scholarly journals Chitosan Covalently Functionalized with Peptides Mapped on Vitronectin and BMP-2 for Bone Tissue Engineering

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2784
Author(s):  
Paola Brun ◽  
Annj Zamuner ◽  
Leonardo Cassari ◽  
Gabriella D’Auria ◽  
Lucia Falcigno ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Photoelectron Spectroscopy ◽  
Adverse Reactions ◽  
Tissue Growth ◽  
Calcium Deposition ◽  
Porous Scaffolds ◽  
X Ray ◽  
Osteoblastic Phenotype ◽  
Toxic Material ◽  
Ft Ir

Worldwide, over 20 million patients suffer from bone disorders annually. Bone scaffolds are designed to integrate into host tissue without causing adverse reactions. Recently, chitosan, an easily available natural polymer, has been considered a suitable scaffold for bone tissue growth as it is a biocompatible, biodegradable, and non-toxic material with antimicrobial activity and osteoinductive capacity. In this work, chitosan was covalently and selectively biofunctionalized with two suitably designed bioactive synthetic peptides: a Vitronectin sequence (HVP) and a BMP-2 peptide (GBMP1a). Nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) investigations highlighted the presence of the peptides grafted to chitosan (named Chit-HVP and Chit-GBMP1a). Chit-HVP and Chit-GBMP1a porous scaffolds promoted human osteoblasts adhesion, proliferation, calcium deposition, and gene expression of three crucial osteoblast proteins. In particular, Chit-HVP highly promoted adhesion and proliferation of osteoblasts, while Chit-GBMP1a guided cell differentiation towards osteoblastic phenotype.

scholarly journals Synthesis of Magnetic Ferrocene-Containing Polymer with Photothermal Effects for Rapid Degradation of Methylene Blue

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 558
Author(s):  
Wenhui Zhu ◽  
Caiyun Zhang ◽  
Yali Chen ◽  
Qiliang Deng
Keyword(s):  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Degradation Rate ◽  
Model Compound ◽  
Vibrating Sample Magnetometer ◽  
Simulated Sunlight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Photothermal materials are attracting more and more attention. In this research, we synthesized a ferrocene-containing polymer with magnetism and photothermal properties. The resulting polymer was characterized by Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Its photo-thermocatalytic activity was investigated by choosing methylene blue (MB) as a model compound. The degradation percent of MB under an irradiated 808 nm laser reaches 99.5% within 15 min, and the degradation rate is 0.5517 min−1, which is 145 times more than that of room temperature degradation. Under irradiation with simulated sunlight, the degradation rate is 0.0092 min−1, which is approximately 2.5 times more than that of room temperature degradation. The present study may open up a feasible route to degrade organic pollutants.

Chemical Structures of Native Oxides Formed During Wet Chemical Treatments on NH4F Treated Si(111) Surfaces

1992 ◽  
Vol 259 ◽  
Author(s):  
Takeo Hattori ◽  
Hiroki Ogawa
Keyword(s):  
Photoelectron Spectroscopy ◽  
Attenuated Total Reflection ◽  
Native Oxide ◽  
X Ray ◽  
Chemical Treatments ◽  
Chemical Structures ◽  
Native Oxides ◽  
Ft Ir ◽  
Wet Chemical ◽  
Silicon Interface

ABSTRACTChemical structures of native oxides formed during wet chemical treatments on NH4F treated Si(111) surfaces were investigated using X-ray Photoelectron Spectroscopy (XPS) and Fourier Transformed Infrared Attenuated Total Reflection(FT-IR-ATR). It was found that the amounts of Si-H bonds in native oxides and those at native oxide/silicon interface are negligibly small in the case of native oxides formed in H2SO4-H2O2-H2O solution. Based on this discovery, it was confirmed that native oxides can be characterized by the amount of Si-H bonds in native oxides. Furthermore, it was found that the combination of various wet chemical treatments with the treatment in NH4OH-H2O2-H2O solution results in the drastic decrease in the amount of Si-H bonds in native oxides.

scholarly journals Dual Light- and pH-Responsive Composite of Polyazo-Derivative Grafted Cellulose Nanocrystals

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1725 ◽  
Author(s):  
Xiaohong Liu ◽  
Ming Li ◽  
Xuemei Zheng ◽  
Elias Retulainen ◽  
Shiyu Fu
Keyword(s):  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
X Ray Diffraction ◽  
Responsive Materials ◽  
X Ray ◽  
Ph Response ◽  
Transmission Electron ◽  
Ft Ir ◽  
Hexyl Methacrylate

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.

