15 results on '"Raj Kumar Dani"'
Search Results
2. Pulsed Magnetic Field Induced Fast Drug Release from Magneto Liposomes via Ultrasound Generation
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Viktor Chikan, Shenqiang Ren, Saralyn Ogden, Hongwang Wang, Raj Kumar Dani, Tej B. Shrestha, Punit Prakash, Amanda F. Baxter, Matthew T. Basel, George Podaru, Stefan H. Bossmann, and Prem S. Thapa
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Liposome ,Materials science ,Nanotechnology ,Fluoresceins ,Fluorescence ,Surfaces, Coatings and Films ,Magnetic field ,Drug Liberation ,Magnesium Sulfate ,Drug Delivery Systems ,Magnetic Fields ,Sound ,Pharmacokinetics ,Liposomes ,Drug delivery ,Materials Chemistry ,Biophysics ,Magnetic nanoparticles ,Ultrasonics ,Physical and Theoretical Chemistry ,Magnetite Nanoparticles ,Lipid bilayer ,Magneto ,Fluorescent Dyes - Abstract
Fast drug delivery is very important to utilize drug molecules that are short-lived under physiological conditions. Techniques that can release model molecules under physiological conditions could play an important role to discover the pharmacokinetics of short-lived substances in the body. Here an experimental method is developed for the fast release of the liposomes' payload without a significant increase in (local) temperatures. This goal is achieved by using short magnetic pulses to disrupt the lipid bilayer of liposomes loaded with magnetic nanoparticles. The drug release has been tested by two independent assays. The first assay relies on the AC impedance measurements of MgSO4 released from the magnetic liposomes. The second standard release assay is based on the increase of the fluorescence signal from 5(6)-carboxyfluorescein dye when the dye is released from the magneto liposomes. The efficiency of drug release ranges from a few percent to up to 40% in the case of the MgSO4. The experiments also indicate that the magnetic nanoparticles generate ultrasound, which is assumed to have a role in the release of the model drugs from the magneto liposomes.
- Published
- 2014
3. Magnetic-Fe/Fe3O4-nanoparticle-bound SN38 as carboxylesterase-cleavable prodrug for the delivery to tumors within monocytes/macrophages
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Sivasai Balivada, Ping Li, Tej B. Shrestha, Olga Koper, Gwi-Moon Seo, Prem S. Thapa, Raj Kumar Dani, Matthew T. Basel, Viktor Chikan, Marla Pyle, Deryl L. Troyer, Heidy Prock, Stefan H. Bossmann, David S. Moore, and Hongwang Wang
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General Physics and Astronomy ,Pharmacology ,magnetic Fe/Fe3O4 nanoparticles ,lcsh:Chemical technology ,lcsh:Technology ,Full Research Paper ,Carboxylesterase ,Immune system ,medicine ,Nanotechnology ,General Materials Science ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,lcsh:Science ,cell-based delivery ,biology ,Chemistry ,lcsh:T ,Topoisomerase ,Cancer ,Prodrug ,medicine.disease ,lcsh:QC1-999 ,Nanoscience ,SN38 ,Magnetic hyperthermia ,Cancer cell ,Biophysics ,biology.protein ,Magnetic nanoparticles ,lcsh:Q ,lcsh:Physics ,chemotherapeutic prodrug - Abstract
The targeted delivery of therapeutics to the tumor site is highly desirable in cancer treatment, because it is capable of minimizing collateral damage. Herein, we report the synthesis of a nanoplatform, which is composed of a 15 ± 1 nm diameter core/shell Fe/Fe3O4 magnetic nanoparticles (MNPs) and the topoisomerase I blocker SN38 bound to the surface of the MNPs via a carboxylesterase cleavable linker. This nanoplatform demonstrated high heating ability (SAR = 522 ± 40 W/g) in an AC-magnetic field. For the purpose of targeted delivery, this nanoplatform was loaded into tumor-homing double-stable RAW264.7 cells (mouse monocyte/macrophage-like cells (Mo/Ma)), which have been engineered to express intracellular carboxylesterase (InCE) upon addition of doxycycline by a Tet-On Advanced system. The nanoplatform was taken up efficiently by these tumor-homing cells. They showed low toxicity even at high nanoplatform concentration. SN38 was released successfully by switching on the Tet-On Advanced system. We have demonstrated that this nanoplatform can be potentially used for thermochemotherapy. We will be able to achieve the following goals: (1) Specifically deliver the SN38 prodrug and magnetic nanoparticles to the cancer site as the payload of tumor-homing double-stable RAW264.7 cells; (2) Release of chemotherapeutic SN38 at the cancer site by means of the self-containing Tet-On Advanced system; (3) Provide localized magnetic hyperthermia to enhance the cancer treatment, both by killing cancer cells through magnetic heating and by activating the immune system.
