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Recent Advances In Surface Tailoring Of Thin Film Forward Osmosis Membranes: A Review, Javad Farahbakhsh, Mitra Golgoli, Mehdi Khiadani, Mohadeseh Najafi, Wafa Suwaileh, Amir Razmjou, Masoumeh Zargar Jan 2024

Recent Advances In Surface Tailoring Of Thin Film Forward Osmosis Membranes: A Review, Javad Farahbakhsh, Mitra Golgoli, Mehdi Khiadani, Mohadeseh Najafi, Wafa Suwaileh, Amir Razmjou, Masoumeh Zargar

Research outputs 2022 to 2026

The recent advancements in fabricating forward osmosis (FO) membranes have shown promising results in desalination and water treatment. Different methods have been applied to improve FO performance, such as using mixed or new draw solutions, enhancing the recovery of draw solutions, membrane modification, and developing FO-hybrid systems. However, reliable methods to address the current issues, including reverse salt flux, fouling, and antibacterial activities, are still in progress. In recent decades, surface modification has been applied to different membrane processes, including FO membranes. Introducing nanochannels, bioparticles, new monomers, and hydrophilic-based materials to the surface layer of FO membranes has significantly impacted …


Study Of The Stability Of Heparin/Collagen Layer-By-Layer Coatings, Hector M. Apodaca Reyes May 2023

Study Of The Stability Of Heparin/Collagen Layer-By-Layer Coatings, Hector M. Apodaca Reyes

Chemical Engineering Undergraduate Honors Theses

Pairing heparin with collagen-based medical implants has opened a whole new area of research for enhancing the desired effect of current implants. In fact, heparin (HEP) and collagen (COL) layer-by-layer (LbL) coatings have shown impressive results in forming polyelectrolyte multilayers. It has been already seen on skin grafts, nerve guide conduits (NGCs), and drug delivery devices yielding promising results. Due to being a simple, cost-efficient, and versatile option to fabricate thin biomimetic films, this self-assembly technique is one of the most effective methods to immobilize extracellular matrix (collagen and heparin) onto medical devices and implants. Even though previous studies have …


Controlling Mechanical Properties In Thim Multilayer Hydrogels Through Network Structure, Maksim Dolmat Jan 2023

Controlling Mechanical Properties In Thim Multilayer Hydrogels Through Network Structure, Maksim Dolmat

All ETDs from UAB

Polymer thin films possess unique properties, cost-effectiveness, and flexibility, making them vital for enhancing surface functionality. Layer-by-layer (LbL) assembly allows for synthesis of ultrathin polymeric films with precise control over film thickness, material selection, surface chemistry, and responsiveness. Current advancements in LbL assembly focus on understanding film formation and deposition conditions on film’s structure and properties. Covalent cross-linking of physically bonded LbL networks forms multilayer hydrogel networks capable of absorbing large amounts of water. The use of stimuli-responsive polymers has facilitated the advancement of "smart" materials capable of responding to external stimuli. Stimuli-responsive hydrogels exhibit reversible volume changes, making them …


Biodegradable Active Bio-Nanocomposite Film For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal Nov 2022

Biodegradable Active Bio-Nanocomposite Film For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal

Articles

The increased environmental pollution has led to finding sustainable solutions for non-renewable plastic-based food packaging materials. Thus, the use of biomaterial-based packaging material has become an immense trend. This work aims at developing an antimicrobial biodegradable chitosanalginate bio-nano composite film with TiO2 nanoparticle (NPs) for food packaging applications. The film was developed by a solution casting method. The chemical, mechanical, thermal, barrier, antimicrobial, and biodegradable properties of the packaging films were evaluated. Packaging studies were performed for 15 days for cherry tomatoes. The designed packaging material had enhanced the mechanical properties with a significantly (p < 0.05) higher tensile strength of 15.76 folds and 2 fold higher elongation at break. The UV barrier properties increased by 88.6%, while the film transparency decreased by 87.23%. Molecular interaction of N-H covalent bonds was observed between alginate and chitosan together with TiO2 NPs. The developed bio-nano composite film showed antimicrobial activity against foodborne pathogens E. coli, S. aureus, S. typhi, and L. monocytogene with a log reduction of 7.08, 7.28, 6.04 & 6.02 log CFU/ml respectively at 24 hours incubation period. The film was completely biodegraded and a weight loss of 89.06% was observed in bio-nanocomposite film during the 3 months. Shelf-life estimation of cherry tomato using developed packaging films showed an increase in the shelf-life up to 8 days with stable pH, total soluble solids, and weight with no bacterial growth when packaged with prepared film. Owing to their improved mechanical, UV barrier, antibacterial, and biodegradability, the prepared active bio-nano composite packaging films could be considered a potential candidate for fruit packaging.


