Dithiocarbamate chemistry is used as a crosslinking tool to fabricate FePt colloidal microcapsule... more Dithiocarbamate chemistry is used as a crosslinking tool to fabricate FePt colloidal microcapsules which provide a versatile scaffold for "host-guest" recognition at the liquid-liquid interface.
Dithiocarbamate-mediated bond formation combined with soft lithography was used for the selective... more Dithiocarbamate-mediated bond formation combined with soft lithography was used for the selective immobilization of amine-functionalized silica nanoparticles on gold substrates. The available amine groups on the upper surface of the immobilized silica nanoparticles were further utilized for postdeposition of additional materials including particles, dyes, and biomolecules. The robustness of dithiocarbamate-mediated immobilization enables orthogonal assembly on surfaces via selective removal of the masking thiol ligands using iodine vapor etching followed by further functionalization.
In an effort to reduce the flammability of polyurethane foam, a thin film of renewable inorganic ... more In an effort to reduce the flammability of polyurethane foam, a thin film of renewable inorganic nanoparticles (i.e., anionic vermiculite [VMT] and cationic boehmite [BMT]) was deposited on polyurethane foam via layer-by-layer (LbL) assembly. One, two, and three bilayers (BL) of BMT-VMT resulted in foam with retained shape after being exposed to a butane flame for 10 s, while uncoated foam was completely consumed. Cone calorimetry confirmed that the coated foam exhibited a 55% reduction in peak heat release rate with only a single bilayer deposited. Moreover, this protective nanocoating reduced total smoke release by 50% relative to untreated foam. This study revealed that 1 BL, adding just 4.5 wt % to PU foam, is an effective and conformal flame retardant coating. These results demonstrate one of the most efficient and renewable nanocoatings prepared using LbL assembly, taking this technology another step closer to commercial viability.
The proprotein convertase site-1 protease (S1P) converts latent ER-membrane bound transcription f... more The proprotein convertase site-1 protease (S1P) converts latent ER-membrane bound transcription factors SREBPs and ATF6 to their active forms. SREBPs are involved in cholesterol and fatty acid homeostasis whereas ATF6 is involved in unfolded protein response pathways (UPR). Cartilage-specific ablation of S1P in mice (S1Pcko) results in abnormal cartilage devoid of type II collagen protein (Col II). S1Pcko mice also lack endochondral bone development. To analyze S1Pcko cartilage we performed double-labeled immunofluorescence studies for matrix proteins that demonstrated that type IIB procollagen is trapped inside the ER in S1Pcko chondrocytes. This retention is specific to type IIB procollagen; other cartilage proteins such as type IIA procollagen, cartilage oligomeric matrix protein (COMP) and aggrecan are not affected. The S1Pcko cartilage thus exhibits COMP-, aggrecan-, and type IIA procollagen-derived matrices but is characterized by the absence of a type IIB procollagen-derived ...
Langmuir : the ACS journal of surfaces and colloids, Jan 15, 2009
Stimuli-responsive colloidal microcapsules have been fabricated at the oil-water interface using ... more Stimuli-responsive colloidal microcapsules have been fabricated at the oil-water interface using molecular recognition between functionalized gold nanoparticles. Water-soluble beta-cyclodextrin-capped gold nanoparticles and organo-soluble adamantyl-functionalized gold nanoparticles are self-assembled at the water-toluene interface via specific host-guest molecular interactions to provide robust microcapsules. Multivalent interactions of complementary ligands on the nanoparticle surface provide stability to these capsules. Unlike covalently cross-linked microcapsules, the reversible nature of these bridging interactions can be used to manipulate the size of these capsules via introduction of competing adamantane containing amphiphilic guest molecules. Partial disruption of interfacial cross-linking allows microcapsules to coalesce with each other to form larger capsules.
