Micro-/Nano-Structured Ceramic Scaffolds That Mimic Natural Cancellous Bone

Micro-/nano-structured scaffolds with a weight composition of 46.6% α-tricalcium phosphate (α-TCP)—53.4% silicocarnotite (SC) were synthesized by the polymer replica method. The scanning electron microscopy (SEM) analysis of the scaffolds and natural cancellous bone was performed for comparison purposes. Scaffolds were obtained at three cooling rates via the eutectoid temperature (50 °C/h, 16.5 °C/h, 5.5 °C/h), which allowed the surface nanostructure and mechanical strength to be controlled. Surface nanostructures were characterized by transmission electron microscopy (TEM) and Raman analysis. Both phases α-TCP and SC present in the scaffolds were well-identified, looked compact and dense, and had neither porosities nor cracks. The non-cytotoxic effect was evaluated in vitro by the proliferation ability of adult human mesenchymal stem cells (ah-MSCs) seeded on scaffold surfaces. There was no evidence for cytotoxicity and the number of cells increased with culture time. A dense cell-hydroxyapatite layer formed until 28 days. The SEM analysis suggested cell-mediated extracellular matrix formation. Finally, scaffolds were functionalized with the alkaline phosphatase enzyme (ALP) to achieve biological functionalization. The ALP was successfully grafted onto scaffolds, whose enzymatic activity was maintained. Scaffolds mimicked the micro-/nano-structure and chemical composition of natural cancellous bone by considering cell biology and biomolecule functionalization.

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Rapid Biological Synthesis of Silver Nanoparticles and It's In Vitro Anti-Bacterial and Larvicidal Activities

Advanced Science Engineering and Medicine ◽

10.1166/asem.2020.2561 ◽

2020 ◽

Vol 12 (5) ◽

pp. 593-602

Author(s):

Gattu Sampath ◽

Douglas JH Shyu ◽

Neelamegam Rameshkumar ◽

Muthukalingan Krishnan ◽

Krishnan Raguvaran ◽

...

Keyword(s):

Electron Microscopy ◽

Structural Damage ◽

Sem Analysis ◽

Biological Synthesis ◽

Infrared Spectrometry ◽

Average Crystalline Size ◽

Transmission Electron ◽

Golden Yellow ◽

Larvicidal Activities

The current investigation explains the Acacia nilotica (A. nilotica) leaf extract capped silver nanoparticle (AgNPs) synthesis. The instant formation of AgNPs was confirmed by altering the color golden yellow to dark brown and the characteristic SPR band determines by the UV-visible spectrometer. The structural specification was assessed using Fourier transform infrared spectrometry (FTIR), X-ray diffraction crystallography (XRD), High-resolution transmission electron microscopy, Atomic force microscopy (AFM), energy dispersive electron microscopy, zeta potential, dynamic light scattering. The particle size ranged 20–80 nm, the average crystalline size 35.26 nm were determined by HR-TEM and XRD. Further in vitro antimicrobial activity was tested against different bacteria by combining antibiotic with the AgNPs. Among all the tested bacteria, the Staphylococcus aureus (S. aureus) showed the highest (16.2 ± 0.6 mm) zone of inhibition. The Scanning electron microscope (SEM) analysis clearly showed the structural damage of S. aureus and Escherichia coli (E. coli) by increasing AgNPs concentration at 4 hr treatment. In addition, the larvicidal assay was performed against Culex quinquefasciatus (C. quinquefasciatus) and Aedes aegypti (A. aegypti). The higher efficiency of AgNPs was absorbed in A. aegypti (LC50 = 279 22 ppm) and C. quinque- fasciatus (LC50 = 168.98 ppm). The results proved that the An-AgNPs act as a multi-faceted effect on bacterial and controlling vectors.

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Management of Ralstonia solanacearum in tomato using ZnO nanoparticles synthesized through Matricaria chamomilla

Plant Disease ◽

10.1094/pdis-08-20-1763-re ◽

2021 ◽

Author(s):

Raja Asad Ali Khan ◽

Yuanyang Tang ◽

Ishrat Naz ◽

Syed Sartaj Alam ◽

Wenzhao Wang ◽

...

