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Drug Delivery (drug + delivery)
Kinds of Drug Delivery Terms modified by Drug Delivery Selected AbstractsSynthesis of Nonwoven Nanofibers by Electrospinning , A Promising Biomaterial for Tissue Engineering and Drug Delivery,ADVANCED ENGINEERING MATERIALS, Issue 8 2010N. Naveen PHB nanofibers are synthesized by electrospinning of a PHB solution prepared using HFIP as the solvent. The nanofibrous scaffold supports rapid cell growth with normal morphology and attains a viability of 87% after 48,h. Kanamycin sulphate-loaded PHB nanofiber mats are synthesized, with the antibiotic on the surface and sandwiched within the nanofiber mats: their antimicrobial property is proved by the good zone of inhibition tested against Staphylococcus aureus. The drug shows more than 95% release within 8,h. These results indicate that nanofibers loaded with the antibiotic have potential applications as a template for tissue engineering and as a drug carrier. [source] Photopolymerizable Hydrogels Made from Polymer-Conjugated Albumin for Affinity-Based Drug Delivery,ADVANCED ENGINEERING MATERIALS, Issue 1-2 2010Liat Oss-Ronen As a drug delivery vehicle, biodegradable albumin hydrogels can combine the high binding capacity of albumin with the structural stability of a polymeric hydrogel network to enable controlled release of small molecules based on both binding affinity and physical interactions. In the present study, we report on the development of a hybrid hydrogel composed of albumin conjugated to poly(ethylene glycol) (PEG) for drug delivery applications where controlled release is accomplished using the natural affinity of the drugs to the serum albumin. Bovine serum albumin was conjugated to PEG-diacrylate having a molecular weight of 1.5, 4, or 10,kDa to form a PEGylated albumin macromolecule (mono-PEGylated or multi-PEGylated). Biodegradable hydrogels were formed from the PEGylated albumin using photopolymerization. Two model drugs, Warfarin and Naproxen, were used for equilibrium dialysis and release experiments from the hydrogels, both having relatively low molecular weights and a known high affinity for albumin. Equilibrium dialysis experiments showed that multi-PEGylation of albumin significantly decreased the drug affinity to the protein compared to non-PEGylated controls, irrespective of the PEG molecular weight. However, the results from drug release experiments showed that mono-PEGylation of albumin did not change its natural affinity to the drug. Comparing the release profiles with a Fickian diffusion model provided strong evidence that hydrogels containing mono-PEGylated albumin exhibited sub-diffusive drug release properties based on the affinity of the drug to the tethered protein. [source] A Novel Biodegradable and Light-Breakable Diblock Copolymer Micelle for Drug Delivery,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Zhigang Xie A facile approach to the preparation of light-responsive copolymer micelles is developed. This approach is based on the attachment of hydrophobic groups to one block of a diblock copolymer via a light-sensitive linkage. The micelles can be dissociated under light irradiation and release the encapsulated pyrene. The obtained polymeric micelles are expected to be of use as drug-delivery vehicles. [source] Hollow Mesoporous Zirconia Nanocapsules for Drug DeliveryADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Shaoheng Tang Abstract Hollow mesoporous zirconia nanocapsules (hm -ZrO2) with a hollow core/porous shell structure are demonstrated as effective vehicles for anti-cancer drug delivery. While the highly porous feature of the shell allows the drug, doxorubicin(DOX), to easily pass through between the inner void space and surrounding environment of the particles, the void space in the core endows the nanocapsules with high drug loading capacity. The larger the inner hollow diameter, the higher their DOX loading capacity. A loading of 102% related to the weight of hm -ZrO2 is achieved by the nanocapsules with an inner diameter of 385,nm. Due to their pH-dependent charge nature, hm -ZrO2 loaded DOX exhibit pH-dependent drug releasing kinetics. A lower pH offers a faster DOX release rate from hm -ZrO2. Such a property makes the loaded DOX easily release from the nanocapsules when up-taken by living cells. Although the flow cytometry reveals more uptake of hm -ZrO2 particles by normal cells, hm -ZrO2 loaded DOX release more drugs in cancer cells than in normal cells, leading to more cytotoxicity toward tumor cells and less cytotoxicity to healthy cells than free