Functionalized Polymeric Nanoparticles

2004 ◽  
Vol 818 ◽  
Author(s):  
Eric Sussman ◽  
Michael Clark ◽  
V. Prasad Shastri
Keyword(s):  
Drug Delivery ◽  
Photoelectron Spectroscopy ◽  
Cellular Localization ◽  
Polymeric Nanoparticles ◽  
Fluorescent Microscopy ◽  
Single Step ◽  
Layer By Layer ◽  
Bearing Surface ◽  
X Ray ◽  
Surface Functionality

AbstractSurface-functionalized polymeric nanoparticles (NP) are a versatile medium for drug delivery and imaging. The surface functionality is typically exploited to introduce molecules such as polymers and biomolecules to improve cellular localization, DNA binding and circulation. NP bearing surface functionality are typically prepared from polymers possessing functionalizable backbones or by layer-by-layer assembly of polyelectrolytes onto unmodified particles. We have developed a process to produce functionalized polymeric NP in a single step using non-functionalized polymers. This is achieved by the entrapment of polymeric functional moieties from an aqueous phase in a rapidly solidifying polymer core. NP were characterized using light scattering, scanning electron microscopy, zeta potential (ζ) measurement, fluorescent microscopy, and X-ray photoelectron spectroscopy (XPS). Stable NP ranging in diameter from 70 to 400nm with narrow polydispersity (PDI) can be produced by this process. The presence of functional moieties on the NP surface was verified by isoelectric point measurement and XPS. We foresee a number of uses for these functionalized nanoparticles, including drug delivery and modification of hard and soft material surfaces (both synthetic and biological) for tissue engineering.

scholarly journals XPS Modeling of Immobilized Recombinant Angiogenin and Apoliprotein A1 on Biodegradable Nanofibers

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 879
Author(s):  
Anton Manakhov ◽  
Elizaveta Permyakova ◽  
Sergey Ershov ◽  
Svetlana Miroshnichenko ◽  
Mariya Pykhtina ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Growth Factor ◽  
Photoelectron Spectroscopy ◽  
Antioxidant Activities ◽  
Fluorescent Microscopy ◽  
X Ray ◽  
Vascular Growth ◽  
Vascular Growth Factor ◽  
And Migration ◽  
Protein Density

The immobilization of viable proteins is an important step in engineering efficient scaffolds for regenerative medicine. For example, angiogenin, a vascular growth factor, can be considered a neurotrophic factor, influencing the neurogenesis, viability, and migration of neurons. Angiogenin shows an exceptional combination of angiogenic, neurotrophic, neuroprotective, antibacterial, and antioxidant activities. Therefore, this protein is a promising molecule that can be immobilized on carriers used for tissue engineering, particularly for diseases that are complicated by neurotrophic and vascular disorders. Another highly important and viable protein is apoliprotein A1. Nevertheless, the immobilization of these proteins onto promising biodegradable nanofibers has not been tested before. In this work, we carefully studied the immobilization of human recombinant angiogenin and apoliprotein A1 onto plasma-coated nanofibers. We developed a new methodology for the quantification of the protein density of these proteins using X-ray photoelectron spectroscopy (XPS) and modeled the XPS data for angiogenin and apoliprotein A1 (Apo-A1). These findings were also confirmed by the analysis of immobilized Apo-A1 using fluorescent microscopy. The presented methodology was validated by the analysis of fibronectin on the surface of plasma-coated poly(ε-caprolactone) (PCL) nanofibers. This methodology can be expanded for other proteins and it should help to quantify the density of proteins on surfaces using routine XPS data treatment.

X-Ray Photoelectron-Spectroscopic Studies of Carbon Fiber Surfaces. Part IX: The Effect of Microwave Plasma Treatment on Carbon Fiber Surfaces

1989 ◽  
Vol 43 (7) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yaoming Xie ◽  
Peter M. A. Sherwood
Keyword(s):  
Carbon Fiber ◽  
Plasma Treatment ◽  
Photoelectron Spectroscopy ◽  
Prolonged Exposure ◽  
Microwave Plasma ◽  
Spectroscopic Studies ◽  
X Ray ◽  
Fiber Damage ◽  
Surface Functionality ◽  
Fiber Treatment

X-ray photoelectron spectroscopy has been used to monitor the surface chemical changes occurring on type II carbon fibers exposed to air, oxygen, and nitrogen plasmas. In all cases the plasmas caused changes in surface functionality, in terms of both C-O and C-N functionality. Prolonged exposure to the plasmas caused loss of surface functionality for air and oxygen plasmas, and extended treatment caused fiber damage. Plasma treatment of fibers promises to be an effective method of fiber treatment.

