Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of...Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of antibiotic resistance,there is an urgent demand to explore novel antibacterial strategies other than using antibiotics.Recently,using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention.However,the clinical application of biomimetic nano-pillar array is not satisfactory,mainly because its antibacterial ability against Gram-positive strain is not good enough.Thus,the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application.Here,we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO2 for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO2.Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO2 to combat against antibiotic-resistant implant-associated infections.First,to separately verify the topographical antibacterial activity of TiO2 periodic micro/nano-pillar array,we systematically investigated its effects on bacterial adhesion,growth,proliferation,and viability in the dark without involving the photocatalysis of TiO2.The pillar array with sub-micron motif size can significantly inhibit the adhesion,growth,and proliferation of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array.Moreover,the pillar array is not lethal to S.aureus and E.coli in 24 h.Then,the X-ray induced photocatalytic antibacterial property of TiO2 periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work.This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.展开更多
Eye blinking is closely related to human physiology and psychology.It is an effective method of communication among people and can be used in human-machine interactions.Existing blink monitoring methods include videoo...Eye blinking is closely related to human physiology and psychology.It is an effective method of communication among people and can be used in human-machine interactions.Existing blink monitoring methods include videooculography,electro-oculograms and infrared oculography.However,these methods suffer from uncomfortable use,safety risks,limited reliability in strong light or dark environments,and infringed informational security.In this paper,we propose an ultrasound-based portable approach for eye-blinking activity monitoring.Low-power pulse-echo ultrasound featuring biosafety is transmitted and received by microelectromechanical system(MEMS)ultrasonic transducers seamlessly integrated on glasses.The size,weight and power consumption of the transducers are 2.5 mm by 2.5 mm,23.3 mg and 71μW,respectively,which provides better portability than conventional methods using wearable devices.Eye-blinking activities were characterized by open and closed eye states and validated by experiments on dfferent volunteers.Finally,real-time eye-blinking monitoring was successfully demonstrated with a response time less than 1 ms.The proposed solution paves the way for ultrasound-based wearable eye-blinking monitoring and offers miniaturization,light weight,low power consumption,high informational security and biosafety.展开更多
基金supported by the Natural Science Foundation of Tianjin(General Program,No.18JCYBJC19500)the Independent Innovation Fund of Tianjin University(No.2019XZS-0014)the Research Grants Council of Hong Kong(No.HKUST615408).
文摘Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics.Given the global threat and increasing influence of antibiotic resistance,there is an urgent demand to explore novel antibacterial strategies other than using antibiotics.Recently,using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention.However,the clinical application of biomimetic nano-pillar array is not satisfactory,mainly because its antibacterial ability against Gram-positive strain is not good enough.Thus,the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application.Here,we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO2 for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO2.Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO2 to combat against antibiotic-resistant implant-associated infections.First,to separately verify the topographical antibacterial activity of TiO2 periodic micro/nano-pillar array,we systematically investigated its effects on bacterial adhesion,growth,proliferation,and viability in the dark without involving the photocatalysis of TiO2.The pillar array with sub-micron motif size can significantly inhibit the adhesion,growth,and proliferation of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array.Moreover,the pillar array is not lethal to S.aureus and E.coli in 24 h.Then,the X-ray induced photocatalytic antibacterial property of TiO2 periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work.This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.
基金the Natural Science Foundation of China(NSFC Grant No.62001322)the Tianjin Municipal Science and Technology Project(No.20JCQNJCo11200)+1 种基金the National Key Research and Development Program(No.2020YFB2008800)the Nanchang Institute for Microtechnology of Tianjin University for funding.
文摘Eye blinking is closely related to human physiology and psychology.It is an effective method of communication among people and can be used in human-machine interactions.Existing blink monitoring methods include videooculography,electro-oculograms and infrared oculography.However,these methods suffer from uncomfortable use,safety risks,limited reliability in strong light or dark environments,and infringed informational security.In this paper,we propose an ultrasound-based portable approach for eye-blinking activity monitoring.Low-power pulse-echo ultrasound featuring biosafety is transmitted and received by microelectromechanical system(MEMS)ultrasonic transducers seamlessly integrated on glasses.The size,weight and power consumption of the transducers are 2.5 mm by 2.5 mm,23.3 mg and 71μW,respectively,which provides better portability than conventional methods using wearable devices.Eye-blinking activities were characterized by open and closed eye states and validated by experiments on dfferent volunteers.Finally,real-time eye-blinking monitoring was successfully demonstrated with a response time less than 1 ms.The proposed solution paves the way for ultrasound-based wearable eye-blinking monitoring and offers miniaturization,light weight,low power consumption,high informational security and biosafety.
