scholarly journals Novel Nanoparticles Based on N,O-Carboxymethyl Chitosan-Dopamine Amide Conjugate for Nose-to-Brain Delivery

Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 147
Author(s):  
Adriana Trapani ◽  
Stefania Cometa ◽  
Elvira De Giglio ◽  
Filomena Corbo ◽  
Roberta Cassano ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Fluorescent Microscopy ◽  
Covalent Bond ◽  
Brain Delivery ◽  
Dopaminergic Drugs ◽  
Disease Modifying Therapy ◽  
Midbrain Neurons ◽  
Nanoprecipitation Method ◽  
Further Development ◽  
High Chemical Stability

A widely investigated approach to bypass the blood brain barrier is represented by the intranasal delivery of therapeutic agents exploiting the olfactory or trigeminal connections nose-brain. As for Parkinson’s disease (PD), characterized by dopaminergic midbrain neurons degeneration, currently there is no disease modifying therapy. Although several bio-nanomaterials have been evaluated for encapsulation of neurotransmitter dopamine (DA) or dopaminergic drugs in order to restore the DA content in parkinsonian patients, the premature leakage of the therapeutic agent limits this approach. To tackle this drawback, we undertook a study where the active was linked to the polymeric backbone by a covalent bond. Thus, novel nanoparticles (NPs) based on N,O-Carboxymethylchitosan-DA amide conjugate (N,O-CMCS-DA) were prepared by the nanoprecipitation method and characterized from a technological view point, cytotoxicity and uptake by Olfactory Ensheating Cells (OECs). Thermogravimetric analysis showed high chemical stability of N,O-CMCS-DA NPs and X-ray photoelectron spectroscopy evidenced the presence of amide linkages on the NPs surface. MTT test indicated their cytocompatibility with OECs, while cytofluorimetry and fluorescent microscopy revealed the internalization of labelled N,O-CMCS-DA NPs by OECs, that was increased by the presence of mucin. Altogether, these findings seem promising for further development of N,O-CMCS-DA NPs for nose-to-brain delivery application in PD.

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.

Establishing Chemical Bond Layer of Poly(Ethylene Glycol) on NiTi Alloy Surface

2013 ◽  
Vol 785-786 ◽  
pp. 578-581
Author(s):  
Hong Yan Yu ◽  
Lian Cai Wang ◽  
Yan Li ◽  
Xin Miao Zeng ◽  
Xin Qing Zhao
Keyword(s):  
Ethylene Glycol ◽  
Photoelectron Spectroscopy ◽  
Niti Alloy ◽  
Covalent Bond ◽  
Niti Shape Memory Alloy ◽  
Poly Ethylene Glycol ◽  
Γ Irradiation ◽  
Piranha Solution ◽  
Bond Layer ◽  
Poly Ethylene

To get bioorganic surface with improving biological properties, NiTi shape memory alloy was bonded poly (ethylene glycol) (PEG) by sequentially piranha solution treating, silanizing, and then γ-ray irradiation induced grafting. Piranha solution treating gave hydroxylated surfaces for the benefit of next silanization. The trichlorovinylsilane (TCVS) was performed as a bridge to covalent bond treated NiTi substrates and PEG by γ-irradiation. X-ray photoelectron spectroscopy (XPS) was used to indicate that PEG was bonded on silanized NiTi surface by irradiation. Osteoblast culture of 1 day and methyl-thiazol-tetrazolium (MTT) assay showed that PEG bonded on NiTi surface enhanced cell proliferation and cell amount increased significantly with increasing the concentration of bonded PEG.

scholarly journals Cross-Linking With Diamine Monomers to Prepare Graphene Oxide Composite Membranes With Varying D-Spacing for Enhanced Desalination Properties

2021 ◽  
Vol 9 ◽  
Author(s):  
Hong Ju ◽  
Jinzhuo Duan ◽  
Haitong Lu ◽  
Weihui Xu
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Water Flux ◽  
Covalent Bond ◽  
Composite Membranes ◽  
Rejection Rate ◽  
High Water ◽  
Cross Linking ◽  
Separation Performance ◽  
X Ray

