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Articles 91 - 114 of 114

Full-Text Articles in Nanomedicine

Targeted Magnetite Tissue Delivery For Antiretroviral Pharmacokinetics, Tianyuzi Li Aug 2015

Targeted Magnetite Tissue Delivery For Antiretroviral Pharmacokinetics, Tianyuzi Li

Theses & Dissertations

Pharmacokinetics and pharmacodynamics studies are required for bench to bedside translation of any new drug, formulation or device. Multifunctional magnetite nanocarriers enable magnetic resonance imaging tracking of nanomaterial encased antiretroviral drugs serving to improve the effectiveness of formulation developments. Targeting ligands used to deliver nanoparticles to HIV harboring cells can be tested using multifunctional magnetite nanocarriers. To this end, two types of magnetite nanocarriers were developed. These included small magnetite antiretroviral therapy particles. The second were ALN-PEG coated magnetite particles for testing macrophages targeting ligands. Overall, these works should serve to speed the development of long acting nanoformulated ART to …


New Approach To Develop Ultra-High Inhibitory Drug Using The Power Function Of The Stoichiometry Of The Targeted Nanomachine Or Biocomplex, Dan Shu, Fengmei Pi, Chi Wang, Peng Zhang, Peixuan Guo Jul 2015

New Approach To Develop Ultra-High Inhibitory Drug Using The Power Function Of The Stoichiometry Of The Targeted Nanomachine Or Biocomplex, Dan Shu, Fengmei Pi, Chi Wang, Peng Zhang, Peixuan Guo

Pharmaceutical Sciences Faculty Publications

AIMS: To find methods for potent drug development by targeting to biocomplex with high copy number.

METHODS: Phi29 DNA packaging motor components with different stoichiometries were used as model to assay virion assembly with Yang Hui's Triangle [Formula: see text], where Z = stoichiometry, M = drugged subunits per biocomplex, p and q are the fraction of drugged and undrugged subunits in the population.

RESULTS: Inhibition efficiency follows a power function. When number of drugged subunits to block the function of the complex K = 1, the uninhibited biocomplex equals q(z), demonstrating the multiplicative effect of stoichiometry on inhibition with …


Mdr1 Sirna Loaded Hyaluronic Acid-Based Cd44 Targeted Nanoparticle Systems Circumvent Paclitaxel Resistance In Ovarian Cancer, Xiaoqian Yang, Arun K. Iyer, Amit Singh, Edwin Choy, Francis J. Hornicek, Mansoor M. Amiji, Zhenfeng Duan Feb 2015

Mdr1 Sirna Loaded Hyaluronic Acid-Based Cd44 Targeted Nanoparticle Systems Circumvent Paclitaxel Resistance In Ovarian Cancer, Xiaoqian Yang, Arun K. Iyer, Amit Singh, Edwin Choy, Francis J. Hornicek, Mansoor M. Amiji, Zhenfeng Duan

Pharmaceutical Sciences Faculty Publications

Development of multidrug resistance (MDR) is an almost universal phenomenon in patients with ovarian cancer, and this severely limits the ultimate success of chemotherapy in the clinic. Overexpression of the MDR1 gene and corresponding P-glycoprotein (Pgp) is one of the best known MDR mechanisms. MDR1 siRNA based strategies were proposed to circumvent MDR, however, systemic, safe, and effective targeted delivery is still a major challenge. Cluster of differentiation 44 (CD44) targeted hyaluronic acid (HA) based nanoparticle has been shown to successfully deliver chemotherapy agents or siRNAs into tumor cells. The goal of this study is to evaluate the ability of …


Effect Of Formulation Variables On Preparation Of Celecoxib Loaded Polylactide-Co-Glycolide Nanoparticles, Dustin L. Cooper, Sam Harirforoosh Dec 2014

Effect Of Formulation Variables On Preparation Of Celecoxib Loaded Polylactide-Co-Glycolide Nanoparticles, Dustin L. Cooper, Sam Harirforoosh

