Xylan-Modified-Based Hydrogels with Temperature/pH Dual Sensitivity and Controllable Drug Delivery Behavior

Abstract

Among the natural macromolecules potentially used as the scaffold material in hydrogels, xylan has aroused great interest in many fields because of its biocompatibility, low toxicity, and biodegradability. In this work, new pH and thermoresponsive hydrogels were prepared by the cross-linking polymerization of maleic anhydride-modified xylan (MAHX) with N-isopropylacrylamide (NIPAm) and acrylic acid (AA) under UV irradiation to form MAHX-g-P(NIPAm-co-AA) hydrogels. The pore volume, the mechanical properties, and the release rate for drugs of hydrogels could be controlled by the degree of substitution of MAHX. These hydrogels were characterized by swelling ability, lower critical solution temperature (LCST), Fourier-transform infrared (FTIR), and SEM. Furthermore, the cumulative release rate was investigated for acetylsalicylic acid and theophylline, as well as the cytocompatibility MAHX-based hydrogels. Results showed that MAHX-based hydrogels exhibited excellent swelling–deswelling properties, uniform porous structure, and the temperature/pH dual sensitivity. In vitro, the cumulative release rate of acetylsalicylic acid for MAHX-based hydrogels was higher than that for theophylline, and in the gastrointestinal sustained drug release study, the acetylsalicylic acid release rate was extremely slow during the initial 3 h in the gastric fluid (24.26%), and then the cumulative release rate reached to 90.5% after sustained release for 5 h in simulated intestinal fluid. The cytotoxicity experiment demonstrated that MAHX-based hydrogels could promote cell proliferation and had satisfactory biocompatibility with NIH3T3 cells. These results indicated that MAHX-based hydrogels, as new drug carriers, had favorable behavior for intestinal-targeted drug delivery.

Carbon Nanotubes Reinforced Maleic Anhydride-Modified Xylan-g-Poly(N-isopropylacrylamide) Hydrogel with Multifunctional Properties

“…For instance, maleic anhydride was used to react with hydroxyl groups of xylan to form maleic anhydride modified xylan (MAX), which contained both unsaturated double bonds and carboxyl groups with electronegative, hydrophilic and adsorption properties [ 17 ]. MAX could be applied as the raw material for fabricating new functional hydrogels, such as MAX-g-P(NIPAm-co-AA) hydrogel with pH response improved by the carboxyl groups and unsaturated double bonds on the MAX chains and controllable crosslinking density with different degree of substitution (DS) of MAX [ 18 ]. The MAX-PVA hydrogel was developed and could be designed to meet the swelling and strength requirements by varying MA and PVA contents in the hydrogel [ 19 ].…”

Xylan-Based Hydrogels as a Potential Carrier for Drug Delivery: Effect of Pore-Forming Agents

“…The sharp peak appearing at 893 cm −1 is owing to the β-glucosidic bonds between the xylose units. The absorption peak appearing at 1468 cm −1 is associated with the –COO − symmetric stretching vibration of CMX [19]. For the spectrum of the hydrogels, the band at 3268 cm −1 originates from the N–H asymmetric stretching vibration peak of the carbonyl in the amide group in PNIPAm and PAM [31].…”

“…A few studies have focused on xylan-based hydrogels. A xylan-based hydrogel was prepared by the cross-linking polymerization of xylan with N -isopropylacrylamide (NIPAm) and acrylic acid (AA) under UV irradiation [19]. This hydrogel was further used for acetylsalicylic acid release.…”

Fractionation of DMSO-Extracted and NaOH-Extracted Hemicelluloses by Gradient Ethanol Precipitation from Neosinocalamus affinis

“…The spectra of the four DMSO-extracted hemicellulosic fractions, H 30 , H 50 , H 70 , and H 90 , which are precipitated by ethanol with concentration of 30%, 50%, 70%, and 90%, respectively, can be seen in Figure 2. The striking peaks around 3440 cm −1 are due to strong hydrogen-bonded O-H stretching and two absorptions at 2922 and 2853 cm −1 are results of C-H stretching [29]. A sharp peak at 1741 cm −1 is attributed to the characteristic feature of C=O stretching of carbonyl and acetyl groups in the hemicelluloses, which indicated that the acetyl ester bond could be preserved under the DMSO treatment [30].…”