Green Gas-Mediated Cross-Linking Generates Biomolecular Hydrogels with Enhanced Strength and Excellent Hemostasis for Wound Healing

Abstract

Forming biomolecular hydrogels with a combination of high strength and biocompatibility is still a challenge. Herein, we demonstrated a green gas (CO2)-mediated chemical cross-linking strategy that can produce a double-network cellulose/silk fibroin hydrogel (CSH) with significantly elevated mechanical strength while bypassing the toxicity of routine cross-linking agents. Specifically, cellulose and silk fibroin (SF) were first covalently cross-linked in NaOH/urea solution to create the primary network. Then, CO2 gas was introduced into the resultant CSH precursor gels to form carbonates to reduce the pH value of the intra-hydrogel environment from basic to neutral conditions. The pH reduction induced the ordered aggregation of cellulose chains and concomitant hydrogen bonding between these chains, leading to the formation of hydrogels with significantly improved mechanical strength. The CSHs could promote the adhesion and proliferation of the mouse fibroblast cell line (L929), and the CSHs proved to be of low hemolysis and could accelerate blood clotting and decrease blood loss. The CSHs with SF content of 1 wt % healed the wound in vivo within only 12 days through the acceleration of re-epithelialization and revascularization. Consequently, our current work not only reported a feasible alternative for wound dressings but also provided a new green gas-mediated cross-linking strategy for generating mechanically strong, hemostatic, and biocompatible hydrogels.

In Situ Synthesized Selenium Nanoparticles‐Decorated Bacterial Cellulose/Gelatin Hydrogel with Enhanced Antibacterial, Antioxidant, and Anti‐Inflammatory Capabilities for Facilitating Skin Wound Healing

“…The α ‐smooth muscle actin ( α ‐SMA) expression reflects the degree of myofibroblast activation during the wound healing process. [ 50,51 ] As shown in Figure 8C,D, the α ‐SMA expression in the BC/Gel/SeNPs hydrogel group was remarkably enhanced on day 7, while significantly reduced on day 14, as compared to the Gauze and BC hydrogel groups, indicating that the BC/Gel/SeNPs hydrogel could induce the fibroblast proliferation and differentiation into myofibroblasts after 7 days of treatments, which was reduced to a normal state with the wound healing almost completed after 14 days of treatments. This is particularly important to promote the wound healing and avoid granulation hyperplasia and fibrosis, as well as scar formation.…”

Biocompatible and antibacterial soy protein isolate/quaternized chitosan composite sponges for acute upper gastrointestinal hemostasis

“…The compressive properties of the SQS- n were analyzed using a universal testing machine (Instron 3340, ITW, USA). The swelling ratio (SR) of SQS- n was measured as reported previously [ 32 ].…”

Cellulose‐based hydrogels regulated by supramolecular chemistry

“…In this work, as the relatively rigid polymers, cellulose are susceptible to mechanical signal, and their H‐bonds helped the formation of anisotropic structures. Besides these single noncovalent interactions, Mao and colleagues 19 designed hydrogel networks which contained chain entanglements, crystallization, covalent bonds, and H‐bonds (Figure 2C). In these double‐network cellulose/silk fibroin hydrogels, a green gas (CO 2 ) worked as media to induce physical crosslinking.…”