Preparation and Characterization of Ni2+-Montmorillonite/Polyvinyl Alcohol Water-Soluble Nanocomposite Film

2005 ◽  
Vol 13 (8) ◽  
pp. 839-846 ◽  
Author(s):  
Li-Ping Wang ◽  
Yun-Pu Wang ◽  
Fa-Ai Zhang
Keyword(s):  
Polyvinyl Alcohol ◽  
Photoelectron Spectroscopy ◽  
Thermal Characteristics ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
Xps Spectra ◽  
X Ray ◽  
Alcohol Water ◽  
Ft Ir ◽  
Silicate Layers

A new type of nano-composite film was prepared from polyvinyl alcohol, Ni2+-montmorillonite (Ni2+-MMT), defoamer, a levelling agent and a plasticizer. Its thermal characteristics were studied by Differential Scanning Calorimetry (DSC). The intermolecular interactions were measured by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the tensile strength (TS) and elongation at break (%E) were measured. The microstructures were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). FT-IR and XPS spectra indicated that cross-linking has taken place between PVA and Ni2+-MMT. XRD and AFM indicate that the PVA molecules had inserted themselves into the silicate layers of MMT, exfoliating them and dispersing them randomly into the PVA matrix. Compared to pure PVA film, the TS of the films was increased and %E decreased when the Ni2+-Montmorillonite was added and the dissolution temperature of the film was also reduced.

scholarly journals Preparation and characterization of self-cleaning cotton fabric loaded with self-dispersive and reactive biphasic TiO2

2021 ◽  
Author(s):  
Kuang Wang ◽  
Jiayi Chen ◽  
Jialong Tian ◽  
Dawei Gao ◽  
Xiaolei Song ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Cotton Fabrics ◽  
Ammonia Solution ◽  
X Ray ◽  
Washing Fastness ◽  
Fastness Property ◽  
Structure Dispersion ◽  
Ft Ir ◽  
Self Cleaning

Abstract In this article, amino functionalized TiO2 (TiO2/KH550) was obtained in a mild reaction between 3-aminopropyltriethoxysilane and TiO2 with the aid of concentrated ammonia solution. 4-(4,6-dichloro-1,3,5-triazine-2-yl) amino) sodium benzenesulfonate (SAT) was synthesized and characterized by 1H NMR and fourier transform infrared spectroscopy (FT-IR). Self-dispersive and reactive TiO2 (TiO2/KH550/SAT) was prepared by nucleophile substitution reaction between TiO2/KH550 and SAT. Finally, cotton fabrics loaded with different amounts of TiO2/KH550/SAT were achieved by pad-dry-cure method. The chemical structure, dispersion and thermal performance of TiO2, TiO2/KH550 and TiO2/KH550/SAT were investigated by FT-IR, zeta potential and thermogravimetric analysis (TG). The crystalline phase, morphology, chemical composition and optical absorption property of cotton fabrics were studied by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). Moreover, the anti-ultraviolet, self-cleaning and washing fastness properties of cotton fabrics were investigated. It has been found that TiO2/KH550/SAT demonstrated excellent dispersion stability in aqueous even after standing for a month. Cotton fabrics loaded with TiO2/KH550/SAT possessed adorable anti-ultraviolet performance, highly efficient and durable self-cleaning activity as well as appreciable washing fastness property. The mechanism and possible reactions for the preparation of self-cleaning cotton fabrics loaded with TiO2/KH550/SAT were proposed.

