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189 results on '"Dan, Nianhua"'

28. An antibacterial strategy on chrome-free tanned leather: based on β-cyclodextrin aldehyde derivatives and small molecule

Author

Wen Huitao, Yu Guofei, Chen Yining, Dan Nianhua, and Dan Weihua

Abstract

Chrome tanning has dominated in leather production up to now, while facing a significant challenge in terms of chromium. Therefore, the chrome-free tanning process becomes an inevitable choice. However, chrome-free tanned leather (CFTL) is poor in antibacterial properties, which limits its practical application in leather production. In this work, a new environment-friendly antibacterial strategy based β-cyclodextrin (β-CD) aldehyde derivatives and ciprofloxacin hydrochloride (CH) as a small molecule model antibacterial agent was developed to address this issue along with improving the comprehensive performances of leather. The structure and properties of obtained leather were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, thermogravimetric, and its antibacterial effect against E. coli and S. aureus was investigated. The results showed that compared with CFTL without β-CD modification and CH treatment, the Ts, Td and Tp of the leather with this method possessed increased 5.7°C, 4.9°C, and 6.9°C, respectively. After being treated by CH with 90 days of storage, the antibacterial rates against E. coli and S. aureus still reached 99.8% and 97.4%, respectively, which were 29.9% and 34.4% higher than those without β-CD treatment. It, that antibacterial agent is included in the cavity of β-CD on CFTL, will improve the poor antibacterial durability due to the release of the small molecule antimicrobial agent. These findings, therefore, indicated that a new antibacterial method on CFTL with β-cyclodextrin aldehyde derivatives and ciprofloxacin hydrochloride has potential practical application prospects in leather production.

Published
2021

41. Preparation of fragrant collagen fibers by cross-linking with β-cyclodextrin and inclusion of l-menthol: characterization, release behavior and reusability evaluation.

Author

Wen, Huitao, Zheng, Xin, Yu, Guofei, Chen, Yining, Dan, Nianhua, Li, Zhengjun, and Dan, Weihua

Subjects
BEHAVIORAL assessment, CYCLODEXTRINS, MENTHOL, CYCLODEXTRIN derivatives, COLLAGEN, DIFFERENTIAL scanning calorimetry, STABILITY constants, ODORS
Abstract

To solve the poor fragrance retention of collagen-based materials, β-cyclodextrin derivatives bearing multiple aldehyde groups (MACD) were used to cross-link with collagen fibers (COLF) and subsequently to include l-menthol. The structure and performance of MACD, MACD cross-linked COLF (CD-COLF) and CD-COLF included with l-menthol (MEN/CD-COLF) were characterized by Fourier transform infrared (FTIR), ultraviolet-visible spectroscopy (UV-vis), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results showed that the l-menthol loading content in CD-COLF was 2.05 mg/g, 2.85 times higher than that of the uncross-linked COLF. The stability constant (Ka) of MEN/CD-COLF at 25 °C was 364.78 L/mol, ΔH was −19.29 KJ/mol, ΔS was −15.62 J/(mol·K), and ΔG was −14.63 KJ/mol, which indicated the inclusion reaction was spontaneous, and the as-formed MEN/CD-COLF was stable. Meanwhile, the MEN/CD-COLF was more difficult to release l-menthol. The release rate was affected by temperature, the release equilibrium was prolonged, and the cumulative release degree was relatively lower. Furthermore, the fragrant collagen fibers were reused by washing with ethanol and dried under vacuum, and the regeneration was repeated 10 times. Therefore, the fragrant collagen fibers with outstanding characteristics could be promising candidates for applying new generation fragrant materials in biomedicine, leather and the textile industry. [ABSTRACT FROM AUTHOR]

Published
2022
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46. Adhesive Capable of Underwater Adhesion and Wound Hemostasis Prepared Based on Solvent Exchange.

Author

Song, Qiantao, Chen, Yining, Huang, Yanping, Dan, Weihua, Wang, Meng, and Dan, Nianhua

Subjects
MICHAEL reaction, HEMOSTASIS, DIMETHYL sulfoxide, HYDROGEN bonding interactions, ADHESIVES, SOLVENTS
Abstract

Whether used for underwater adhesion or wound hemostasis, adhesives are required to have strong wet adhesion. However, traditional adhesives are difficult to break through the blockade of the hydration interface, so they cannot achieve strong underwater adhesion, and their biological toxicities are also greater, not suitable for wound hemostasis. In this work, small molecule polyethylene glycol diacrylate (PEGDA‐200) and dopamine (DA) with good biocompatibility are used as raw materials to synthesize a long chain polymer (PDDA) with hydrophobic backbone and hydrophilic group through the Michael addition reaction. Based on the hydrogen bond interaction between PDDA and silicotungstic acid (SiW) and the solvent exchange between dimethyl sulfoxide and water, the two are successfully caused to agglomerate and form a viscous aggregate (PDDA‐SiW). PDDA‐SiW not only has strong underwater adhesion to various substrates, but also has strong adhesion and readhesion to fresh pigskins. In addition, PDDA‐SiW also has very low hemolysis and cytotoxicity and strong antibacterial properties, and it is a very good underwater adhesion and wound hemostatic material. [ABSTRACT FROM AUTHOR]

Published
2022
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