Uncontrolled hemorrhage resulting from traumas causes severe health risks. There is an urgent need for expeditious hemostatic materials to treat bleeding incidents. Here, we developed a natural protein-based hemostatic sponge extracted from nonmulberry cocoons that exhibited rapid coagulation and effective absorption. We first built a degumming and dissolution system suitable for the Dictyoploca japonica cocoons to obtain regenerated silk fibroin (DSF). The DSF was then combined with carboxymethyl chitosan (CMCS) by glutaraldehyde (GA) crosslinking to ensure the structural stability of sponges. The resulting DSF–CMCS–GA exhibited remarkable hemostatic properties, displaying the highest absorption rate. It also demonstrated comparable efficacy to commercial hemostatic sponges. The blood-clotting index and hemolysis test showed that the prepared sponge possessed hemostatic activity and good hemocompatibility. Compared with mulberry silk fibroin hemostatic sponges (SF–CMCS–GA), DSF–CMCS–GA showed slightly better effects, making them a potential alternative to mulberry silk. In conclusion, our study introduces the use of Dictyoploca japonica silk fibroin for hemostasis, highlighting the exploitation of wild silkworm resources and providing an excellent silk fibroin-based hemostatic sealant for acute accident wounds and biomedical applications involving massive hemorrhage.
Shuhe Wei,Yan Xiao,Hanwen Jiang,Frédéric Héraly,Liangshun Zhang,Wanyi Huang,Jiayin Yuan,Meidong Lang
Soft actuators capable of large and swift locomotion in combination with biocompatibility hold great potential in medicine and healthcare applications. In this contribution, a polypeptide-type poly(ionic liquid) (termed “PLL-PMIM-Tf 2 N”) was designed and synthesized by post-polymerization modification of poly- L -lysine; Next, via controlled electrostatic complexation with poly(acrylic acid) (PAA) or poly( L -glutamic acid) (PLG), porous membrane actuators termed PLL-PMIM-Tf 2 N/PAA or PLL-PMIM-Tf 2 N/PLG, respectively, were tailor-made. Hemolytic tests support excellent blood cell compatibility of the fully polypeptide-based PLL-PMIM-Tf 2 N/PLG actuator. The as-made soft actuators could bend significantly up to 500°with a maximum curvature of 7 cm −1 in response to solvent vapor in a fast actuation process within 2 s. Their high sensitivity towards solvent molecules equips them with skills to distinguish solvent isomers, as exemplified by butanol isomers, in terms of bending curvature due to varied molecular interactions between the actuator and the isomer. To be highlighted is an unusual irreversible actuated tubular state of the fully polypeptide-based PLL-PMIM-Tf 2 N/PLG actuator that is stable in shape and resembles bionic blood vessels. Such polypeptide-type poly(ionic liquid) actuators are of significant value in future development of biocompatible devices for medical and healthcare applications.
There is an urgent need for vascular scaffolds as a treatment option for cardiovascular diseases in the clinic. Here, we developed a simple and effective method to fabricate vascular scaffolds by direct 3D printing in air with gelatine (Gt) - alginate (Alg) - montmorillonite (MMT) nanocomposite bioinks. This work includes the optimization of key 3D printing parameters and the characterization of microscopic morphology, physicochemical properties, mechanical properties and preliminary biological properties. Successful 3D printing of linear and branched vascular scaffolds showed that the addition of nano-MMT improved the printability and shape accuracy. Scanning electron microscopy revealed that the inner and outer surfaces of the vascular scaffolds exhibited interconnected microporous structures favourable for nutrient delivery and cell infiltration. Axial and radial tensile tests indicated that the tensile strength and elastic modulus were similar to those of the native artery. The burst pressure of Gt-4%Alg-MMT was also in good accordance with the physiological pressure of natural blood vessels. In addition, a haemolysis test demonstrated that the haemolysis rate of Gt-4%Alg-MMT matched the gold standard of blood vessel substitution. A Live & Dead stain and a CCK-8 test confirmed the safe applicability of Gt-Alg-MMT as a biomaterial. Overall, the 3D-printed vascular scaffolds are promising candidates for in situ vascular tissue regeneration.
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