Papers by Keyword: Pluronic F127

Abstract: Supramolecular hydrogels were formed through F127, acryloyl chloride modified F127 inclusion complex with α-cyclodextrin, respectively. The structure of modified copolymers and inclusion complex was characterized by Fourier transform infrared spectroscopy (FTIR) and hydrogen nuclear magnetic resonance (1H-NMR). Hydrogels formed from supramolecular inclusion are imparted channel-type structure investigated by wide angle x-ray diffraction (WAXRD). Differential scanning calorimetry (DSC) and TG experiments showed that thermal stability of hydrogels depend on the nature of axis polymer. The relative model was proposed to elucidate the inclusion complexes and hydrogels formation.

Abstract: In this work, nanocomposites of hydroxyapatite and Pluronic F127 were prepared by a wet chemical method, using acid-basic reaction with Ca/P ratio of 1.67 in 10% (m/V) Pluronic F127 at 0, 37 and 90°C. The final concentration of Pluronic F127 was adjusted to 37% (m/V) at 4°C. Afterwards, the samples were lyophilized. Characterization was performed in purified samples (after Pluronic F127 removal), samples with 10% (m/V) of Pluronic F127 and calcined samples at 1000°C by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). Analyses by XRD of non-calcined samples showed that hydroxyapatite was obtained, in which the samples prepared at 0°C exhibited larger peaks attributed to lower crystallite sizes. For the calcined samples, both Raman spectroscopy and XRD exhibited hydroxyapatite for the syntheses at 37 and 90°C whereas the one prepared 90°C were identified as β-tricalcium phosphate (β-TCP). Morphological analysis by SEM indicated that the hydroxyapatite was sphere or rod agglomerates in mesoporous morphology for the nanocomposites prepared at 0 and 37°C, while the sample prepared at 90°C was nanospheres agglomerated into a smother matrix. After Pluronic F127 removal, samples fabricated at 0 and 37 °C exhibited coalescence of the nanostructures, whereas the sample synthesized at 90°C kept mesoporous. Calcined samples showed sintering and some rods structures.

Abstract: Pluronic F127 has received increasing attention over many years as drug delivery systems, biomaterials, and hydrogels for tissue engineering. In this study, we synthesized temperature-sensitive and cell-adhesive triblock F127 copolymers, in which Arg-Gly-Asp (RGD) peptide ligand was grafted to Pluronic F127-4-methacryloxyethyl trimellitic anhydride (4-META) to obtain F127-META-RGD. The chemical structures of the F127-META-RGD block copolymers were confirmed by FTIR, 1H and 13C NMR, and GPC. The resultant F127-META-RGD showed very similar thermosensitive behaviors to F127 and F127-META. The critical micelle temperature (CMT) of the F127 copolymers decreased in the order of F127 < F127-META < F127-META-RGD, whereas the particle size followed an opposite trend. Interactions between the F127 copolymers and adipose-derived stem cells (ASC) were evaluated in terms of cell adhesion and proliferation on the hydrogel. These thermosensitive RGD-grafted Pluronic hydrogels that display the enhanced cell adhesiveness, are expected to be useful as a functional injectable scaffold for tissue engineering.