An Active Biodegradable Layer-By-Layer Film Based On Chitosan-Alginate-Tio2 For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Shiviani Pathania, Amit K. Jaiswal, Swarma Jaiswal Oct 2022

An Active Biodegradable Layer-By-Layer Film Based On Chitosan-Alginate-Tio2 For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Shiviani Pathania, Amit K. Jaiswal, Swarma Jaiswal

Articles

This work aims at developing biodegradable active chitosan-alginate layer-by-layer bio-nanocomposite film with TiO2NPs using the solvent casting method followed by CaCl2 crosslinking for food packaging applications. The developed films enhanced the tensile strength and elongation at break by 14.76 and 2 folds (p < 0.05) respectively. The UV barrier properties of CH-SA-0.3%TiO2 film increased by 88.6%, while the film transparency decreased by 87.23%. All films showed antimicrobial activity against foodborne pathogens E. coli, S. aureus, S. typhi, and L. monocytogene. The film with 0.1%TiO2 showed the complete killing of gram-positive bacteria. The CH-SA-0.1%TiO2 film was completely biodegraded during the …


Biodegradable Active Bio-Nanocomposite Film For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal May 2022

Biodegradable Active Bio-Nanocomposite Film For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal

Articles

The increased environmental pollution has led to finding sustainable solutions for non-renewable plastic-based food packaging materials. Thus, the use of biomaterial-based packaging material has become an immense trend. This work aims at developing an antimicrobial biodegradable chitosan-alginate bio-nano composite film with TiO2 nanoparticle (NPs) for food packaging applications. The film was developed by a solution casting method. The chemical, mechanical, thermal, barrier, antimicrobial, and biodegradable properties of the packaging films were evaluated. Packaging studies were performed for 15 days for cherry tomatoes. The designed packaging material had enhanced the mechanical properties with a significantly (p < 0.05) higher tensile strength of 15.76 folds and 2 fold higher elongation at break. The UV barrier properties increased by 88.6%, while the film transparency decreased by 87.23%. Molecular interaction of N-H covalent bonds was observed between alginate and chitosan together with TiO2 NPs. The developed bio-nano composite film showed antimicrobial activity against foodborne pathogens E. coli, S. aureus, S. typhi, and L. monocytogene with a log reduction of 7.08, 7.28, 6.04 & 6.02 log CFU/ml respectively at 24 hours incubation period. The film was completely biodegraded and a weight loss of 89.06% was observed in bio-nanocomposite film during the 3 months. Shelf-life estimation of cherry tomato using developed packaging films showed an increase in the shelf-life up to 8 days with stable pH, total soluble solids, and weight with no bacterial growth when packaged with prepared film. Owing to their improved mechanical, UV barrier, antibacterial, and biodegradability, the prepared active bio-nano composite packaging films could be considered a potential candidate for fruit packaging.


Biodegradable Nanocomposite Multifunctional Packaging Film For Fruits, Kalpani Y. Perera, Shubham Sharma, Dileswar Pradhan, Amit Jaiswal, Swarna Jaiswal Sep 2021

Biodegradable Nanocomposite Multifunctional Packaging Film For Fruits, Kalpani Y. Perera, Shubham Sharma, Dileswar Pradhan, Amit Jaiswal, Swarna Jaiswal

