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Polyelectrolyte Microcapsules (polyelectrolyte + microcapsule)
Selected AbstractsContact-Killing Polyelectrolyte Microcapsules Based on Chitosan DerivativesADVANCED FUNCTIONAL MATERIALS, Issue 19 2010Di Cui Abstract Polyelectrolyte-multilayer microcapsules are made by layer-by-layer (LbL) assembly of oppositely charged polyelectrolytes onto sacrificial colloidal particles, followed by core removal. In this paper, contact-killing polyelectrolyte microcapsules are prepared based solely on polysaccharides. To this end, water-soluble quaternized chitosan (QCHI) with varying degrees of substitution (DS) and hyaluronic acid (HA) are assembled into thin films. The quaternary ammonium groups are selectively grafted on the primary amine group of chitosan by exploiting its reaction with glycidyltrimethylammonium chloride (GTMAC) under homogeneous aqueous acidic conditions. The morphology of the capsules is closely dependent on the DS of the quaternized chitosan derivatives, which suggests differences in their complexation with HA. The DS is also a key parameter to control the antibacterial activity of QCHI against Escherichia Coli (E. coli). Thus, capsules containing the QCHI derivative with the highest DS are shown to be the most efficient to kill E. coli while retaining their biocompatibility toward myoblast cells, which suggests their potential as drug carriers able to combat bacterial infections. [source] Inside Front Cover: Novel Engineered Ion Channel Provides Controllable Ion Permeability for Polyelectrolyte Microcapsules Coated with a Lipid Membrane (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 2 2009Mater. In their Full Paper on page 201, Donald Martin and co-workers describe the covering of polyelectrolyte microcapsules with a lipid bilayer that incorporates a novel engineered ion channel to provide a functional capability to control transport across the microcapsule wall. The cover image shows atomic-force microscopy images of these 8-layer polyelectroctrolyte capsules recorded using tapping mode in an aqueous environment. The capsules can be seen to collapse in a folded manner, with an occasional wrinkle that "absorbs" the extra surface area when flattening the spherical surface. [source] Design of a Microfluidic System to Investigate the Mechanical Properties of Layer-by-Layer Fabricated CapsulesMACROMOLECULAR MATERIALS & ENGINEERING, Issue 12 2003Michelle Prevot Abstract A microfluidic system was designed, fabricated and implemented to study the behavior of polyelectrolyte capsules flowing in microscale channels. The device contains microchannels that lead into constrictions intended to capture polyelectrolyte microcapsules which were fabricated with the well-known layer-by-layer (LbL) assembly technique. The behavior of hollow capsules at the constrictions was visualized and the properties of the capsules were investigated before and after introduction into the device. Time series of video frames showing capsules being compressed into a constriction. [source] Red Blood Cell Templated Polyelectrolyte Capsules: A Novel Vehicle for the Stable Encapsulation of DNA and ProteinsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 6 2006Oliver Kreft Abstract Summary: A novel method for the encapsulation of biomacromolecules, such as nucleic acids and proteins, into polyelectrolyte microcapsules is described. Fluorescence-labelled double-stranded DNA and human serum albumin (HSA) are used as model substances for encapsulation in hollow microcapsules templated on human erythrocytes. The encapsulation procedure involves an intermediate drying step. The accumulation of DNA and HSA in the capsules is observed by confocal laser scanning microscopy, UV spectroscopy, and fluorimetry. The mechanism of encapsulation is discussed. Confocal fluorescence microscopy images of encapsulated TRITC-HSA (left) and dsDNA (right). Inserts demonstrate fluorescence profiles for both compounds. [source] | ||||||||||