Pharmacy Faculty Articles and Research

Polymer based nanoparticle formulations have been shown to increase drug bioavailability and/or reduce drug adverse effects. Nonsteroidal anti-inflammatory drugs (e.g. celecoxib) reduce prostaglandin synthesis and cause side effects such as gastrointestinal and renal complications. The aim of this study was to formulate celecoxib entrapped poly lactide-co-glycolide based nanoparticles through a solvent evaporation process using didodecyldimethylammonium bromide or poly vinyl alcohol as stabilizer. Nanoparticles were characterized for zeta potential, particle size, entrapment efficiency, and morphology. Effects of stabilizer concentration (0.1, 0.25, 0.5, and 1% w/v), drug amount (5, 10, 15, and 20 mg), and emulsifier (lecithin) on nanoparticle characterization were examined …


Nanotoxicity In Cells Of The Immune System, Jonathan J. Pelc May 2014

Nanotoxicity In Cells Of The Immune System, Jonathan J. Pelc

Science Scholars

Nanoparticles (NPs) provide a new medical approach to drug therapy. As with every new approach, safety precautions need to be taken, and the immediate and long-term effects for many NPs are still unclear. When administering a medical treatment into the human body, the first issue that needs to be addressed is host detection of the medicine and inflammation as a possible result of the treatment. If a new NP treatment causes inflammation before it releases its medicine, that treatment may be ineffective, even damaging to the patient. Small metallic and organic particles have been shown to elicit an inflammatory responses …


Design And Optimization Of Plga-Based Diclofenac Loaded Nanoparticles, Dustin L. Cooper, Sam Harirforoosh Jan 2014

Design And Optimization Of Plga-Based Diclofenac Loaded Nanoparticles, Dustin L. Cooper, Sam Harirforoosh

Pharmacy Faculty Articles and Research

Drug based nanoparticle (NP) formulations have gained considerable attention over the past decade for their use in various drug formulations. NPs have been shown to increase bioavailability, decrease side effects of highly toxic drugs, and prolong drug release. Nonsteroidal anti-inflammatory drugs such as diclofenac block cyclooxygenase expression and reduce prostaglandin synthesis, which can lead to several side effects such as gastrointestinal bleeding and renal insufficiency. The aim of this study was to formulate and characterize diclofenac entrapped poly(lactide-co-glycolide) (PLGA) based nanoparticles. Nanoparticles were formulated using an emulsion-diffusion-evaporation technique with varying concentrations of poly vinyl alcohol (PVA) (0.1, 0.25, 0.5, or …


In Vitro Analysis Of Nanoparticulate Hydroxyapatite/Chitosan Composites As Potential Drug Delivery Platforms For The Sustained Release Of Antibiotics In The Treatment Of Osteomyelitis, Vuk Uskoković, Tejal A. Dasai Jan 2014

In Vitro Analysis Of Nanoparticulate Hydroxyapatite/Chitosan Composites As Potential Drug Delivery Platforms For The Sustained Release Of Antibiotics In The Treatment Of Osteomyelitis, Vuk Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

Nanoparticulate composites of hydroxyapatite (HAp) and chitosan were synthesized by ultrasound-assisted sequential precipitation and characterized for their microstructure at the atomic scale, surface charge, drug release properties, and combined antibacterial and osteogenic response. Crystallinity of HAp nanoparticles was reduced because of the interference of the surface layers of chitosan with the dissolution/reprecipitation-mediated recrystallization mechanism that conditions the transition from the as-precipitated amorphous calcium phosphate phase to the most thermodynamically stable one—HAp. Embedment of 5–10 nm sized, narrowly dispersed HAp nanoparticles within the polymeric matrix mitigated the burst release of the small molecule model drug, fluorescein, bound to HAp by physisorption, …


Simultaneous Bactericidal And Osteogenic Effect Of Nanoparticulate Calcium Phosphate Powders Loaded With Clindamycin On Osteoblasts Infected With Staphylococcus Aureus, Vuk Uskoković, Tejal A. Dasai Jan 2014

Simultaneous Bactericidal And Osteogenic Effect Of Nanoparticulate Calcium Phosphate Powders Loaded With Clindamycin On Osteoblasts Infected With Staphylococcus Aureus, Vuk Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

S aureus internalized by bone cells and shielded from the immune system provides a reservoir of bacteria in recurring osteomyelitis. Its targeting by the antibiotic therapy may thus be more relevant for treating chronic bone infection than eliminating only the pathogens colonizing the bone matrix. Assessed was the combined osteogenic and antibacterial effect of clindamycinloaded calcium phosphate nanoparticles of different monophasic compositions on co-cultures comprising osteoblasts infected with S aureus. Antibiotic-carrying particles were internalized by osteoblasts and minimized the concentration of intracellular bacteria. In vitro treatments of the infected cells, however, could not prevent cell necrosis due to the …