- Published
- 2012
4. Cell-delivered magnetic nanoparticles caused hyperthermia-mediated increased survival in a murine pancreatic cancer model
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Gayani Abayaweera, Viktor Chikan, Raj Kumar Dani, Olga Koper, Marla Pyle, Gwi-Moon Seo, Hongwang Wang, Sivasai Balivada, Matthew T. Basel, Deryl L. Troyer, Stefan H. Bossmann, Tej B. Shrestha, and Masaaki Tamura
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Pathology ,medicine.medical_treatment ,Cell ,pancreatic cancer ,Pharmaceutical Science ,Transplants ,02 engineering and technology ,Ferric Compounds ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,International Journal of Nanomedicine ,Drug Discovery ,Original Research ,General Medicine ,021001 nanoscience & nanotechnology ,3. Good health ,Survival Rate ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,disseminated peritoneal carcinomatosis ,0210 nano-technology ,Iron oxide nanoparticles ,Hyperthermia ,medicine.medical_specialty ,Materials science ,Intraperitoneal injection ,Biophysics ,Bioengineering ,Biomaterials ,03 medical and health sciences ,Magnetics ,targeted magnetic hyperthermia ,Pancreatic cancer ,medicine ,Animals ,Monocyte ,Macrophages ,Organic Chemistry ,Cancer ,Hyperthermia, Induced ,medicine.disease ,Pancreatic Neoplasms ,Disease Models, Animal ,Magnetic Fields ,chemistry ,Cancer research ,Magnetic nanoparticles ,Nanoparticles ,cytotherapy - Abstract
Matthew T Basel1, Sivasai Balivada1, Hongwang Wang2, Tej B Shrestha1, Gwi Moon Seo1, Marla Pyle1, Gayani Abayaweera2, Raj Dani2, Olga B Koper2, Masaaki Tamura1, Viktor Chikan2, Stefan H Bossmann2, Deryl L Troyer11Department of Anatomy and Physiology, College of Veterinary Medicine, 2Department of Chemistry, Kansas State University, Manhattan, KS, USAAbstract: Using magnetic nanoparticles to absorb alternating magnetic field energy as a method of generating localized hyperthermia has been shown to be a potential cancer treatment. This report demonstrates a system that uses tumor homing cells to actively carry iron/iron oxide nanoparticles into tumor tissue for alternating magnetic field treatment. Paramagnetic iron/iron oxide nanoparticles were synthesized and loaded into RAW264.7 cells (mouse monocyte/macrophage-like cells), which have been shown to be tumor homing cells. A murine model of disseminated peritoneal pancreatic cancer was then generated by intraperitoneal injection of Pan02 cells. After tumor development, monocyte/macrophage-like cells loaded with iron/iron oxide nanoparticles were injected intraperitoneally and allowed to migrate into the tumor. Three days after injection, mice were exposed to an alternating magnetic field for 20 minutes to cause the cell-delivered nanoparticles to generate heat. This treatment regimen was repeated three times. A survival study demonstrated that this system can significantly increase survival in a murine pancreatic cancer model, with an average post-tumor insertion life expectancy increase of 31%. This system has the potential to become a useful method for specifically and actively delivering nanoparticles for local hyperthermia treatment of cancer.Keywords: cytotherapy, pancreatic cancer, disseminated peritoneal carcinomatosis, targeted magnetic hyperthermia, nanoparticles
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- 2012
5. Attenuation of Mouse Melanoma by A/C Magnetic Field after Delivery of Bi-Magnetic Nanoparticles by Neural Progenitor Cells
