Integrated endotoxin-adsorption and antibacterial properties of platelet-membrane-coated copper silicate hollow microspheres for wound healing

Abstract

Serious infection caused by drug-resistant gram-negative bacteria and their secreted toxins (e.g., lipopolysaccharide) is a serious threat to human health. Thus, treatment strategies that efficiently kill bacteria and reducing the impact of their toxins simultaneously are urgently required. Herein, a novel antibacterial platform composed of a mesoporous copper silicate microsphere (CSO) core and a platelet membrane (PM) shell was prepared (CSO@PM). CSO@PM specifically targets bacteria owing to formyl peptide receptors on the PM and, combined with photothermal therapy (PTT), exhibits highly effective bacter icidal activity. Importantly, CSO@PM can adsorb lipopolysaccharide secreted by gram-negative bacteria, resulting in inflammation reduction. Thus, CSO@PM stimulates re-epithelialization and granulation-tissue formation, promoting wound healing. Moreover, this antibacterial platform exhibits no obvious toxicity at all the test concentrations in vitro and in vivo. Thus, CSO@PM exhibits a robust antibacterial effect and a strong toxin-adsorption capacity, facilitating the clinical treatment of many bacterial infections and the development of next-generation antibacterial nanoagents. Graphical Abstract

Nitric oxide-propelled nanomotors for bacterial biofilm elimination and endotoxin removal to treat infected burn wounds

“…LPS activation of RAW264.7 macrophages through toll-like receptor 4 triggered a series of signaling pathways to produce ROS, which are critical contributors in the pathogenesis of impaired wound healing. 18 Elevated ROS levels may affect cell proliferation and lead to apoptosis through oxidative damage of DNA, proteins and cell membrane. 50 LPS-induced ROS generation inside macrophages after different treatments was monitored using DCFH-DA as the ROS indicator, which can be quickly oxidized and converted to dichlorofluorescein that exhibits green fluorescence.…”

“…Recently, Peng et al fabricated mesoporous copper silicate microspheres with coated platelet membranes; the photothermal effect of the microsphere cores exhibited bactericidal activity and the platelet membrane shells adsorbed LPS to reduce wound inflammation. 18 However, no attempt has been made to remove the adsorbed LPS from the infected site, which should benefit the rapid healing of burn wounds.…”

Recent trends in platelet membrane-cloaked nanoparticles for application of inflammatory diseases

“…Phospholipids, the primary components of PM, can be used to adsorb toxins, meanwhile the unique surface properties of platelets can be activated to express the key mediators of inflammation (Boulaftali et al, 2013 ). Given the functional diversity of platelets and their close relationships with inflammation and bacterial infection, Peng et al ( 2021 ) prepared a novel antimicrobial platform (CSO@PM) with mesoporous copper silicate microsphere (CSO) as the core and PM as the shell ( Figure 7 ). Compared with exposed CSO, CSO@PM has a well-organized nuclear–shell structure.…”

“… Schematic showing the preparation of CSO@PM NPs and the treatment of wounds infected with multi-drug-resistant Gram-negative bacteria. CSO@PM NPs specifically target bacteria, adsorbing their LPS and, in combination with NIR laser irradiation, effectively kill them, reducing inflammatory reactions and ultimately promoting wound healing (Peng et al, 2021 ). Copyright 2021, The Author(s).…”

Mesoporous silica-coated silver nanoparticles as ciprofloxacin/siRNA carriers for accelerated infected wound healing

“…With the emergence of nanotechnology, nanoparticles (NPs) are considered as promising alternatives to traditional antibiotics, owing to their bactericidal activity, excellent biocompatibility, and broad-spectrum antibacterial properties [7][8][9][10]. Among them, silver (Ag) NPs have attracted great attention due to their strong and extensive antibacterial activity [11].…”