Articles

Biopolymers have been used in food packaging in recent years due to high pollution rates and decreased biodegradation of synthetic polymers. Chitosan (CH) and Sodium alginate (SA) are both biodegradable biopolymers with excellent film forming capability. TiO2 nanoparticles have high mechanical strength, degradation ability and antimicrobial properties, which are beneficial in food packaging. The aim of the current work is to develop the biodegradable multifunctional nanocomposite film for fruit (i.e., Pear) packaging applications. Bionanocomposite film was prepared by solvent casting method using CH-SA and various concentrations of TiO2. The multifunctional properties such as UV barrier, thermal, water retention, mechanical, chemical, …


Development And Evaluation Of A Functional Human Cardiac Tissue Equivalent Fabricated From Multi-Lineage Human Induced Pluripotent Stem Cell Derived Cells, Danielle Pretorius Jan 2021

Development And Evaluation Of A Functional Human Cardiac Tissue Equivalent Fabricated From Multi-Lineage Human Induced Pluripotent Stem Cell Derived Cells, Danielle Pretorius

All ETDs from UAB

The human heart is an exceptionally complex muscular organ that is vital for survival. Electrical impulses signal activation of mechanical contractions, pumping blood through the entire body and allowing for oxygen-exchange to occur. Unfortunately, certain disease states or traumatic injuries such as myocardial infarctions hamper the heart’s efficiency and function by damaging its structure. Ideal treatment would allow for the replacement or regeneration of the damaged tissue with cells and material harvested from the patient, thus avoiding the potential for immune rejection. Engineered cardiac tissues fabricated from human induced pluripotent stem cells have shown great promise for restoring function in …


Stimuli Response In Ph And Temperature-Responsive Hydrogels As Probed By Neutron Reflectivity, William Todd Higgins Jan 2020

Stimuli Response In Ph And Temperature-Responsive Hydrogels As Probed By Neutron Reflectivity, William Todd Higgins

All ETDs from UAB

Polymer materials can be used as platforms to incorporate sensing materials, and increasingly the structure and chemistry of polymer chains is exploited in new and novel way and the unique nanoscale properties are studied. Polymers which can be dissolved in water are particularly interesting as primary components or for modifications in biomaterial applications, as many of them can have variable solubility in response to pH, temperature, or other solution conditions. This can allow the formation of microcapsules, for example, which can release drug triggered via specific solution conditions to release chemotherapeutic drug; in comparison to traditional injection or slow-release bulk …


Synthesis, Stabilization, And Modification Of Zinc Oxide Nanoparticles For Biological Applications, Allison Kimberly Freese May 2019

Synthesis, Stabilization, And Modification Of Zinc Oxide Nanoparticles For Biological Applications, Allison Kimberly Freese

MSU Graduate Theses

Nanoparticles have become very useful as delivery systems in biomedicine. The nanoparticles can be layered with different compounds to produce a vessel for transport of biological materials. Specifically, gold nanoparticles layered with a reducing agent, lysozyme, and polyelectrolytes can be synthesized to transport lysozyme into a cell. However, zinc oxide nanoparticles are cheaper, biocompatible nanoparticles that can be used for the same process. Here in, zinc oxide nanoparticle conjugates were synthesized, modified, and analyzed to be used as a biological material delivery system. The zinc oxide nanoparticles were synthesized using zinc chloride and sodium hydroxide. The particles were then layered …


Metal Complexation In Hydrogen-Bonded Microcapsules Of Poly(N-Vinylpyrrolidone) And Tannic Acid For Medical Imaging And Controlled Drug Delivery, Patrick Aaron Alford Jan 2019

Metal Complexation In Hydrogen-Bonded Microcapsules Of Poly(N-Vinylpyrrolidone) And Tannic Acid For Medical Imaging And Controlled Drug Delivery, Patrick Aaron Alford

All ETDs from UAB

Even the most effective and widely used drugs in modern disease treatment can be compromised by low bioavailability and off-target damage which leads to detrimental side effects. Polymeric drug carriers have been developing in recent times with the aim of rendering the therapeutic cargo inert and protecting it from the body’s natural defense mechanisms until arrival at the target site, upon which a specific stimulus will cause the drug to release from the carrier locally. To this end, antioxidant capability in drug carriers can help mediate the cascade of reactive oxygen species that meet injected materials and, in doing so, …


