Temperature-Tunable Nanoparticles for Selective Biointerface.

Drugs can be delivered by a temperature change-driven shrinking of the nanocarrier followed by the cargo release. This paper describes a different structural response to temperature, performed by nanoparticles of poly(N-isopropylacrylamide) and hyaluronic acid. Around 35 °C, the hydrophobicity of the vinyl polymer drives a core-shell rearrangement with the acrylamide chains confined in the core and the polysaccharide moiety forming the shell. In this arrangement, the nanoparticles enable the active targeting of tumor cells, due to the specific interaction of hyaluronic acid with the CD44 receptors. When doxorubicin-loaded nanoparticles are up-taken, the polysaccharide part degrades in the cytoplasm and the cytotoxic effect of the anticancer drug in colon adenocarcinoma cells has a 2-fold increase with respect to healthy fibroblasts. These core-shell particles have hyaluronic acid as the key factor for the specific targeting of tumor cells and drug release with poly(N-isopropylacrylamide) driving the transition.

PEG mediated synthesis and pharmacological evaluation of some fluoro substituted pyrazoline derivatives as antiinflammatory and analgesic agents.

A new series of fluoro substituted pyrazoline derivatives 5a-g and 6a-g were synthesized in good to excellent yield from the corresponding pyrazole chalcones, 4a-g, by using polyethylene glycol-400 (PEG-400) as an alternative reaction medium. The newly synthesized compounds were characterized and screened for their in vivo antiinflammatory and analgesic activity. Compounds 5g and 6g were found to be more potent than standard drug Diclofenac and six other compounds 5b, 5c, 5f, 6b, 6c and 6f showed significant antiinflammatory activity as compared to standard drug. Compounds 5c, 5d, 5e, 5f, 6c, 6d, 6e and 6f showed significant analgesic activity as compared to standard drug Aspirin.

Multiresponsive hyaluronan-p(NiPAAm) "click"-linked hydrogels.

Combined reversible addition-fragmentation chain transfer (RAFT) and chemoselective "click" chemistry are used for assembling two polymeric chains into a hybrid network capable to respond simultaneously or separately to different external stimuli. An azido-derivative of hyaluronate is clicked together with a new telechelic RAFT-generated p(NiPAAm), carrying a propargyl function at both ends, suitable as macromolecular "clickable" cross-linker with controlled molecular weight. This hybrid system displays a multiresponsive behavior versus temperature, pH, and ionic strength, maintaining cumulative as well as separate sensitivities to the external stimuli. Hyaluronidase catalyzed degradation of the hydrogels, mimicking the extracellular matrix degradation process, is an additional asset for the use of this class of hydrogels as scaffold. Tumor cells, HT-29, grow on the surface of these hybrid hydrogels more than the healthy ones, as NIH3T3. This finding opens a road to micro- and nano-devices based on hyaluronic acid as a promising biopolymer to pursue localized drug delivery.

Synthesis and biological evaluation of new 2-chloro-3-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)quinoline derivatives via click chemistry approach.

Synthesis of new 2-chloro-3-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)quinoline derivatives (4a-h) using 1,3-dipolar cycloaddition (click chemistry) reaction of 3-(azidomethyl)-2-chloro-quinoline derivatives (3a-h) with phenyl acetylene in the presence of Cu(I) catalyst has been achieved in very high yield. These molecules were evaluated in vitro for their antifungal and antibacterial activity. Most of the compounds exhibited significant antifungal and antibacterial activity against all the tested strains.