DOX. [source] Fabrication and Drug Delivery of Ultrathin Mesoporous Bioactive Glass Hollow FibersADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Youliang Hong Abstract Ultrathin mesoporous bioactive glass hollow fibers (MBGHFs) fabricated using an electrospinning technique and combined with a phase-separation-induced agent, poly(ethylene oxide) (PEO), are described. The rapid solvent evaporation during electrospinning and the PEO-induced phase separation process demonstrated play vital roles in the formation of ultrathin bioactive glass fibers with hollow cores and mesoporous walls. Immersing the MBGHFs in simulated body fluid rapidly results in the development of a layer of enamel-like apatite mesocrystals at the fiber surfaces and apatite nanocrystals inside the hollow cores. Drug loading and release experiments indicate that the drug loading capacity and drug release behavior of the MBGHFs strongly depends on the fiber length. MBGHFs with fiber length >50,µm can become excellent carriers for drug delivery. The shortening of the fiber length reduces drug loading amounts and accelerates drug release. The MBGHFs reported here with sophisticated structure, high bioactivity, and good drug delivery capability can be a promising scaffold for hard tissue repair and wound healing when organized into 3D macroporous membranes. [source] Charge-Reversal Drug Conjugate for Targeted Cancer Cell Nuclear Drug DeliveryADVANCED FUNCTIONAL MATERIALS, Issue 22 2009Zhuxian Zhou Abstract DNA-toxin anticancer drugs target nuclear DNA or its associated enzymes to elicit their pharmaceutical effects, but cancer cells have not only membrane-associated but also many intracellular drug-resistance mechanisms that limit their nuclear localization. Thus, delivering such drugs directly to the nucleus would bypass the drug-resistance barriers. The cationic polymer poly(L -lysine) (PLL) is capable of nuclear localization and may be used as a drug carrier for nuclear drug delivery, but its cationic charges make it toxic and cause problems in in-vivo applications. Herein, PLL is used to demonstrate a pH-triggered charge-reversal carrier to solve this problem. PLL's primary amines are amidized as acid-labile , -carboxylic amides (PLL/amide). The negatively charged PLL/amide has a very low toxicity and low interaction with cells and, therefore, may be used in vivo. But once in cancer cells' acidic lysosomes, the acid-labile amides hydrolyze into primary amines. The regenerated PLL escapes from the lysosomes and traverses into the nucleus. A cancer-cell targeted nuclear-localization polymer,drug conjugate has, thereby, been developed by introducing folic-acid targeting groups and an anticancer drug camptothecin (CPT) to PLL/amide (FA-PLL/amide-CPT). The conjugate efficiently enters folate-receptor overexpressing cancer cells and traverses to their nuclei. The CPT conjugated to the carrier by intracellular cleavable disulfide bonds shows much improved cytotoxicity. [source] Anticancer Drug Delivery: Doxorubicin-Conjugated Immuno-Nanoparticles for Intracellular Anticancer Drug Delivery (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Mater. Self-assembled polymeric nanoparticles of the amphiphilic copolymer poly(TMCC-co-LA)-g-PEG-furan can couple both anti-HER2 antibodies and chemotherapeutic doxorubicin (DOX) on their surfaces, report Molly Shoichet and co-workers on page 1689. This novel strategy selectively delivers DOX to the cell nucleus of HER2-overexpressing breast cancer cells while maintaining the pharmaceutical toxicity of DOX, paving the way to targeted drug delivery in breast cancer treatment. [source] Doxorubicin-Conjugated Immuno-Nanoparticles for Intracellular Anticancer Drug DeliveryADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Meng Shi Abstract A polymeric nanoparticle comprised of surface furan groups is used to bind, by Diels,Alder (DA) coupling chemistry, both targeting anti-human epidermal growth factor receptor 2 (anti-HER2) antibodies and chemotherapeutic doxorubicin (DOX) for targeted, intracellular delivery of DOX. In this new approach for delivery, where both chemotherapeutic and targeting ligand are attached, for the first time, to the surface of the delivery vehicle, the nuclear localization of DOX in HER2-overexpressing breast cancer SKBR-3 cells is demonstrated, as determined by confocal laser scanning microscopy. Flow cytometric analysis shows that the conjugated DOX maintains its biological function and induces similar apoptotic progression in SKBR-3 cells as free DOX. The viable cell counts of SKBR-3 cancer cells following incubation