Anti-bacterial surface protection for prostheses

• Main Author: Freire, João Pacheco Afonso
• Publication Date: 2022
• Format: Master thesis
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10362/143770
• topic: Biofilms; Cellulose acetate; Electrospinning; Drug release; Metallic substrates; Polymeric substrates; Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia

This work aimed to study the application of multifunctional polymeric coatings on metallic and polymeric surfaces, study the drug incorporation and evaluate its release to prevent the formation of biofilms and the rejection of medical implants. This is particularly important considering that infections are one of the main reasons for prosthe-sis failure and that about 50% of primary implants are replaced or removed with consequent injury to patients and economic costs. Thus, there is a huge demand for improved short- and long-term durability of implants. Cellulose acetate was the material chosen due to its biocompatibility and its ability to retain drugs. Using the electrospinning technique, the surfaces were coated with membranes formed by fibres. These retain the mechanical properties of cellulose acetate and facilitate drug release due to its porous structure. This allows the release of large amounts of drugs, in specific places and in a controlled way. Thus, increasing the effectiveness of drugs and decreasing the chances of an implant being rejected. Work carried out includes mechanical testing of membranes and membrane adhesion to surfaces, drug release tests, and membrane swelling and degradation tests to simulate in vivo performance. Tita-nium and stainless-steel used in implants and flexible polymers (thermoplastic polyurethane) were the substrates studied, which had different surface treatments to improve adhesion of the deposited mem-branes. The adhesion of cellulose acetate fibre membranes to metallic substrates was very good, but it will be necessary to improve adhesion to polymeric substrates. The incorporation of drug in the fibres was successful, but the control of its release must be implemented in future studies.