Development of Gelatin-Thai Silk Fibroin Microspheres for Three Dimensional Cell Culture

2014 ◽  
Vol 931-932 ◽  
pp. 200-204
Author(s):  
S. Sinthop ◽  
S. Patumraj ◽  
S. Kanokpanont
Keyword(s):  
Silk Fibroin ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Tissue Engineering Scaffolds ◽  
Gelatin Microspheres ◽  
Size And Morphology ◽  
Average Size

Microspheres have been widely used for tissue engineering scaffolds. Microspheres have many advantages over the macrostructure such as high surface area for cell adhesion and proliferation and low mass transfer limits. In this study, we fabricated microspheres from gelatin and silk fibroin using water-in-oil (w/o) emulsion technique and glutaraldehyde crosslinking. Gelatin (G) and silk fibroin (SF) were blended at different G/SF weight blending ratios of 100/0, 90/10, 70/30, and 50/50. Physical and chemical properties of the microspheres including size and morphology were characterized. The Average size of microspheres obtained were at 858.42±41.93, 832.97± 9.44 , 785.24±17.66 and 735.83 ±13.19 μm, respectively. Morphology of G/SF microspheres was observed under a scanning electron microscope. Blending of silk fibroin increased the crosslinking degrees and water absorption. It also reduced degradation rate, comparing to the gelatin microspheres. Thein vitroattachment and proliferation of rat bone marrow derived mesenchymal stem cells (MSC) cultured on G/SF microspheres were evaluated. G/SF 50/50 microspheres promoted the highest attachment of MSC on microspheres (46.0±5.8% of initial seeding at 6 hr). The G/SF 70/30 microspheres promoted the higher cell proliferation of MSC compared the others. Specific growth rate of the cells on the microspheres was at 9.85x10-3h-1.

Exploratory Investigation of Synthetic Zeolites by Near-Infrared Fourier-Transform Raman Microspectroscopy

1997 ◽  
Vol 3 (S2) ◽  
pp. 861-862
Author(s):  
Edgar S. Etz
Keyword(s):  
Surface Science ◽  
Near Infrared ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Standard Reference Materials ◽  
Structure Information ◽  
Synthetic Zeolites ◽  
High Surface Area Materials

Zeolites are complex, three-dimensional, hydrated crystalline aluminosilicates that have porous structures with channels or cages of various dimensions. In the simplest way they can be represented by (Na2,K,Ca,Ba) [(Al,Si)O2]nxH2O. They may be either of natural or synthetic origin. As high-surface-area materials, they take on great technological importance, foremost in surface science and catalysis. The structure of the zeolite is critical to its function. Structure information is commonly obtained by x-ray and neutron diffraction, NMR, IR, and Raman spectroscopy techniques. Synthetic zeolites are produced in enormous quantities worldwide and are key to critical technologies. Yet, no real zeolite standards exit that are defined and certified. NIST, with input from industry and academia, has begun a measurement program to certify various physico-chemical properties for a suite of synthetic zeolite powder standard reference materials (SRMs) and research materials (RMs). These proposed "standard" zeolite materials span a range of pore sizes, SiO2/Al2O3 ratios, ring sizes, structural building units, and cage sizes.

Sol-gel-derived glass scaffold with high pore interconnectivity and enhanced bioactivity

2009 ◽  
Vol 24 (12) ◽  
pp. 3495-3502 ◽  
Author(s):  
Ana C. Marques ◽  
Rui M. Almeida ◽  
Amath Thiema ◽  
Shaojie Wang ◽  
Matthias Falk ◽  
...  
Keyword(s):  
Exchange Process ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Three Dimensional ◽  
Average Diameter ◽  
Solvent Exchange ◽  
Sol Gel Transition ◽  
The One

We report on the preparation of a bioactive CaO–SiO2 monolithic scaffold with interconnected bimodal nanomacro porosity, which simulates the morphology of a natural trabecular bone, by a newly developed modified sol-gel process. This method inherently creates nanopores, whose average diameter can be tailored to approximately 5–20 nm by solvent exchange. To achieve interconnected macroporosity (pores ∼5–300 μm in size), a polymer [poly(ethylene oxide)] is added, which causes phase separation simultaneously with the sol-gel transition. High-resolution scanning electron microscopy and mercury intrusion porosimetry demonstrate a high degree of three-dimensional interconnectivity and sharp distributions of pore size. In vitro bioactivity tests in simulated body fluid (SBF) show bioactivity of the material after soaking for approximately 5 h, as verified by the formation of a hydroxyapatite layer deep into the scaffold structure. Analysis of the SBF after the reaction indicates the dissolution of the samples, another desired feature of temporary scaffolds for bone regeneration. MG63 osteoblast-like cells seeded on our sol-gel glass samples responded better to samples with nanopores enlarged by a solvent exchange process than to the one with normal nanopores. Thus, the benefits of the high surface area achieved by sol-gel and solvent exchange procedures are most clearly demonstrated for the first time.

