Tissue Adhesive, Self-Healing, Biocompatible, Hemostasis, and Antibacterial Properties of Fungal-Derived Carboxymethyl Chitosan-Polydopamine Hydrogels

Abstract

In this work, fungal mushroom-derived carboxymethyl chitosan-polydopamine hydrogels (FCMCS-PDA) with multifunctionality (tissue adhesive, hemostasis, self-healing, and antibacterial properties) were developed for wound dressing applications. The hydrogel is obtained through dynamic Schiff base cross-linking and hydrogen bonds between FCMCS-PDA and covalently cross-linked polyacrylamide (PAM) networks. The FCMCS-PDA-PAM hydrogels have a good swelling ratio, biodegradable properties, excellent mechanical properties, and a highly interconnected porous structure with PDA microfibrils. Interestingly, the PDA microfibrils were formed along with FCMCS fibers in the hydrogel networks, which has a high impact on the biological performance of hydrogels. The maximum adhesion strength of the hydrogel to porcine skin was achieved at about 29.6 ± 2.9 kPa. The hydrogel had good self-healing and recoverable properties. The PDA-containing hydrogels show good antibacterial properties on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. Moreover, the adhesive hydrogels depicted good viability and attachment of skin fibroblasts and keratinocyte cells. Importantly, FCMCS and PDA combined resulted in fast blood coagulation within 60 s. Hence, the adhesive hydrogel with multifunctionality has excellent potential as a wound dressing material for infected wounds.

Keywords: hydrogel; mussel inspired; non-animal fungal mushroom carboxymethyl chitosan; polydopamine; tissue adhesive; wound dressing applications.

Scheme 1

Schematic representation of formation of PDA-FCMCS-PAM hydrogels.

Figure 1

The 0.4DA-FCMCS hydrogel adhesion for (a) fingers and (a-1) its stretchable condition, (b) leaf and its stretchability (b-1), (c) 100 g plastic tube and plastic tube, (c-1) plastic tube and 100 g plastic tube, (d) plastic tube and rubber, (d-1) rubber and 100 g plastic tube, (e) steel and 80 g plastic tube, (e-1) 100 g plastic tube and 100 g of steel, (f) computer screen, (f-1) transparency of hydrogel on computer screen, (g) glass plate, and (h) foldable to author’s finger.

Figure 2

FTIR spectra of hydrogels.

Figure 3

(a) Rheology storage modulus (G′), (b) loss factor (Tanδ) of hydrogels, (c) compressive properties of hydrogels, (d) cyclic compressive property of 0.4DA-FCMCS hydrogel, and (e) tensile stress–strain curve of hydrogels.

Figure 4

(a) Digital photographs of self-healing of 0.4DA-FCMCS hydrogel and its stretchability, (b) dynamic rheology of 0.4DA-FCMCS hydrogel under two different strains (1% and 1000%), (c) rheology of storage modulus for 0.4DA-FCMCS hydrogel; black figure shows strain amplitude from 0.1% to 1000% and red figure shows the release of strain amplitude from 1000% to 1% with respect to time, and (d) tensile stress–strain curve of original hydrogel and self-healed hydrogel.

Figure 5

SEM images of hydrogels (a) FCMCS (low resolution) and (a-1–a-3) (high resolution), (b) 0.2DA-FCMCS (low resolution) and (b-1–b-3) (high resolution), and (c) 0.4DA-FCMCS (low resolution) and (c-1–c-3) (high resolution).

Figure 6

(a) Pore size and (b) porosity of hydrogels.

Figure 7

(a) Swelling and (b) biodegradation of hydrogels.

Figure 8

(a) % cell viability of (a) skin fibroblasts and (b) keratinocytes cells (N = 3, * p < 0.05).

Figure 9

Biocompatibility of L/D fluorescence images of skin fibroblasts and keratinocytes cells treated with FCMCS, 0.2DA-FMCS, and 0.4DA-FCMCS hydrogels.

Figure 10

SEM images of skin fibroblasts and keratinocyte cells on FCMCS, 0.2DA-FMCS, and 0.4DA-FCMCS hydrogels.

Figure 11

(a) Digital photograph images of blood clotting, (b) blood clotting time of hydrogels, (c) digital photograph images of hemolysis, and (d) % hemolysis of hydrogels.

Figure 12

Antibacterial activity of hydrogels against (a) E. coli and (b) S. aureus using disc diffusion method, SEM images of bacterial adhesive property of hydrogels against (c) E. coli and (d) S.aureus and (e) adhesion strength of hydrogels to porcine skin (N = 3, * p < 0.05).