| Summary: |
Bone tissue infections, namely osteomyelitis, osteitis, spondylodiscitis, septic arthritis and prosthetic joint infections (PJI), still represent the worst complications of orthopaedic surgery and traumatology. Infection at the site of implantation of a prosthesis or implant biomaterial remains a major complication hindering the long-term use of implanted materials. It is known that the presence of a foreign body greatly decreases the number of microorganisms required to establish an infection. The sources of bacteria that cause the vast majority of implant-associated infections include perioperative contamination, exit site contamination for percutaneous devices and hematogenous spread out from locations distal to the implant area[1, 2]. The most promising anti-infective strategies for PJI seek to inhibit bacterial adhesion prior to biofilm formation. Reducing bacterial adhesion during the initial 6 h period following implantation is particularly relevant to avoid the occurrence of device-associated infection[2].
This project aims at understanding the mechanisms of bone tissue infection associated with biomaterials, by studying the mechanisms of bacterial adhesion and consequent formation of biofilm, and to develop new antibacterial surfaces based on nanohydroxyapatite for bone implants that should minimize biofilm accumulation and subsequent infection leading to implants failure. These surfaces may incorporate antibacterial agents such as quorum sensing inhibitors, polysaccharides, proteins or titania in order to prevent multispecies biofilm accumulation.
Nanohydroxyapatite antibacterial surfaces for bone implants will be produced at Instituto de Engenharia Biomédica (INEB). They will be characterized in terms of topography, hydrophobicity, surface composition and release profile of antibacterial agents.
Bacterial strains from prosthetic joint infections will be collected from infected prostheses and implants, properly isolated and identified. These strains  |
Summary
Bone tissue infections, namely osteomyelitis, osteitis, spondylodiscitis, septic arthritis and prosthetic joint infections (PJI), still represent the worst complications of orthopaedic surgery and traumatology. Infection at the site of implantation of a prosthesis or implant biomaterial remains a major complication hindering the long-term use of implanted materials. It is known that the presence of a foreign body greatly decreases the number of microorganisms required to establish an infection. The sources of bacteria that cause the vast majority of implant-associated infections include perioperative contamination, exit site contamination for percutaneous devices and hematogenous spread out from locations distal to the implant area[1, 2]. The most promising anti-infective strategies for PJI seek to inhibit bacterial adhesion prior to biofilm formation. Reducing bacterial adhesion during the initial 6 h period following implantation is particularly relevant to avoid the occurrence of device-associated infection[2].
This project aims at understanding the mechanisms of bone tissue infection associated with biomaterials, by studying the mechanisms of bacterial adhesion and consequent formation of biofilm, and to develop new antibacterial surfaces based on nanohydroxyapatite for bone implants that should minimize biofilm accumulation and subsequent infection leading to implants failure. These surfaces may incorporate antibacterial agents such as quorum sensing inhibitors, polysaccharides, proteins or titania in order to prevent multispecies biofilm accumulation.
Nanohydroxyapatite antibacterial surfaces for bone implants will be produced at Instituto de Engenharia Biomédica (INEB). They will be characterized in terms of topography, hydrophobicity, surface composition and release profile of antibacterial agents.
Bacterial strains from prosthetic joint infections will be collected from infected prostheses and implants, properly isolated and identified. These strains will be used to study mechanisms of bacterial adhesion and formation of mono and multispecies biofilms on the above mentioned surfaces. These biofilms will be formed in flow reactors under conditions mimicking those observed near bone implants, namely low flow rates, low oxygen level, presence of proteins, darkness and body temperature. |