Conducting polymer polyelectrolyte microspheres are typically composed of a cationic conducting polymer and an anionic polymer. The polymer chains inside these microspheres are physically or chemically cross-linked, creating a network that enables high water retention. Poly(3,4-ethylenedioxythiophene) (PEDOT) being an electrically conductive polymer exhibits a high conductivity and has great biotechnological applications.
View Article and Find Full Text PDFA novel hybrid membrane was developed on the basis of poly(-phenylene isophthalamide) (PA) by introducing an original complex modifier into the polymer; this modifier consisted of equal amounts of heteroarm star macromolecules with a fullerene C core (HSM) and the ionic liquid [BMIM][TfN] (IL). The effect of the (HSM:IL) complex modifier on characteristics of the PA membrane was evaluated using physical, mechanical, thermal, and gas separation techniques. The structure of the PA/(HSM:IL) membrane was studied by scanning electron microscopy (SEM).
View Article and Find Full Text PDFThis study aims to improve properties of Ultem polyetherimide (PEI) by incorporating up to 2 wt% additives of the perovskite oxide LaYbAlO (LYA). The structure of dense PEI/LYA films was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) in combination with an analysis of their elemental composition using energy-dispersive spectroscopy (EDS). The PEI/LYA films exhibit a two-layer structure.
View Article and Find Full Text PDFIn this study, novel composites were produced by blending partially cyclized polyacrylonitrile (PAN) and poly(amide-imide) (PAI) in N-methylpyrrolidone in order to fabricate asymmetric membranes via phase inversion method. The compatibility of PAI and PAN through possible intermolecular interaction was examined by quantum chemical calculations. The composite membranes were characterized by FTIR, SEM, contact angle measurements, etc.
View Article and Find Full Text PDFMultiblock copolymers containing linear polydimethylsiloxane or polymethyltrifluoropropylsiloxane and ladder-like polyphenylsiloxane were synthesized in a one-step pathway. The functional homopolymer blocks and final multiblock copolymers were characterized using solution and solid-state multinuclear H, C, F, and Si NMR spectroscopy. It was shown that the ladder-like block contains silanol units, which influence the adhesion properties of multiblock copolymers and morphology of their casted films.
View Article and Find Full Text PDFModification of polymer matrix by hybrid fillers is a promising way to produce membranes with excellent separation efficiency due to variations in membrane structure. High-performance membranes for the pervaporation dehydration were produced by modifying poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) to facilitate lactic acid purification. Ionic liquid (IL), heteroarm star macromolecules (HSM), and their combination (IL:HSM) were employed as additives to the polymer matrix.
View Article and Find Full Text PDFIn order to prolong the release and reduce the toxicity of anticancer drug - doxorubicin (DOX), delivery systems (DS) using different polyanions have been developed. Structural (size, morphological stability) and functional (encapsulation efficiency, DOX release) characteristics of three types of DS are compared: CaCO porous vaterites doped with polyanions by co-precipitation and coating techniques, and DOX-polyanion conjugates. Using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), it was shown that the doping enhances the morphological stability of CaCO-based DS during the DOC loading.
View Article and Find Full Text PDFThe interaction of silver nitrate with star-shaped poly(2-ethyl-2-oxazoline) and poly(2-isopropyl-2-oxazoline) containing central thiacalix[4]arene cores, which proceeds under visible light in aqueous solutions at ambient temperature, was studied. It was found that this process led to the formation of stable colloidal solutions of silver nanoparticles. The kinetics of the formation of the nanoparticles was investigated by the observation of a time-dependent increase in the intensity of the plasmon resonance peak that is related to the nanoparticles and appears in the range of 400 to 700 nm.
View Article and Find Full Text PDFTwo-level systems for oral delivery of therapeutic peptides were developed; the carriers consist of CaCO cores included into alginate granules. Such systems were first used for the delivery of low molecular weight drugs. It was shown that efficiency of encapsulation of peptides depends on their pI value, hydrophobicity, characteristics of the compounds used for doping CaCO cores, their surface potential and the techniques employed for loading peptides into the first-level carriers.
View Article and Find Full Text PDFTwo-level delivery systems (DSs) for oral administration of therapeutic proteins and peptides were developed. The first level consists of outer walls of Lycopodium clavatum spores (sporopollenin exine capsules, SECs) with included target objects; the alginate microgranules serve as the second (outer) level. Alginate (a pH-dependent natural polymer) protects peptides from gastric acidity and enzyme exposure and provides slow release of target objects in an alkaline intestinal medium.
View Article and Find Full Text PDFWe designed novel hybrid inorganic/organic capsules with unique physicochemical features enabling multimodal triggering by physical (UV light, ultrasound) and chemical (enzymatic treatment) stimuli. Notably, the UV- and ultrasound response was achieved by a synergetic combination of TiO and SiO nanostructures which were in situ deposited into the polymer shell of microcapsules during sol-gel synthesis. This results in the formation of a composite hybrid shell with enhanced mechanical stability.
View Article and Find Full Text PDFThe regularities of release of therapeutic antioxidant enzyme superoxide dismutase (SOD) from various alginate-based delivery systems (DS) into simulated gastric and intestinal fluids were determined. The following systems were used: Ca-alginate granules (AG) prepared by various methods, porous carbonate cores with multilayer polyelectrolyte coating as well as the new two-level DS (Ca-AG containing carbonate cores loaded with proteins). The influence of the method of granule preparation, composition of gelation bath and ionic composition of the simulated fluids on release profiles of the protein from different DS was revealed.
View Article and Find Full Text PDFThe calcium carbonate (CaCO3) cores being templates for model proteins encapsulation were obtained for developing oral drug delivery systems. The influence of the characteristics of the core formation (the time, the temperature, the stirring intensity, the ultrasound treatment and drying conditions) on the size and morphology of the carbonate cores was studied. The core size was shown to decrease with increasing the stirring time and stirring intensity.
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