with different nanoparticle formulations demonstrates that the combined DOX and anti-HER2 nanoparticle is more efficacious than the nanoparticle formulation with either DOX or anti-HER2 alone. While free DOX shows similar cytotoxicity against both cancerous SKBR-3 cells and healthy HMEC-1 cells, the combined DOX-anti-HER2 nanoparticle is significantly more cytotoxic against SKBR-3 cells than HMEC-1 cells, suggesting the benefit of nanoparticle-conjugated DOX for cell type-specific targeting. The DOX-conjugated immuno-nanoparticle represents an entirely new method for localized co-delivery of chemotherapeutics and antibodies. [source] Design and Fabrication of Magnetically Functionalized Core/Shell Microspheres for Smart Drug DeliveryADVANCED FUNCTIONAL MATERIALS, Issue 2 2009Xiuqing Gong Abstract The fabrication of magnetically functionalized core/shell microspheres by using the microfluidic flow-focusing (MFF) approach is reported. The shell of each microsphere is embedded with magnetic nanoparticles, thereby enabling the microspheres to deform under an applied magnetic field. By encapsulating a drug, for example, aspirin, inside the microspheres, the drug release of the microspheres is enhanced under the compression,extension oscillations that are induced by an AC magnetic field. This active pumping mode of drug release can be controlled by varying the frequency and magnitude of the applied magnetic field as well as the time profile of the magnetic field. UV absorption measurements of cumulative aspirin release are carried out to determine the influence of these factors. The drug release behavior is found to be significantly different depending on whether the applied field varies sinusoidally or in a step-function manner with time. [source] Poly(vinyl alcohol) Scaffolds with Tailored Morphologies for Drug Delivery and Controlled Release,ADVANCED FUNCTIONAL MATERIALS, Issue 17 2007C. Gutiérrez Abstract Poly(vinyl alcohol) (PVA) scaffolds are prepared by a cryogenic process that consists of the unidirectional freezing of a PVA solution. The scaffolds exhibit a microchanneled structure, the morphology of which (in terms of pore diameter, surface area, and thickness of matter accumulated between adjacent microchannels) can be finely tailored by the averaged molecular weight of PVA, the PVA concentration in the solution, and the freezing rate of the PVA solution. The resulting PVA scaffolds are suitable substrates for drug-delivery purposes, the drug release being controlled (from tens of minutes up to several days) by the morphology of the microchanneled structure. In,vitro experiments reveal the efficiency of PVA scaffolds for controlling the release of ciprofloxacin into a bacteria culture medium. [source] Encapsulation of Water-Insoluble Drugs in Polymer Capsules Prepared Using Mesoporous Silica Templates for Intracellular Drug DeliveryADVANCED MATERIALS, Issue 38 2010Yajun Wang Water-insoluble compounds were encapsulated in polymer capsules through mesoporous silica nanoparticle-mediated layer-by-layer assembly. The drug-loaded capsules exhibit excellent colloidal stability and high potency to colorectal cancer cells in vitro with similar cytotoxicity to the free drug dissolved in organic solvent. [source] Nanotemplating of Biodegradable Polymer Membranes for Constant-Rate Drug DeliveryADVANCED MATERIALS, Issue 21 2010Daniel A. Bernards A nanoporous biodegradable polymer (polycaprolactone) is fabricated utilizing a zinc oxide nanotemplate (see figure). Chemical characterization verifies removal of the template, and preliminary tests on the cytotoxicity demonstrate basic biocompatibility. Diffusion of a model small molecule and a protein are shown to be first and zero order, respectively, indicating these nanoporous membranes may be useful for controlled release of protein-based therapeutics. [source] Drug Delivery: Drawing Lithography: Three-Dimensional Fabrication of an Ultrahigh-Aspect-Ratio Microneedle (Adv. Mater.ADVANCED MATERIALS, Issue 4 20104/2010) Ultrahigh-aspect-ratio microneedles can be fabricated via "drawing lithography", a novel technique in which a thermosetting polymer is directly drawn from a two-dimensional solid surface without the need for a mask and light irradiation. Kwang Lee and co-workers demonstrate this technique on p. 483. The inside cover shows a scanning electron microscopy (SEM) image of three-dimensional structures with ultrahigh aspect ratios, potentially suitable as drug-delivery devices that could replace hypodermic syringes. [source] Magnetically Triggered Reversible Controlled Drug Delivery from Microfabricated