Novel Modification of Collagen: Realizing Desired Water Solubility and Thermostability in a Conflict-Free Way

Junhui Yang; Cuicui Ding; Lele Tang; Feng Deng; Qili Yang; Hui Wu; Lihui Chen; Yonghao Ni; Liulian Huang; Min Zhang

doi:10.1021/acsomega.9b03846

Novel Modification of Collagen: Realizing Desired Water Solubility and Thermostability in a Conflict-Free Way

ACS Omega. 2020 Mar 11;5(11):5772-5780. doi: 10.1021/acsomega.9b03846. eCollection 2020 Mar 24.

Authors

Junhui Yang¹, Cuicui Ding², Lele Tang¹, Feng Deng¹, Qili Yang¹, Hui Wu¹, Lihui Chen¹, Yonghao Ni^{1

3}, Liulian Huang¹, Min Zhang¹

Affiliations

¹ College of Materials Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
² College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350108, PR China.
³ Department of Chemical Engineering and Limerick Pulp & Paper Centre, University of New Brunswick, Fredericton E3B 5A3, Canada.

Abstract

Because of poor water solubility and low thermostability, the application of collagen is limited seriously in fields such as injectable biomaterials and cosmetics. In order to overcome the two drawbacks simultaneously, a novel bifunctional modifier based on the esterification of polyacrylic acid (PAA) with N-hydroxysuccinimide (NHS) was prepared. The esterification degree of PAA-NHS esters was increased upon increasing the NHS dose, which was confirmed by Fourier-transform infrared (FTIR) and nuclear magnetic resonance spectrascopy. FTIR results indicated that the triple helix of the modified collagens remained integrated, whereas the molecular weight became larger, as reflected by the sodium dodecyl sulfate-polyacrylamide gel electrophoresis pattern. The modified collagens displayed excellent water solubility under neutral condition, owing to lower isoelectric point (3.1-4.3) than that of native collagen (7.1). Meanwhile, denaturation temperatures of the modified collagens were increased by 4.8-5.9 °C after modification. The modified collagen displayed hierarchical microstructures, as reflected by field-emission scanning electron microscopy, while atomic force microscopy further revealed a "fishing net-like" network in the nanoscale, reflecting a unique aggregation behavior of collagen macromolecules after modification. As a whole, the PAA-NHS ester as a bifunctional modifier endowed collagen with desired water solubility and thermostability in a conflict-free manner, which was beneficial to the process and application of the water-soluble collagen.