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Stefan H. Bossmann, Carl B. Myers, Xiaoxuan Leaym, Raja Shekar Rachakatla, Masaaki Tamura, Thilani N. Samarakoon, Hongwang Wang, Viktor Chikan, Sivasai Balivada, Franklin Orban Kroh, Gwi-Moon Seo, Olga Koper, Marla Pyle, Deryl L. Troyer, Brandon Walker, and Raj Kumar Dani
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Proteomics ,Materials science ,Iron ,Magnetic Field Therapy ,General Physics and Astronomy ,Nanotechnology ,Ferric Compounds ,Nervous System ,Article ,Mice ,Cell Line, Tumor ,medicine ,Animals ,Humans ,General Materials Science ,Viability assay ,Cytotoxicity ,Melanoma ,Stem Cells ,Electric Conductivity ,Temperature ,General Engineering ,Biological Transport ,medicine.disease ,Neural stem cell ,Magnetic hyperthermia ,Biophysics ,Nanoparticles ,Magnetic nanoparticles ,Female ,Stem cell ,Stem Cell Transplantation - Abstract
Localized magnetic hyperthermia as a treatment modality for cancer has generated renewed interest, particularly if it can be targeted to the tumor site. We examined whether tumor-tropic neural progenitor cells (NPCs) could be utilized as cell delivery vehicles for achieving preferential accumulation of core/shell iron/iron oxide magnetic nanoparticles (MNPs) within a mouse model of melanoma. We developed aminosiloxane-porphyrin functionalized MNPs, evaluated cell viability and loading efficiency, and transplanted neural progenitor cells loaded with this cargo into mice with melanoma. NPCs were efficiently loaded with core/shell Fe/Fe3O4 MNPs with minimal cytotoxicity; the MNPs accumulated as aggregates in the cytosol. The NPCs loaded with MNPs could travel to subcutaneous melanomas, and after A/C (alternating current) magnetic field (AMF) exposure, the targeted delivery of MNPs by the cells resulted in a measurable regression of the tumors. The tumor attenuation was significant (p
- Published
- 2010
6. Direct Observation of Gold Nanoparticle Assemblies with the Porin MspA on Mica
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Paul E. Smith, Michael Niederweis, Myungshim Kang, Viktor Chikan, Stefan H. Bossmann, Matthew T. Basel, Mikhail Pavlenok, and Raj Kumar Dani
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Models, Molecular ,Materials science ,Protein Conformation ,Surface Properties ,Mycobacterium smegmatis ,Metal Nanoparticles ,Porins ,General Physics and Astronomy ,Nanoparticle ,Plasma protein binding ,Buffers ,Article ,Protein structure ,Nanotechnology ,General Materials Science ,biology ,Protein Stability ,Methanol ,General Engineering ,Water ,Periplasmic space ,biology.organism_classification ,Crystallography ,Colloidal gold ,Porin ,Aluminum Silicates ,Gold ,Mica ,Hydrophobic and Hydrophilic Interactions ,Protein Binding - Abstract
The octameric porin MspA from Mycobacterium smegmatis is sufficiently stable to form a non-membrane-supported stand-alone porin on Mica surfaces. About 98% of all MspA octamers were found to stand upright on Mica, with their periplasmic loop regions bound to the hydrophilic Mica surface. Both, small (d = 3.7 nm) and large (d = 17 nm) gold nanoparticles bind to MspA, however in different positions: small gold nanoparticles bind within the MspA pore, whereas the large gold nanoparticles bind to the upper region of MspA. These experiments demonstrate that gold nanoparticles can be positioned at different, well-defined distances from the underlying surface using the MspA pore as a template. These findings represent a significant step towards the use of electrically insulating stable proteins in combination with metal nanoparticles in nanodevices.
