Erythrocyte membrane-camouflaged nanoworms with on-demand antibiotic release for eradicating biofilms using near-infrared irradiation

The increase in the number of resistant bacteria caused by the abuse of antibiotics and the emergence of biofilms significantly reduce the effectiveness of antibiotics.Bacterial infections are detrimental to our life and health.To reduce the abuse of antibiotics and treat biofilm-related bacterial infections,a biomimetic nano-antibacterial system,RBCM-NW-G namely,that controls the release of antibiotics through near infrared was prepared.The hollow porous structure and the high surface activity of nanoworms are used to realize antibiotic loading,and then,biomimetics are applied with red blood cell membranes(RBCM).RBCM-NW-G,which retains the performance of RBCM,shows enhanced permeability and retention effects.Fluorescence imaging in mice showed the effective accumulation of RBCM-NW-G at the site of infection.In addition,the biomimetic nanoparticles showed a longer blood circulation time and good biocompatibility.Anti-biofilm test results showed damage to biofilms due to a photothermal effect and a highly efficient antibacterial performance under the synergy of the photothermal effect,silver iron,and antibiotics.Finally,by constructing a mouse infection model,the great potential of RBCM-NW-G in the treatment of in vivo infections was confirmed.

Microcluster colloidosomes for hemostat delivery into complex wounds:A platform inspired by the attack action of torpedoes

Complex yet lethal wounds with uncontrollable bleeding hinder conventional hemostats from clotting blood at the source or deep sites of injury vasculature,thereby causing massive blood loss and significantly increased mortality.Inspired by the attack action of torpedoes,we synthesized microcluster(MC)colloidosomes equipped with magnetic-mediated navigation and“blast”systems to deliver hemostats into the cavity of vase-type wounds.CaCO_(3)/Fe_(2)O_(3)(CF)microparticles functionalized with Arg-Gly-Asp(RGD)modified polyelectrolyte multilayers were co-assembled with oppositely charged zwitterionic carbon dots(CDs)to form MC colloidosomes,which were loaded with thrombin and protonated tranexamic acid(TXA-NH_(3)^(+)).The composite microparticles moved against blood flow under magnetic mediation and simultaneously disassembled for the burst release of thrombin stimulated by TXA-NH_(3)^(+).The CO_(2) bubbles generated during disassembly produced a“blast”that propelled thrombin into the wound cavity.Severe bleeding in a vase-type hemorrhage model in the rabbit liver was rapidly controlled within~60 s.Furthermore,in vivo subcutaneous muscle and liver implantation models demonstrated excellent biodegradability of MC colloidosomes.This study is the first to propose a novel strategy based on the principle of torpedoes for transporting hemostats into vase-type wounds to achieve rapid hemostasis,creating a new paradigm for combating trauma treatment.

Magnetic field-mediated Janus particles with sustained driving capability for severe bleeding control in perforating and inflected wounds

Severe bleeding in perforating and inflected wounds with forky cavities or fine voids encountered during prehospital treatments and surgical procedures is a complex challenge.Therefore,we present a novel hemostatic strategy based on magnetic field-mediated guidance.The biphasic Janus magnetic particle(MSS@Fe2O3-T)comprised aggregates ofα-Fe2O3 nanoparticles(Fe_(2)O_(3) NPs)as the motion actuator,negatively modified microporous starch(MSS)as the base hemostatic substrate,and thrombin as the loaded hemostatic drug.Before application,the particles were first wrapped using NaHCO_(3) and then doped with protonated tranexamic acid(TXA-NH_(3)^(+)),which ensured their high self-dispersibility in liquids.During application,the particles promptly self-diffused in blood by bubble propulsion and travelled to deep bleeding sites against reverse rushing blood flow under magnetic guidance.In vivo tests confirmed the superior hemostatic performance of the particles in perforating and inflected wounds(“V”-shaped femoral artery and“J”-shaped liver bleeding models).The present strategy,for the first time,extends the range of magnetically guided drug carriers to address the challenges in the hemorrhage control of perforating and inflected wounds.

Dual-Driven Hemostats Featured with Puncturing Erythrocytes for Severe Bleeding in Complex Wounds

Achieving rapid hemostasis in complex and deep wounds with secluded hemorrhagic sites is still a challenge because of the difficulty in delivering hemostats to these sites.In this study,a Janus particle,SEC-Fe@CaT with dual-driven forces,bubble-driving,and magnetic field–(MF–)mediated driving,was prepared via in situ loading of Fe_(3)O_(4) on a sunflower sporopollenin exine capsule(SEC),and followed by growth of flower-shaped CaCO3 clusters.The bubble-driving forces enabled SEC-Fe@CaT to self-diffuse in the blood to eliminate agglomeration,and the MF-mediated driving force facilitated the SEC-Fe@CaT countercurrent against blood to access deep bleeding sites in the wounds.During the movement in blood flow,the meteor hammer-like SEC from SEC-Fe@CaT can puncture red blood cells(RBCs)to release procoagulants,thus promoting activation of platelet and rapid hemostasis.Animal tests suggested that SEC-Fe@CaT stopped bleeding in as short as 30 and 45 s in femoral artery and liver hemorrhage models,respectively.In contrast,the similar commercial product Celox™required approximately 70 s to stop the bleeding in both bleeding modes.This study demonstrates a new hemostat platform for rapid hemostasis in deep and complex wounds.It was the first attempt integrating geometric structure of sunflower pollen with dual-driven movement in hemostasis.

Bioinspired Hemostatic Strategy via Pulse Ejections for Severe Bleeding Wounds

Efficient hemostasis during emergency trauma with massive bleeding remains a critical challenge in prehospital settings.Thus,multiple hemostatic strategies are critical for treating large bleeding wounds.In this study,inspired by bombardier beetles to eject toxic spray for defense,a shape-memory aerogel with an aligned microchannel structure was proposed,employing thrombin-carrying microparticles loaded as a built-in engine to generate pulse ejections for enhanced drug permeation.Bioinspired aerogels,after contact with blood,can rapidly expand inside the wound,offering robust physical barrier blocking,sealing the bleeding wound,and generating a spontaneous local chemical reaction causing an explosivelike generation of CO_(2) microbubbles,which provide propulsion thrust to accelerate burst ejection from arrays of microchannels for deeper and faster drug diffusion.The ejection behavior,drug release kinetics,and permeation capacity were evaluated using a theoretical model and experimentally demonstrated.This novel aerogel showed remarkable hemostatic performance in severely bleeding wounds in a swine model and demonstrated good degradability and biocompatibility,displaying great potential for clinical application in humans.