Highly Electroactive Tissue Engineering Scaffolds Based on Nanocellulose/Sulfonated Carbon Nanotube Composite Hydrogels for Myocardial Tissue Repair.

Myocardial infarction (MI) has been a serious threat to the health of modern people for a long time. The introduction of tissue engineering (TE) therapy into the treatment of MI is one of the most promising therapeutic schedules. Considering the intrinsic electrophysiological activity of cardiac tissue, we utilized 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCNs) with excellent biocompatibility as the substrate, and sulfonated carbon nanotubes (SCNTs) with remarkable conductivity and water dispersibility as the electrically active material, to prepare TOCN-SCNT composite hydrogels. By adjusting the content of SCNTs from 0 to 5 wt %, TOCN-SCNT hydrogels exhibited conductivity ranging from 5.2 × 10-6 to 6.2 × 10-2 S cm-1. Just with 1 wt % incorporation of SCNTs, the hydrogel played a role in promoting the adhesive growth and proliferation of cells. The hydrogel expressed higher Connexin 43 (Cx-43) and cardiac troponin-T proteins compared with controls, demonstrating great potential in constructing a myocardial TE scaffold.

Hydrangea-like nanocellulose microspheres with high dye adsorption and drug encapsulation prepared by emulsion method.

Currently, microspheres with high adsorption capacity play a crucial role in dye adsorption and drug loading. In this study, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCN) could be used to form nanocellulose microspheres by the emulsion method. The prepared hydrangea-like nanocellulose microspheres presented a stable three-dimensional network porous structure and exhibited excellent adsorption properties. The TOCN microspheres had a high adsorption capacity for methylene blue (MB) and methyl orange (MO) with the optimal adsorption capacity of 412.1 mg g-1 and 286.5 mg g-1 under neutral conditions, respectively. The TOCN microspheres displayed excellent adsorption selectivity on MB/MO mixed dyes, which could be used to selectively adsorb MB. Besides, the encapsulation rate of the positively charged drug doxorubicin hydrochloride (DOX) was as high as 93 %, and the drug loading capacity was as high as 34.5 %. Overall, our prepared nanocellulose microspheres had great potential for application in dye adsorption and drug delivery systems.

Highly Sensitive Multifunctional Electronic Skin Based on Nanocellulose/MXene Composite Films with Good Electromagnetic Shielding Biocompatible Antibacterial Properties.

Electronic skin has aroused extensive research interest due to high similarity with human skin. Realizing a multifunctional electronic skin that is highly consistent with skin functions and endowed with more other functions is now a more urgent need and important challenge. Here, we use 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized cellulose nanofibril (TOCN) dispersion and highly conductive Ti3C2TX dispersion to prepare TOCN/Ti3C2TX composite film through vacuum-assisted filtration. The obtained composite film imitating the nacre-like lamellar structure of natural shells has good mechanical properties (124.6 MPa of tensile strength). Meanwhile, the composite film also showed excellent electromagnetic shielding performance (36 dB), biocompatibility, and antibacterial properties. In addition, the piezoresistive sensor assembled from the composite film exhibited a high sensitivity (11.6 kPa-1), fast response and recovery time (≤10 ms), ultralow monitoring limit (0.2 Pa), and long-term stability (>10 000 cycles). It also could detect human daily activities such as finger bent, chewing, and so on.