Antibacterial Surfaces for Biomedical Applications
Doctoral thesis, 2020
Medical devices such as orthopedic implants are intended to serve for improved quality of life. However, clinical success cannot be taken for granted and the most common reason for failure is due to biomaterials associated infection (BAI). An implantation surgical site is a susceptible environment for bacterial colonization, which in combination with compromised immune system, results in that bacteria can develop biofilms on the implant surface or in adjacent tissue. Once such a biofilm has established, it may lead to an infection that cannot be eradicated by means of traditional antibiotics, often resulting in revision surgery. Wounds after post implantation surgery is another risk for bacterial colonization into underlying tissue and increases further the susceptibility to infection. These and other bacteria related complications are today becoming more serious due to the rapid increase of antibiotic resistance worldwide. This has resulted in that many available antibiotics are losing their potency against bacteria and consequently, treating an infection with antibiotics is not working as effectively as in the past.
The objective of this thesis was to find new solutions to address the complications associated with bacterial colonization through applying preventive measures by designing antibacterial surfaces for inhibition of early biomaterials associated and wound infection. For this purpose, two types of antibacterial surfaces were designed and evaluated. In the first type, a local drug-delivery system based on mesoporous Titania thin films were developed. These films were to serve as implant coatings where antibiotics are released locally at the implantation site to prevent biofilm formation and subsequent tissue colonization. In the second approach, antibacterial surfaces were developed through covalent immobilization of a cationic antimicrobial peptide (AMP), thus creating surfaces that kill bacteria upon contact.
The overall results in this thesis, which are presented as four papers, suggest that the developed antibacterial surfaces are promising to use in future biomedical applications.
contact killing surfaces