Injectable Antibacterial Gelatin-Based Hydrogel Incorporated with Two-Dimensional Nanosheets for Multimodal Healing of Bacteria-Infected Wounds

Abstract

The design and development of multifunctional injectable hydrogels with high photothermal antibacterial activity and shape adaptability to accelerate bacteria-infected wound healing is of critical importance in clinical applications. In this study, a hybrid hydrogel composed of gelatin, iron, and MnO 2 nanosheets was prepared by multiple interactions, including coordinative and hydrogen bonding as well as electrostatic attraction. The introduced MnO 2 and Fe components made the hydrogels photothermally and chemodynamically active, thereby endowing them with potent antibacterial capabilities against both Gram-negative and Grampositive bacteria. Because of the Fenton activity of the hydrogels, they could produce abandoned oxygen, which is highly crucial in the healing process of wounds. They also showed good cytocompatibility and hemocompatibility as well as high hemostatic properties. Moreover, the injectable hydrogels could fill irregular wounds and significantly accelerate bacteria-infected wound healing through decreasing the inflammatory response and increasing blood vessels. These features indicated the promising potential of the multifunctional hydrogel for healing infected full-thickness wounds.

Engineering a platelet-rich plasma-based multifunctional injectable hydrogel with photothermal, antibacterial, and antioxidant properties for skin regeneration

“…82 In vitro blood clotting properties of the hydrogels and gauze were measured using the whole blood-clotting index three times (60, 120, and 240 s) at 37 °C. 7 Gauze as a traditional hemostatic model was used as the control. Both AGC–PPP–PDA, and AGC–PRP–PDA groups indicated a lower BCI than the control group and no significant difference between the AGC–PPP–PDA and AGC–PRP–PDA groups was observed (Fig.…”

“…The temperature was recorded every minute using the infrared thermal camera. The photothermal conversion efficiency ( η ) of the AGC–PRP–PDA hydrogel was calculated using the following equation: 7,37,38 Hence, first, the time constant of heat transfer ( τ s ) was calculated by linear time data versus −ln( θ ) from the cooling phase, as follows:…”

“…The temperature was recorded every minute using the infrared thermal camera. The photothermal conversion efficiency (η) of the AGC-PRP-PDA hydrogel was calculated using the following equation: 7,37,38 η…”

“…These results demonstrated successful fabrication of the hydrogels through attractive interactions between the functional groups of the hydrogels by coordinative and hydrogen bonding interactions. 7,17 All of the hydrogels exhibited a high water content, which is essential in the wound repair process (Fig. 3B).…”

“…5,6 Injectable hydrogels, in particular, can fill any irregular wound shape, providing a physical barrier that shields the wound area from bacterial infection quickly. [7][8][9] Numerous natural polymer-based hydrogels, such as chitosan, hyaluronic acid, and alginate, have been used as wound dressings to promote skin regeneration. 10,11 Alginate, a natural polysaccharide, can form biocompatible hydrogels through ionic cross-linking with multivalent cations (e.g., Ca 2+ , Sr 2+ , and Ba 2+ ).…”