Polymeric Multireservoir DevicesADVANCED MATERIALS, Issue 40 2009Kaiyong Cai The pulsed reversible release of dual drugs from biodegradable polymeric multireservoir devices is successfully demonstrated. The controlled release is achieved by incorporating magnetic particles in the devices as switch carriers. It is possible to intentionally switch on/off the drug release at any desired time for a chosen duration. [source] Programmable Drug Delivery: Core-Sheath Nanofibers Containing Colloidal Arrays in the Core for Programmable Multi-Agent Delivery (Adv. Mater.ADVANCED MATERIALS, Issue 9 20099/2009) Eun Chul Cho, Unyong Jeong, and co-workers demonstrate on p. 968 the programmable release of multiple agents by using polymeric core-sheath nanofibers consisting of arrays of colloids in the core and polymeric sheath. The fibers were produced by one-step single nozzle electrospinning. Loading different species of active agents in each colloid can provide independent control over the release of each agent. [source] Integrating Biosensors and Drug Delivery: A Step Closer Toward Scalable Responsive Drug-Delivery SystemsADVANCED MATERIALS, Issue 6 2009Han-Kuan Anthony Tsai A miniature biosensor immobilized on the backside of a gold lid is protected inside a microfabricated vial. To activate the protected biosensor, the conjugated polymer/gold lid is opened by the application of 800,mV. Both independent sensing and drug delivery from the microvalves are demonstrated. [source] Two Photon Polymerization of Polymer,Ceramic Hybrid Materials for Transdermal Drug DeliveryINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 1 2007A. Ovsianikov Three-dimensional microneedle devices were created by femtosecond laser two photon polymerization (2PP) of organically modified ceramic (Ormocer®) hybrid materials. Arrays of in-plane and out-of-plane hollow microneedles (microneedle length=800 ,m, microneedle base diameter=150,300 ,m) with various aspect ratios were fabricated. The fracture and penetration properties of the microneedle arrays were examined using compression load testing. In these studies, the microneedle arrays penetrated cadaveric porcine adipose tissue without fracture. Human epidermal keratinocyte viability on the Ormocer® surfaces polymerized using 2PP was similar to that on control surfaces. These results suggest that 2PP is able to create microneedle structures for transdermal drug delivery with a larger range of geometries than conventional microfabrication techniques. [source] Short Papers in Drug DeliveryJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue S1 2008Article first published online: 18 FEB 2010 First page of article [source] SESSION 1 Drug DeliveryJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue S1 2006Article first published online: 18 FEB 2010 First page of article [source] Poster Session 1 , Drug DeliveryJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue S1 2004Article first published online: 18 FEB 2010 First page of article [source] Poster Session 1 , Drug DeliveryJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue S1 2003Article first published online: 18 FEB 2010 First page of article [source] Poster Session 3 , Drug DeliveryJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue S1 2003Article first published online: 18 FEB 2010 First page of article [source] Poster Session 1 , Drug DeliveryJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue S1 2002Article first published online: 18 FEB 2010 First page of article [source] Mesostructured Silica for Optical Functionality, Nanomachines, and Drug DeliveryJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2009Yaroslav Klichko Silica thin films and nanoparticles prepared using sol,gel chemistry are derivatized with active molecules to generate new functional materials. The mild conditions associated with sol,gel processing allow for the incorporation of a range of dopants including organic or inorganic dyes, biomolecules, surfactants, and molecular machines. Silica nanoparticles embedded with inorganic nanocrystals, and films containing living cells have also been synthesized. Silica templated with surfactants to create mesostructure contains physically and chemically different regions that can be selectively derivatized using defined techniques to create dynamic materials. Using two different techniques, donor,acceptor pairs can be doped into separated regions simultaneously and photo-induced electron transfer between the molecules can be measured. Mesoporous silica materials are also useful supports for molecular machines. Machines including