As a new type of membrane material, graphene oxide (GO) can easily form sub-nanometer interlayer channels, which can effectively screen salt ions. The composite membrane and structure with a high water flux and good ion rejection rate were compared by the cross-linking of GO with three different diamine monomers: ethylenediamine (EDA), urea (UR), and p-phenylenediamine (PPD). X-ray photoelectron spectroscopy (XPS) results showed that unmodified GO mainly comprises π-π interactions and hydrogen bonds, but after crosslinking with diamine, both GO and mixed cellulose (MCE) membranes are chemically bonded to the diamine. The GO-UR/MCE membrane achieved a water flux similar to the original GO membrane, while the water flux of GO-PPD/MCE and GO-EDA/MCE dropped. X-ray diffraction results demonstrated that the covalent bond between GO and diamine can effectively inhibit the extension of d-spacing during the transition between dry and wet states. The separation performance of the GO-UR/MCE membrane was the best. GO-PPD/MCE had the largest contact angle and the worst hydrophilicity, but its water flux was still greater than GO-EDA/MCE. This result indicated that the introduction of different functional groups during the diamine monomer cross-linking of GO caused some changes in the performance structure of the membrane.

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.

Preparation and Characterization of Chromium Containing amorphous Hydrogenated Carbon Films (A-C:H/Cr)

1995 ◽  
Vol 388 ◽  
Author(s):  
R. Gampp ◽  
P. Gantenbein ◽  
P. Oelhafen
Keyword(s):  
Chromium Carbide ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Rf Plasma ◽  
Silicon Substrates ◽  
Amorphous Hydrogenated Carbon ◽  
High Chemical Stability

AbstractChromium containing amorphous hydrogenated carbon films (a-C:H/Cr) were prepared in a process that combines rf plasma activated chemical vapor deposition of methane and magnetron sputtering of a chromium target. During the deposition the silicon substrates were kept at 200°C and dc biased at -200 V in order to obtain films with high chemical stability which is required for the application as solar selective surfaces. the films with different Cr concentrations (5 to 49 at.%) were characterized by in situ x-ray photoelectron spectroscopy (XPS). Up to 40 at.%, chromium proves to be built into the cermet-like films in the form of chromium carbide clusters. above 40 at.%, chromium is partly metallic. a modification of the a-C:H matrix in the vicinity of the chromium carbide clusters has been observed.

scholarly journals Synthesis and physical properties of biodegradable nanocomposites fabricated using acrylic acid-grafted poly(butylene carbonate-co-terephthalate) and organically-modified layered zinc phenylphosphonate

2021 ◽  
Author(s):  
Yi-Fang Lee ◽  
Tzong-Ming Wu
Keyword(s):  
Acrylic Acid ◽  
Photoelectron Spectroscopy ◽  
Covalent Bond ◽  
Interlayer Spacing ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Nuclear Magnetic Resonance Spectra ◽  
Organically Modified ◽  
Biodegradable Nanocomposites

Abstract A set of novel biocompatible aliphatic-aromatic nanocomposites, including numerous acrylic acid-grafted poly(butylene carbonate-co-terephthalate) (g-PBCT) and organically-modified layered zinc phenylphosphonate (m-PPZn), were successfully synthesized via polycondensation and transesterification. A primary covalent linkage was produced between the biocompatible polymer and the inorganic reinforcements. Fourier transform infrared spectroscopy and 13C-nuclear magnetic resonance spectra demonstrated the successful grafting of acrylic acid into the PBCT (g-PBCT). Both wide-angle X-ray diffraction data and X-ray photoelectron spectroscopy analysis showed that the g-PBCT polymer matrix was intercalated into the interlayer spacing of the m-PPZn and was chemically interacted with the m-PPZn. The addition of m-PPZn in the g-PBCT matrix significantly improved its storage modulus. A slight increase in thermal stability was observed in all the g-PBCT/m-PPZn composites. Both results are attributed to the presence of covalent bond between g-PBCT and m-PPZn.

scholarly journals Reliability Investigation of a Carbon Nanotube Array Thermal Interface Material

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2080 ◽  
Author(s):  
Andreas Nylander ◽  
Josef Hansson ◽  
Majid Kabiri Samani ◽  
Christian Chandra Darmawan ◽  
Ana Borta Boyon ◽  
...  
Keyword(s):  
Thermal Cycling ◽  
Thermal Performance ◽  
Photoelectron Spectroscopy ◽  
Thermal Contact ◽  
Thermal Interface Material ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Thermal Interface Resistance ◽  
Further Development ◽  
Interface Materials