Nanoparticulate Drug Delivery Platforms For Advancing Bone Infection Therapies, Vuk Uskoković, Tejal A. Dasai Jan 2014

Nanoparticulate Drug Delivery Platforms For Advancing Bone Infection Therapies, Vuk Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

Introduction—The ongoing surge of resistance of bacterial pathogens to antibiotic therapies and the consistently aging median member of the human race signal an impending increase in the incidence of chronic bone infection. Nanotechnological platforms for local and sustained delivery of therapeutics hold the greatest potential for providing minimally invasive and maximally regenerative therapies for this rare but persistent condition.

Areas covered—Shortcomings of the clinically available treatment options, including poly(methyl methacrylate) beads and calcium sulfate cements, are discussed and their transcending using calcium-phosphate/polymeric nanoparticulate composites is foreseen. Bone is a composite wherein the weakness of each component alone is …


Combination Of Sirna-Directed Gene Silencing With Cisplatin Reverses Drug Resistance In Human Non-Small Cell Lung Cancer, Shanthi Ganesh, Arun K. Iyer, Jan Weller, David V. Morrissey, Mansoor M. Amiji Jul 2013

Combination Of Sirna-Directed Gene Silencing With Cisplatin Reverses Drug Resistance In Human Non-Small Cell Lung Cancer, Shanthi Ganesh, Arun K. Iyer, Jan Weller, David V. Morrissey, Mansoor M. Amiji

Pharmaceutical Sciences Faculty Publications

One of the most challenging aspects of lung cancer therapy is the rapid acquisition of multidrug-resistant (MDR) phenotype. One effective approach would be to identify and downregulate resistance-causing genes in tumors using small interfering RNAs (siRNAs) to increase the sensitivity of tumor cells to chemotherapeutic challenge. After identifying the overexpressed resistance-related antiapoptotic genes (survivin and bcl-2) in cisplatin-resistant cells, the siRNA sequences were designed and screened to select the most efficacious candidates. Modifications were introduced in them to minimize off-target effects. Subsequently, the combination of siRNA and cisplatin that gave the maximum synergy was identified in resistant cells. We then …


Calcium Phosphate Nanoparticles: A Future Therapeutic Platform For The Treatment Of Osteomyelitis?, Tejal A. Dasai, Vuk Uskoković Jan 2013

Calcium Phosphate Nanoparticles: A Future Therapeutic Platform For The Treatment Of Osteomyelitis?, Tejal A. Dasai, Vuk Uskoković

Pharmacy Faculty Articles and Research

No abstract provided.


Phase Composition Control Of Calcium Phosphate Nanoparticles For Tunable Drug Delivery Kinetics And Treatment Of Osteomyelitis. Part 2: Antibacterial And Osteoblastic Response, Vuk Uskoković, Tejal A. Dasai Jan 2013

Phase Composition Control Of Calcium Phosphate Nanoparticles For Tunable Drug Delivery Kinetics And Treatment Of Osteomyelitis. Part 2: Antibacterial And Osteoblastic Response, Vuk Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

Osteomyelitis has been traditionally treated by the combination of long-term antibiotic therapies and surgical removal of diseased tissue. The multifunctional material was developed in this study with the aim to improve this therapeutic approach by: (a) enabling locally delivered and sustained release of antibiotics at a tunable rate, so as to eliminate the need for repetitive administration of systemically distributed antibiotics; and (b) controllably dissolving itself, so as to promote natural remineralization of the portion of bone lost to disease. We report hereby on the effect of the previously synthesized calcium phosphates (CAPs) with tunable solubilities and drug release time …


Bmp7 Gene Transfer Via Gold Nanoparticles Into Stroma Inhibits Corneal Fibrosis In Vivo, Ashish Tandon, Ajay Sharma, Jason T. Rodier, Alexander M. Klibanov, Frank G. Rieger, Rajiv R. Mohan Jan 2013