snap-tops and nanoimpellers that are designed to control the release of guest molecules trapped within the pores are described. Mesoporous silica nanoparticles are promising materials for drug delivery and other biomedical applications because they are nontoxic and can be taken up by living cells. Through appropriate design and synthesis, multifunctional mesoporous silica nanoparticles for sophisticated bio-applications are created. [source] The Influence of Pendant Hydroxyl Groups on Enzymatic Degradation and Drug Delivery of Amphiphilic Poly[glycidol- block -(, -caprolactone)] CopolymersMACROMOLECULAR BIOSCIENCE, Issue 11 2009Jing Mao Abstract An amphiphilic diblock copolymer PG- b -PCL with well-controlled structure and pendant hydroxyl groups along hydrophilic block was synthesized by sequential anionic ring-opening polymerization. The micellization and drug release of PG- b -PCL copolymers using pyrene as a fluorescence probe were investigated for determining the influences of copolymer composition and lipase concentration on drug loading capacity and controlled release behavior. The biodegradation of PG- b -PCL copolymers was studied with microspheres as research samples. It has been concluded that the polar hydroxyl groups along each repeat unit of hydrophilic PG block in PG- b -PCL copolymer have great influences on drug encapsulation, drug release, and enzymatic degradation of micelles and microspheres. [source] Photocrosslinked DNA Nanospheres for Drug DeliveryMACROMOLECULAR RAPID COMMUNICATIONS, Issue 13 2010Young Hoon Roh Abstract DNA has been employed as both a genetic and a generic material. X-shaped DNA (X-DNA) in particular has four branched arms, providing multivalent functionalities that can allow for simultaneous multiple crosslinking. Here we report the synthesis of four acrylate-functionalized X-DNA monomers that can be further photocrosslinked to form monodisperse and tunable DNA nanospheres. In particular, the size and surface charge of these nanospheres were precisely controlled in a linear fashion, simply by tuning the monomer concentration in the reaction. The morphology and surface properties of the nanospheres were characterized using FT-IR, HPLC, TEM, AFM, zeta potential, and DLS analysis. In vitro studies in mammalian cells revealed that these DNA nanospheres demonstrated significant efficacy in the delivery of doxorubicin. These results highlight the potential of using DNA as material building blocks to design novel nanocarriers with properties tailored for the delivery of drugs in general and DNA/RNA in particular. [source] Intrathecal Drug Delivery for Chronic Back Pain: Better Science for Clinical InnovationPAIN MEDICINE, Issue 1 2004MPH Editor in Chief, Rollin M. Gallagher MD No abstract is available for this article. [source] Innentitelbild: Facile, Template-Free Synthesis of Stimuli-Responsive Polymer Nanocapsules for Targeted Drug Delivery (Angew. Chem.ANGEWANDTE CHEMIE, Issue 26 201026/2010) Sesam öffne Dich! Eine templatfreie Synthese auf Stimuli reagierender Polymernanokapseln, die für die gezielte Wirkstoff-Freisetzung nützlich sein könnten, stellen K. Kim et,al. in der Zuschrift auf S.,4507,ff. vor. Es wird gezeigt, dass reduktionslabile Polymernanokapseln aus CB[6] und Disulfidbrücken nicht nur eine einfache, nichtkovalente Oberflächenmodifikation für die zielspezifische Anlieferung, sondern auch die Freisetzung eingeschlossener Ladung in intrazellulärer Umgebung als Reaktion auf ein vorgegebenes Redoxstimulans ermöglichen. [source] Facile, Template-Free Synthesis of Stimuli-Responsive Polymer Nanocapsules for Targeted Drug Delivery,ANGEWANDTE CHEMIE, Issue 26 2010Eunju Kim Dr. Sesam öffne Dich! Die Synthese stimuliresponsiver Polymernanokapseln wird beschrieben. Die reduktionslabile Polymernanokapsel ermöglicht eine einfache, nichtkovalente Oberflächenmodifikation und die Freisetzung eingeschlossener Ladung in intrazellulärer Umgebung als Reaktion auf ein vorgegebenes Redoxstimulans. [source] Nanoparticles for Drug Delivery Prepared from Amphiphilic PLGA Zwitterionic Block Copolymers with Sharp Contrast in Polarity between Two Blocks,ANGEWANDTE CHEMIE, Issue 22 2010Zhiqiang Cao Blockcopolymere aus Poly(carboxybetain) (PCB) und Poly(milchsäure-co-glycolsäure) (PLGA) mit tBu-Gruppen als Teil der PCB-Monomere bilden außergewöhnlich stabile PLGA-Kern/PCB-Schale-Nanopartikel, die aufgrund der COO, -Gruppen in der PCB-Schale ein hohes Funktionalisierungspotenzial aufweisen (siehe Bild; EDC=1-Ethyl-3-(3-dimethylaminopropyl)carbodiimid, NHS=N -Hydroxysuccinimid). [source] | |||||||||||||||||||||||||||||||||||||