scholarly journals Acylation Modification ofAntheraea pernyiSilk Fibroin Using Succinic Anhydride and Its Effects on Enzymatic Degradation Behavior

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Xiufang Li ◽  
Ceng Zhang ◽  
Lingshuang Wang ◽  
Caili Ma ◽  
Weichao Yang ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Silk Fibroin ◽  
Degradation Rate ◽  
Succinic Anhydride ◽  
Three Dimensional ◽  
Degradation Behavior ◽  
Tissue Engineering Scaffolds ◽  
Regeneration Rate ◽  
The Impact

The degradation rate of tissue engineering scaffolds should match the regeneration rate of new tissues. Controlling the degradation behavior of silk fibroin is an important subject for silk-based tissue engineering scaffolds. In this study,Antheraea pernyisilk fibroin was successfully modified with succinic anhydride and then characterized by zeta potential, ninhydrin method, and FTIR.In vitro, three-dimensional scaffolds prepared with modified silk fibroin were incubated in collagenase IA solution for 18 days to evaluate the impact of acylation on the degradation behavior. The results demonstrated that the degradation rate of modified silk fibroin scaffolds was more rapid than unmodified ones. The content of theβ-sheet structure in silk fibroin obviously decreased after acylation, resulting in a high degradation rate. Above all, the degradation behavior of silk fibroin scaffolds could be regulated by acylation to match the requirements of various tissues regeneration.

scholarly journals 3D Fuzzy Graphene Microelectrode Array for Neurotransmitter Sensing at Sub-cellular Spatial Resolution

2020 ◽  
Author(s):  
Elisa Castagnola ◽  
Raghav Garg ◽  
Sahil Rastogi ◽  
Tzahi Cohen-Karni ◽  
Xinyan Tracy Cui
Keyword(s):  
Surface Area ◽  
Spatial Resolution ◽  
Microelectrode Array ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Electrochemical Sensing ◽  
Brain Functions

<div>Dopamine (DA) is a monoamine neurotransmitter involved in the modulation of various physiological brain functions, including learning, motivation, reward, and motor functions. The development of a high sensitivity real-time sensor for multi-site detection of DA with high spatial resolution has critical implications for both neuroscience and clinical communities to improve understanding and treatments of neurological and neuropsychiatric disorders. Here, we present high-surface area out-of-plane grown three-dimensional (3D) fuzzy graphene (3DFG) microelectrode arrays (MEAs) for highly selective, sensitive, and stable DA electrochemical sensing. 3DFG microelectrodes present a remarkable sensitivity to DA (2.87 ± 0.25 nA/nM, with</div><div>LOD of 990±15 pM), the highest reported for nanocarbon MEAs using Fast Scan Cyclic Voltammetry (FSCV). The high surface area of 3DFG allows for miniaturization of electrode down to 2 x 2 μm^2, without compromising the electrochemical performance. Moreover, 3DFG MEAs are electrochemically stable under 7.2 million scans of continuous FSCV cycling, present exceptional selectivity over the most common interferents in vitro with minimum fouling by electrochemical byproducts, and can discriminate DA and serotonin (5-HT) in response to the injection of their 50:50 mixture. These results highlight the potential of 3DFG MEAs as a promising platform for FSCV based multi-site detection of DA with high sensitivity, selectivity, and spatial resolution.</div>

scholarly journals 3D Fuzzy Graphene Microelectrode Array for Neurotransmitter Sensing at Sub-cellular Spatial Resolution

2020 ◽  
Author(s):  
Elisa Castagnola ◽  
Raghav Garg ◽  
Sahil Rastogi ◽  
Tzahi Cohen-Karni ◽  
Xinyan Tracy Cui
Keyword(s):  
Surface Area ◽  
Spatial Resolution ◽  
Microelectrode Array ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Electrochemical Sensing ◽  
Brain Functions