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- 2009
7. MspA Porin−Gold Nanoparticle Assemblies: Enhanced Binding through a Controlled Cysteine Mutation
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Paul E. Smith, Stefan H. Bossmann, Viktor Chikan, Raj Kumar Dani, Mausam Kalita, and Myungshim Kang
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Size-exclusion chromatography ,Mutant ,Metal Nanoparticles ,Porins ,Nanoparticle ,Bioengineering ,Mycobacterial porin ,Microscopy, Electron, Transmission ,General Materials Science ,Cysteine ,Chromatography, High Pressure Liquid ,biology ,Chemistry ,Mechanical Engineering ,Mycobacterium smegmatis ,Neutron Activation Analysis ,General Chemistry ,Condensed Matter Physics ,biology.organism_classification ,Crystallography ,Spectrometry, Fluorescence ,Colloidal gold ,Mutation ,Porin ,Gold - Abstract
In this study, the interactions of two gold nanoparticles of different sizes (average diameters of 3.7 +/- 2.6 and 17 +/- 3 nm) with octameric mycobacterial porin A from Mycobacterium smegmatis (MspA) and a mutant of MspA featuring a cysteine mutation in position 126 (Q126C) are investigated. From the observation of enhanced photoluminescence quenching, it is inferred that the presence of eight cysteines in the MspA Q126C mutant significantly enhances the binding of selected small gold nanoparticles within the inner pore of MspA. The large gold nanoparticle/porin complex shows photoluminescence enhancement, which is expected since the larger nanoparticles cannot dock within the homopore of MspA due to size exclusion. In addition to the fluorescence experiments, observation of energy transfer from the small gold nanoparticles to the MspA shows the close proximity of the small gold nanoparticles with the porin. Interestingly, the energy transfer of the large nanoparticle/MspA complex is completely missing. From high-performance liquid chromatography data, the estimated binding constants for small Au@MspA, large Au@MspA, small Au@MspAcys, and large Au@MspAcys are 1.3 x 10 (9), 2.22 x 10 (10),10 (12) (irreversible), and 1.7 x 10 (10), respectively.
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- 2008
8. Nested Helmholtz coil design for producing homogeneous transient rotating magnetic fields
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John W. Moore, Raj Kumar Dani, Punit Prakash, Viktor Chikan, and George Podaru
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Rotating magnetic field ,Helmholtz coil ,Materials science ,Electromagnet ,Magnetic energy ,Acoustics ,law.invention ,Magnetic field ,Nuclear magnetic resonance ,law ,Electromagnetic coil ,Magnetic pressure ,Instrumentation ,Excitation - Abstract
Electromagnets that can produce strong rotating magnetic fields at kHz frequencies are potentially very useful to exert rotating force on magnetic nanoparticles as small as few nanometers in size. In this article, the construction of a pulsed high-voltage rotating electromagnet is demonstrated based on a nested Helmholtz coil design. The energy for the coils is provided by two high-voltage discharge capacitors. The triggered spark gaps used in the experiments show sufficient accuracy to achieve the high frequency rotating magnetic field. The measured strength of the rotating magnetic field is 200 mT. This magnetic field is scalable by increasing the number of turns on the coils, by reducing the dimensions of the coils and by increasing the discharge current/voltage of the capacitors.