Bmp7 Gene Transfer Via Gold Nanoparticles Into Stroma Inhibits Corneal Fibrosis In Vivo, Ashish Tandon, Ajay Sharma, Jason T. Rodier, Alexander M. Klibanov, Frank G. Rieger, Rajiv R. Mohan

Pharmacy Faculty Articles and Research

This study examined the effects of BMP7 gene transfer on corneal wound healing and fibrosis inhibition in vivo using a rabbit model. Corneal haze in rabbits was produced with the excimer laser performing -9 diopters photorefractive keratectomy. BMP7 gene was introduced into rabbit keratocytes by polyethylimine-conjugated gold nanoparticles (PEI2- GNPs) transfection solution single 5-minute topical application on the eye. Corneal haze and ocular health in live animals was gauged with stereo- and slit-lamp biomicroscopy. The levels of fibrosis [a-smooth muscle actin (aSMA), F-actin and fibronectin], immune reaction (CD11b and F4/80), keratocyte apoptosis (TUNEL), calcification (alizarin red, vonKossa and osteocalcin), and …


Nanoparticles Of Cobalt-Substituted Hydroxyapatite In Regeneration Of Mandibular Osteoporotic Bones, Nenad Ignjatović, Zorica Ajduković, Vojin Savić, Stevo Najman, Dragan Mihailović, Perica Vasilijević, Zoran Stojanović, Vuk Uskoković, Dragab Uskoković Jan 2013

Nanoparticles Of Cobalt-Substituted Hydroxyapatite In Regeneration Of Mandibular Osteoporotic Bones, Nenad Ignjatović, Zorica Ajduković, Vojin Savić, Stevo Najman, Dragan Mihailović, Perica Vasilijević, Zoran Stojanović, Vuk Uskoković, Dragab Uskoković

Pharmacy Faculty Articles and Research

Indications exist that paramagnetic calcium phosphates may be able to promote regeneration of bone faster than their regular, diamagnetic counterparts. In this study, analyzed was the influence of paramagnetic cobalt-substituted hydroxyapatite nanoparticles on osteoporotic alveolar bone regeneration in rats. Simultaneously, biocompatibility of the material was tested in vitro, on osteoblastic MC3T3-E1 and epithelial Caco-2 cells in culture. The material was shown to be biocompatible and nontoxic when added to epithelial monolayers in vitro, while it caused a substantial decrease in the cell viability as well as deformation of the cytoskeleton and cell morphology when incubated with the osteoblastic …


Bsa Nanoparticles For Sirna Delivery: Coating Effects On Nanoparticle Properties, Plasma Protein Adsorption, And In Vitro Sirna Delivery, Haran Yogasundaram, Markian Stephan Bahniuk, Harsh-Deep Singh, Hamidreza Montazeri Aliabadi, Hasan Uludag, Larry David Unsworth Jan 2012

Bsa Nanoparticles For Sirna Delivery: Coating Effects On Nanoparticle Properties, Plasma Protein Adsorption, And In Vitro Sirna Delivery, Haran Yogasundaram, Markian Stephan Bahniuk, Harsh-Deep Singh, Hamidreza Montazeri Aliabadi, Hasan Uludag, Larry David Unsworth

Pharmacy Faculty Articles and Research

Developing vehicles for the delivery of therapeutic molecules, like siRNA, is an area of active research. Nanoparticles composed of bovine serum albumin, stabilized via the adsorption of poly-L-lysine (PLL), have been shown to be potentially inert drug-delivery vehicles. With the primary goal of reducing nonspecific protein adsorption, the effect of using comb-type structures of poly(ethylene glycol) (1 kDa, PEG) units conjugated to PLL (4.2 and 24 kDa) on BSA-NP properties, apparent siRNA release rate, cell viability, and cell uptake were evaluated. PEGylated PLL coatings resulted in NPs with ζ-potentials close to neutral. Incubation with platelet-poor plasma showed the composition of …


Attenuation Of Corneal Myofibroblast Development Through Nanoparticle-Mediated Soluble Transforming Growth Factor-Β Type Ii Receptor (Stgfβrii) Gene Transfer, Ajay Sharma, Jason T. Rodier, Ashish Tandon, Alexander M. Klibanov, Rajiv R. Mohan Jan 2012