scholarly journals Direct Conjugation of Resveratrol on Hydrophilic Gold Nanoparticles: Structural and Cytotoxic Studies for Biomedical Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1898
Author(s):  
Iole Venditti ◽  
Giovanna Iucci ◽  
Ilaria Fratoddi ◽  
Manuela Cipolletti ◽  
Emiliano Montalesi ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Conjugated Systems ◽  
Cell Vitality ◽  
Anticancer Effects ◽  
Radiation Induced ◽  
Ft Ir ◽  
Cytotoxic Studies ◽  
X Ray Absorption

Strongly hydrophilic gold nanoparticles (AuNPs), functionalized with citrate and L-cysteine, were synthetized and used as Resveratrol (RSV) vehicle to improve its bioavailability. Two different conjugation procedures were investigated: the first by adding RSV during AuNPs synthesis (1) and the second by adding RSV after AuNPs synthesis (2). The two different conjugated systems, namely AuNPs@RSV1 and AuNPs@RSV2 respectively, showed good loading efficiency (η%): η1 = 80 ± 5% for AuNPs@RSV1 and η2 = 20 ± 3% for AuNPs@RSV2. Both conjugated systems were investigated by means of Dynamic Light Scattering (DLS), confirming hydrophilic behavior and nanodimension (<2RH> 1 = 45 ± 12 nm and <2RH> 2 = 170 ± 30 nm). Fourier Transform Infrared Spectroscopy (FT-IR), Synchrotron Radiation induced X-Ray Photoelectron Spectroscopy (SR-XPS) and Near Edge X-ray Absorption Fine Structure (NEXAFS) techniques were applied to deeply understand the hooking mode of RSV on AuNPs surface in the two differently conjugated systems. Moreover, the biocompatibility of AuNPs and AuNPs@RSV1 was evaluated in the concentration range 1.0–45.5 µg/mL by assessing their effect on breast cancer cell vitality. The obtained data confirmed that, at the concentration used, AuNPs do not induce cell death, whereas AuNPs@RSV1 maintains the same anticancer effects as the unconjugated RSV.

scholarly journals Hydrogenative Cyclization of Levulinic Acid to γ-Valerolactone with Methanol and Ni-Fe Bimetallic Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1096
Author(s):  
Ligang Luo ◽  
Xiao Han ◽  
Qin Zeng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Levulinic Acid ◽  
Hydrogen Donor ◽  
Effect Of Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Temperature Programmed

A series of Ni-Fe/SBA-15 catalysts was prepared and tested for the catalytic hydrogenation of levulinic acid to γ-valerolactone, adopting methanol as the only hydrogen donor, and investigating the synergism between Fe and Ni, both supported on SBA-15, towards this reaction. The characterization of the synthesized catalysts was carried out by XRD (X-ray powder diffraction), TEM (transmission electron microscopy), H2-TPD (hydrogen temperature-programmed desorption), XPS (X-ray photoelectron spectroscopy), and in situ FT-IR (Fourier transform–infrared spectroscopy) techniques. H2-TPD and XPS results have shown that electron transfer occurs from Fe to Ni, which is helpful both for the activation of the C=O bond and for the dissociative activation of H2 molecules, also in agreement with the results of the in situ FT-IR spectroscopy. The effect of temperature and reaction time on γ-valerolactone production was also investigated, identifying the best reaction conditions at 200 °C and 180 min, allowing for the complete conversion of levulinic acid and the complete selectivity to γ-valerolactone. Moreover, methanol was identified as an efficient hydrogen donor, if used in combination with the Ni-Fe/SBA-15 catalyst. The obtained results are promising, especially if compared with those obtained with the traditional and more expensive molecular hydrogen and noble-based catalysts.

scholarly journals Surface-Modified Poly(l-lactide-co-glycolide) Scaffolds for the Treatment of Osteochondral Critical Size Defects—In Vivo Studies on Rabbits

2020 ◽  
Vol 21 (20) ◽  
pp. 7541
Author(s):  
Małgorzata Krok-Borkowicz ◽  
Katarzyna Reczyńska ◽  
Łucja Rumian ◽  
Elżbieta Menaszek ◽  
Maciej Orzelski ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Tissue Regeneration ◽  
Photoelectron Spectroscopy ◽  
Sessile Drop ◽  
Bone Tissue Regeneration ◽  
In Vivo Studies ◽  
In Vivo Model ◽  
Type I ◽  
X Ray

