InterNano Nanomanufacturing Repository
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1523 research outputs found
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Morphology Control in TiO2 Nanorod/Polythiophene Composites for Bulk Heterojunction Solar Cells Using Hydrogen Bonding
Bioelectrochemistry of Non-covalent Immobilized Alcohol Dehydrogenase on Oxidized Diamond Nanoparticles
PolyMPC-Doxorubicin Prodrugs
We demonstrate the conjugation of the cancer drug doxorubicin (DOX) to poly(methacryloyloxyethyl phosphorylcholine) (polyMPC), linked by hydrazone groups, using (1) a one-pot ATRP/click sequence, and (2) a post-polymerization conjugation strategy. While the one-pot method gave polyMPC-DOX conjugates in a facile single step, post-polymerization conjugation gave higher-molecular-weight polymers with very high DOX loadings. DOX release from the polyMPC backbone was pH-dependent (faster at pH 5.0 than at pH 7.4) owing to the hydrazone linkage. Half-life values of DOX release ranged from 2 to 40 h at pH 5.0. Cell culture experiments showed that highly loaded polyMPC-DOX conjugates exhibited higher intracellular drug accumulation and lower half-maximal inhibitory concentration (IC50) values, while a polymer with 30 wt % drug loading showed a maximum tolerated dose in the range of 30-50 mg/kg DOX equivalent weight in healthy mice
Water-Soluble Electrospun Nanofibers as a Method for On-Chip Reagent Storage
This work demonstrates the ability to electrospin reagents into water-soluble nanofibers resulting in a stable on-chip enzyme storage format. Polyvinylpyrrolidone (PVP) nanofibers were spun with incorporation of the enzyme horseradish peroxidase (HRP). Scanning electron microscopy (SEM) of the spun nanofibers was used to confirm the non-woven structure which had an average diameter of 155 ± 34 nm. The HRP containing fibers were tested for their change in activity following electrospinning and during storage. A colorimetric assay was used to characterize the activity of HRP by reaction with the nanofiber mats in a microtiter plate and monitoring the change in absorption over time. Immediately following electrospinning, the activity peak for the HRP decreased by approximately 20%. After a storage study over 280 days, 40% of the activity remained. In addition to activity, the fibers were observed to solubilize in the microfluidic chamber. The chromogenic 3,3´x,5,5´x-tetramethylbenzidine solution reacted immediately with the fibers as they passed through a microfluidic channel. The ability to store enzymes and other reagents on-chip in a rapidly dispersible format could reduce the assay steps required of an operator to perform
Electrical Conductivity in a Mixed-Species Biofilm
Geobacter sulfurreducens can form electrically conductive biofilms, but the potential for conductivity through mixed-species biofilms has not been examined. A current-producing biofilm grown from a wastewater sludge inoculum was highly conductive with low charge transfer resistance even though microorganisms other than Geobacteraceae accounted for nearly half the microbial community