Chitosan based Janus cryogel with anisotropic wettability, antibacterial activity, and rapid shape memory for effective hemostasis

Excessive bleeding and bacterial infection leading to death is a major concern worldwide, particularly in cases of deep and narrow noncompressible hemorrhage. Herein, a novel Janus cryogel with anisotropic surface wettability, antibacterial activity, and rapid shape recovery was designed by constructing a hydrophilic porous cryogel using chitosan (CS), acacia gum (AG), and quaternized mesoporous bioglass (QMBG), with subsequent surface hydrophobic modification using octadecanol. The asymmetric hydrophobic surface modification of octadecanal endowed OCAQ with outstanding antiblood and antibacterial permeability, effectively preventing blood outflow and the invasion of bacteria to the wound. The hydrophilic parts with interconnected macroporous structure give the cryogel with ultra-high water uptake (5167 ± 182 %) and rapid water-trigged shape recover ability (≈2.1 s). The presence of active CS, AG, and QMBG in cryogel contributes to its exceptional blood clotting ability. Janus cryogel presents outstanding hemostatic performance (0.14 ± 0.03 g) in rat's liver injury model. Moreover, Janus cryogel exhibits excellent antibacterial properties due to the combination of its hydrophobic surface and antimicrobial quaternary amine groups. Meanwhile, the Janus cryogel has favorable hemocompatibility and biocompatibility. A Therefore, the Janus cryogel will become a candidate with great potential for clinical application of noncompressible wound as a multifunctional dressing.