Chem. J. Chinese Universities ›› 2022, Vol. 43 ›› Issue (4): 20210841.doi: 10.7503/cjcu20210841

• Polymer Chemistry • Previous Articles     Next Articles

Three-dimensional Printing of Photocrosslinked Self-supporting Silk Fibroin Hydrogels

HUANG Yi1,2, LYU Lingling2, PAN Xiaopeng2, SUN Guangdong2, LI Yongqiang2, YAO Juming1(), SHAO Jianzhong2()   

  1. 1.School of Materials Science and Engineering
    2.Engineering Research Center for Eco?Dyeing and Finishing of Textiles,Ministry of Education,Zhejiang Sci?Tech University,Hangzhou 310018,China
    3.Zhejiang Sci?Tech University Tongxiang Research Institute,Tongxiang 314500,China
  • Received:2021-12-18 Online:2022-04-10 Published:2022-02-12
  • Contact: YAO Juming E-mail:yaoj@zstu.edu.cn;jshao@zstu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(52103068);the Natural Science Foundation of Zhejiang Province, China(LY21E030019);the Postdoctoral Foundation of Zhejiang Sci-Tech University Tongxiang Research Institute, China(TYY202014);the Fundamental Research Funds of Zhejiang Sci-Tech University, China(2021Q008)

Abstract:

As a biological macromolecular material degummed from silk fiber, silk fibroin(SF) is considered to be an ideal candidate for bioink components in three-dimensional(3D) bioprinting because of its excellent biocompatibility, biodegradability and tunable mechanical properties. However, the conventional silk fibroin crosslinking methods cannot meet the requirements of 3D printing on the real-time forming efficiency and biocompatibility. In order to realize the 3D rapid prototyping of silk fibroin, the in-situ photocrosslinking processing technology of self-supporting silk fibroin hydrogel was proposed by combining the blue light-induced self-crosslinking method with 3D extruded printing technology. The basic rheological properties, photocrosslinking properties and moulding processability of silk fibroin solution were studied by using rotary rheometer, photorheological test system and modified 3D extruded printing equipment. The results showed that the silk fibroin solution(<20%, mass fraction) was mainly characterized by viscidity, and its inadequate structural strength and stability cannot meet the requirements of 3D extruded printing for material formability, shape retention and printing accuracy. Rapid photocrosslinking molding processing of silk fibroin hydrogel can be achieved by light-induced self-crosslinking in the presence of tris(2,2-bipyridyl) ruthenium(II) chloride hexahydrate[Ru(Ⅱ)] and potassium persulfate(KPS) as blue light initiators. Tyrosine residues on adjacent SF macromolecular chains can be oxidized into tyrosine free radicals under the action of excited active species, and then coupled and crosslinked into di-tyrosine structure. Photocrosslinking behavior of silk fibroin under blue light irradiation conformed to exponential growth model. Due to the “filter effect” of the photosensitizer on the incident light, silk fibroin solution showed the optimized photocrosslinking performance when the dose of the photosensitizer Ru(Ⅱ) was 0.05 mmol/L. By further adjusting the parameters such as air pressure, needle aperture, moving speed and curing rate, semi-transparent and micro-elastic silk fibroin hydrogel can be printed in real time by 3D extruded printing equipment under continuous blue light irradiation. The efficient and accurate construction of silk fibroin gel materials from single-layer geometric structure to multi-layer three-dimensional network structure can be realized, which provides a new idea for biological 3D printing of self-supporting silk fibroin gel materials.

Key words: Photocrosslinking, Silk fibroin hydrogel, 3D printing, Gelation behavior, Elastic modulus

CLC Number: 

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