Poly(l-lactide-co-glycolide) (PLGA) porous scaffolds were modified with collagen type I (PLGA/coll) or hydroxyapatite (PLGA/HAp) and implanted in rabbits osteochondral defects to check their biocompatibility and bone tissue regeneration potential. The scaffolds were fabricated using solvent casting/particulate leaching method. Their total porosity was 85% and the pore size was in the range of 250–320 µm. The physico-chemical properties of the scaffolds were evaluated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), sessile drop, and compression tests. Three types of the scaffolds (unmodified PLGA, PLGA/coll, and PLGA/HAp) were implanted into the defects created in New Zealand rabbit femoral trochlears; empty defect acted as control. Samples were extracted after 1, 4, 12, and 26 weeks from the implantation, evaluated using micro-computed tomography (µCT), and stained by Masson–Goldner and hematoxylin-eosin. The results showed that the proposed method is suitable for fabrication of highly porous PLGA scaffolds. Effective deposition of both coll and HAp was confirmed on all surfaces of the pores through the entire scaffold volume. In the in vivo model, PLGA and PLGA/HAp scaffolds enhanced tissue ingrowth as shown by histological and morphometric analyses. Bone formation was the highest for PLGA/HAp scaffolds as evidenced by µCT. Neo-tissue formation in the defect site was well correlated with degradation kinetics of the scaffold material. Interestingly, around PLGA/coll extensive inflammation and inhibited tissue healing were detected, presumably due to immunological response of the host towards collagen of bovine origin. To summarize, PLGA scaffolds modified with HAp are the most promising materials for bone tissue regeneration.

scholarly journals Preparation of Modified Chitosan Microsphere-Supported Copper Catalysts for the Borylation of α,β-Unsaturated Compounds

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1417 ◽  
Author(s):  
Wang ◽  
Xiao ◽  
Huang ◽  
Zheng ◽  
Luo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Copper Catalysts ◽  
Reduction Reaction ◽  
X Ray ◽  
Modified Chitosan ◽  
Transmission Electron ◽  
Ft Ir ◽  
Repeated Use ◽  
Supported Copper Catalysts

Chitosan microspheres modified by 2-pyridinecarboxaldehyde were prepared and used in the construction of a heterogeneous catalyst loaded with nano-Cu prepared by a reduction reaction. The chemical structure of the catalyst was investigated by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS). Under mild conditions, such as no ligand at room temperature, the catalyst was successfully applied to catalyze the borylation of α,β-unsaturated receptors in a water-methanol medium, yielding 17%–100% of the corresponding -hydroxy product. Even after repeated use five times, the catalyst still exhibited excellent catalytic activity.

scholarly journals Preparation, Characterization, and Performance Analysis of S-Doped Bi2MoO6 Nanosheets

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1341 ◽  
Author(s):  
Ruiqi Wang ◽  
Duanyang Li ◽  
Hailong Wang ◽  
Chenglun Liu ◽  
Longjun Xu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Degradation Rate ◽  
X Ray Diffraction ◽  
Photo Degradation ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
And Performance ◽  
Adsorption Desorption ◽  
Excellent Stability

S-doped Bi2MoO6 nanosheets were successfully synthesized by a simple hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms, Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), elemental mapping spectroscopy, photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS), and UV-visible diffused reflectance spectra (UV-vis DRS). The photo-electrochemical performance of the samples was investigated via an electrochemical workstation. The S-doped Bi2MoO6 nanosheets exhibited enhanced photocatalytic activity under visible light irradiation. The photo-degradation rate of Rhodamine B (RhB) by S-doped Bi2MoO6 (1 wt%) reached 97% after 60 min, which was higher than that of the pure Bi2MoO6 and other S-doped products. The degradation rate of the recovered S-doped Bi2MoO6 (1 wt%) was still nearly 90% in the third cycle, indicating an excellent stability of the catalyst. The radical-capture experiments confirmed that superoxide radicals (·O2−) and holes (h+) were the main active substances in the photocatalytic degradation of RhB by S-doped Bi2MoO6.

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