<div>Dopamine (DA) is a monoamine neurotransmitter involved in the modulation of various physiological brain functions, including learning, motivation, reward, and motor functions. The development of a high sensitivity real-time sensor for multi-site detection of DA with high spatial resolution has critical implications for both neuroscience and clinical communities to improve understanding and treatments of neurological and neuropsychiatric disorders. Here, we present high-surface area out-of-plane grown three-dimensional (3D) fuzzy graphene (3DFG) microelectrode arrays (MEAs) for highly selective, sensitive, and stable DA electrochemical sensing. 3DFG microelectrodes present a remarkable sensitivity to DA (2.87 ± 0.25 nA/nM, with</div><div>LOD of 990±15 pM), the highest reported for nanocarbon MEAs using Fast Scan Cyclic Voltammetry (FSCV). The high surface area of 3DFG allows for miniaturization of electrode down to 2 x 2 μm^2, without compromising the electrochemical performance. Moreover, 3DFG MEAs are electrochemically stable under 7.2 million scans of continuous FSCV cycling, present exceptional selectivity over the most common interferents in vitro with minimum fouling by electrochemical byproducts, and can discriminate DA and serotonin (5-HT) in response to the injection of their 50:50 mixture. These results highlight the potential of 3DFG MEAs as a promising platform for FSCV based multi-site detection of DA with high sensitivity, selectivity, and spatial resolution.</div>

Bi-layered electrospun nanofibrous polyurethane-gelatin scaffold with targeted heparin release profiles for tissue engineering applications

2017 ◽  
Vol 37 (9) ◽  
pp. 933-941 ◽  
Author(s):  
Mohammad Mahdi Safikhani ◽  
Ali Zamanian ◽  
Farnaz Ghorbani ◽  
Azadeh Asefnejad ◽  
Mostafa Shahrezaee
Keyword(s):  
Tissue Engineering ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Coagulation Factor ◽  
Volume Ratio ◽  
Fibroblast Cell ◽  
Porous Scaffolds ◽  
Nanofibrous Scaffolds

Abstract Tissue engineering is a biotechnology that is used to develop biological substitutes to restore, maintain, or improve functions. Thus, the porous scaffolds are used to accommodate cells in tissue engineering. In this research, three dimensional (3D) bi-layered polyurethane (PU)-gelatin nanofibrous scaffolds were prepared by the electrospinning method, after which the capability of the released heparin as an anti-coagulation factor was evaluated. Electrospinning has been extensively investigated for the preparation of fibers that exhibit a high surface area to volume ratio. Results showed that scanning electron microscopy (SEM) micrographs exhibited a smooth surface as well as a highly porous and bead-free structure, in which fibers were distributed in the range of 100–600 nm. The modulus and ultimate tensile strength (UTS) decreased and increased, respectively, after crosslinking the reaction of polymers. This process also reduced swelling ratio, the hydrolytic biodegradation rate, and the release rate as a function of time. Moreover, an in vitro assay demonstrated that 3D nanofibrous scaffolds supported L929 fibroblast cell viability and that cells adhered and spread on the fibers. Based on the obtained results, the heparin-loaded electrospinning nanofibrous scaffolds have initial physicochemical and mechanical properties to protect neo-tissue formation.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Functionalized Nano-graphene Oxide as Multi-modal Clinic for Effective Drug Delivery

2017 ◽  
Vol 10 (4) ◽  
pp. 3768-3771
Author(s):  
Soumitra Satapathi ◽  
Rutusmita Mishra ◽  
Manisha Chatterjee ◽  
Partha Roy ◽  
Somesh Mohapatra
Keyword(s):  
Drug Delivery ◽  
Graphene Oxide ◽  
Cancer Cell ◽  
High Surface ◽  
High Surface Area ◽  
Cancer Cell Line ◽  
Xrd Analysis ◽  
Graphene Derivatives ◽  
Nano Graphene

Nano-materials based drug delivery modalities to specific organs and tissues has become one of the critical endeavors in pharmaceutical research. Recently, two-dimensional graphene has elicited considerable research interest because of its potential application in drug delivery systems. Here we report, the drug delivery applications of PEGylated nano-graphene oxide (nGO-PEG), complexed with a multiphoton active and anti-cancerous diarylheptanoid drug curcumin. Specifically, graphene-derivatives were used as nanovectors for the delivery of the hydrophobic anticancer drug curcumin due to its high surface area and easy surface functionalization. nGO was synthesized by modified Hummer’s method and confirmed by XRD analysis. The formation of nGO, nGO-PEG and nGO-PEG-Curcumin complex were monitored through UV-vis, IR spectroscopy. MTT assay and AO/EB staining found that nGO-PEG-Curcumin complex afforded highly potent cancer cell killing in vitro with a human breast cancer cell line MCF7.