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- 2015
9. Temperature-tunable iron oxide nanoparticles for remote-controlled drug release
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Oleh Taratula, Canan Schumann, Raj Kumar Dani, and Olena Taratula
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Thermogravimetric analysis ,Polymers ,Iron oxide ,Pharmaceutical Science ,Nanoparticle ,Nanotechnology ,Antineoplastic Agents ,Aquatic Science ,Ferric Compounds ,chemistry.chemical_compound ,Drug Delivery Systems ,Cell Line, Tumor ,Drug Discovery ,Copolymer ,Humans ,Ecology, Evolution, Behavior and Systematics ,chemistry.chemical_classification ,Ecology ,Temperature ,General Medicine ,Polymer ,Controlled release ,Drug Liberation ,chemistry ,Chemical engineering ,Doxorubicin ,Delayed-Action Preparations ,Drug delivery ,Nanoparticles ,Agronomy and Crop Science ,Iron oxide nanoparticles ,Research Article - Abstract
Herein, we report the successful development of a novel nanosystem capable of an efficient delivery and temperature-triggered drug release specifically aimed at cancer. The water-soluble 130.1 ± 0.2 nm iron oxide nanoparticles (IONPs) were obtained via synthesis of a monodispersed iron oxide core stabilized with tetramethylammonium hydroxide pentahydrate (TMAOH), followed by coating with the thermoresponsive copolymer poly-(NIPAM-stat-AAm)-block-PEI (PNAP). The PNAP layer on the surface of the IONP undergoes reversible temperature-dependent structural changes from a swollen to a collapsed state resulting in the controlled release of anticancer drugs loaded in the delivery vehicle. We demonstrated that the phase transition temperature of the prepared copolymer can be precisely tuned to the desired value in the range of 36°C–44°C by changing the monomers ratio during the preparation of the nanoparticles. Evidence of modification of the IONPs with the thermoresponsive copolymer is proven by ATR-FTIR and a quantitative analysis of the polymeric and iron oxide content obtained by thermogravimetric analysis. When loaded with doxorubicin (DOX), the IONPs-PNAP revealed a triggered drug release at a temperature that is a few degrees higher than the phase transition temperature of a copolymer. Furthermore, an in vitro study demonstrated an efficient internalization of the nanoparticles into the cancer cells and showed that the drug-free IONPs-PNAP were nontoxic toward the cells. In contrast, sufficient therapeutic effect was observed for the DOX-loaded nanosystem as a function of temperature. Thus, the developed temperature-tunable IONPs-based delivery system showed high potential for remotely triggered drug delivery and the eradication of cancer cells.
- Published
- 2013
10. Multifunctional nanomedicine platform for concurrent delivery of chemotherapeutic drugs and mild hyperthermia to ovarian cancer cells
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Olena Taratula, Andrew Wang, Han Song, Oleh Taratula, Raj Kumar Dani, Canan Schumann, Pallavi Dhagat, and Hong Xu
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Fever ,Pharmaceutical Science ,Antineoplastic Agents ,Pharmacology ,Ferric Compounds ,Polyethylene Glycols ,chemistry.chemical_compound ,Magnetics ,Immune system ,Drug Delivery Systems ,Cell Line, Tumor ,medicine ,Humans ,Doxorubicin ,Particle Size ,Cytotoxicity ,Magnetite Nanoparticles ,Ovarian Neoplasms ,Drug Carriers ,business.industry ,medicine.disease ,Nanomedicine ,chemistry ,Cancer cell ,Female ,Nanocarriers ,Ovarian cancer ,business ,Iron oxide nanoparticles ,medicine.drug - Abstract
A multifunctional tumor-targeting delivery system was developed and evaluated for an efficient treatment of drug-resistant ovarian cancer by combinatorial therapeutic modality based on chemotherapy and mild hyperthermia. The engineered iron oxide nanoparticle (IONPs)-based nanocarrier served as an efficient delivery vehicle for doxorubicin and provided the ability to heat cancer cells remotely upon exposure to an alternating magnetic field (AMF). The nanocarrier was additionally modified with polyethylene glycol and LHRH peptide to improve its biocompatibility and ability to target tumor cells. The synthesized delivery system has an average size of 97.1 nm and a zeta potential close to zero, both parameters favorable for increased stability in biological media and decreased elimination by the immune system. The nanocarrier demonstrated faster drug release in acidic conditions that mimic the tumor environment. It was also observed that the LHRH targeted delivery system could effectively enter drug resistant ovarian cancer cells, and the fate of doxorubicin was tracked with fluorescence microscope. Mild hyperthermia (40 °C) generated by IONPs under exposure to AMF synergistically increased the cytotoxicity of doxorubicin delivered by the developed nanocarrier to cancer cells. Thus, the developed IONPs-based delivery system has high potential in the effective treatment of ovarian cancer by combinatorial approach.
