue, which may be potentially useful in the which severely limited its therapeutic clinical setting. When irradiated with focused applications. 35,36 A nanoparticle delivery laser pulses of suitable wavelength, targeted system, consisting of PEG coated gold gold nanospheres, nanorods, nanoshells and nanoparticle loaded with TNF–α, was nanocages can kill bacteria and cancer constructed to maximize the tumour damage cells. 31–33 It was estimated that 70–80°C was and minimize the systemic toxicity of TNF– achieved through light absorption by the gold α.37 Combination of local heating and nanoparticles and up to 150 antibodies can be nanoparticle–based delivery of TNF–α conjugated to a nanoshell through a resulted in enhanced therapeutic efficacy than bifunctional PEG linker. 32,33 One intriguing either treatment alone. Thermally induced observation is that most of these studies tumour growth delay was enhanced by pre– targeted either EGFR or human epidermal treatment with the nanoparticle, when given growth factor receptor 2 (HER2), obviously intravenously at the proper dosage and due to the ready availability of monoclonal timing. Tumor blood flow suppression, as antibodies (already approved by the Food and well as tumour perfusion defects, suggested Drug Administration [FDA] for cancer vascular damage mediated tumour cell killing. therapy) that recognize these two proteins. Surprisingly, following intravenous administration, little to no accumulation in the 4. Tissue Welding: Nanoshells may represent RES (eg. liver and spleen) or other healthy a rapid means of treating lacerations in an organs of the animals was observed. 37 emergency room setting. As an example, Gobin et al . have used nanoshells as an Conclusion exogenous NIR absorber for welding deep tissue wounds. 32,34 In this study, a nanoshell Because of their unique features and based solder (nanoshells+bovine serum vast potential for a variety of biomedical albumin (BSA) was applied to full thickness applications, gold nanoshells and other gold incisions made on rats, after which the nanoparticles represent a major achievement incisions were irradiated with NIR laser light in nanotechnology. The synergy of ideal for several minutes to initiate tissue welding. chemical, physical and optical properties in a

BBB[1][1][2013]023-034 Modi et al______ISSN-2347-5447 single particle is a resounding affirmation of scattering. J Am Chem Soc. 2008; 130: the promise of nanotechnology in general. 2780–2782. Gold nanoshells have opened new 6. Frangioni JV. 2003. In–vivo near–infrared frontiers in medicine. Because they are fluorescence imaging. Curr Opin Chem Biol. biocompatible, optically tunable, strongly 2003; 7: 626–634. 7. Oldenburg SJ, Westcott SL, Averitt RD, et photo luminescent and bind to antibodies, al . Surface enhanced Raman scattering in nanoshells are highly suitable for in-vivo the near infrared using metal nanoshell imaging studies. Likewise, because they substrates . J Chem Phys. 1999; 111: 4729– accumulate within tumors due to passive and 4735. active mechanisms, they hold great promise 8. Caruso F, Spasova M, Salgueirino–Maceira for revolutionizing cancer detection. Their V, et al . 2001. Multilayer assemblies of success in multiple animal studies has silica–encapsulated gold nanoparticles on confirmed a great potential as agents for decomposable colloid templates. Adv Mater. photothermal cancer therapy, with the added 2001; 13: 1090–1094. benefit of serving as contrast agents for 9. Oldenburg SJ, Averitt RD, Westcott SL, et cancer detection. Clinical trials, which are al . Nanoengineering of optical resonances. Chem Phys Lett. 1998; 288: 243–247. currently under way, will most likely establish 10. Suzuki D, Kawaguchi H. Gold nanoparticle their efficacy for the treatment of human localization at the core surface by using forms of cancer. thermosensitive core–shell particles as a In this way, the title would be perfect template. Langmuir. 2005; 21: 12016– for gold nanoshells as it’s work like a soldier 12024. against cancer tumour cells. All other 11. Kawasaki ES, Player A. Nanotechnology, treatments also can be provided for that. , and the development of new, Other vast applications in nanotechnology, effective therapies for cancer. gold nanoshells would definitely new era for Nanomedicine. 2005;1: 101–109. the treatment against non–curable diseases. 12. Radloff C, Vaia RA, Brunton J, et al . 2005. Metal nanoshell assembly on a virus bioscaffold. Nano Lett. 2005; 5: 1187–1191. References 13. Averitt RD, Sarkar D and Halas NJ. Plasmon Resonance Shifts of Au–coated 1. Brongersma ML. Nanoshells: Gifts in a Au2S Nanoshells: Insights into Gold Wrapper. Nature Materials. 2003; 2: Multicomponent nanoparticles Growth. Phys 296–297. Rev Letters. 1997; 78: 4217–4220. 2. Oldenburg SJ, Averitt RD, Westcott, SL, 14. Stober W, Fink A and Bohn E. Controlled and Halas NJ.Nanoengineering of Optical growth of monodisperse silica spheres in the Resonances.Chemical Physics Letters.1988; micron size range. Journal of Colloid and 288: 243–247. Interface Science.1968; 26: 62–69. 3. O’Neal DP, Hirsch LR, Halas NJ, et al . 15. Duff DG, Baiker A and Edwards PP.A new Photo–thermal tumour abla– tion in mice hydrosol of gold clusters.Formation and using near infrared absorbing nanoparticles. particle size variation. Langmuir. 1993; 9: Cancer Lett. 2004; 209: 171–176. 2301–2309. 4. Mieszawska AJ, Zamborini FP. Gold 16. Leff DV, Brandt L and Heath JR. (1996) nanorods grown directly on surfaces from Synthesis and characterization of microscale patterns of gold seeds. Chem hydrophobic, organically–soluble gold Mater. 2005; 17: 3415–3420. nanocrystals functionalized with primary 5. Liu X, Dai Q, Austin L, et al. A one–step amines.Langmuir. 1996; 12: 4723–30. homogeneous immunoassay for cancer 17. Roosen Roosen AR and Carter WC. biomarker detection using gold nanoparticle Simulations of microstructural evolution: probes coupled with dynamic light