Synthesis and Characterization of Zn Oxide Hexagonal Nano-Pole Films on Quartz Glass Substrate

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Jie Chen ◽  
Jun Wang
Keyword(s):  
Growth Mechanism ◽  
Quartz Glass ◽  
Photoelectron Spectroscopy ◽  
Glass Substrate ◽  
Sol Gel ◽  
Layer Growth ◽  
Layer By Layer ◽  
Quartz Glass Substrate ◽  
Wurtzite Phase ◽  
X Ray

Hexagon-shaped Zn oxide nano-pole films with terraces and steps have been successfully fabricated by means of a combined approach involving sol-gel process, high-temperature heat treatment, and the hydrothermal method. The surface chemistry and morphological features of the films were characterized by means of x-ray photoelectron spectroscopy and scanning electron microcopy. All the diffraction peaks in x-ray diffraction pattern match with those of the hexagonal wurtzite phase of Zn oxide. Transmittance measurements show that the optical transmittance of the sample synthesized at 520°C on quartz glass substrate is the highest, reaching about 65% in the visible-light region. Based on the detailed structural characterization and the nucleation-growth kinetics, we find that the whole crystallization process of wurtzite Zn oxide nano-poles includes nanocatalysis and layer-by-layer growth mechanism. The present study provides an important understanding of the growth mechanism for nano-pole synthesis of Zn oxide and related materials.

scholarly journals Single-step surface functionalization of polymeric nanoparticles for targeted drug delivery

Biomaterials ◽  
2009 ◽  
Vol 30 (5) ◽  
pp. 859-866 ◽  
Author(s):  
Yogesh B. Patil ◽  
Udaya S. Toti ◽  
Ayman Khdair ◽  
Linan Ma ◽  
Jayanth Panyam
Keyword(s):  
Drug Delivery ◽  
Surface Functionalization ◽  
Targeted Drug Delivery ◽  
Polymeric Nanoparticles ◽  
Single Step ◽  
Targeted Drug

Nanocomposite Synthesis from a Natural Clay-Rich Soils and Exhausted Coffee Grounds for Environmental Applications

2020 ◽  
Vol 63 ◽  
pp. 47-63
Author(s):  
Vianey Urdapilleta-Inchaurregui ◽  
Fabián Fernández-Luqueño ◽  
Aidé Minerva Torres-Huerta ◽  
Daniela Roa-Velázquez ◽  
Francisco Javier Rodríguez-Varela ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Gas Adsorption ◽  
Energy Gap ◽  
Single Step ◽  
Natural Soil ◽  
Thermal Method ◽  
X Ray ◽  
Coffee Grounds

Natural clays, engineered Ag-nanoparticles (NP), TiO2-NP, and exhausted coffee grounds were used to synthesize a nanocomposite 7NC using a Vertisol soil through a single-step by thermal method, to build a nanomaterial to degrade or filtrate pollutants from soils, water or air. The surface characteristics and the porosity of the composite were studied through nitrogen gas adsorption at liquid nitrogen temperature and application of the Brunauer–Emmett–Teller (BET) equation and the results indicated that the microporous composites ranged a surface area of 17.36 m2 g-1. X-ray diffraction showed crystalline structure and crystalline phase of the nanocomposites. HR-TEM-STEM results demonstrated that TiO2-NP surrounded Ag-NP, and both were impregnated on natural soil nanoparticles. Oxidation states of the Ag-NP and TiO2-NP were analyzed by X-ray photoelectron spectroscopy (XPS) The energy gap of nanocomposite 7NC was determined using the Kubelka-Munck model from Ultraviolet–visible diffuse reflectance (UV–Visible DRS) spectra. The photocatalytic activity of these nanocomposites was evaluated, and the results indicated that nanocomposite with Vertisol-soil-NP (7NC) degraded the harmful organic compound methylene blue (MB) while the antimicrobial activity and resistance against Escherichia coli and Staphylococcus aureus and the zone of inhibition (ZOI) also were analyzed. The nanocomposites Ag-NP/TiO2-NP/natural-soil-NP/exhausted coffee-ground showed its for the development of an efficient material for environmental remediation with photocatalytic and antimicrobial activity.

