The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Kristi S. Anseth - One of the best experts on this subject based on the ideXlab platform.
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crosslinked hyaluronan scaffolds as a biologically Active Carrier for valvular interstitial cells
Biomaterials, 2005Co-Authors: Kristyn S. Masters, Darshita N. Shah, Leslie A. Leinwand, Kristi S. AnsethAbstract:Hyaluronic acid (HA), a major component of the cardiac jelly during heart morphogenesis, is a polysaccharide that upon modification can be photopolymerized into hydrogels. Previous work in our lab has found that photopolymerizable HA hydrogels are suitable scaffolds for the culture and proliferation of valvular interstitial cells (VICs), the most prevalent cell type in native heart valves. The physical properties of HA gels are easily modified through alteration in material crosslink density or by copolymerizing with other reActive macromolecules. Degradation products of HA gels and the starting macromers significantly increased VIC proliferation when added to cell cultures. With low molecular weight HA (<6700 Da) exhibiting greatest stimulation of VIC proliferation. Low molecular weight HA degradation products added to VIC cultures also resulted in a four-fold increase in total matrix production and a two-fold increase in elastin production over untreated controls. VIC internalization of HA, as shown by cellular uptake of fluorescently labeled HA, likely activates signaling cascades resulting in the biological responses seen here. Lastly, VICs encapsulated within HA hydrogels remained viable, and significant elastin production was observed after 6 weeks of culture. This work shows promise for the creation of a tissue-engineered heart valve utilizing the synergistic relationship between hyaluronic acid and VICs.
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Crosslinked hyaluronan scaffolds as a biologically Active Carrier for valvular interstitial cells
Biomaterials, 2005Co-Authors: Kristyn S. Masters, Darshita N. Shah, Leslie A. Leinwand, Kristi S. AnsethAbstract:Hyaluronic acid (HA), a major component of the cardiac jelly during heart morphogenesis, is a polysaccharide that upon modification can be photopolymerized into hydrogels. Previous work in our lab has found that photopolymerizable HA hydrogels are suitable scaffolds for the culture and proliferation of valvular interstitial cells (VICs), the most prevalent cell type in native heart valves. The physical properties of HA gels are easily modified through alteration in material crosslink density or by copolymerizing with other reActive macromolecules. Degradation products of HA gels and the starting macromers significantly increased VIC proliferation when added to cell cultures. With low molecular weight HA (
Carla Caramella - One of the best experts on this subject based on the ideXlab platform.
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Zn2+-exchanged clinoptilolite-rich rock as Active Carrier for antibiotics in anti-acne topical therapy: In-vitro characterization and preliminary formulation studies
Applied Clay Science, 2006Co-Authors: Maria Cristina Bonferoni, Guido Cerri, M. De Gennaro, Claudia Clelia Assunta Juliano, Carla CaramellaAbstract:The combination of erythromycin and zinc in the topical antibiotic therapy of acne has been proved useful to reduce the development of antibiotic-resistant strains. An Italian zeolite-rich rock, containing 66 wt.% of clinoptilolite, has been used to prepare an Active Carrier for erythromycin. The zeolite has been conditioned in zinc form by a set of cation exchange processes, then erythromycin has been adsorbed onto the micronized rock by vacuum drying. After 6 month ageing, almost 95% of the loaded drug was found, indicating good stability of the Zn-Carrier-erythromycin system. Minimum inhibitory concentration (M.I.C.) assay on Propionibacterium acnes showed that the process of adsorption of erythromycin does not affect its antimicrobial activity. Both drug and zinc release were evaluated from the Carrier powder: the erythromycin release was more than 80% in the first hour and independent on hydrodynamic conditions (United States Pharmacopoeia dissolution apparatus or Franz cell). The release of zinc was fast, and more dependent on the hydrodynamic conditions. The influence of formulating the Carrier by dispersion in two anhydrous bases, an absorption petrolatum base (HP) and a water soluble polyethylenglycol base (PEG), was evaluated. In both cases erythromycin and zinc showed a release quantitatively similar to that of the powder, although the release rate was slightly lower from the more hydrophobic HP base.
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Zeolites in biomedical application: Zn-exchanged clinoptilolite-rich rock as Active Carrier for antibiotics in anti-acne topical therapy ☆
Applied Clay Science, 2004Co-Authors: Guido Cerri, Maria Cristina Bonferoni, M. De Gennaro, Carla CaramellaAbstract:A clinoptilolite-rich rock was evaluated as inorganic Zn2+ releasing Carrier for antibiotic erythromycin. The perspective is its use in the topical treatment of acne, a diffused skin pathology, given the efficacy of zinc-erythromycin combination against resistant Propionibacterium strains. The tested rock is an ash-rich epiclastite collected in Northern–Central part of Sardinia island (Italy). ICP chemical analyses of the bulk rock evidenced a composition compatible with topical applications. A 66 wt.% of clinoptilolite content was determined by means of XRD analysis (reference intensity ratio [RIR] technique). EDS chemical analyses of zeolite crystals were performed on polished thin section. The CEC of the rock is 1.45±0.08 meq/g. Using a specific exchange method, the material was previously Na-conditioned then Zn-conditioned. A substantially complete Zn-form was obtained, as demonstrated by AAS analyses. A back-exchange reaction toward Na-form was performed in the same conditions (65 °C in 1 M NaCl solution): zinc release was fast and almost complete (94%). Zn-conditioned powder was then micronized to achieve a volume/surface ratio suitable for a topical therapy. After micronization, the specific surface area, determined by BET gas adsorption, was 30.2 m2/g, and 92% of the powdered rock was lower than 30 μm in size (measured by a Coulter Counter apparatus); the so-called “volume-surface diameter” was 6.48 μm, compatible with the intended topical application. Zn2+ release was measured on micronized rock at 37 °C both in physiologic solution as in 0.05 M KH2PO4/Na2HPO4 buffer. Also in these conditions, a prompt and significant zinc release was recorded: after 30 min, 68% and 60%, respectively. Erythromycin was charged onto the micronized material using a solvent evaporation method. HPLC determinations showed that 85% of the drug contacted with the Carrier was loaded. The simultaneous release of zinc and erythromycin were evaluated in phosphate buffer. Eighty-two percent of the loaded antibiotic was released after 30 min. Zinc exchange is substantially unaffected by the contemporary drug release. The request to file an international patent for this pharmaceutical application has been accepted by the European International Preliminary Examination Office.
