Though acknowledged as the essential material in bone bleeding control with advantages of low cost, excellent malleability and smooth consistency for operation, traditional bone wax is associated with adverse effects such as foreign body reaction, granuloma growth, and bone healing failure. Herein, we presented a novel ready-to-use bone wax (NBW) based on DCPA (CaHPO 4 ) granules (DCPA-G) and modified waxy starch (MWS), proposed to overcome problems of bone wax but preserving its impressive workability in hemorrhage control. Thanks to rheological and adhesive properties of MWS after exposure to water, NBW was found to be cohesive, malleable, water content dependent tissue adhesive and liquid sealing abilities. Moreover, after hardening under humid environment due to the interaction between MWS and DCPA-G, NBW exhibited compressive strength that is comparable to that of cancellous bone. After smeared to defect model, water leakage was avoided by NBW. Besides, this material showed superior hemostasis and osteogenesis ability over traditional bone wax in vitro . Simultaneously, in vivo tests confirmed the efficiency of NBW in bleeding control and bone regeneration, indicating it a promising candidate in bleeding bone treatment.
Da-Yuan Wang,Guang Yang,Xiao-Xiao Zhang,Henny C. van der Mei,Yijin Ren,Henk J. Busscher,Linqi Shi
Exposure of infectious biofilms to dispersants induces high bacterial concentrations in blood that may cause sepsis. Preventing sepsis requires simultaneous biofilm dispersal and bacterial killing. Here, self-targeting DCPA(2-(4-((1,5-bis(octadecenoyl)1,5-dioxopentan-2-yl)carbamoyl)pyridin-1-ium-1-yl)acetate) liposomes with complexed water were self-assembled with ciprofloxacin loaded in-membrane and PEGylated as a lipid-membrane component, together with bromelain loaded in-core. Inside biofilms, DCPA-H 2 O and PEGylated ciprofloxacin became protonated, disturbing the balance in the lipid-membrane to cause liposome-burst and simultaneous release of bromelain and ciprofloxacin. Simultaneous release of bromelain and ciprofloxacin enhanced bacterial killing in Staphylococcus aureus biofilms as compared with free bromelain and/or ciprofloxacin. After tail-vein injection in mice, liposomes accumulated inside intra-abdominal staphylococcal biofilms. Subsequent liposome-burst and simultaneous release of bromelain and ciprofloxacin yielded degradation of the biofilm matrix by bromelain and higher bacterial killing without inducing septic symptoms as obtained by injection of free bromelain and ciprofloxacin. This shows the advantage of simultaneous release from liposomes of bromelain and ciprofloxacin inside a biofilm.