Silk Fibroin/Tannin/ZnO Nanocomposite Hydrogel with Hemostatic Activities

Abstract

The inevitable bleeding and infections caused by disasters and accidents are the main causes of death owing to extrinsic trauma. Hemostatic agents are often used to quickly suppress bleeding and infection, and they can solve this problem in a short time. Silk fibroin (SF) has poor processibility in water, owing to incomplete solubility therein. In this study, aiming to overcome this disadvantage, a modified silk fibroin (SF-BGE), easily soluble in water, was prepared by introducing butyl glycidyl ether (BGE) into its side chain. Subsequently, a small amount of tannic acid (TA) was introduced to prepare an SF-BGE /TA solution, and ZnO nanoparticles (NPs) were added to the solution to form the coordination bonds between the ZnO and TA, leading to an SF-based nanocomposite hydrogel. A structural characterization of the SF-BGE, SF-BGE/TA, SF-BGE/TA/ZnO, and the coordination bonds between ZnO/TA was observed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and the phase change was observed by rheological measurements. The pore formation of the SF-BGE/TA/ZnO hydrogel and dispersibility of ZnO were verified through energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM). The cytocompatible and hemostatic performances of the SF-BGE/TA/ZnO NPs composite hydrogels were evaluated, and the hydrogels showed superior hemostatic and cytocompatible activities. Therefore, the SF-based nanocomposite hydrogel is considered as a promising material for hemostasis.

Keywords: composite hydrogel; hemostatic; silk fibroin; tannic acid; zinc oxide nanoparticle.

Figure 1

(a) Schematic of the modified SF (SF-BGE), tannic acid (TA), ZnO nanoparticles (NPs), SF-BGE/TA solution, and SF-BGE/TA/ZnO hydrogel hemostasis. (b) Schematic of the hemostasis trials in the rat tail amputation model and antibacterial and hemostatic process of SF-BGE/TA/ZnO NPs.

Figure 2

(a) ¹H NMR spectra of pristine SF and SF-BGE. (b) Photographs demonstrating of SF-BGE and SF-BGE/TA solutions and SF-BGE/TA/ZnO hydrogel. (c) ATR-FTIR spectra of SF-BGE, TA, SF-BGE/TA, and SF-BGE/TA/ZnO hydrogel. (d) G′ and G″ of SF-BGE, TA, SF-BGE/TA, and SF-BGE/TA/ZnO hydrogel.

Figure 3

SEM images of (a) SF-BGE, (b) SF-BGE/TA, and (c) SF-BGE/TA/ZnO hydrogel. (d) EDS mapping image of the SF-BGE/TA/ZnO hydrogel.

Figure 4

Indirect cytotoxicity test of SF-BGE, SF-BGE/TA, and SF-BGE/TA/ZnO samples on L929 fibroblast with (a) LIVE/DEAD staining (green: live, red: dead) and (b) cell viability (%) quantified based on the cell counting kit-8 (CCK-8) assay using extracts of SF-BGE and SF-BGE/TA solutions and SF-BGE/TA/ZnO hydrogel for 24 h. As a control, Dulbecco’s phosphate-buffered saline (DPBS) was used (inset scale bar is 200 µm). The data are expressed as the mean ± standard deviation (n = 3). All samples are not significantly different (per one-way analysis of variance (ANOVA) and Tukey’s post hoc test).

Figure 5

(a) Photographs of blood loss after tail amputation and administration of SF-BGE, SF-BGE/TA and SF-BGE/TA/ZnO hydrogel. (b) Blood loss (mg) from injury rat tail of control, SF-BGE, SF-BGE/TA, and SF-BGE/TA/ZnO hydrogel. The results are reported as the mean ± standard deviation (n = 3). Statistical significance was analyzed by one-way ANOVA and Tukey’s post hoc test (* p < 0.05, ** p < 0.01).