Surface Characterization of Lipid/Chitosan Nanoparticles Assemblies, Using X-Ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry

2008 ◽  
Vol 8 (1) ◽  
pp. 358-365 ◽  
Author(s):  
Ana Grenha ◽  
Begoña Seijo ◽  
Carmen Serra ◽  
Carmen Remuñán-López
Keyword(s):  
Mass Spectrometry ◽  
Drug Delivery ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Chitosan Nanoparticles ◽  
Time Of Flight ◽  
Lipid Film ◽  
X Ray ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Chitosan/tripolyphosphate nanoparticles are promising drug delivery systems, which show excellent capacity for protein entrapment and improvement of mucosal peptide absorption. We have recently developed a new drug delivery system consisting of assemblies formed between preformed chitosan nanoparticles and phospholipids (dipalmitoylphosphatidylcholine and dimiristoylphosphatidyl-glycerol) which are endogenous to the lung. These assemblies are prepared by lipid film hydration with a nanoparticles suspension. The aim of this work was to elucidate the architecture of these structures using sensitive surface analysis techniques such as X-ray photoelectron spectroscopy and static time-of-flight secondary ion mass spectrometry, as well as to determine their physicochemical characteristics. The combination of zeta potential measurements with the results obtained by X-ray photoelectron spectroscopy and static time-of-flight secondary ion mass spectrometry, demonstrated that a complete lipid coating of the nanoparticles can be achieved using a lipid film formed by both dipalmitoylphosphatidylcholine and dimiristoylphosphatidylglycerol, this way conferring to the lipid film a strong negative charge, which favors the interaction with the positively charged nanoparticles. Therefore, the major role of electrostatic interactions as driving forces to control the organisation of the lipid/nanoparticles assemblies was clearly evident. The implications of these findings for the structural organisation of the assemblies, for their in vitro behaviour, as well as for their mechanism of formation are discussed.

scholarly journals Characterisation of C–F Polymer Film Formation on the Air-Bearing Surface Etched Sidewall of Fluorine-Based Plasma Interacting with AL2O3–TiC Substrate

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Alonggot Limcharoen ◽  
Pichet Limsuwan ◽  
Chupong Pakpum ◽  
Krisda Siangchaew
Keyword(s):  
Raman Spectroscopy ◽  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
Isopropyl Alcohol ◽  
Film Formation ◽  
Air Bearing ◽  
Cleaning Process ◽  
Bearing Surface ◽  
X Ray ◽  
Scanning Electron

C–F polymer redeposition is generated on the etched sidewall of the patterned air-bearing surface (ABS). This C–F polymer is a by-product from fluorine-based plasma using a Surface Technology Systems multiplex-pro air-bearing etch (ABE). The morphology of the re-deposition and the composite element was observed by a scanning electron microscope (SEM). The chemical bonding results were characterised via X-ray photoelectron spectroscopy, attenuated total reflected infrared spectroscopy and visible Raman spectroscopy. The purpose of this work is to demonstrate a modification of AlF3re-deposition to C–F polymer re-deposition, which is easily stripped out by an isopropyl alcohol-based solution. The benefit of this research is the removal of the re-deposition in the resist strip process without additional cleaning process steps.

