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[Display omitted] • Collagen/carboxylated CNF composite aerogels are successfully fabricated. • CDs can promote the in vitro self-assembly behavior of collagen. • CDs are beneficial for improving the properties of the collagen composite aerogels. • Composite aerogels have an excellent pH-responsive for drug delivery system. pH-responsive materials have great potential for use in various advanced fields, such as microreactors and drug delivery. This work proposes a promising strategy for preparing composite aerogels with pH-responsive properties based on collagen (COL) and TEMPO-oxidized cellulose nanofibers (CNFs) through the self-assembly behavior of COL molecules for controlled-drug release. COL fibrils and carboxylated CNFs (cCNFs) exhibited a high-density, physical cross-linked supramolecular double network structure. Specifically, cyclodextrins (CDs) were introduced to optimize the structural stability and slow-release capability of the composite aerogels. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analyses were used to characterize the structure of the aerogels, and the swelling behavior and water contact angle of the aerogels were evaluated. Using 5-fluorouracil (5-FU) as the model drug, the slow-release mechanism was subsequently revealed. Compared with the COL aerogels and COL/cCNF composite aerogels, the COL/cCNF@CD composite aerogels exhibited enhanced structural stability and slow-release performance through the synergistic enhancement effect of cCNFs and CDs. The aerogels also exhibited sensitivity to pH for regulating 5-FU release, and the COL composite aerogels with CDs and cCNFs maintained excellent cytocompatibility. In conclusion, CDs had a positive effect on the structural stability and pH-responsiveness of the composite aerogels and promoted the possible utilization of aerogels in drug delivery systems. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide combined with acid treatment demonstrates its respective characteristics for the separation of lignocellulosic biomass. Herein, holocellulose was extracted from Cattail leaves (CL) by a two-step treatment with alkali and hydrogen peroxide-acetic acid (HPAA). Then carboxylated nanocellulose was hydrolyzed with a mixed organic/inorganic acid. The chemical composition of the holocellulose and the physicochemical properties of the separated carboxylated nanocellulose were comparable. Carboxyl groups were introduced on the nanocellulose as a result of the esterification process with citric acid (CA), which endows the nanocellulose with high thermal stability (315–318 °C) and good light transmission (>80 %). Furthermore, morphological analyses revealed that nanocellulose had a spider-web-like structure with diameter between 5 and 20 nm. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide combined with acid treatment demonstrates its respective characteristics for the separation of lignocellulosic biomass. Herein, holocellulose was extracted from Cattail leaves (CL) by a two-step treatment with alkali and hydrogen peroxide-acetic acid (HPAA). Then carboxylated nanocellulose was hydrolyzed with a mixed organic/inorganic acid. The chemical composition of the holocellulose and the physicochemical properties of the separated carboxylated nanocellulose were comparable. Carboxyl groups were introduced on the nanocellulose as a result of the esterification process with citric acid (CA), which endows the nanocellulose with high thermal stability (315–318 °C) and good light transmission (>80 %). Furthermore, morphological analyses revealed that nanocellulose had a spider-web-like structure with diameter between 5 and 20 nm. [ABSTRACT FROM AUTHOR]