Degradable Gelatin-Based IPN Cryogel Hemostat for Rapidly Stopping Deep Noncompressible Hemorrhage and Simultaneously Improving Wound Healing

Abstract

Biodegradable cryogel wound dressing which can stop deep noncompressible hemorrhage and simultaneously promote wound healing is a highly promising biomaterial in clinics. Here, we prepared a series of biodegradable interpenetrating polymer network (IPN) dry cryogel hemostats by cryopolymerization of gelatin and dopamine. The IPN structure of cross-linked gelatin and polydopamine endows the cryogels good injectability, robust mechanical property, and shape memory property. The cryogels showed better whole bloodclotting capacity and more blood cell and platelet adhesion and activation than gauze and gelatin hemostatic sponge. The cryogels present less blood loss and shorter hemostasis time than gauze and gelatin hemostatic sponges in the mouse liver trauma model, rat liver incision model, and rabbit liver cross incision model. Especially, the hemostatic effect of the cryogel on deep narrow noncompressible hemorrhage was determined by the rabbit liver defect deep narrow noncompressible hemorrhage model. The cryogel rapidly stopped deep massive noncompressible hemorrhage in the swine subclavian artery and vein complete transection model. Besides, the component of polydopamine endows cryogels with excellent antioxidant activity and NIR irradiationassisted photothermal antibacterial ability. Gelatin/dopamine cryogels were more effective in promoting wound healing than Tegaderm films. The developed biodegradable cryogels with a simple preparation process and low cost and which can be easily carried and used present huge potential as novel wound dressing for rapid hemostasis and promoting wound healing.

Microchannelled chitosan sponge grafting with hydrophobic alkyl chain for enhanced noncompressible hemorrhage and tissue regeneration

“…The interconnectivity of the porous structure played a key role in accelerating hemostasis and guiding tissue regeneration, which usually was ignored in most previous studies 5,6,10,13 . The MACSs were expected to exhibit an obvious advantage in the treatment of noncompressible hemorrhage and in situ tissue regeneration in comparison with reported porous hemostats 5,6,10,14 . Accordingly, the porosity of the MACSs gradually increased from 70 ± 2.0 to 90 ± 0.6% with an increase in lling ratio of PLA micro ber, which were signi cantly higher than the 31 ± 0.7% of the ACS (Fig.…”

“…1N). Water/blood absorbability of the MACSs The main hemostatic mechanism of expandable hemostats was mechanical compression on the bleeding site, which mainly resulted from water/blood-triggered shape recovery and volume expansion 1,5,14,27,29 . Thus, strong water/blood absorbability was indispensable for expandable hemostats.…”

“…4H). Indeed, a large number of studies have demonstrated that, compared to water, blood is more likely to prolong the shape recovery time of hemostats due to its higher viscosity 14,15 . In contrast, there was no signi cant difference in shape recovery time for the MACSs after the absorption of water and blood.…”

“…However, they displayed limited absorption of blood and required decades of seconds to restore their shapes, which may cause the prologation of hemostasis time and more blood loss 5 . Injectable cryogels with high blood absorbability and rapid-shape recovery capacity have also been developed for treatment of noncompressible hemorrhage 6,14,15 . The hemostatic effect of these materials was achieved by restoring shape and applying mechanical compression on the wound.…”

“…However, the pores inside these hemostats generated by gas foaming or ice crystal removing methods possess low interconnectivity, which might slow down the blood ow into hemostats, resulting in weakened hemostatic e ciency. The effect of pore structure, especially interconnectivity, on hemostatic performance was usually ignored in the design and construction of hemostats 5,8,10,14 . Besides, some of these hemostats lacked strong active pro-coagulant and anti-infective properties, which may result in their failure to complete the hemostasis in a timely and effective way and in their inability to protect wounds from bacterial infection.…”