Structural and Morphological Properties of Ultrathin HfO2 Dielectrics on 4H-SiC (0001)

2006 ◽  
Vol 527-529 ◽  
pp. 1075-1078 ◽  
Author(s):  
Carey M. Tanner ◽  
Jun Lu ◽  
Hans Olof Blom ◽  
Jane P. Chang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Field Effect Transistors ◽  
High Energy ◽  
Oxide Semiconductor ◽  
Ex Situ ◽  
Morphological Properties ◽  
Layer By Layer ◽  
Island Growth ◽  
X Ray

The material properties of HfO2 thin films were studied to evaluate their potential as a high-κ gate dielectric in 4H-SiC power metal-oxide-semiconductor field effect transistors. Stoichiometric HfO2 films were deposited on n-type 4H-SiC (0001) by atomic layer deposition (ALD) at substrate temperatures of 250-450°C. No significant interfacial layer formation was observed by in-situ X-ray photoelectron spectroscopy (XPS) and an abrupt interface was confirmed by high-resolution transmission electron microscopy (HRTEM). A temperature-dependent transition from amorphous layer-by-layer growth to crystalline three-dimensional island growth was identified by in-situ reflection high-energy electron diffraction (RHEED) and ex-situ atomic force microscopy (AFM). X-ray diffraction (XRD) confirmed the presence of monoclinic HfO2 domains in crystallized films.

Preparation of Poly(diallydimethyl ammonium chloride) (PDDA)/Au Nanocomposite Film by In Situ Electrochemical Reduction and its Electrocatalytic Properties

2010 ◽  
Vol 123-125 ◽  
pp. 189-192
Author(s):  
Hong Wei Shi ◽  
Li Zhang ◽  
Cong Wang ◽  
Ke Ying Zhang
Keyword(s):  
Electrochemical Reduction ◽  
Ammonium Chloride ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Composite Films ◽  
Nanocomposite Films ◽  
Layer By Layer ◽  
X Ray ◽  
Assembly Technique

Nanocomposite films containing Au nanoparticles were fabricated by alternating adsorption of poly(diallydimethyl ammonium chloride) (PDDA) and HAuCl4 using layer-by-layer self-assembly technique and subsequent in situ electrochemical reduction of the AuCl4- ions. The composition and properties of the composite films were characterized by ultraviolet-visible spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV).The UV-vis characteristic absorbances of PDDA and Au increase almost linearly with the number of bilayers, which suggests a progressive deposition with almost an equal amount of the PDDA and Au in each cycle. X-ray photoelectron spectroscopy further confirms the presence of the main components (such as PDDA and Au) of the nanocomposite films. Furthermore, the nanocomposite films also exhibit good electrocatalytic activity for the oxidation of ascorbic acid (AA), which may be used in electrochemical biosensors.

siRNA Drug Delivery by Biodegradable Polymeric Nanoparticles

2006 ◽  
Vol 6 (9) ◽  
pp. 2821-2828 ◽  
Author(s):  
Xudong Yuan ◽  
Ling Li ◽  
Appu Rathinavelu ◽  
Jinsong Hao ◽  
Madhusudhanan Narasimhan ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Gene Silencing ◽  
Polymeric Nanoparticles ◽  
Drug Carrier ◽  
Fluorescent Microscopy ◽  
Cell Types ◽  
Plga Nanoparticles ◽  
Future Research ◽  
Diverse Range ◽  
Small Interference Rna

RNA interference (RNAi) is an emerging technology in which the introduction of double-stranded RNA (dsRNA) into a diverse range of organisms and cell types causes degradation of the complementary mRNA. It offers a broad spectrum of applications in both biological and medical research. Small interference RNA (siRNA) was recently explored for its therapeutical potential. However, the drug delivery of siRNA oligos is very novel and is in great need of future research. To this end, a biodegradable poly(D,L-lactide-co-glycolide) (PLGA) nanoparticle drug carrier system was prepared to load siRNA oligos with desired physicochemical properties. The nanoparticles were characterized by scanning electron microscopy and laser diffraction particle sizer. The delivery of siRNA into the targeted 293T cells was observed using fluorescent-labeled double-stranded Cy3-oligos. The model siRNA oligos, si-GFP-RNA, were also successfully loaded into PLGA nanoparticles and delivered in 293T cells. The gene silencing effect and the inhibition of GFP expression were investigated using fluorescent microscopy. Both positive and negative controls were used to compare with the new siRNA nanoparticle delivery system. It was found that nanoparticles offered both effective delivery of siRNA and prominent GFP gene silencing effect. Compared to conventional carrier systems, the new biodegradable polymeric nanoparticle system may also offer improved formulation stability, which is practically beneficial and may be used in the future clinical studies of siRNA therapeutics.

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