Keyword(s):

Electron Microscopy ◽

Ralstonia Solanacearum ◽

Sem Analysis ◽

In Vivo Studies ◽

Bacterial Cells ◽

Matricaria Chamomilla ◽

Bacterial Wilt Disease ◽

Transmission Electron

Matricaria chamomilla flower extract was used as a biocompatible material for synthesis of zinc oxide nanoparticles (ZnONPs). The synthesized NPs were evaluated for their antibacterial potential in vitro and in vivo against Ralstonia solanacearum that causes devastating bacterial wilt disease in tomato and other crops. Synthesized ZnONPs were further analyzed by UV-Visible spectroscopy, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The synthesized polydisperse ZnONPs were found to be in the size range of 8.9 to 32.6 nm, and at 18.0 µg ml-1 exhibited maximum in vitro growth inhibition of R. solanacearum. SEM analysis of affected bacterial cells showed morphological deformation such as disruption of cell membrane, cell wall and leakage of cell contents. Results of in vivo studies also showed that application of ZnONPs to the artificially inoculated tomato plants with R. solanacearum significantly enhanced the plant growth by reducing bacterial soil population and disease severity as compared to untreated control. Biosynthesized ZnONPs could be an effective approach to control R. solanacearum.

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Maytansine-Induced Mitotic Arrest in Human Lymphoblasts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079747 ◽

1977 ◽

Vol 35 ◽

pp. 460-461

Author(s):

Tai-Te Chao ◽

John Sullivan ◽

Awtar Krishan

Keyword(s):

Electron Microscopy ◽

Cell Cycle ◽

Transmission Electron Microscopy ◽

Tubulin Polymerization ◽

Vinca Alkaloids ◽

Antimitotic Activity ◽

Transmission Electron ◽

Flow Microfluorometry ◽

Brain Tubulin

Maytansine, a novel ansa macrolide (1), has potent anti-tumor and antimitotic activity (2, 3). It blocks cell cycle traverse in mitosis with resultant accumulation of metaphase cells (4). Inhibition of brain tubulin polymerization in vitro by maytansine has also been reported (3). The C-mitotic effect of this drug is similar to that of the well known Vinca- alkaloids, vinblastine and vincristine. This study was carried out to examine the effects of maytansine on the cell cycle traverse and the fine struc- I ture of human lymphoblasts.Log-phase cultures of CCRF-CEM human lymphoblasts were exposed to maytansine concentrations from 10-6 M to 10-10 M for 18 hrs. Aliquots of cells were removed for cell cycle analysis by flow microfluorometry (FMF) (5) and also processed for transmission electron microscopy (TEM). FMF analysis of cells treated with 10-8 M maytansine showed a reduction in the number of G1 cells and a corresponding build-up of cells with G2/M DNA content.

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Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100116620 ◽

1975 ◽

Vol 33 ◽

pp. 600-601

Author(s):

John C. Garancis ◽

Robert O. Hussa ◽

Michael T. Story ◽

Donald Yorde ◽

Roland A. Pattillo

Keyword(s):

Electron Microscopy ◽

Cellular Proliferation ◽

Morphological Changes ◽

Culture Fluid ◽

Cellular Functions ◽

Human Trophoblast ◽

Transmission Electron ◽

Marked Activity ◽

Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

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Ethosomes and Transethosomes for Mangiferin Transdermal Delivery

Antioxidants ◽

10.3390/antiox10050768 ◽

2021 ◽

Vol 10 (5) ◽

pp. 768

Author(s):

Maddalena Sguizzato ◽

Francesca Ferrara ◽

Supandeep Singh Hallan ◽

Anna Baldisserotto ◽

Markus Drechsler ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Radical Scavenging ◽

Human Keratinocytes ◽

Antioxidant Response ◽

Correlation Spectroscopy ◽

Inflammatory Status ◽

Transmission Electron ◽

Anti Inflammatory

Mangiferin is a natural glucosyl xanthone with antioxidant and anti-inflammatory activity, making it suitable for protection against cutaneous diseases. In this study ethosomes and transethosomes were designed as topical delivery systems for mangiferin. A preformulation study was conducted using different surfactants in association with phosphatidylcholine. Vesicle dimensional distribution was monitored by photon correlation spectroscopy, while antioxidant capacity and cytotoxicity were respectively assessed by free radical scavenging analysis and MTT on HaCaT keratinocytes. Selected nanosystems were further investigated by cryogenic transmission electron microscopy, while mangiferin entrapment capacity was evaluated by ultracentrifugation and HPLC. The diffusion kinetics of mangiferin from ethosomes and transethosomes evaluated by Franz cell was faster in the case of transethosomes. The suitability of mangiferin-containing nanovesicles in the treatment of skin disorders related to pollutants was investigated, evaluating, in vitro, the antioxidant and anti-inflammatory effect of ethosomes and transethosomes on human keratinocytes exposed to cigarette smoke as an oxidative and inflammatory challenger. The ability to induce an antioxidant response (HO-1) and anti-inflammatory status (IL-6 and NF-kB) was determined by RT-PCR and immunofluorescence. The data demonstrated the effectiveness of mangiferin loaded in nanosystems to protect cells from damage. Finally, to gain insight into the keratinocytes’ uptake of ethosome and transethosome, transmission electron microscopy analyses were conducted, showing that both nanosystems were able to pass intact within the cells.