Shayan Mookherjea - One of the best experts on this subject based on the ideXlab platform.
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efficient cw four wave mixing in silicon on insulator micro rings with Active Carrier removal
IEEE Photonics Technology Letters, 2013Co-Authors: Jun Rong Ong, Ranjee Kuma, Rya Aguinaldo, Shayan MookherjeaAbstract:Silicon-on-insulator rib waveguides with passive loss of -0.74 dB/cm and free-Carrier lifetime reduction via reverse biased p-i-n diodes are used to show efficient continuous wave four-wave mixing with 2 × reduction in required pump power for comparably high conversion efficiency of -8.2 dB, similar to best reports. A conversion efficiency of -13.4 dB is also subsequently achieved using 20 μm radius micro-ring resonators at significantly reduced pump power.
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Efficient continuous-wave four-wave mixing in SOI waveguides with Active Carrier removal
CLEO: 2013, 2013Co-Authors: Jun Rong Ong, Ranjeet Kumar, Shayan MookherjeaAbstract:Silicon-on-insulator rib waveguides with low loss of −0.74 dB/cm and free-Carrier lifetime reduction via reverse biased P/N diodes are used to show highly efficient CW four-wave mixing with conversion efficiency of −8 dB.
Kristyn S. Masters - One of the best experts on this subject based on the ideXlab platform.
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crosslinked hyaluronan scaffolds as a biologically Active Carrier for valvular interstitial cells
Biomaterials, 2005Co-Authors: Kristyn S. Masters, Darshita N. Shah, Leslie A. Leinwand, Kristi S. AnsethAbstract:Hyaluronic acid (HA), a major component of the cardiac jelly during heart morphogenesis, is a polysaccharide that upon modification can be photopolymerized into hydrogels. Previous work in our lab has found that photopolymerizable HA hydrogels are suitable scaffolds for the culture and proliferation of valvular interstitial cells (VICs), the most prevalent cell type in native heart valves. The physical properties of HA gels are easily modified through alteration in material crosslink density or by copolymerizing with other reActive macromolecules. Degradation products of HA gels and the starting macromers significantly increased VIC proliferation when added to cell cultures. With low molecular weight HA (<6700 Da) exhibiting greatest stimulation of VIC proliferation. Low molecular weight HA degradation products added to VIC cultures also resulted in a four-fold increase in total matrix production and a two-fold increase in elastin production over untreated controls. VIC internalization of HA, as shown by cellular uptake of fluorescently labeled HA, likely activates signaling cascades resulting in the biological responses seen here. Lastly, VICs encapsulated within HA hydrogels remained viable, and significant elastin production was observed after 6 weeks of culture. This work shows promise for the creation of a tissue-engineered heart valve utilizing the synergistic relationship between hyaluronic acid and VICs.
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Crosslinked hyaluronan scaffolds as a biologically Active Carrier for valvular interstitial cells
Biomaterials, 2005Co-Authors: Kristyn S. Masters, Darshita N. Shah, Leslie A. Leinwand, Kristi S. AnsethAbstract:Hyaluronic acid (HA), a major component of the cardiac jelly during heart morphogenesis, is a polysaccharide that upon modification can be photopolymerized into hydrogels. Previous work in our lab has found that photopolymerizable HA hydrogels are suitable scaffolds for the culture and proliferation of valvular interstitial cells (VICs), the most prevalent cell type in native heart valves. The physical properties of HA gels are easily modified through alteration in material crosslink density or by copolymerizing with other reActive macromolecules. Degradation products of HA gels and the starting macromers significantly increased VIC proliferation when added to cell cultures. With low molecular weight HA (
Tomás Girbés - One of the best experts on this subject based on the ideXlab platform.
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Effect of continued exposition to ethanol on activity of the ammonium and fructose transport systems in Saccharomyces cerevisiae var. ellipsoideus.
Biotechnology and bioengineering, 1991Co-Authors: Rosario Iglesias, José Miguel Ferreras, Francisco Javier Arias, Raquel Muñoz, Tomás GirbésAbstract:Ethanol and cycloheximide inhibited the function of the ammonium transport system in growing cultures of Saccharomyces cerevisiae var. ellipsoideus measured as methylamine uptake. The effect was reversible with ethanol and irreversible with the antibiotic. The kinetic data are consistent with a reduction of the number of Active Carrier molecules located in the plasma membrane. In contrast, neither ethanol nor cycloheximide affected the specific rate of fructose uptake.