Synthesis And Characterization Of Novel Diphosphonium Polymers With The Emphasis On Supramolecular Assembly, Catherine Alexis Conrad May 2018

Synthesis And Characterization Of Novel Diphosphonium Polymers With The Emphasis On Supramolecular Assembly, Catherine Alexis Conrad

All Theses

Three different series of diphosphonium polymers were synthesized in order to analyze the supramolecular assembly of these polyelectrolytes with varying polyanions. Variation of the rigidity of the spacer between the phosphonium units determined that flexibility leads to increased absorption and consistency to film growth when observed through layer-by-layer assembly with UV-vis spectroscopy and atomic force microscopy. With the flexible ethylene spacer, films formed linearly up to 800 bilayers thick. An additional series of xylene based flexible diphosphonium polymers were synthesized with increasing numbers of methylene unit spacers. Analysis of materials was conducted through thermogravimetric analysis, X-ray crystallography, and layer-by-layer analysis …


Biomimetic Layer-By-Layer Self-Assembly Of Nanofilms, Nanocoatings, And 3d Scaffolds For Tissue Engineering, Shichao Zhang, Malcolm Xing, Bingyun Li Jan 2018

Biomimetic Layer-By-Layer Self-Assembly Of Nanofilms, Nanocoatings, And 3d Scaffolds For Tissue Engineering, Shichao Zhang, Malcolm Xing, Bingyun Li

Faculty & Staff Scholarship

Achieving surface design and control of biomaterial scaffolds with nanometer- or micrometer-scaled functional films is critical to mimic the unique features of native extracellular matrices, which has significant technological implications for tissue engineering including cell-seeded scaffolds, microbioreactors, cell assembly, tissue regeneration, etc. Compared with other techniques available for surface design, layer-by-layer (LbL) self-assembly technology has attracted extensive attention because of its integrated features of simplicity, versatility, and nanoscale control. Here we present a brief overview of current state-of-the-art research related to the LbL self-assembly technique and its assembled biomaterials as scaffolds for tissue engineering. An overview of the LbL self-assembly …


Shaped Stimuli-Responsive Layer-By-Layer Hydrogels For Targeted Drug Delivery, Bing Xue Jan 2018

Shaped Stimuli-Responsive Layer-By-Layer Hydrogels For Targeted Drug Delivery, Bing Xue

All ETDs from UAB

The development of polymeric delivery systems help overcome the intrinsic drawbacks of systemically-delivered therapeutic drugs, such as poor solubility and stability, multidrug resistance, inefficient accumulation in the diseased sites and unexpected toxicity to normal tissues. Polymeric vehicles possessing stimuli-sensitivity can prevent premature drug leakage and enable controlled cargo release. The modification with bioactive ligands aids to the accumulation of carriers in the targeted tissues to locally increase the concentration of therapeutics and decrease off-target toxicity. The manipulation of physical characteristics (e.g. size, shape) is also essential in the design of drug delivery systems since these properties play pivotal roles in …


Novel Sputtered Stationary Phases For Solid Phase Microextraction, And Other Coatings And Materials For Surface Applications, Anubhav Diwan Mar 2016

Novel Sputtered Stationary Phases For Solid Phase Microextraction, And Other Coatings And Materials For Surface Applications, Anubhav Diwan

Theses and Dissertations

The primary focus of my work has been to prepare new solid adsorbents for solid phase microextraction (SPME) via sputtering of silicon. The orientation of the silica substrates/fibers and the sputtering pressure induced the formation of porous and columnar structures. Sputtering was performed for different times to yield fibers with different thicknesses. Piranha treatment of the surface increased the concentration of silanol groups, which underwent condensation with vapor deposited octadecyldimethylmonomethoxy silane to incorporate octadecyl chains onto the fiber surfaces. Silanized, sputtered fibers were preconditioned for 3 h at 320 °C to remove the unreacted chains. Comparison of the extraction efficiencies …