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- 2013
11. Bifunctional magnetic nanoparticles for early detection and magnetic hyperthermia cancer therapy
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Raj Kumar Dani, Hongwang Wang, Raja Shekar Rachakatla, Sivasai Balivada, Deryl L. Troyer, Viktor Chikan, Stephen H.Bossmann, and Thilani N. Samarakoon
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chemistry.chemical_compound ,Materials science ,Magnetic hyperthermia ,chemistry ,Genetics ,Cancer therapy ,Cancer research ,Early detection ,Magnetic nanoparticles ,Bifunctional ,Molecular Biology ,Biochemistry ,Biotechnology - Published
- 2009
12. Effects of interband transitions on Faraday rotation in metallic nanoparticles
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Gary Mathew Wysin, Raj Kumar Dani, Viktor Chikan, and Nathan Young
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Physics ,Electron density ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed matter physics ,FOS: Physical sciences ,Physics::Optics ,Fermi surface ,02 engineering and technology ,Optical field ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Drude model ,Electromagnetic radiation ,Magnetic field ,symbols.namesake ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,0103 physical sciences ,Faraday effect ,symbols ,General Materials Science ,010306 general physics ,0210 nano-technology ,Plasmon - Abstract
The Faraday rotation in metallic nanoparticles is considered based on a quantum model for the dielectric function \epsilon(\omega) in the presence of a DC magnetic field B. We focus on effects in \epsilon(\omega) due to interband transitions (IBTs), which are important in the blue and ultraviolet for noble metals used in plasmonics. The dielectric function is found using the perturbation of the electron density matrix due to the optical field of incident electromagnetic radiation. The calculation is applied to transitions between two bands (d and p, for example) separated by a gap, as one finds in gold at the L-point of the Fermi surface. The result of the DC magnetic field is a shift in the effective optical frequency causing IBTs by $\pm \mu_B B / \hbar$, where opposite signs are associated with left/right circular polarizations. Faraday rotation for a dilute solution of 17 nm diameter gold nanoparticles is measured and compared with both the IBT theory and a simpler Drude model for the bound electron response. Effects of the plasmon resonance mode on Faraday rotation in nanoparticles are also discussed., Comment: 19 pages, 7 figures
- Published
- 2013
13. Faraday rotation enhancement of gold coated Fe2O3 nanoparticles: Comparison of experiment and theory
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Gary Mathew Wysin, Raj Kumar Dani, Viktor Chikan, Stefan H. Bossmann, and Hongwang Wang
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Materials science ,Spins ,business.industry ,General Physics and Astronomy ,Nanoparticle ,Molecular physics ,law.invention ,symbols.namesake ,Optics ,law ,Faraday effect ,Volume fraction ,symbols ,Magnetic nanoparticles ,Physical and Theoretical Chemistry ,Surface plasmon resonance ,business ,Faraday cage ,Plasmon - Abstract
Understanding plasmonic enhancement of nanoscale magnetic materials is important to evaluate their potential for application. In this study, the Faraday rotation (FR) enhancement of gold coated Fe(2)O(3) nanoparticles (NP) is investigated experimentally and theoretically. The experiment shows that the Faraday rotation of a Fe(2)O(3) NP solution changes from approximately 3 rad/Tm to 10 rad/Tm as 5 nm gold shell is coated on a 9.7 nm Fe(2)O(3) core at 632 nm. The results also show how the volume fraction normalized Faraday rotation varies with the gold shell thickness. From the comparison of experiment and calculated Faraday rotation based on the Maxwell-Garnett theory, it is concluded that the enhancement and shell dependence of Faraday rotation of Fe(2)O(3) NPs is a result of the shifting plasmon resonance of the composite NP. In addition, the clustering of the NPs induces a different phase lag on the Faraday signal, which suggests that the collective response of the magnetic NP aggregates needs to be considered even in solution. From the Faraday phase lag, the estimated time of the full alignment of the magnetic spins of bare (cluster size 160 nm) and gold coated NPs (cluster size 90 nm) are found to be 0.65 and 0.17 μs. The calculation includes a simple theoretical approach based on the Bruggeman theory to account for the aggregation and its effect on the Faraday rotation. The Bruggeman model provides a qualitatively better agreement with the experimentally observed Faraday rotation and points out the importance of making a connection between component properties and the average "effective" optical behavior of the Faraday medium containing magnetic nanoparticles.
