24 research outputs found
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Polybenzimidazoles and methods of making and using thereof
Disclosed are polybenzimidazoles containing sulfonyl groups. The polymers can be synthesized in Eaton's reagent from 3,3′,4,4′-tetraaminodiphenylsulfone, which itself can be synthesized from 4,4′-dichlorodiphenylsulfone. Methods of synthesizing the polymers are disclosed. The disclosed polymers can be used for high temperature H2/CO2 separation membranes and other uses.Board of Regents, University of Texas Syste
Remote Actuation of Magnetic Nanoparticles For Cancer Cell Selective Treatment Through Cytoskeletal Disruption
Motion of micron and sub-micron size magnetic particles in alternating magnetic fields can activate mechanosensitive cellular functions or physically destruct cancer cells. However, such effects are usually observed with relatively large magnetic particles (>250 nm) that would be difficult if at all possible to deliver to remote sites in the body to treat disease. Here we show a completely new mechanism of selective toxicity of superparamagnetic nanoparticles (SMNP) of 7 to 8 nm in diameter to cancer cells. These particles are coated by block copolymers, which facilitates their entry into the cells and clustering in the lysosomes, where they are then magneto-mechanically actuated by remotely applied alternating current (AC) magnetic fields of very low frequency (50 Hz). Such fields and treatments are safe for surrounding tissues but produce cytoskeletal disruption and subsequent death of cancer cells while leaving healthy cells intact
Book Review: Educating the Disabled: Enabling Learners in Inclusive Settings
Author: George R. Taylor & Frances T. Harrington
Reviewer: Judy Riffle
Publisher: Scarecrow Press, Inc., 2003
Cloth, ISBN: 0-8108-4614-4
Paper, ISBN: 0-8108-4616-0
How to Obtain: www.amazon.com or www.scarecroweducation.com (15% discount)
Cost: Paperback - 43.95 US
Encapsulation of PI3K Inhibitor LY294002 within Polymer Nanoparticles Using Ion Pairing Flash Nanoprecipitation
Flash nanoprecipitation (FNP) is a turbulent mixing process capable of reproducibly producing polymer nanoparticles loaded with active pharmaceutical ingredients (APIs). The nanoparticles produced with this method consist of a hydrophobic core surrounded by a hydrophilic corona. FNP produces nanoparticles with very high loading levels of nonionic hydrophobic APIs. However, hydrophobic compounds with ionizable groups are not as efficiently incorporated. To overcome this, ion pairing agents (IPs) can be incorporated into the FNP formulation to produce highly hydrophobic drug salts that efficiently precipitate during mixing. We demonstrate the encapsulation of the PI3K inhibitor, LY294002, within poly(ethylene glycol)-b-poly(D,L lactic acid) nanoparticles. We investigated how incorporating two hydrophobic IPs (palmitic acid (PA) and hexadecylphosphonic acid (HDPA)) during the FNP process affected the LY294002 loading and size of the resulting nanoparticles. The effect of organic solvent choice on the synthesis process was also examined. While the presence of either hydrophobic IP effectively increased the encapsulation of LY294002 during FNP, HDPA resulted in well-defined colloidally stable particles, while the PA resulted in ill-defined aggregates. The incorporation of hydrophobic IPs with FNP opens the door for the intravenous administration of APIs that were previously deemed unusable due to their hydrophobic nature
Nanomedicine for intracellular therapy
Intracellular pathogens like
Salmonella evade host phagocytic killing by various mechanisms. Classical antimicrobial therapy requires multiple dosages and frequent administration of drugs for a long duration. Intracellular delivery of antimicrobials using nanoparticle may effectively devise therapies for bacterial infections. This review will address the mechanisms used by
Salmonella to avoid host pathogenic killing, reasons for therapeutic failure and advances in nanoparticle drug delivery technology for efficient intracellular bacterial clearance
Antibacterial efficacy of core-shell nanostructures encapsulating gentamicin against an in vivo intracellular Salmonella model
Pluronic based core-shell nanostructures encapsulating gentamicin were designed in this study. Block copolymers of (PAA
−+
Na-
b
-(PEO-
b
-PPO-
b
-PEO)-b-PAA
−+
Na) were blended with PAA
−
Na
+
and complexed with the polycationic antibiotic gentamicin to form nanostructures. Synthesized nanostructures had a hydrodynamic diameter of 210 nm, zeta potentials of −0.7 (±0.2), and incorporated ∼20% by weight of gentamicin. Nanostructures upon co-incubation with J774A.1 macrophage cells showed no adverse toxicity
in vitro
. Nanostructures administered
in vivo
either at multiple dosage of 5 μg g
−1
or single dosage of 15 μg g
−1
in AJ-646 mice infected with
Salmonella
resulted in significant reduction of viable bacteria in the liver and spleen. Histopathological evaluation for concentration-dependent toxicity at a dosage of 15 μg g
−1
revealed mineralized deposits in 50% kidney tissues of free gentamicin-treated mice which in contrast was absent in nanostructure-treated mice. Thus, encapsulation of gentamicin in nanostructures may reduce toxicity and improve
in vivo
bacterial clearance