Preclinical biodistribution studies with INGN 007, an oncolytic adenovirus (Ad) vector, supportin... more Preclinical biodistribution studies with INGN 007, an oncolytic adenovirus (Ad) vector, supporting an early stage clinical trial were conducted in Syrian hamsters, which are permissive for Ad replication, and mice, which are a standard model for assessing toxicity and biodistribution of replication-defective (RD) Ad vectors. Vector dissemination and pharmacokinetics following intravenous administration were examined by real-time PCR in nine tissues
Higher body mass index (BMI) increases the risk of meniscus injury and knee osteoarthritis (OA). ... more Higher body mass index (BMI) increases the risk of meniscus injury and knee osteoarthritis (OA). However, it is unknown if and how obesity affects meniscus biology. We analyzed transcriptome-wide gene expression profiles of injured human menisci to test the hypothesis that meniscal gene expression signatures relate to patient BMI. Meniscus samples were obtained from patients undergoing arthroscopic partial meniscectomy. Transcriptome-wide analysis of gene expression followed by validation of selected transcripts by QuantiGene Plex assay was performed. Correlations of gene expression with BMI and relative fold changes (≥1.5-fold) in 3 BMI categories (lean [BMI 18.5-24.9 kg/m(2) ], overweight [BMI 25.0-29.9 kg/m(2) ], and obese [BMI >30.0 kg/m(2) ]) were analyzed, and integrated functional classifications were probed computationally. The obese versus overweight comparison resulted in the largest set of differences (565 transcripts) followed by obese versus lean (280 transcripts) and overweight versus lean (125 transcripts). Biologic reproducibility was confirmed by cluster analysis of expressed transcripts. Differentially regulated transcripts represented important functional classifications. Transcripts associated with oxygen transport, calcium ion binding, and cell homeostasis were elevated with BMI, while those related to extracellular matrix deposition, cell migration, and glucosamine metabolic processes were repressed. While these functional classifications may play key roles in cartilage/meniscus homeostasis, failure of extracellular matrix deposition and increase in calcium ion binding likely contribute to OA development following meniscal injury. Our results indicate greater differences in gene expression between obese and overweight groups than between overweight and lean groups. This may indicate that there is a weight threshold at which injured meniscus responds severely to increased BMI. BMI-related changes in gene expression present a plausible explanation for the role of meniscal injury in OA development among obese patients.
Osteoarthritis (OA) is one of the most debilitating diseases affecting mankind with severe financ... more Osteoarthritis (OA) is one of the most debilitating diseases affecting mankind with severe financial and emotional consequences. The heterogeneity of the human population, lack of complete understanding of the OA disease process, and the slow progressive nature of the disease characterized by prolonged periods of nonsymptomatic, degenerative changes has hampered development of ideal diagnostic and prognostic portfolios. The difficulties associated with early OA diagnosis by exclusively radiographic techniques has propelled a need to identify specific biomarkers for rapid and effective early OA diagnosis, better patient prognosis, and for monitoring the efficacy of pharmacological interventions to the disease process. This review highlights some of the biochemical biomarkers in current use in OA, their applications and limitations. Investigation of single nucleotide polymorphisms as genetic biomarkers and the application of technologies such as lipidomics and metabolomics to OA are generating potentially additional biomarkers that could be helpful for detecting early OA phenomena in humans.
Synergistic dipole-dipole and hydrogen-bonding interactions are used to assemble nanostructured m... more Synergistic dipole-dipole and hydrogen-bonding interactions are used to assemble nanostructured materials. Precipitation of a hydrogen-bonding donor-acceptor molecule 8-[[p-[bis(ethyl)amino]phenyl]azo]-isobutylflavin (ABFL) yields nanowires approximately 50-150 nm in diameter and lengths of several millimeters. Precipitation of the non-hydrogen-bonding analog, methylated ABFL (MABFL), generates micrometer-sized hexagonal platelets that are 5-10 microm in length, 1-5 microm in width, and 0.1-0.5 microm thick. The structural similarity of the two molecules allows intermediate morphologies to be formed via co-precipitation. Doping experiments demonstrate efficient control over nanowire length and diameter due to the disruption of the hydrogen bonding within the nanowires.
Stimuli-responsive colloidal microcapsules have been fabricated at the oil-water interface using ... more Stimuli-responsive colloidal microcapsules have been fabricated at the oil-water interface using molecular recognition between functionalized gold nanoparticles. Water-soluble beta-cyclodextrin-capped gold nanoparticles and organo-soluble adamantyl-functionalized gold nanoparticles are self-assembled at the water-toluene interface via specific host-guest molecular interactions to provide robust microcapsules. Multivalent interactions of complementary ligands on the nanoparticle surface provide stability to these capsules. Unlike covalently cross-linked microcapsules, the reversible nature of these bridging interactions can be used to manipulate the size of these capsules via introduction of competing adamantane containing amphiphilic guest molecules. Partial disruption of interfacial cross-linking allows microcapsules to coalesce with each other to form larger capsules.
