Terpolymer Solution Research Articles

Thermoresponsive-fluorescent isopropylacrylamide–vinylpyridine–pyrenemethylacrylamide terpolymer and its complexation behaviour with DNA

Temperature and pH-responsive, fluorescent random terpolymer of N-isopropylacrylamide (NIPA), 4-vinylpyridine (4VP) and N-pyrenemethylacrylamide (PyMeA) was synthesized. Temperature and pH-dependent fluorescence behaviour of poly(NIPA–4VP–PyMeA) terpolymer was investigated by fluorescence spectroscopy. The protonation of terpolymer (i.e. high cationic charge) in the acidic pH region provided significantly higher values for the ratio of the first to third vibronic band intensities (I1/I3) with respect to that found for pyrene in an aqueous medium (i.e. 1.87). I1/I3 ratio significantly decreased with increasing pH depending upon the decreasing polarity of microenvironment due to the deprotonation of terpolymer. As a new potential carrier for DNA-delivery, the interaction of fluorescent poly(NIPA–4VP–PyMeA) terpolymer with DNA was investigated. The addition of DNA into the fluorescent terpolymer solution resulted in the formation of stable, colloidal terpolymer-DNA complex due to the bridge formation between phosphate groups of DNA and protonated 4VP units of the fluorescent terpolymer. The hydrodynamic diameter of DNA-poly(NIPA–4VP–PyMeA) terpolymer complex increased with increasing DNA concentration. The formation of colloidal complex particles lower than 1μm at the pHs close to the physiological pH value showed that poly(NIPA–VP–PyMeA) terpolymer could be utilized as a new fluorescent non-viral vector for DNA delivery.

Electrospinning of nylon-6,66,1010 terpolymer

Ultrafine nylon fibers were prepared by electrospinning of nylon-6,66,1010 terpolymer solution in 2,2,2-trifluoroethanol (TFE). The morphology, crystallinity and mechanical properties of the electrospun nylon-6,66,1010 fibers were investigated by scanning electron microscope (SEM), differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and tensile test. The effects of electrospun process parameters such as solution concentration, voltage and tip-to-collector distance on the morphology and the average size of the electrospun fibers were also studied. The results show that the spinnable concentration of nylon-6,66,1010/TFE solution is in the range of 6–14 wt%, and higher solution concentration favors the formation of uniform fibers without beads. The diameters of the electrospun fibers increase with increasing the solution concentration and decrease slightly with increasing the voltage and needle tip-to-collector distance. But no obvious morphology changes were found with the increase of the voltage and collection distance. DSC and WAXD results suggest that the electrospun nylon-6,66,1010 membranes have lower crystallinity than those of the corresponding casting films. The electrospun nylon-6,66,1010 membrane obtained from the 14 wt% concentration exhibits the largest tensile strength and elongation at break.

Synthesis of oligocaprolactone vinyl ether macromonomers and their use for indomethacin encapsulation in polymer nanoparticles based on polycaprolactone macromonomer–maleic anhydride–N‐vinyl pyrrolidone terpolymers

AbstractOligocaprolactone macromonomers functionalized with vinyl ether have been synthesized by polymerization of ε‐caprolactone in the presence of hydroxy ethyl or butyl vinyl ether and characterised by NMR and Maldi time‐of‐flight mass spectroscopy. These macromonomers have been copolymerized with maleic anhydride and N‐vinyl pyrrolidone to give terpolymers, which have been used to obtain nanoparticles by the phase‐separation‐dialysis method. Previously dissolving indomethacin in the terpolymer solution allows one to encapsulate the drug inside the nanoparticles. Copyright © 2005 Society of Chemical Industry