Cellulose fibers-reinforced self-expanding porous composite with multiple hemostatic efficacy and shape adaptability for uncontrollable massive hemorrhage treatment

Uncontrollable hemorrhage leads to high mortality and thus effective bleeding control becomes increasingly important in the military field and civilian trauma arena.However,current hemostats not only present limitation when treating major bleeding,but also have various side effects.Here we report a self-expanding porous composites(CMCP)based on novel carboxymethyl cellulose(CMC)fibers and acetalized polyvinyl alcohol(PVA)for lethal hemorrhage control.The CMC fibers with uniform fibrous structure,high liquid absorption and procoagulant ability,are evenly interspersed inside the composite matrix.The obtained composites possess unique fiber-porous network,excellent absorption capacity,fast liquid-triggered self-expanding ability and robust fatigue resistance,and their physicochemical performance can be fine-tuned through varying the CMC content.In vitro tests show that the porous composite exhibits strong blood clotting ability,high adhesion to blood cells and protein,and the ability to activate platelet and the coagulation system.In vivo hemostatic evaluation further confirms that the CMCP presents high hemostatic efficacy and multiple hemostatic effects in swine femoral artery major hemorrhage model.Additionally,the CMCP will not fall off from the injury site,and is also easy to surgically remove from the wound cavity after the hemostasis.Importantly,results of CT tomography and 3D reconstruction indicate that CMCP can achieve shape adaptation to the surrounding tissues and the wound cavities with different depths and shapes,to accelerate hemostasis while protecting wound tissue and preventing infection.

A novel bioactive polyurethane with controlled degradation and L-Arg release used as strong adhesive tissue patch for hemostasis and promoting wound healing

Effective strategy of hemostasis and promoting angiogenesis are becoming increasingly urgent in modern medicine due to millions of deaths caused by tissue damage and inflammation. The tissue adhesive has been favored as an optimistic and efficient path to stop bleeding, while, current adhesive presents limitations on wound care or potential degradation safety in clinical practice. Therefore, it is of great clinical significance to construct multifunctional wound adhesive to address the issues. Based on pro-angiogenic property of L-Arginine (L-Arg), in this study, the novel tissue adhesive (G-DLPUs) constructed by L-Arg-based degradable polyurethane (DLPU) and GelMA were prepared for wound care. After systematic characterization, we found that the G-DLPUs were endowed with excellent capability in shape-adaptive adhesion. Moreover, the L-Arg released and the generation of NO during degradation were verified which would enhance wound healing. Following the in vivo biocompatibility was verified, the hemostatic effect of the damaged organ was tested using a rat liver hemor-rhage model, from which reveals that the G-DLPUs can reduce liver bleeding by nearly 75% and no obvious inflammatory cells observed around the tissue. Moreover, the wound care effect was confirmed in a mouse full-thickness skin defect model, showing that the hydrogel adhesive significantly improves the thickness of newly formed dermis and enhance vascularization (CD31 staining). In summary, the G-DLPUs are promising candidate to act as multifunctional wound care adhesive for both damaged organ and trauma.

Polylysine-decorated macroporous microcarriers laden with adipose-derived stem cells promote nerve regeneration in vivo

Cell transplantation is an effective strategy to improve the repair effect of nerve guide conduits(NGCs).However,problems such as low loading efficiency and cell anoikis undermine the outcomes.Microcarriers are efficient 3D cell culture scaffolds,which can also prevent cell anoikis by providing substrate for adhesion during transplantation.Here,we demonstrate for the first time microcarrier-based cell transplantation in peripheral nerve repair.We first prepared macroporous chitosan microcarriers(CSMCs)by the emulsion-phase separation method,and then decorated the CSMCs with polylysine(pl-CSMCs)to improve cell affinity.We then loaded the pl-CSMCs with adipose-derived stem cells(ADSCs)and injected them into electrospun polycaprolactone/chitosan NGCs to repair rat sciatic nerve defects.The ADSCs-laden pl-CSMCs effectively improved nerve regeneration as demonstrated by evaluation of histology,motor function recovery,electrophysiology,and gastrocnemius recovery.With efficient cell transplantation,convenient operation,and the multiple merits of ADSCs,the ADSCs-laden pl-CSMCs hold good potential in peripheral nerve repair.

Design and characterization of plasticized bacterial cellulose/waterborne polyurethane composite with antibacterial function for nasal stenting

A nasal stent capable of preventing adhesions and inflammation is of great value in treating nasal diseases.In order to solve the problems of tissue adhesion and inflammation response,we prepared plasticized bacterial cellulose(BCG)and waterborne polyurethane(WPU)composite with antibacterial function used as a novel nasal stent.The gelation behavior of BCG could contribute to protecting the paranasal sinus mucosa;meanwhile,the WPU with improved mechanical property was aimed at supporting the narrow nasal cavity.The thickness,size and the supporting force of the nasal stent could be adjusted according to the specific conditions of the nasal.Thermogravimetric analysis,contact angle and water absorption test were applied to investigate the thermal,hydrophilic and water absorption properties of the composite materials.The composite materials loaded with poly(hexamethylene biguanide)hydrochloride maintained well antibacterial activity over 12days.Animal experiments further revealed that the mucosal epithelium mucosae damage of BCG-WPU composite was minor compared with that of WPU.This new type of drug-loaded nasal stent can effectively address the postoperative adhesions and infections while ensuring the health of nasal mucosal,and thus has an immense clinical application prospects in treating nasal diseases.