Blood‐Coagulation‐Inspired Dynamic Bridging Strategy for the Fabrication of Multiscale‐Assembled Hierarchical Porous Material

Abstract

Porous materials, from macroscopic bulk materials (MBs) with (sub‐)millimeter‐scale pores to tiny particles (TPs) with (sub‐)nanometer‐scale pores, have attracted ever‐growing interest in various fields. However, the integration of multi‐scale pores in one composite is promising but challenging, owing to the considerable gap in the scale of the pores. Inspired by blood coagulation, a fibrin‐based dynamic bridging strategy is developed to fabricate a multiscale‐assembled hierarchical porous material (MHPM), in which fibrin formed as the sub‐framework for the weaving‐narrow of MBs and the enwinding‐load of TPs. The bio‐polymerization nature makes the fabrication rapid, facile, and universal for the customizable integration of seven kinds of TPs and four kinds of MBs. Besides, the integration is controllable with high load capacity of TPs and is stable against external shock forces. The unique multi‐level structure endows the MHPM with large and accessible surface area, and efficient mass transfer pathways, synergistically leading to high adsorption capacity and rapid kinetics in multiple adsorption models. This work suggests a strategy for the rational multi‐level design and fabrication of hierarchical porous architectures.

Bioinspired Asymmetric Double-Layer Dressings for Stepwise Treatment of Hemorrhagic Wounds

“…Scanning electron microscopy (SEM, Figure d) further revealed that there were fewer and larger pores in the thick BSP layer, in remarkable contrast to the denser and smaller micropores in the thin PNS@CMCS layer. The cross-linking degree of hydrogels and solid contents have been recognized as critical factors to affect the microstructure and pore sizes of lyophilized hydrogel sponges. , In our study, the BSP-containing carbomer sponges with less carbomer content even showed more loose porous structures (Figure S2), indicating the loose cross-linking and low solid contents in the BSP layer. By contrast, the lyophilized PNS-containing CMCS hydrogels with the higher alginate contents showed denser structures (Figure S3), suggesting a large cross-linking degree and high solid contents in the BSP layer.…”

“…30−32 Although these elements have been used in different dressings, in terms of the management of hemorrhagic wounds, 33,34 current dressings are still lacking to meet the demands of coordinated hemostasis and angiogenesis during the whole stages of wound healing. 35,36 In this paper, our design of the double-layer BSP-PNS@ CMCS dressings along with the stepwise treatment strategy is expected for the advanced management of hemorrhagic wounds. The desired dressing (BSP-PNS@CMCS) with natural skin-mimicking asymmetric double-layer structures was fabricated via a two-step approach of lyophilizing BSP and PNS-laden CMCS hydrogels.…”

“…Such dressing (BSP-PNS@CMCS) is designed with an inner loose layer of Bletilla striata polysaccharide (BSP) sponges for adhering and retaining the blood cells via those loose pore-channels during the initial bleeding period and an outer dense layer of carboxymethyl chitosan (CMCS) loaded with panax notoginseng saponines (PNS) for promoting angiogenesis and defensing outside pathogenic microorganisms during subsequent tissue reconstruction period. BSP has been widely used for the development of advanced hemostatic materials and wound dressings, because it could accelerate coagulation by shortening the activation time of coagulation-related enzymes and increasing fibrinogen contents. , By contrast, PNS, the main constituent of panax notoginseng (Sanqi), has been employed in the design of microspheres/scaffolds for wound healing due to its intrinsic proangiogenic effects and tissue regenerative activity. , Additionally, CMCS, known as a carboxymethylated derivate of chitosan (CS), can bind and interact with the negatively charged bacterial cell membranes, exhibiting enhanced antibacterial property in various wound managements. − Although these elements have been used in different dressings, in terms of the management of hemorrhagic wounds, , current dressings are still lacking to meet the demands of coordinated hemostasis and angiogenesis during the whole stages of wound healing. , …”

Bioactive Hydrogels with Pro‐coagulation Effect for Hemostasis†

“…The nano/micro‐structure of materials can be manipulated to increase catalytic efficacy by enlarging contact areas. [ 220,237 ]…”