Multiscale polymer engineering, involving chemical modification to control their triboelectric polarities as well as physicomechanical modification to maximize charge transfer and structural durability, is paramount to developing a high‐performance triboelectric nanogenerator (TENG). This report introduces a highly efficient and comprehensive strategy to engineer high‐performance TENG based on multifunctional polysuccinimide (PSI). With the ability of PSI to undergo facile nucleophilic addition with amines, sodium sulfate and quaternary ammonium chlorides having opposite charged groups are conjugated to PSI in varying densities. The resulting Sulfo‐PSI and TMAC‐PSI, respectively, processed into nanofibrous films, demonstrate highly enhanced and variable triboelectric properties based on the charge type and density. To further enhance the mechanical toughness and biocompatibility necessary for wearable applications, these PSI nanofibers are processed into alginate aerogel (AG). The sustained triboelectric performance of this nanofiber‐AG TENG as a wearable energy harvester and biosensor is examined and validated in detail.
Fibrosis is one of the most frequent occurrences during one's lifetime, identified by various physiological changes including, most notably, excessive deposition of extracellular matrix (ECM). Despite its physiological importance, it is still a significant challenge to conduct a systematic investigation of tissue fibrosis, mainly due to the lack of in vitro 3D tissue model that can accurately portray the characteristic features of fibrotic events. Herein, a hybrid hydrogel system incorporating dispersible nanofibers is developed to emulate highly collagenous deposits formed within a fibrotic tissue leading to altered mechanotopographical properties. Micrometer‐length, aqueous‐stable nanofibers consisting of crosslinked gelatin network embedded with graphene oxide (GO) or reduced graphene (rGO) are infused into hydrogel, resulting in controllable mechanotopographical properties while maintaining permeability sufficiently enough for various cellular activities. Ultimately, the ability to induce fibrotic behavior of fibroblasts cultured in these mechanotopography‐controlled, nanofiber‐laden hydrogels is investigated in detail.
Long tendon substitutes could be fabricated from MSCs and a collagen type I gel by cyclic stretching and showed tendon-like parallel collagen fibers and spindle-shaped cells. The use of MSCs in combination with adequate scaffold materials has great therapeutic potential for the development of autologous transplantable tendon substitutes.
From this study, we conclude that wound-fluid collected from the V.A.C.-device via the polyurethane-foam or tubing for purposes of analyzing concentrations of TGF-beta 1 should not be different from fluid collected using the foil technique.
Hydrogels and nanofibers have been firmly established as go‐to materials for various biomedical applications. They have been mostly utilized separately, rarely together, because of their distinctive attributes and shortcomings. However, the potential benefits of integrating nanofibers with hydrogels to synergistically combine their functionalities while attenuating their drawbacks are increasingly recognized. Compared to other nanocomposite materials, incorporating nanofibers into hydrogel has the distinct advantage of emulating the hierarchical structure of natural extracellular environment needed for cell and tissue culture. The most important technological aspect of developing “nanofiber‐composite hydrogel” is generating nanofibers made of various polymers that are crosslinked and short enough to maintain stable dispersion in hydrated environment. In this review, recent research efforts to develop nanofiber‐composite hydrogels are presented, with added emphasis on nanofiber processing techniques. Several notable examples of implementing nanofiber‐composite hydrogels for biomedical applications are also introduced.This article is protected by copyright. All rights reserved
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