Oxygen-Free Layer-By-Layer Assembly Of Lithiated Composites On Graphene For Advanced Hydrogen Storage, Guanglin Xia, Yingbin Tan, Xiaowei Chen, Fang Fang, Dalin Sun, Xingguo Li, Zaiping Guo, Xuebin Yu Jan 2016

Oxygen-Free Layer-By-Layer Assembly Of Lithiated Composites On Graphene For Advanced Hydrogen Storage, Guanglin Xia, Yingbin Tan, Xiaowei Chen, Fang Fang, Dalin Sun, Xingguo Li, Zaiping Guo, Xuebin Yu

Australian Institute for Innovative Materials - Papers

A facile hydrogenation-induced self-assembly strategy to synthesize lithium hydride (LiH) nanosheets with a thickness of 2 nm that are uniformly distributed on graphene is reported and designed. Taking advantage of LiH nanosheets with high reactivity and a homogeneous distribution on graphene support as a nanoreactor, the confined chemical synthesis of oxygen-free lithiated composites is effectively and efficiently realized.


Metabolic Toxicity Studies Using High Throughput Bioreactor Assay And Liquid Chromatography Coupled With Mass Spectrometry (Lc-Ms/ Ms), Dandan Li Dec 2014

Metabolic Toxicity Studies Using High Throughput Bioreactor Assay And Liquid Chromatography Coupled With Mass Spectrometry (Lc-Ms/ Ms), Dandan Li

Doctoral Dissertations

Metabolic toxicity is one of main concerns in drug discovery and development. High efficient and low cost metabolic toxicity assessment is still a major challenge for pharmaceutical industry. This thesis focuses on the development of high throughput in vitro metabolic toxicity assay coupling with liquid chromatography tandem mass spectrometry for metabolic adducts generation, characterization and quantitation. The key technology was based on electrostatic fabrication of polyelectrolytes and biomolecules on magnetic beads to form bioreactors in 96 well plate format and acquired metabolites induced toxicity molecular information by LC-MS experiments.

Chapter one will address the goals and significance of the metabolic …


Poly(N-Vinylcaprolactam) Based Thermoresponsive Nanostructured Materials, Xing Liang Jan 2014

Poly(N-Vinylcaprolactam) Based Thermoresponsive Nanostructured Materials, Xing Liang

All ETDs from UAB

Poly(N-vinylcaprolactam) (PVCL) is a temperature-responsive polymer displaying a low critical solution temperature (LCST) around 30 to 40℃ in aqueous solutions that is close to the human physiological temperature. In addition, compared to other ther-moresponsive polymers, PVCL is nontoxic and biocompatible. In this thesis, we will fo-cus on the synthesis, fabrication and characterization of PVCL-based thermoresponsive nanostructured materials, such as films, hydrogels and block copolymers and their poten-tial applications in biomedical and medical areas. In chapter 2, we report on nanothin multilayer hydrogels of cross-linked PVCL that exhibited distinctive and reversible thermoresponsive behavior. The single-component PVCL hydrogels were produced by selective …


Layer-By-Layer Assemblies For Membrane-Based Enzymatic Catalysis, Andrew R. Tomaino Jan 2014

Layer-By-Layer Assemblies For Membrane-Based Enzymatic Catalysis, Andrew R. Tomaino

Theses and Dissertations--Chemical and Materials Engineering

While considerable progress has been made towards understanding the effect that membrane-based layer-by-layer (LbL) immobilizations have on the activity and stability of enzymatic catalysis, detailed work is required in order to fundamentally quantify and optimize the functionalization and operating conditions that define these properties. This work aims to probe deeper into the nature of transport mechanisms by use of pressure-induced, flow-driven enzymatic catalysis of LbL-functionalized hydrophilized poly(vinyldiene) (PVDF)-poly(acrylic acid) (PAA)-poly(allylamine hydrochloride) (PAH)-glucose oxidase (GOx) membranes. These membranes were coupled in a sealed series following cellulose acetate (CA) membranes for the elimination of product accumulation within the feed-side solution during operation. …


Ultrasonication Assisted Layer-By-Layer Technology For The Preparation Of Multi-Functional Anticancer Drugs Paclitaxel And Lapatinib, Xingcai Zhang Jan 2013

Ultrasonication Assisted Layer-By-Layer Technology For The Preparation Of Multi-Functional Anticancer Drugs Paclitaxel And Lapatinib, Xingcai Zhang

Doctoral Dissertations

In this dissertation, ultrasonication assisted Layer-by-Layer (LbL) technology for the preparation of multifunctional poorly water-soluble anticancer drug nanoparticles, paclitaxel and lapatinib, has been developed. Many FDA approved drugs are very low soluble in water; therefore, it is very difficult to load and control their release and targeting efficiently, which greatly confines their application. The development of this method will pave the way for the development and application of those low soluble anticancer drugs.