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Facile synthesis of Au/ZnO/Ag nanoparticles using Glechoma hederacea L. extract, and their activity against leukemia

Biomedical Microdevices ◽

10.1007/s10544-021-00557-0 ◽

2021 ◽

Vol 23 (1) ◽

Author(s):

Renata Dobrucka ◽

Aleksandra Romaniuk-Drapała ◽

Mariusz Kaczmarek

Keyword(s):

Electron Microscopy ◽

Ag Nanoparticles ◽

Mononuclear Cells ◽

Leukemia Cell ◽

Leukemia Cell Line ◽

Mtt Test ◽

Transmission Electron ◽

Almost All ◽

Glechoma Hederacea

AbstractMetal combinations have been attracting the attention of scientists for some time. They usually exhibit new characteristics that are different from the ones possessed by their components. In this work, Au/ZnO/Ag nanoparticles were synthesized biologically using Glechoma hederacea L. extract. The synthesized Au/ZnO/Ag nanoparticles were characterized by UV-Vis, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and Atomic Force Microscopy (AFM). The microscopic methods confirmed the presence of spherical nanoparticles of 50–70 nm. The influence of biologically synthesized Au/ZnO/Ag nanoparticles on the vitality of human cells was evaluated in vitro with the use of established human Acute T Cell Leukemia cell line, Jurkat (ATCC® TIB-152™), as well as mononuclear cells isolated from peripheral blood (PBMC) of voluntary donors. Cell survival and the half-maximal inhibitory concentration index (IC50) were analyzed by the MTT test. The studies showed that the total loss of cell viability occurred at the Au/ZnO/Ag nanoparticle concentration range of 10 µmol–50 µmol. The use of Au/ZnO/Ag nanoparticles at the concentration of 100 µmol eliminated almost all living cells from the culture in 24h. The above observation confirms the result obtained during the MTT test.

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Cemp1-p3 Peptide Promotes the Transformation of Octacalcium Phosphate into Hydroxyapatite Crystals

Crystals ◽

10.3390/cryst10121131 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1131

Author(s):

Maricela Santana ◽

Gonzalo Montoya ◽

Raúl Herrera ◽

Lía Hoz ◽

Enrique Romo ◽

...

Keyword(s):

Electron Microscopy ◽

Octacalcium Phosphate ◽

Sequence Motifs ◽

Simple Method ◽

Transmission Electron ◽

Precursor Phase ◽

Mineralized Tissues ◽

Potent Growth

Dental cementum contains unique molecules that regulate the mineralization process in vitro and in vivo, such as cementum protein 1 (CEMP1). This protein possesses amino acid sequence motifs like the human recombinant CEMP1 with biological activity. This novel cementum protein 1-derived peptide (CEMP1-p3, from the CEMP1’s N-terminal domain: (QPLPKGCAAVKAEVGIPAPH), consists of 20 amino acids. Hydroxyapatite (HA) crystals could be obtained through the combination of the amorphous precursor phase and macromolecules such as proteins and peptides. We used a simple method to synthesize peptide/hydroxyapatite nanocomposites using OCP and CEMP1-p3. The characterization of the crystals through scanning electron microscopy (SEM), powder X-ray diffraction (XRD), high--resolution transmission electron microscopy (HRTEM), and Raman spectroscopy revealed that CEMP1-p3 transformed OCP into hydroxyapatite (HA) under constant ionic strength and in a buffered solution. CEMP1-p3 binds and highly adsorbs to OCP and is a potent growth stimulator of OCP crystals. CEMP1-p3 fosters the transformation of OCP into HA crystals with crystalline planes (300) and (004) that correspond to the cell of hexagonal HA. Octacalcium phosphate crystals treated with CEMP1-p3 grown in simulated physiological buffer acquired hexagonal arrangement corresponding to HA. These findings provide new insights into the potential application of CEMP1-p3 on possible biomimetic approaches to generate materials for the repair and regeneration of mineralized tissues, or restorative materials in the orthopedic field.