As feature density increases within microelectronics, so does the dissipated power density, which puts an increased demand on thermal management. Thermal interface materials (TIMs) are used at the interface between contacting surfaces to reduce the thermal resistance, and is a critical component within many electronics systems. Arrays of carbon nanotubes (CNTs) have gained significant interest for application as TIMs, due to the high thermal conductivity, no internal thermal contact resistances and an excellent conformability. While studies show excellent thermal performance, there has to date been no investigation into the reliability of CNT array TIMs. In this study, CNT array TIMs bonded with polymer to close a Si-Cu interface were subjected to thermal cycling. Thermal interface resistance measurements showed a large degradation of the thermal performance of the interface within the first 100 cycles. More detailed thermal investigation of the interface components showed that the connection between CNTs and catalyst substrate degrades during thermal cycling even in the absence of thermal expansion mismatch, and the nature of this degradation was further analyzed using X-ray photoelectron spectroscopy. This study indicates that the reliability will be an important consideration for further development and commercialization of CNT array TIMs.

scholarly journals Chemical Synthesis and Characterization of Poly(poly(ethylene glycol) methacrylate)-Grafted CdTe Nanocrystals via RAFT Polymerization for Covalent Immobilization of Adenosine

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 77 ◽  
Author(s):  
Trinh Duy Nguyen ◽  
Hieu Vu-Quang ◽  
Thanh Sang Vo ◽  
Duy Chinh Nguyen ◽  
Dai-Viet N. Vo ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Photoelectron Spectroscopy ◽  
Raft Polymerization ◽  
Condensation Reaction ◽  
Covalent Bond ◽  
Poly Ethylene Glycol ◽  
X Ray ◽  
Glycol Methacrylate ◽  
Cdte Qds ◽  
Poly Ethylene

This paper describes the functionalization of poly(poly(ethylene glycol) methacrylate) (PPEGMA)-grafted CdTe (PPEGMA-g-CdTe) quantum dots (QDs) via surface-initiated reversible addition–fragmentation chain transfer (SI-RAFT) polymerization for immobilization of adenosine. Initially, the hydroxyl-coated CdTe QDs, synthesized using 2-mercaptoethanol (ME) as a capping agent, were coupled with a RAFT agent, S-benzyl S′-trimethoxysilylpropyltrithiocarbonate (BTPT), through a condensation reaction. Then, 2,2′-azobisisobutyronitrile (AIBN) was used to successfully initiate in situ RAFT polymerization to generate PPEGMA-g-CdTe nanocomposites. Adenosine-above-PPEGMA-grafted CdTe (Ado-i-PPEGMA-g-CdTe) hybrids were formed by the polymer shell, which had successfully undergone bioconjugation and postfunctionalization by adenosine (as a nucleoside). Fourier transform infrared (FT-IR) spectrophotometry, energy-dispersive X-ray (EDX) spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy results indicated that a robust covalent bond was created between the organic PPEGMA part, cadmium telluride (CdTe) QDs, and the adenosine conjugate. The optical properties of the PPEGMA-g-CdTe and Ado-i-PPEGMA-g-CdTe hybrids were investigated by photoluminescence (PL) spectroscopy, and the results suggest that they have a great potential for application as optimal materials in biomedicine.

scholarly journals Ultrathin conformal polycyclosiloxane films to improve silicon cycling stability

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw4856 ◽  
Author(s):  
B. H. Shen ◽  
S. Wang ◽  
W. E. Tenhaeff
Keyword(s):  
Photoelectron Spectroscopy ◽  
Coulombic Efficiency ◽  
Lithium Ion ◽  
Chemical Vapor ◽  
Silicon Thin Film ◽  
Capacity Retention ◽  
Initiated Chemical Vapor Deposition ◽  
Current Densities ◽  
Si Anodes ◽  
Further Development

Electrochemical reduction of lithium ion battery electrolyte on Si anodes was mitigated by synthesizing nanoscale, conformal polymer films as artificial solid electrolyte interface (SEI) layers. Initiated chemical vapor deposition (iCVD) was used to deposit poly(1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane) (pV4D4) onto silicon thin film electrodes. pV4D4 films (25 nm) on Si electrodes improved initial coulombic efficiency by 12.9% and capacity retention over 100 cycles by 64.9% relative to untreated electrodes. pV4D4 coatings improved rate capabilities, enabling higher lithiation capacity at all current densities. Impedance spectroscopy showed that SEI resistance grew from 50 to 191 ohms in untreated Si and only 34 to 90 ohms in pV4D4-coated Si over 30 cycles. Post-cycling Fourier transform infrared and x-ray photoelectron spectroscopy showed that pV4D4 moderated electrolyte reduction and altered SEI composition, with LiF formation being favored. This work will guide further development of polymeric artificial SEIs to mitigate electrolyte reduction and enhance capacity retention in Si electrodes.

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