In the first part of this dissertation, the first approach for powerful ultrasonication, the top-down approach (sonicating bulk drug crystals in polyelectrolyte solution), was successfully applied for …


Synthesis Of Ph-Responsive Multilayer Hydrogels And Amphiphilic Block Copolymers, Yun Wang Jan 2013

Synthesis Of Ph-Responsive Multilayer Hydrogels And Amphiphilic Block Copolymers, Yun Wang

All ETDs from UAB

The research presented in this thesis is focused at the design and fabrication of pH-responsive layer-by-layer (LbL) hydrogels and the synthesis of the ABA block copolymer poly(2-methyloxazoline)-block-poly(dimethylsiloxane)-block-poly(2-methyl-oxazoline) (PMOXA-b-PDMS-b-PMOXA). Ultrathin stimuli-responsive layer-by-layer hydrogels, as compared to bulk hydrogels, can respond to external stimuli in a short time range (usually within seconds) which renders them particularly useful in sensing. Moreover, layer-by-layer technique allows the hydrogel film to be deposited with controlled thickness growth. However, the fabrication of LbL hydrogels with controllable cross-linking density and swelling degree still remains challenging. In chapter two, novel pH-sensitive LbL hydrogels based on poly(4-vinyl pyridine) (P4VP) were …


In Situ Synthesis Of Oligonucleotide Arrays On Surfaces Coated With Crosslinked Polymer Multilayers, Adam H. Broderick, Matthew R. Lockett, Maren E. Buck, Yuan Yuan, Lloyd M. Smith, David M. Lynn Mar 2012

In Situ Synthesis Of Oligonucleotide Arrays On Surfaces Coated With Crosslinked Polymer Multilayers, Adam H. Broderick, Matthew R. Lockett, Maren E. Buck, Yuan Yuan, Lloyd M. Smith, David M. Lynn

Chemistry: Faculty Publications

We report an approach to the in situ synthesis of oligonucleotide arrays on surfaces coated with crosslinked polymer multilayers. Our approach makes use of methods for the "reactive" layer-by-layer assembly of thin, amine-reactive multilayers using branched polyethyleneimine (PEI) and the azlactone-functionalized polymer poly(2-vinyl-4,4′-dimethylazlactone) (PVDMA). Postfabrication treatment of film-coated glass substrates with d-glucamine or 4-amino-1-butanol yielded hydroxyl-functionalized films suitable for the Maskless Array Synthesis (MAS) of oligonucleotide arrays. Glucamine-functionalized films yielded arrays of oligonucleotides with fluorescence intensities and signal-to-noise ratios (after hybridization with fluorescently labeled complementary strands) comparable to those of arrays fabricated on conventional silanized glass substrates. These arrays could …


Surface Morphology Of Platelet Adhesion Influenced By Activators, Inhibitors And Shear Stress, Melanie Groan Watson Oct 2010

Surface Morphology Of Platelet Adhesion Influenced By Activators, Inhibitors And Shear Stress, Melanie Groan Watson

Doctoral Dissertations

Platelet activation involves multiple events, one of which is the generation and release of nitric oxide (NO), a platelet aggregation inhibitor. Platelets simultaneously send and receive various agents that promote a positive and negative feedback control system during hemostasis. Although the purpose of platelet-derived NO is not fully understood, NO is known to inhibit platelet recruitment. NO's relatively large diffusion coefficient allows it to diffuse more rapidly than platelet agonists. It may thus be able to inhibit recruitment of platelets near the periphery of a growing thrombus before agonists have substantially accumulated in those regions.

