In this study, the authors report a novel class of super tough nanocomposite hydrogels with physically dual‐crosslinking effects (DC hydrogels) through introducing strong ionic coordination interactions. Herein, graphene oxide (GO) nanosheets and iron (Fe3+) ions act as physical cross‐linkers. GO nanosheets trigger the formation of the first cross‐linking points through hydrogen bonding with poly(acrylamide‐co‐acrylic acid) (p(AAm‐co‐AAc)) chains, while the second cross‐linking points are formed by strong ionic coordination interactions between Fe3+ ions and COO− groups of p(AAm‐co‐AAc) chains. The optimal tough DC hydrogel displays superstretchability (≈20.8 times), remarkable tensile strength (≈3.7 MPa), high toughness (≈48.71 MJ m−3), good self‐recovery property (≈84.1% toughness recovery within 4 h without any external stimuli) and fatigue resistance. In summary, this study opens up a new avenue to design and fabricate highly tough hydrogels with outstanding comprehensive properties by the synergistic effects of nanocomposite and dual‐crosslinked hydrogels.

This study was aimed at evaluating the effect of two cooking methods on in vitro digestibility of starch and the change in its microstructure. Rice was cooked by microwave and conductive heating (CH), then stored at −18, 4, 25°C, the in vitro digestibility of starch was measured by in vitro simulative digestion method and the micromorphology was obtained by SEM. Rice starch heated by microwave had greater swell and smaller gaps between starch granules when compared with that heated in a conductive way. The concentrations of reducing sugar and glucose of in vitro digestibility of the rice starch cooked by microwave heating (MH) are higher than that by CH (p≤0.01). After storage, the in vitro digestibility of starch lowered, namely, the content of rapidly digestible starch (RDS) decreased, however, the content of slowly digestible starch (SDS) and resistant starch (RS) increased. After 72 h of storage the in vitro digestibility of rice starch cooked by MH was inferior to that by CH. The higher the storage temperature was, the worse the in vitro digestibility of starch was. This applied to both heating methods. The best digestibility effect was achieved when the rice was cooked by MH and stored at −18°C. Meanwhile, the kinetic model of in vitro digestibility of starch demonstrated that the equilibrium percentage and kinetic constant of the reducing sugar and glucose declined as the storage time increased.

In this work, the authors report an effective one‐pot method to prepare poly(ε‐caprolactone) (PCL)‐incorporated bovine serum albumin (BSA)/calcium alginate/hydroxyapatite (HAp) nanocomposite (NC) scaffolds by templating oil‐in‐water high internal phase emulsion (HIPE), which includes alginate, BSA, and HAp in water phase and PCL in oil phase. The water phase of HIPEs is solidified to form hydrogels containing emulsion droplets via gelation of alginate induced by Ca2+ ions released from HAp. And the prepared hydrogels are freeze‐dried to obtain PCL‐incorporated porous scaffolds. The obtained scaffolds possess interconnected pore structures. Increasing PCL concentration clearly enhances the compressive property and BSA stability, decreases the swelling ratio of scaffolds, which assists in improving the scaffold stability. The anti‐inflammatory drug ibuprofen can be highly efficiently loaded into scaffolds and released in a sustained rate. Furthermore, mouse bone mesenchymal stem cells can successfully proliferate on the scaffolds, proving the biocompatibility of scaffolds. All results show that the PCL‐incorporated NC scaffolds possess promising potentials in tissue engineering application.

No abstract

This work is focused on evaluating the structure (granular morphology, crystalline structure, molecular order structure), and properties (resistant starch content, swelling power, amylose leaching) of resistant starch (RS) prepared from corn starch by an autoclaving and autoclaving-microwave method. The results indicated that compared with native starch, all of the RS granules became loose, bigger, and rough fragmented, and displayed a B þ V crystalline structure. Meanwhile, the relative crystallinity, helix content, molecular orders for RS samples decrease. The RSs displayed mainly RS3 and RS5 types, with enhanced thermal stability. Compared to autoclaving method, the autoclaving-microwave treatment significantly increases the RS content from 30.15% to 40.70%, since microwave could promote the formation of the double helix in RS. In particular, the RS prepared by autoclaving-microwave (HRS-CM) exhibits the highest degree of crystallinity, ordered structure, and degree of double helical structure as confirmed by XRD, FT-Raman, and 13 C NMR.