Dithiocarbamate chemistry is used as a crosslinking tool to fabricate FePt colloidal microcapsule... more Dithiocarbamate chemistry is used as a crosslinking tool to fabricate FePt colloidal microcapsules which provide a versatile scaffold for "host-guest" recognition at the liquid-liquid interface.
Dithiocarbamate-mediated bond formation combined with soft lithography was used for the selective... more Dithiocarbamate-mediated bond formation combined with soft lithography was used for the selective immobilization of amine-functionalized silica nanoparticles on gold substrates. The available amine groups on the upper surface of the immobilized silica nanoparticles were further utilized for postdeposition of additional materials including particles, dyes, and biomolecules. The robustness of dithiocarbamate-mediated immobilization enables orthogonal assembly on surfaces via selective removal of the masking thiol ligands using iodine vapor etching followed by further functionalization.
In an effort to reduce the flammability of polyurethane foam, a thin film of renewable inorganic ... more In an effort to reduce the flammability of polyurethane foam, a thin film of renewable inorganic nanoparticles (i.e., anionic vermiculite [VMT] and cationic boehmite [BMT]) was deposited on polyurethane foam via layer-by-layer (LbL) assembly. One, two, and three bilayers (BL) of BMT-VMT resulted in foam with retained shape after being exposed to a butane flame for 10 s, while uncoated foam was completely consumed. Cone calorimetry confirmed that the coated foam exhibited a 55% reduction in peak heat release rate with only a single bilayer deposited. Moreover, this protective nanocoating reduced total smoke release by 50% relative to untreated foam. This study revealed that 1 BL, adding just 4.5 wt % to PU foam, is an effective and conformal flame retardant coating. These results demonstrate one of the most efficient and renewable nanocoatings prepared using LbL assembly, taking this technology another step closer to commercial viability.
The proprotein convertase site-1 protease (S1P) converts latent ER-membrane bound transcription f... more The proprotein convertase site-1 protease (S1P) converts latent ER-membrane bound transcription factors SREBPs and ATF6 to their active forms. SREBPs are involved in cholesterol and fatty acid homeostasis whereas ATF6 is involved in unfolded protein response pathways (UPR). Cartilage-specific ablation of S1P in mice (S1Pcko) results in abnormal cartilage devoid of type II collagen protein (Col II). S1Pcko mice also lack endochondral bone development. To analyze S1Pcko cartilage we performed double-labeled immunofluorescence studies for matrix proteins that demonstrated that type IIB procollagen is trapped inside the ER in S1Pcko chondrocytes. This retention is specific to type IIB procollagen; other cartilage proteins such as type IIA procollagen, cartilage oligomeric matrix protein (COMP) and aggrecan are not affected. The S1Pcko cartilage thus exhibits COMP-, aggrecan-, and type IIA procollagen-derived matrices but is characterized by the absence of a type IIB procollagen-derived ...
Langmuir : the ACS journal of surfaces and colloids, Jan 15, 2009
Stimuli-responsive colloidal microcapsules have been fabricated at the oil-water interface using ... more Stimuli-responsive colloidal microcapsules have been fabricated at the oil-water interface using molecular recognition between functionalized gold nanoparticles. Water-soluble beta-cyclodextrin-capped gold nanoparticles and organo-soluble adamantyl-functionalized gold nanoparticles are self-assembled at the water-toluene interface via specific host-guest molecular interactions to provide robust microcapsules. Multivalent interactions of complementary ligands on the nanoparticle surface provide stability to these capsules. Unlike covalently cross-linked microcapsules, the reversible nature of these bridging interactions can be used to manipulate the size of these capsules via introduction of competing adamantane containing amphiphilic guest molecules. Partial disruption of interfacial cross-linking allows microcapsules to coalesce with each other to form larger capsules.