Results from two studies in …


An Improved Layer-By-Layer Self-Assembly Technique To Generate Biointerfaces For Platelet Adhesion Studies: Dynamic Lbl, Juan Manuel Lopez Oct 2010

An Improved Layer-By-Layer Self-Assembly Technique To Generate Biointerfaces For Platelet Adhesion Studies: Dynamic Lbl, Juan Manuel Lopez

Doctoral Dissertations

Layer-by-layer self-assembly (LbL) is a technique that generates engineered nano-scale films, coatings, and particles. These nanoscale films have recently been used in multiple biomedical applications. Concurrently, microfabrication methods and advances in microfluidics are being developed and combined to create "Lab-on-a-Chip" technologies. The potential to perform complex biological assays in vitro as a first-line screening technique before moving on to animal models has made the concept of lab on a chip a valuable research tool.

Prior studies in the Biofluids Laboratory at Louisiana Tech have used layer-by-layer and in vitro biological assays to study thrombogenesis in a controlled, repeatable, engineered environment. …


Nano-Imprinted Thin Films Of Reactive, Azlactone-Containing Polymers: Combining Methods For The Topographic Patterning Of Cell Substrates With Opportunities For Facile Post-Fabrication Chemical Functionalization, Nathaniel J. Fredin, Ryan M. Flessner, Christopher M. Jewell, Shane L. Bechler, Maren E. Buck, David M. Lynn Sep 2010

Nano-Imprinted Thin Films Of Reactive, Azlactone-Containing Polymers: Combining Methods For The Topographic Patterning Of Cell Substrates With Opportunities For Facile Post-Fabrication Chemical Functionalization, Nathaniel J. Fredin, Ryan M. Flessner, Christopher M. Jewell, Shane L. Bechler, Maren E. Buck, David M. Lynn

Chemistry: Faculty Publications

Laser scanning confocal microscopy (LSCM) and atomic force microscopy (AFM) were used to characterize changes in nanoscale structure that occur when ultrathin polyelectrolyte multilayers (PEMs) are incubated in aqueous media. The PEMs investigated here were fabricated by the deposition of alternating layers of plasmid DNA and a hydrolytically degradable polyamine onto a precursor film composed of alternating layers of linear poly(ethylene imine) (LPEI) and sodium poly(styrene sulfonate) (SPS). Past studies of these materials in the context of gene delivery revealed transformations from a morphology that is smooth and uniform to one characterized by the formation of nanometer-scale particulate structures. We …


Functionalization Of Fibers Using Azlactone-Containing Polymers: Layer-By-Layer Fabrication Of Reactive Thin Films On The Surfaces Of Hair And Cellulose-Based Materials, Maren E. Buck, David M. Lynn May 2010

Functionalization Of Fibers Using Azlactone-Containing Polymers: Layer-By-Layer Fabrication Of Reactive Thin Films On The Surfaces Of Hair And Cellulose-Based Materials, Maren E. Buck, David M. Lynn

Chemistry: Faculty Publications

We report an approach to the functionalization of fibers and fiber-based materials that is based on the deposition of reactive azlactone-functionalized polymers and the "reactive" layer-by-layer assembly of azlactone-containing thin films. We demonstrate (i) that the azlactone-functionalized polymer poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) can be used to modify the surfaces of a model protein-based fiber (horsehair) and cellulose-based materials (e.g., cotton and paper), and (ii) that fibers functionalized in this manner can be used to support the fabrication of covalently cross-linked and reactive polymer multilayers assembled using PVDMA and poly(ethyleneimine) (PEI). The growth, chemical reactivity, and uniformity of films deposited on these substrates …


Oxygen Supplementing, Biocompatible Outer Membranes For Enhanced Performance Of Implantable Glucose Sensors, Hardeep Singh May 2010

Oxygen Supplementing, Biocompatible Outer Membranes For Enhanced Performance Of Implantable Glucose Sensors, Hardeep Singh

