Antithrombosis
therapy is confronted with short half-lives of thrombolytic
agents, limited therapeutic effects, and bleeding complications. Drug
delivery systems of thrombolytic agents face challenges in effective
penetration into thrombi, which are characterized by well-organized
fibrin filled with abundant activated platelets. Herein, Janus rod
(JR)-shaped micromotors are constructed by side-by-side electrospinning
and cryosection, possessing advantages in controlling the Janus structure
and aspect ratio of microrods. Silicon phthalocyanine (Pc) and CaO2 nanoparticles (NPs) are loaded into the separate sides of
JRs, and Arg-Gly-Asp (RGD) peptides are grafted on the surface to
obtain Pc/Ca@r-JRs for the sonodynamic therapy (SDT) of thrombosis
without using any thrombolytic agents. Decomposition of CaO2 NPs ejects O2 bubbles from one side of JRs, and ultrasonication
of O2 bubbles produces the cavitation effect, both generating
mechanical force to drive the thrombus penetration. The integration
of ultrasonication-propelled motion and RGD mediation effectively
increases the targeting capabilities of r-JRs to activated platelets.
In addition to mechanical thrombolysis, ultrasonication of the released
Pc produces 1O2 to destruct fibrin networks
of clots. In vitro thrombolysis of whole blood clots shows that ultrasonication
of Pc/Ca@r-JRs has a significantly higher thrombolysis rate (73.6%)
than those without propelled motion or RGD-mediated clot targeting.
In a lower limb thrombosis model, intravenous administration of Pc/Ca@r-JRs
indicates 3.4-fold higher accumulations at the clot site than those
of JRs, and ultrasonication-propelled motion further increases thrombus
retention 2.1 times. Treatment with Pc/Ca@r-JRs and ultrasonication
fully removes thrombi and significantly prolongs tail bleeding time.
Thus, this study has achieved precise and prompt thrombolysis through
selective targeting to clots, efficient penetration into dense networks
of thrombi, and SDT-executed thrombolysis.
Cancer chemotherapy remains challenging to pass through various biological and pathological barriers from blood circulation, tumor infiltration and cellular uptake before intracellular release of antineoplastic agents. Herein, icebreaker-inspired Janus nanomotors...
Antibacterial wound dressings are confronted with the challenges in real-time imaging of infected wounds and effective removal of bacterial debris after sterilization to promote the healing process. Herein, injectable theranostic hydrogels were constructed from antimicrobial peptide ε-polylysine (ePL) and polydopamine (PDA) nanoparticles for real-time diagnosis of infected wounds, imaging-guided antibacterial photodynamic therapy (PDT), and on-demand removal of bacterial debris. Ureido-pyrimidinone was conjugated on ePL to produce PLU hydrogels through quadruple hydrogen bonding, and the inoculation of tetrakis(4-carboxyphenyl)porphyrin (TCPP)-loaded PDA (PTc) nanoparticles introduced Schiff base linkages in PLU@PTc hydrogels. The double-cross-linked networks enhance mechanical performance, adhesion strength, and self-healing properties of hydrogels, and the dynamic cross-linking enables their photothermal removal. The injection of PLU precursors and PTc NPs generates in situ sol−gel transformation, and the acid-triggered release of TCPP restores fluorescence emissions for real-time imaging of infected wounds under 410 nm illumination. Then, the released TCPP in the infected wounds is illuminated at 660 nm to launch a precise antibacterial PDT, which is strengthened by the bacterial capture on hydrogels. Hydrogels with wrapped bacterial debris are removed under illumination at 808 nm, and the hydrogel dressing change accelerates healing of infected wounds through simultaneous relief of oxidative stress, regulation of inflammatory factors, acceleration of collagen deposition, and promotion of angiogenesis. Thus, this study demonstrates a feasible strategy for wound infection theranostics through bacterial infection-triggered visual imaging, efficient nonantibiotic sterilization, and on-demand dressing change and bacterial debris removal.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.