Thermoreversible gelation in aqueous binary solvents of chemically modified agarose

Preparation and biological evaluation of a novel agarose-grafting-hyaluronan scaffold for accelerated wound regeneration

At present, seeking an effective dressing for wound regeneration has drawn considerable interest. In this paper, a novel agarose-grafting-hyaluronan (Ag-g-HA) scaffold was synthesized for rapid wound healing. Elemental analysis results showed that the HA grafting rate of Ag-g-HA was ∼69%. Ag-g-HA remained bioactive to accelerate cell proliferation and stimulate secretion of TNF-α for macrophagocyte RAW 264.7, and collagen I and collagen III for fibroblast 3T3. An i n vivo study demonstrated that Ag-g-HA showed a faster repair cycle and a better skin histological structure for a full-thickness skin defect. The collagen I, collagen III and TNF-α secreted by mice for Ag-g-HA were similiar to HA. Ag-g-HA showed a similiar biological activity to HA but had a longer degradation time through its improved insolubility. These findings demonstrate that the Ag-g-HA scaffold accelerated wound healing, and could be a promising novel scaffold for tissue engineering and regenerative medicine.

Oxyalkylation modification as a promising method for preparing low-melting-point agarose

In this study, agarose was chemically modified with ethylene oxide, 1,2-epoxypropane and 1,2-epoxybutane, to prepare hydroxyethyl agarose (HEAG), hydroxypropyl agarose (HPAG), and hydroxybutyl agarose (HBAG). The structures and properties of the products were characterized by Fourier transform infrared spectroscopy (FTIR), ¹H NMR spectroscopy, X-ray diffractometry (XRD), rheology measurement and gel electrophoresis. The results showed that the gelling temperature (T_g) of HEAG, HPAG, and HBAG were decreased to 28.3 °C, 29.0 °C and 28.7 °C respectively, with the melting temperature (T_m) simultaneously declined to 64.2 °C, 63.8 °C and 63.0 °C, respectively. Meanwhile, the gel strength of HBAG, HEAG, and HPAG were dramatically reduced to 194 g/cm², 312 g/cm² and 279 g/cm², respectively. Furthermore, HEAG and HPAG showed excellent separation efficiency which is in accordance with commercialized low-melting-point (LMP) agarose (Amersco 0815). These results indicated that oxyalkylation is a promising and economical method for the preparation of LMP agarose.

Homogeneous reversed-phase agarose thermogels for electrochromatography

A method for the derivatization of agarose by covalent attachment of hydrophobic ligands for reversed-phase (RP) chromatographic separation and ionic groups for generation of electroosmosis under electrochromatographic conditions in the capillaries or microfluidic channels filled with the thermogel of this agarose derivative is described. The product renders a capability of reversible thermogelation. The thermogels formed provide sufficient hydrophobicity and electroosmosis for the separations of the analytes under RP mobile-phase conditions and electric field applied. The gels may be used repeatedly without loss of resolution. They are thermally replaceable and UV transparent (providing possibility in column/in-gel detection), require no covalent attachment to the capillary inner wall (or microchip channel), and are suitable for isocratic or gradient operation in the aqueous-organic mobile phases.