BBB[1][1][2013]023-034 Modi et al______ISSN-2347-5447

anisotropic growth and coarsening . Physica 27. Cognet L, Tardin C, Boyer D, et al. Single A. 1998; 261: 232–247. metallic nanoparticle imaging for protein 18. Tang L, Liu L and Elwing HB. Complement detection in cells. Proc Natl Acad Sci USA. activation andinflammation triggered by 2003; 100: 11350–11355. model biomaterial surfaces. Journal of 28. Etzioni R, Urban N, Ramsey S, McIntosh Biomedical Materials Research.1998; 41: M, Schwartz S, Reid B, Radich J, Anderson 333–340. G and Hartwell L.The case for early 19. Loo C, Hirsch L, Lee MH, Chang E, West detection. Nature Reviews Cancer. 2003; 3: J, Halas N and Drezek R. Gold nanoshell 243–252. bioconjugates for molecular imaging in 29. Aaron J, Nitin N, Travis K, Kumar S, living cells. Optics Letters. 2005; 30: 1012– Collier T, Park SY, Jose–Yacaman M, 1014. Coghlan L, Follen M and Richards–Kortum 20. Sokolov K, Follen M, Aaron J, Pavlova I, R. Plasmon resonance coupling of metal Malpica A, Lotan R and Richards–Kortum nanoparticles for molecular imaging of R. Real–time vital optical imaging of carcinogenesis in–vivo . Journal of precancer using anti–epidermal growth Biomedical Optics. 2007; 12: 034007. factor receptor antibodies conjugated to gold 30. Huang X, El–Sayed IH, Qian W, et al . nanoparticles. Cancer Research.2003; 63: Cancer cells assemble and align gold 1999–2004. nanorods conjugated to antibodies to 21. Eggeling C, Widengren J, Rigler R and produce highly enhanced, sharp and Seidel CAM. Photobleaching of fluorescent polarized surface Raman spectra: a potential dyes under conditions used for single– cancer diagnostic marker. Nano Lett. 2007; molecule detection: evidence of two–step 7: 1591–1597. photolysis. Analytical Chemistry. 1998; 70: 31. Cang H, Sun T, Li ZY, et al . Gold 2651–2659. nanocages as contrast agents for 22. Vial A, Grimault AS, Macias D, Barchiesi D spectroscopic optical coherence and de la Chapelle ML. Improved analytical tomography . Opt Lett. 2005; 30: 3048–3050. fit of gold dispersion: application to the 32. Hirsch LR, Jackson JB, Lee A, et al . A modeling of extinction spectra with a finite- whole blood immunoassay using gold difference time–domain method. Physical nanoshells. Anal Chem. 2003; 75: 2377– Review B. 2005; 71, 85416. 2381. 23. Loo C, Hirsch L, Lee MH, et al . Gold 33. Gobin AM, O'Neal DP, Halas NJ, Drezek R nanoshell bioconjugates for molecular and West JL.Near infrared laser tissue imaging in living cells. OptLett. 2005; 30: welding using nanoshells as an exogenous 1012–1014. absorber. Lasers in Surgery and 24. Barton J, Romanowski M, Halas N and Medicine.2005; 37: 123–129. Drezek R. Nanoshells as an OCT Contrast 34. Wang J, Zhu X, Tu Q, et al . Capture of p53 Agent. Proceedings of SPIE. 2004; 5316. In by electrodes modified with consensus DNA press . duplexes and amplified voltammetric 25. Hirsch LR, Stafford RJ, Bankson JA, detection using ferrocene–capped gold Sershen SR, Rivera B, Price RE, Hazle JD, nanoparticle/streptavidin conjugates. Anal Halas NJ, and West JL. Nanoshell–mediated Chem. 2008; 80: 769–774. Near–infrared Thermal Therapy of Tumors 35. Mocellin S, Nitti D. TNF and cancer: the Under Magnetic Resonance Guidance. Proc two sides of the coin. Front Biosci. 2008; Natl Acad Sci USA. 2003; 100: 13549– 13: 2774–2783. 13554. 36. Nitin N, Javier DJ, Richards–Kortum R. 26. Peleg G, Lewis A, Linial M, et al . 1999. Oligonucleotide–coated metallic Nonlinear optical measurement of nanoparticles as a flexible platform for membrane potential around single molecules molecular imaging agents . Bioconjug Chem. at selected cellular sites. Proc Natl Acad Sci 2007; 18: 2090–2096. USA. 1999; 96: 6700–6704.

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37. Visaria RK, Griffin RJ, Williams BW, et al . tumour necrosis factor– alpha delivery. 2006. Enhancement of tumour thermal Mol Cancer Ther. 2006; 5: 1014–1020. therapy using gold nanoparticle–assisted

Figure.1 . Visual Demonstration of Turbidity of Gold nanoshells

Figure.2. Different types of Gold Nanoparticles

Figure.3 & 4 . Preparation of Gold Nanoshells

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Figure.5 . Electron microscopic images of gold/silica nanoshells during cell growth

Figure.6. Synthesis of Gold Nanoshells

Figure.7 . Nanoshells treated with IR

Figure.8. Antibody ligands attached at cancer cells specific site

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Figure.9 . Laser light applied on target cancer cells

Figure.10 . With application of Laser light, target cancer cells burn out with the help of Anti–EGFR Solution

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