Attenuation Of Corneal Myofibroblast Development Through Nanoparticle-Mediated Soluble Transforming Growth Factor-Β Type Ii Receptor (Stgfβrii) Gene Transfer, Ajay Sharma, Jason T. Rodier, Ashish Tandon, Alexander M. Klibanov, Rajiv R. Mohan

Pharmacy Faculty Articles and Research

Purpose: To explore (i) the potential of polyethylenimine (PEI)-DNA nanoparticles as a vector for delivering genes into human corneal fibroblasts, and (ii) whether the nanoparticle-mediated soluble extracellular domain of the transforming growth factor–β type II receptor (sTGFβRII) gene therapy could be used to reduce myofibroblasts and fibrosis in the cornea using an in vitro model.

Methods: PEI-DNA nanoparticles were prepared at a nitrogen-to-phosphate ratio of 30 by mixing linear PEI and a plasmid encoding sTGFβRII conjugated to the fragment crystallizable (Fc) portion of human immunoglobulin. The PEI-DNA polyplex formation was confirmed through gel retardation assay. Human corneal fibroblasts (HCFs) were …


Inhibition Of Abcb1 (Mdr1) Expression By An Sirna Nanoparticulate Delivery System To Overcome Drug Resistance In Osteosarcoma, Michiro Susa, Arun K. Iyer, Keinosuke Ryu, Edwin Choy, Francis J. Hornicek, Henry Mankin, Lara Milane, Mansoor M. Amiji, Zhenfeng Duan May 2010

Inhibition Of Abcb1 (Mdr1) Expression By An Sirna Nanoparticulate Delivery System To Overcome Drug Resistance In Osteosarcoma, Michiro Susa, Arun K. Iyer, Keinosuke Ryu, Edwin Choy, Francis J. Hornicek, Henry Mankin, Lara Milane, Mansoor M. Amiji, Zhenfeng Duan

Pharmaceutical Sciences Faculty Publications

Background: The use of neo-adjuvant chemotherapy in treating osteosarcoma has improved patients’ average 5 year survival rate from 20% to 70% in the past 30 years. However, for patients who progress after chemotherapy, its effectiveness diminishes due to the emergence of multi-drug resistance (MDR) after prolonged therapy.

Methodology/Principal Findings: In order to overcome both the dose-limiting side effects of conventional chemotherapeutic agents and the therapeutic failure resulting from MDR, we designed and evaluated a novel drug delivery system for MDR1 siRNA delivery. Novel biocompatible, lipid-modified dextran-based polymeric nanoparticles were used as the platform for MDR1 siRNA delivery; and the efficacy …


Doxorubicin Loaded Polymeric Nanoparticulate Delivery System To Overcome Drug Resistance In Osteosarcoma, Michiro Susa, Arun K. Iyer, Keinosuke Ryu, Francis J. Hornicek, Henry Mankin, Mansoor M. Amiji, Zhenfeng Duan Nov 2009

Doxorubicin Loaded Polymeric Nanoparticulate Delivery System To Overcome Drug Resistance In Osteosarcoma, Michiro Susa, Arun K. Iyer, Keinosuke Ryu, Francis J. Hornicek, Henry Mankin, Mansoor M. Amiji, Zhenfeng Duan

Pharmaceutical Sciences Faculty Publications

Background: Drug resistance is a primary hindrance for the efficiency of chemotherapy against osteosarcoma. Although chemotherapy has improved the prognosis of osteosarcoma patients dramatically after introduction of neo-adjuvant therapy in the early 1980's, the outcome has since reached plateau at approximately 70% for 5 year survival. The remaining 30% of the patients eventually develop resistance to multiple types of chemotherapy. In order to overcome both the dose-limiting side effects of conventional chemotherapeutic agents and the therapeutic failure incurred from multidrug resistant (MDR) tumor cells, we explored the possibility of loading doxorubicin onto biocompatible, lipid-modified dextran-based polymeric nanoparticles and evaluated the …


Synthesis Of Multifunctional Nanogels Using A Protected Macromonomer Approach, Neetu Singh, L. Andrew Lyon Jan 2008

Synthesis Of Multifunctional Nanogels Using A Protected Macromonomer Approach, Neetu Singh, L. Andrew Lyon