- Published
- 2011
14. Abstract LB-205: Using cell-delivered nanoparticles to cause local hyperthermia increases survival in a murine metastatic pancreatic cancer model
- Author
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Hongwang Wang, Deryl L. Troyer, Stefan H. Bossmann, Viktor Chikan, Gayani Abayaweera, Tej B. Shrestha, Gwi-Moon Seo, Raj Kumar Dani, Matthew T. Basel, Marla Pyle, and Sivasai Balivada
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Hyperthermia ,Cancer Research ,business.industry ,Cancer ,medicine.disease ,chemistry.chemical_compound ,Oncology ,chemistry ,Pancreatic tumor ,Pancreatic cancer ,Immunology ,Cancer cell ,Cancer research ,Medicine ,Macrophage ,Magnetic nanoparticles ,business ,Iron oxide nanoparticles - Abstract
Hyperthermia has been a method for cancer treatment for several decades now because cancer cells are slightly more susceptible to hyperthermia than healthy cells. Unfortunately, whole body hyperthermia has prohibitive side effects limiting its use or usefulness. Local hyperthermia, directed only to tumor tissue, could alleviate this problem and prove to be a potent cancer treatment. One method of generating local hyperthermia is to deliver magnetic nanoparticles to the tumor site and then generate heat using an alternating magnetic field (AMF). Here we demonstrate a system that uses tumor homing cells to actively carry iron/iron oxide nanoparticles into tumor tissue for AMF treatment. Paramagnetic iron/iron oxide nanoparticles were synthesized that absorb and convert AMF energy into heat very efficiently. These nanoparticles were loaded into Raw264.7 cells (mouse monocyte/macrophage like cells, Mo/Ma), that we have previously shown to be tumor homing cells. Test showed that the nanoparticles loaded at high concentration in the cells with very low toxicity. To test the system, a murine pancreatic cancer model was generated by injection of Pan02 cells i.p. After tumor development, Mo/Ma loaded with iron/iron oxide nanoparticles were injected i.p. and allowed to crawl into the tumor. Three days after injection, mice were exposed to an alternative magnetic field for twenty minutes to cause the cell-delivered nanoparticles to generate heat. This treatment regimen was repeated three times. A survival study demonstrated that this system can significantly increase survival in a murine pancreatic cancer model, with an average post-diagnosis life expectancy increase of 33%. Thus, for the first time, a cell-delivered nanoparticle system for generating localized hyperthermia has been demonstrated that can significantly prolong the life of i.p. pancreatic tumor bearing mice. This system has the potential to become a useful method for specifically and actively delivering nanoparticles for local hyperthermia treatment of cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-205. doi:10.1158/1538-7445.AM2011-LB-205
- Published
- 2011
15. MspA Porin−Gold Nanoparticle Assemblies: Enhanced Binding through a Controlled Cysteine Mutation.
- Author
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Raj Kumar Dani, Myungshim Kang, Mausam Kalita, Paul E. Smith, Stefan H. Bossmann, and Viktor Chikan
- Subjects
- *
NANOPARTICLES , *MYCOBACTERIUM , *PHOTOLUMINESCENCE , *ENERGY transfer - Abstract
In this study, the interactions of two gold nanoparticles of different sizes (average diameters of 3.7 ± 2.6 and 17 ± 3 nm) with octameric mycobacterial porin A from Mycobacterium smegmatis(MspA) and a mutant of MspA featuring a cysteine mutation in position 126 (Q126C) are investigated. From the observation of enhanced photoluminescence quenching, it is inferred that the presence of eight cysteines in the MspA Q126C mutant significantly enhances the binding of selected small gold nanoparticles within the inner pore of MspA. The large gold nanoparticle/porin complex shows photoluminescence enhancement, which is expected since the larger nanoparticles cannot dock within the homopore of MspA due to size exclusion. In addition to the fluorescence experiments, observation of energy transfer from the small gold nanoparticles to the MspA shows the close proximity of the small gold nanoparticles with the porin. Interestingly, the energy transfer of the large nanoparticle/MspA complex is completely missing. From high-performance liquid chromatography data, the estimated binding constants for small Au@MspA, large Au@MspA, small Au@MspA cys, and large Au@MspA cysare 1.3 × 10 9, 2.22 × 10 10, > 10 12(irreversible), and 1.7 × 10 10, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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