2 research outputs found
Enzyme-Regulated Fast Self-Healing of a Pillararene-Based Hydrogel
Self-healing,
one of the exciting properties of materials, is frequently
used to repair the damage of biological and artificial systems. Here
we have used enzymatic catalysis approaches to develop a fast self-healing
hydrogel, which has been constructed by dynamic aldimine cross-linking
of pillar[5]Âarene-derivant and dialdehyde-functionalized PEG followed
by encapsulation of glucose oxidase (GOx) and catalase (CAT). In specific,
the two hydroxyl groups at terminal of PEG<sub>4000</sub> are functionalized
with benzaldehydes that can interact with amino-containing pillar[5]Âarene-derivant
through dynamic aldimine cross-links, resulting in reversible dynamic
hydrogels. Modulus analysis indicated that storage modulus (<i>G</i>′) and loss modulus (<i>G</i>″)
of the hydrogel increased obviously as the concentration of dialdehyde-functionalized
PEG<sub>4000</sub> (DF-PEG<sub>4000</sub>) increased or the pH values
decreased. Once glucose oxidase (GOx) and catalase (CAT) are located,
the hydrogel could be fast repaired, with self-healing efficiency
up to 100%. Notably tensile test showed that the repair process of
pillararene-based hydrogel can finish in several minutes upon enzyme
catalysis, while it needed more than 24 h to achieve this recovery
without enzymes. This enzyme-regulated self-healing hydrogel would
hold promise for delivering drugs and for soft tissue regeneration
in the future
Self-Assembly of Cricoid Proteins Induced by “Soft Nanoparticles”: An Approach To Design Multienzyme-Cooperative Antioxidative Systems
A strategy to construct high-ordered protein nanowires by electrostatic assembly of cricoid proteins and “soft nanoparticles” was developed. Poly(amido amine) (PAMAM) dendrimers on high generation that have been shown to be near-globular macromolecules with all of the amino groups distributing throughout the surface were ideal electropositive “soft nanoparticles” to induce electrostatic assembly of electronegative cricoid proteins. Atomic force microscopy and transmission electron microscopy all showed that one “soft nanoparticle” (generation 5 PAMAM, PD5) could electrostatically interact with two cricoid proteins (stable protein one, SP1) in an opposite orientation to form sandwich structure, further leading to self-assembled protein nanowires. The designed nanostructures could act as versatile scaffolds to develop multienzyme-cooperative antioxidative systems. By means of inducing catalytic selenocysteine and manganese porphyrin to SP1 and PD5, respectively, we successfully designed antioxidative protein nanowires with both excellent glutathione peroxidase and superoxide dismutase activities. Also, the introduction of selenocysteine and manganese porphyrin did not affect the assembly morphologies. Moreover, this multienzyme-cooperative antioxidative system exhibited excellent biological effect and low cell cytotoxicity