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nanoparticles possessing multiple functionalities provide synthetic handles for varied surface chemistries, making them useful for a range of applications such as biotargeting and drug delivery. However, the combination of interfering functionalities on the same particle is often challenging. We have employed a synthetic scheme involving chemical protection/deprotection to combine interfering functional groups on the same hydrogel nanoparticle. The synthesis of amine-containing poly(N-isopropylacrylamide) nanogels was carried out via free radical precipitation polymerization by incorporating a Fmoc-protected amine poly(ethylene glycol) (PEG) macromonomer. The Fmoc group was then removed to obtain free amines, which were shown to be available for conjugation. We further …


Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall May 2006

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …


Studies On The Formation Of Dna-Cationic Lipid Composite Films And Dna Hybridization In The Composites, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Krishna N. Ganesh May 2001

Studies On The Formation Of Dna-Cationic Lipid Composite Films And Dna Hybridization In The Composites, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Krishna N. Ganesh

Faculty Works

The formation of composite films of double-stranded DNA and cationic lipid molecules (octadecylamine, ODA) and the hybridization of complementary single-stranded DNA molecules in such composite films are demonstrated. The immobilization of DNA is accomplished by simple immersion of a thermally evaporated ODA film in the DNA solution at close to physiological pH. The entrapment of the DNA molecules in the cationic lipid film is dominated by attractive electrostatic interaction between the negatively charged phosphate backbone of the DNA molecules and the protonated amine molecules in the thermally evaporated film and has been quantified using quartz crystal microgravimetry (QCM). Fluorescence studies …


Cationic Surfactant Mediated Hybridization And Hydrophobization Of Dna Molecules At The Liquid/Liquid Interface And Their Phase Transfer, Murali Sastry, Ashavani Kumar, Mrunalini Pattarkine, Vidya Ramakrishnan, Krishna N. Ganesh Jan 2001

Cationic Surfactant Mediated Hybridization And Hydrophobization Of Dna Molecules At The Liquid/Liquid Interface And Their Phase Transfer, Murali Sastry, Ashavani Kumar, Mrunalini Pattarkine, Vidya Ramakrishnan, Krishna N. Ganesh

Faculty Works

Hybridization of complementary oligonucleotides mediated by a cationic surfactant at the water/hexane interface leads to hydrophobic, double-helical DNA which may be readily phase transferred to the organic phase and cast into thin films on solid substrates.


Hybridization Of Dna By Sequential Immobilization Of Oligonucleotides At The Air-Water Interface, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Anand Gole, K. N. Ganesh Nov 2000

Hybridization Of Dna By Sequential Immobilization Of Oligonucleotides At The Air-Water Interface, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Anand Gole, K. N. Ganesh

Faculty Works

The hybridization of DNA by sequential electrostatic and hydrogen-bonding immobilization of single-stranded complementary oligonucleotides at the air-water interface with cationic Langmuir monolayers is demonstrated. The complexation of the single-stranded DNA molecules with octadecylamine (ODA) Langmuir monolayers was followed in time by monitoring the pressure-area isotherms. A large (and slow) expansion of the ODA monolayer was observed during each stage of complexation in the following sequence: primary single-stranded DNA followed by complementary single-stranded DNA followed by the intercalator, ethidium bromide. Langmuir-Blodgett (LB) films of the ODA-DNA complex were formed on different substrates and characterized using quartz-crystal microgravimetry (QCM), Fourier transform infrared …


Anion Induced Blue To Purple Transition In Bacteriorhodopsin, Mrunalini Pattarkine, Anil K. Singh Jun 1996

Anion Induced Blue To Purple Transition In Bacteriorhodopsin, Mrunalini Pattarkine, Anil K. Singh

Faculty Works

Purple membrane (PM, λ" role="presentation">λmax" role="presentation">max 570 nm) of H. halobium on treatment with sulphuric acid changes its colour to blue (λ" role="presentation">λmax" role="presentation">max 608 nm). The purple chromophore can be regenerated from the blue chromophore by exogeneous addition of anions such as CI−" role="presentation">− and HPO42−" role="presentation">2−4. Chloride ion is found to be more effective than the dibasic phosphate ion in regenerating the purple chromophore. Nevertheless, one thing common to the anion regeneration is that both CI−" role="presentation">− and HPO42−" role="presentation">2−4 show marked pH effect. At pH 1.0 the efficiency of …