Smart Gn-Keto Nanohybrid Embedded Topical System for Effective Management of Dermatophytosis

2019 ◽  
Vol 9 (1) ◽  
pp. 21-28
Author(s):  
Nisha Sharma ◽  
Shashikiran Misra
Keyword(s):  
Antifungal Activity ◽  
Fungal Infections ◽  
High Surface ◽  
High Surface Area ◽  
Vital Role ◽  
Common Disease ◽  
Microdilution Method ◽  
Enhanced Solubility ◽  
Bioactive Agents

Background and Objectives: Dermatophytosis (topical fungal infection) is the 4th common disease in the last decade, affecting 20-25% world’s population. Patients of AIDS, cancer, old age senescence, diabetes, cystic fibrosis become more vulnerable to dermatophytosis. The conventional topical dosage proves effective as prophylactic in preliminary stage. In the advanced stage, the therapeutics interacts with healthy tissues before reaching the pathogen site, showing undesirable effects, thus resulting in pitiable patient compliance. The youngest carbon nano-trope “Graphene” is recently used to manipulate bioactive agents for therapeutic purposes. Here, we explore graphene via smart engineering by virtue of high surface area and high payload for therapeutics and developed graphene–ketoconazole nanohybrid (Gn-keto) for potent efficacy towards dermatophytes in a controlled manner. </P><P> Methods: Polymethacrylate derivative Eudragit (ERL100 and ERS 100) microspheres embedded with keto and Gn-keto nanohybrid were formulated and characterized through FTIR, TGA, and SEM. In vitro drug release and antifungal activity of formulated Gn-keto microspheres were assessed for controlled release and better efficacy against selected dermatophytes. </P><P> Results: Presence of numerous pores within the surface of ERL100 microspheres advocated enhanced solubility and diffusion at the site of action. Controlled diffusion across the dialysis membrane was observed with ERS100 microspheres owing to the nonporous surface and poor permeability. Antifungal activity against T. rubrum and M. canis using microdilution method focused on a preeminent activity (99.785 % growth inhibition) of developed nanohybrid loaded microspheres as compared to 80.876% of keto loaded microspheres for T. rubrum. The culture of M. canis was found to be less susceptible to formulated microspheres. Conclusion: Synergistic antifungal activity was achieved by nanohybrid Gn-Keto loaded microspheres against selected topical fungal infections suggesting a vital role of graphene towards fungi.

scholarly journals Glucose/Graphene-Based Aerogels for Gas Adsorption and Electric Double Layer Capacitors

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Kang-Kai Liu ◽  
Biao Jin ◽  
Long-Yue Meng
Keyword(s):  
Gas Adsorption ◽  
High Surface ◽  
Aqueous Media ◽  
High Surface Area ◽  
Three Dimensional ◽  
High Specific Capacitance ◽  
Mesopore Size Distribution ◽  
Excellent Electrochemical Performance ◽  
Double Layer Capacitors ◽  
Hydrothermal Reduction

In this study, three-dimensional glucose/graphene-based aerogels (G/GAs) were synthesized using the hydrothermal reduction and CO2 activation method. Graphene oxide (GO) was used as a matrix, and glucose was used as a binder for the orientation of the GO morphology in an aqueous media. We determined that G/GAs exhibited narrow mesopore size distribution, a high surface area (763 m2 g−1), and hierarchical macroporous and mesoporous structures. These features contributed to G/GAs being promising adsorbents for the removal of CO2 (76.5 mg g−1 at 298 K), CH4 (16.8 mg g−1 at 298 K), and H2 (12.1 mg g−1 at 77 K). G/GAs presented excellent electrochemical performance, featuring a high specific capacitance of 305.5 F g−1 at 1 A g−1, and good cyclic stability of 98.5% retention after 10,000 consecutive charge-discharge cycles at 10 A g−1. This study provided an efficient approach for preparing graphene aerogels exhibiting hierarchical porosity for gas adsorption and supercapacitors.

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