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Biocompatibility Characteristics of Titanium Coated with Multi Walled Carbon Nanotubes—Hydroxyapatite Nanocomposites

Materials ◽

10.3390/ma12020224 ◽

2019 ◽

Vol 12 (2) ◽

pp. 224 ◽

Cited By ~ 5

Author(s):

Jung-Eun Park ◽

Yong-Seok Jang ◽

Tae-Sung Bae ◽

Min-Ho Lee

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Sol Gel ◽

Pure Titanium ◽

Cell Proliferation And Differentiation ◽

Transmission Electron ◽

Proliferation And Differentiation ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

Multi walled carbon nanotubes-hydroxyapatite (MWCNTs-HA) with various contents of MWCNTs was synthesized using the sol-gel method. MWCNTs-HA composites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). HA particles were generated on the surface of MWCNT. Produced MWCNTs-HA nanocomposites were coated on pure titanium (PT). Characteristic of the titanium coated MWCNTs-HA was evaluated by field-emission scanning electron microscopy (FE-SEM) and XRD. The results show that the titanium surface was covered with MWCNTs-HA nanoparticles and MWCNTs help form the crystalized hydroxyapatite. Furthermore, the MWCNTs-HA coated titanium was investigated for in vitro cellular responses. Cell proliferation and differentiation were improved on the surface of MWCNT-HA coated titanium.

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Human Islet Amyloid Polypeptide Fibril Binding to Catalase: A Transmission Electron Microscopy and Microplate Study

The Scientific World JOURNAL ◽

10.1100/tsw.2010.73 ◽

2010 ◽

Vol 10 ◽

pp. 879-893 ◽

Cited By ~ 10

Author(s):

Nathaniel G. N. Milton ◽

J. Robin Harris

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Islet Amyloid Polypeptide ◽

Amyloid Β ◽

Human Islet ◽

Islet Amyloid ◽

Human Islet Amyloid Polypeptide ◽

Transmission Electron

The diabetes-associated human islet amyloid polypeptide (IAPP) is a 37-amino-acid peptide that forms fibrilsin vitroandin vivo. Human IAPP fibrils are toxic in a similar manner to Alzheimer's amyloid-β (Aβ) and prion protein (PrP) fibrils. Previous studies have shown that catalase binds to Aβ fibrils and appears to recognize a region containing the Gly-Ala-Ile-Ile sequence that is similar to the Gly-Ala-Ile-Leu sequence found in human IAPP residues 24-27. This study presents a transmission electron microscopy (TEM)—based analysis of fibril formation and the binding of human erythrocyte catalase to IAPP fibrils. The results show that human IAPP 1-37, 8-37, and 20-29 peptides form fibrils with diverse and polymorphic structures. All three forms of IAPP bound catalase, and complexes of IAPP 1-37 or 8-37 with catalase were identified by immunoassay. The binding of biotinylated IAPP to catalase was high affinity with a KDof 0.77nM, and could be inhibited by either human or rat IAPP 1-37 and 8-37 forms. Fibrils formed by the PrP 118-135 peptide with a Gly-Ala-Val-Val sequence also bound catalase. These results suggest that catalase recognizes a Gly-Ala-Ile-Leu—like sequence in amyloid fibril-forming peptides. For IAPP 1-37 and 8-37, the catalase binding was primarily directed towards fibrillar rather than ribbon-like structures, suggesting differences in the accessibility of the human IAPP 24-27 Gly-Ala-Ile-Leu region. This suggests that catalase may be able to discriminate between different structural forms of IAPP fibrils. The ability of catalase to bind IAPP, Aβ, and PrP fibrils demonstrates the presence of similar accessible structural motifs that may be targets for antiamyloid therapeutic development.

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Polymethylmethacrylate (PMMA) Encapsulated Graphene Oxide Nanocomposite: Pre-modification, Synthesis, and Latex Stability

10.20944/preprints202007.0647.v1 ◽

2020 ◽

Author(s):

Hui Wang ◽

Letian Wang ◽

Shanyu Meng ◽

Hanxue Lin ◽

Melanie Correll ◽

...

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Critical Role ◽

Miniemulsion Polymerization ◽

Sem Analysis ◽

High Molecular Weight Polymer ◽

Molecular Weight Polymer ◽

Transmission Electron ◽

Composite Production ◽

Uniform Particle Size

The compatibility of graphene or graphene oxide with its dispersion medium (polymer) plays a critical role in the formation nanocomposite materials with significant property improvements. Environmentally friendly miniemulsion polymerization, which allows a formation of nanoencapsulation in an aqueous phase and high molecular weight polymer/composite production is one promising method. In this study, we screened a series of amphiphilic modifiers and found that the quaternary ammonium (ar-vinyl benzyl) trimethyl ammonium chloride (VBTAC) pending carbon double bonds could effectively modify the graphene oxide (GO) to be compatible with the organophilic monomer. After that, free radical miniemulsion polymerization could successfully synthesize stable latex of exfoliated poly (methyl methacrylate) (PMMA)/ GO nanocomposite. The final latex had an extended storage life and a relatively uniform particle size distribution. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) analysis of this latex and its films indicated successful encapsulation of exfoliated nano-dimensional graphene oxide inside a polymer matrix.

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