Paula Giraldo: Reducing infection risks by modifying titanium implants
Infections at orthopaedic implants pose a significant challenge. Paula Milena Giraldo Osorno, a doctoral student at the Department of Biomaterials, University of Gothenburg, is investigating how altering the surface of titanium-based implants can decrease infection risks and improve patient outcomes.
PAULA GIRALDO OSORNO
Dissertation defense: 6 September 2024 (click for details)
Doctoral thesis: On targeting host-pathogen interaction to prevent biomaterial-associated infections on titanium implants
Research area: Biomaterials
Sahlgrenska Academy, The Institute of Clinical Sciences
Throughout history, replacing human limbs to restore lost function – whether due to illness or trauma – has been fundamental for humanity. Orthopaedic implants marked a major advancement in this area.
Today, orthopaedic implants do more than just replace limbs. They repair lost function, restore mobility, and even promote tissue regeneration. Although the success rates for orthopaedic implants are high, with many patients experiencing reduced pain and regained mobility, biomaterial-associated infections remain a persistent issue.
“When an implant fails, the consequences for the patient can be severe. Therefore, developing implants that either prevent infection or improve the body’s immune response is crucial,” says Paula Milena Giraldo Osorno, a doctoral student at the University of Gothenburg.
She works in the Department of Biomaterials at the Institute of Clinical Sciences, as part of the Marie-Curie BIOREMIA European Training Network. Her research focuses on how modifying titanium-based biomaterials can help prevent infections by studying how these materials interact with the immune system.
Enhancing immune responses
What is the focus of your doctoral thesis?
“This research investigates how therapeutic compounds and surface modifications to titanium implants can enhance immune responses and prevent biomaterial-associated infections. We focus on interactions between macrophages, bacteria, and biomaterials to find effective solutions,” explains Paula Giraldo, adding:
“By modifying implant surfaces, we aim to enhance the immune response and fight bacteria like Staphylococcus aureus and Pseudomonas aeruginosa. Our studies evaluate how these surface changes affect bacterial colonization, and immune responses, specifically macrophage behavior, ultimately seeking to improve implant success and patient outcomes.”
Findings and patient benefits
Paula Giraldo highlights the most significant findings from her research and their practical implications:
- When macrophages and Staphylococcus aureus compete for initial colonization of a titanium-based biomaterial, the timing of their arrival to the surface affected the outcome more than the specific material properties under evaluation.
- A molecule related to aspirin, sodium salicylate, disrupted the communication system of Pseudomonas aeruginosa, making it less pathogenic and enhancing the immune response.
- Copper-coated titanium exhibited strong bactericidal properties against Staphylococcus aureus and an initial but transient cytotoxicity towards macrophages.
- Macrophages stimulated by virulence factors from Staphylococcus aureus are polarized towards a proinflammatory phenotype and negatively affect bone health via communication with osteocytes.
“We have gained important knowledge on the cellular and molecular interactions between macrophages and bacteria at biomaterial surfaces. The developed models and methodological platforms will be important for the evaluation of future antimicrobial medical devices,” says Paula Giraldo, continuing:
“The antimicrobial strategies evaluated in this thesis showed potential for the control of biomaterial-associated infections.”
Text: Jakob Lundberg
