Implant-associated Staphylococcus aureus(S.aureus)osteomyelitis is a severe challenge in orthopedics.While antibiotic-loaded bone cement is a standardized therapeutic approach for S.aureus osteomyelitis,it falls short...Implant-associated Staphylococcus aureus(S.aureus)osteomyelitis is a severe challenge in orthopedics.While antibiotic-loaded bone cement is a standardized therapeutic approach for S.aureus osteomyelitis,it falls short in eradicating Staphylococcus abscess communities(SACs)and bacteria within osteocyte-lacuna canalicular network(OLCN)and repairing bone defects.To address limitations,we developed a borosilicate bioactive glass(BSG)combined with ferroferric oxide(Fe_(3)O_(4))magnetic scaffold to enhance antibacterial efficacy and bone repair capabilities.We conducted comprehensive assessments of the osteoinductive,immunomodulatory,antibacterial properties,and thermal response of this scaffold,with or without an alternating magnetic field(AMF).Utilizing a well-established implant-related S.aureus tibial infection rabbit model,we evaluated its antibacterial performance in vivo.RNA transcriptome sequencing demonstrated that BSG+5%Fe_(3)O_(4)enhanced the immune response to bacteria and promoted osteogenic differentiation and mineralization of MSCs.Notably,BSG+5%Fe_(3)O_(4)upregulated gene expression of NOD-like receptor and TNF pathway in MSCs,alongside increased the expression of osteogenic factors(RUNX2,ALP and OCN)in vitro.Flow cytometry on macrophage exhibited a polarization effect towards M2,accompanied by upregulation of anti-inflammatory genes(TGF-β1 and IL-1Ra)and downregulation of pro-inflammatory genes(IL-6 and IL-1β)among macrophages.In vivo CT imaging revealed the absence of osteolysis and periosteal response in rabbits treated with BSG+5%Fe_(3)O_(4)+AMF at 42 days.Histological analysis indicated complete controls of SACs and bacteria within OLCN by day 42,along with new bone formation,signifying effective control of S.aureus osteomyelitis.Further investigations will focus on the in vivo biosafety and biological mechanism of this scaffold within infectious microenvironment.展开更多
基金support from National Key R&D Program of China(2023YFC2416900and 2021YFC2400500)The International Postdoctoral Exchange Fellowship Program of Chongqing(2021JLPY004)+4 种基金The Fellowship of China Postdoctoral Science Foundation(2021M693758)National Natural Science Foundation of China(U22A20357,52072398and 32161160327)Natural Science Foundation Postdoctoral Science Foundation Project of Chongqing(cstc2021jcyj-bsh0019)Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0134)Shenzhen Science and Technology Program(JCYJ20230807140714030)。
文摘Implant-associated Staphylococcus aureus(S.aureus)osteomyelitis is a severe challenge in orthopedics.While antibiotic-loaded bone cement is a standardized therapeutic approach for S.aureus osteomyelitis,it falls short in eradicating Staphylococcus abscess communities(SACs)and bacteria within osteocyte-lacuna canalicular network(OLCN)and repairing bone defects.To address limitations,we developed a borosilicate bioactive glass(BSG)combined with ferroferric oxide(Fe_(3)O_(4))magnetic scaffold to enhance antibacterial efficacy and bone repair capabilities.We conducted comprehensive assessments of the osteoinductive,immunomodulatory,antibacterial properties,and thermal response of this scaffold,with or without an alternating magnetic field(AMF).Utilizing a well-established implant-related S.aureus tibial infection rabbit model,we evaluated its antibacterial performance in vivo.RNA transcriptome sequencing demonstrated that BSG+5%Fe_(3)O_(4)enhanced the immune response to bacteria and promoted osteogenic differentiation and mineralization of MSCs.Notably,BSG+5%Fe_(3)O_(4)upregulated gene expression of NOD-like receptor and TNF pathway in MSCs,alongside increased the expression of osteogenic factors(RUNX2,ALP and OCN)in vitro.Flow cytometry on macrophage exhibited a polarization effect towards M2,accompanied by upregulation of anti-inflammatory genes(TGF-β1 and IL-1Ra)and downregulation of pro-inflammatory genes(IL-6 and IL-1β)among macrophages.In vivo CT imaging revealed the absence of osteolysis and periosteal response in rabbits treated with BSG+5%Fe_(3)O_(4)+AMF at 42 days.Histological analysis indicated complete controls of SACs and bacteria within OLCN by day 42,along with new bone formation,signifying effective control of S.aureus osteomyelitis.Further investigations will focus on the in vivo biosafety and biological mechanism of this scaffold within infectious microenvironment.