Preclinical biodistribution studies with INGN 007, an oncolytic adenovirus (Ad) vector, supportin... more Preclinical biodistribution studies with INGN 007, an oncolytic adenovirus (Ad) vector, supporting an early stage clinical trial were conducted in Syrian hamsters, which are permissive for Ad replication, and mice, which are a standard model for assessing toxicity and biodistribution of replication-defective (RD) Ad vectors. Vector dissemination and pharmacokinetics following intravenous administration were examined by real-time PCR in nine tissues
Higher body mass index (BMI) increases the risk of meniscus injury and knee osteoarthritis (OA). ... more Higher body mass index (BMI) increases the risk of meniscus injury and knee osteoarthritis (OA). However, it is unknown if and how obesity affects meniscus biology. We analyzed transcriptome-wide gene expression profiles of injured human menisci to test the hypothesis that meniscal gene expression signatures relate to patient BMI. Meniscus samples were obtained from patients undergoing arthroscopic partial meniscectomy. Transcriptome-wide analysis of gene expression followed by validation of selected transcripts by QuantiGene Plex assay was performed. Correlations of gene expression with BMI and relative fold changes (≥1.5-fold) in 3 BMI categories (lean [BMI 18.5-24.9 kg/m(2) ], overweight [BMI 25.0-29.9 kg/m(2) ], and obese [BMI >30.0 kg/m(2) ]) were analyzed, and integrated functional classifications were probed computationally. The obese versus overweight comparison resulted in the largest set of differences (565 transcripts) followed by obese versus lean (280 transcripts) and overweight versus lean (125 transcripts). Biologic reproducibility was confirmed by cluster analysis of expressed transcripts. Differentially regulated transcripts represented important functional classifications. Transcripts associated with oxygen transport, calcium ion binding, and cell homeostasis were elevated with BMI, while those related to extracellular matrix deposition, cell migration, and glucosamine metabolic processes were repressed. While these functional classifications may play key roles in cartilage/meniscus homeostasis, failure of extracellular matrix deposition and increase in calcium ion binding likely contribute to OA development following meniscal injury. Our results indicate greater differences in gene expression between obese and overweight groups than between overweight and lean groups. This may indicate that there is a weight threshold at which injured meniscus responds severely to increased BMI. BMI-related changes in gene expression present a plausible explanation for the role of meniscal injury in OA development among obese patients.
Osteoarthritis (OA) is one of the most debilitating diseases affecting mankind with severe financ... more Osteoarthritis (OA) is one of the most debilitating diseases affecting mankind with severe financial and emotional consequences. The heterogeneity of the human population, lack of complete understanding of the OA disease process, and the slow progressive nature of the disease characterized by prolonged periods of nonsymptomatic, degenerative changes has hampered development of ideal diagnostic and prognostic portfolios. The difficulties associated with early OA diagnosis by exclusively radiographic techniques has propelled a need to identify specific biomarkers for rapid and effective early OA diagnosis, better patient prognosis, and for monitoring the efficacy of pharmacological interventions to the disease process. This review highlights some of the biochemical biomarkers in current use in OA, their applications and limitations. Investigation of single nucleotide polymorphisms as genetic biomarkers and the application of technologies such as lipidomics and metabolomics to OA are generating potentially additional biomarkers that could be helpful for detecting early OA phenomena in humans.
Synergistic dipole-dipole and hydrogen-bonding interactions are used to assemble nanostructured m... more Synergistic dipole-dipole and hydrogen-bonding interactions are used to assemble nanostructured materials. Precipitation of a hydrogen-bonding donor-acceptor molecule 8-[[p-[bis(ethyl)amino]phenyl]azo]-isobutylflavin (ABFL) yields nanowires approximately 50-150 nm in diameter and lengths of several millimeters. Precipitation of the non-hydrogen-bonding analog, methylated ABFL (MABFL), generates micrometer-sized hexagonal platelets that are 5-10 microm in length, 1-5 microm in width, and 0.1-0.5 microm thick. The structural similarity of the two molecules allows intermediate morphologies to be formed via co-precipitation. Doping experiments demonstrate efficient control over nanowire length and diameter due to the disruption of the hydrogen bonding within the nanowires.
Stimuli-responsive colloidal microcapsules have been fabricated at the oil-water interface using ... more Stimuli-responsive colloidal microcapsules have been fabricated at the oil-water interface using molecular recognition between functionalized gold nanoparticles. Water-soluble beta-cyclodextrin-capped gold nanoparticles and organo-soluble adamantyl-functionalized gold nanoparticles are self-assembled at the water-toluene interface via specific host-guest molecular interactions to provide robust microcapsules. Multivalent interactions of complementary ligands on the nanoparticle surface provide stability to these capsules. Unlike covalently cross-linked microcapsules, the reversible nature of these bridging interactions can be used to manipulate the size of these capsules via introduction of competing adamantane containing amphiphilic guest molecules. Partial disruption of interfacial cross-linking allows microcapsules to coalesce with each other to form larger capsules.
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Papers by Debabrata Patra