Honors Scholar Theses

Lack of linearity and sensitivity, oxygen dependence, biofouling and tissue inflammation hinder the development of implantable biosensors for continuous monitoring of glucose. Herein, we report the development of stacked outer membranes based on LBL/PVA hydrogels that improve sensor sensitivity, linearity, oxygen independence and counter biofouling and inflammation. While the inner LBL membrane affords tunable diffusivity, the outer PVA is capable of releasing anti-inflammatory drugs/tissue response modifying agents to counter acute and chronic inflammation, and to induce neo-angiogenesis at the implant site. Sensors were fabricated by immobilizing GOx enzyme on top of 50 μm platinum wires, followed by deposition of stacked …


Layer-By-Layer Assembly Of {Nanoclay-(Sol-Gel Oxide)}N And {Nanoclay-(Oxide Nanoparticle)}N Multilayers: Synthesis And Growth Mechanisms, Hao Chen May 2010

Layer-By-Layer Assembly Of {Nanoclay-(Sol-Gel Oxide)}N And {Nanoclay-(Oxide Nanoparticle)}N Multilayers: Synthesis And Growth Mechanisms, Hao Chen

All Dissertations

Two new classes of all-inorganic nanostructured multilayers, {MMTx-(sol-gel oxide)}n and {MMTx-(oxide nanoparticle)}n, have been successfully synthesized for the first time. They were made by adapting a layer-by-layer (LbL) assembly method initially developed to synthesize polyelectrolyte-based multilayers. In most previous studies, this electrostatic-assisted LbL assembly method used polyelectrolytes/polymers as the 'structural glue' to prepare multilayers. The synthesis of {MMTx-(sol-gel ZrO2)}n multilayers demonstrates for the first time the feasibility of making sol-gel oxide 'glued' all-inorganic multilayers, thereby introducing an innovative nanoscale fabrication concept. The synthesis of {MMTx-(oxide nanoparticle)}n multilayers further illustrates the versatility of LbL assembly technique by achieving a second new …


A Novel Glucose Chemiluminescence Biosensor Based On A Rhodanine Derivative Chemiluminescence System And Multilayer-Enzyme Membrane, Jinghua Yu, Lei Ge, Ping Dai, Congcong Zhang, Shenguang Ge, Jiadong Huang Jan 2010

A Novel Glucose Chemiluminescence Biosensor Based On A Rhodanine Derivative Chemiluminescence System And Multilayer-Enzyme Membrane, Jinghua Yu, Lei Ge, Ping Dai, Congcong Zhang, Shenguang Ge, Jiadong Huang

Turkish Journal of Chemistry

Using glucose oxidase as a model enzyme, a novel rhodanine derivative chemiluminescence biosensor for the determination of glucose was formed based on multilayer-enzyme membrane as receptor, which was assembled via layer-by-layer assembly of sol-gel and glucose oxidase-gold nano-particles inside a glass tube. Compared with the traditional chemiluminescence biosensor, the proposed biosensor had some remarkable advantages, such as good selectivity of substrate, good response performance, good stability, good sensitivity, and longer service life. The linear range was from 1.0 \times 10^{-6} to 5.0 \times 10^{-2} mol L^{-1} (r = 0.9991). The detection limit was 5.0 \times 10^{-7} mol L^{-1}. In this …


Interfacial Polymerization Of Water-Soluble Polyaniline And Its Assembly Using The Layer-By-Layer Technique, E Detsri, S T. Dubas Jul 2009

Interfacial Polymerization Of Water-Soluble Polyaniline And Its Assembly Using The Layer-By-Layer Technique, E Detsri, S T. Dubas

Journal of Metals, Materials and Minerals

The interfacial polymerization of aniline has been used to prepare water-soluble polyaniline. Polyaniline was made water-soluble by interfacial polymerization in the presence of poly(styrene sulfonated, sodium salt) (PSS), which acted as bundling agent to provide water solubility. The prepared polymer composite was later used for the fabrication of polyaniline nano-thin films using the layer-by-layer (LbL) self-assembly technique. Film produced by the LbL technique can be used in electro-chromic films, sensors or electro-catalytic films depending on the type of architectures. This paper first presents, a brief review on conducting polymer prepared by interfacial polymerization. Special interest is given to the synthesis …