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Title:Multifunkcionalna prevleka za preprečevanje biofilma za medicinske pripomočke : doctoral disertation
Authors:ID Ajdnik, Urban (Author)
ID Fras Zemljič, Lidija (Mentor) More about this mentor... New window
ID Finšgar, Matjaž (Mentor) More about this mentor... New window
Files:.pdf DOK_Ajdnik_Urban_2021.pdf (7,54 MB)
MD5: 6B314195D1AD26975245AC3E661D3E32
PID: 20.500.12556/dkum/c01c39aa-8f20-4f4f-955d-75c87d647bc9
 
Language:English
Work type:Doctoral dissertation
Typology:2.08 - Doctoral Dissertation
Organization:FS - Faculty of Mechanical Engineering
Abstract:Doktorska disertacija obravnava razvoj in uporabo multifunkcionalnih prevlek na medicinskih pripomočkih za preprečevanje tvorbe biofilma. Okužbe, povezane s tvorbo biofilma na implantacijskih medicinskih pripomočkih, so najpogostejše zdravstveno-negovalne težave, ki skupaj z mikrobno rezistenco predstavljajo tako zdravstveni, socialni kot ekonomski problem. Pri pripravi multifunkcionalne prevleke so uporabljene (bio)osnovane snovi, kot so hialuronska kislina, površinsko aktivna snov na osnovi lizina (77KS) in hitozan (Chi), derivat hitina, ki je drugi najpogostejši polisaharid v naravi takoj za celulozo. Splošno je znano, da lahko z združevanjem biopolimerov in površinsko aktivnih snovi ustvarimo razne strukture, kot so micelarni agregati, polielektrolitski kompleksi, oborine in geli, ki igrajo pomembno vlogo na področjih prehrambne industrije, kozmetike in farmacije, kjer so uporabljeni kot sistemi za dostavo učinkovin in izdelavo prevlek medicinskih pripomočkov.
Keywords:silikon, polisaharidi, hitozan, površinsko aktivna snov, biofilm, medicinski pripomočki
Place of publishing:Maribor
Place of performance:Maribor
Publisher:[U. Ajdnik]
Year of publishing:2021
Number of pages:XXVIII, 156 str.
PID:20.500.12556/DKUM-78269 New window
UDC:[544.722.2:577.1]:615(043.3)
COBISS.SI-ID:61836803 New window
NUK URN:URN:SI:UM:DK:IQBDZORH
Publication date in DKUM:04.05.2021
Views:1382
Downloads:150
Metadata:XML DC-XML DC-RDF
Categories:KTFMB - FS
:
AJDNIK, Urban, 2021, Multifunkcionalna prevleka za preprečevanje biofilma za medicinske pripomočke : doctoral disertation [online]. Doctoral dissertation. Maribor : U. Ajdnik. [Accessed 29 April 2025]. Retrieved from: https://dk.um.si/IzpisGradiva.php?lang=eng&id=78269
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Licences

License:CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Link:http://creativecommons.org/licenses/by-nc-nd/4.0/
Description:The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
Licensing start date:29.11.2020

Secondary language

Language:Slovenian
Title:Anti-Biofilm multifunctional coating for medical devices
Abstract:The aim of this Doctoral Dissertation was to develop an anti-biofilm multifunctional coating of the next generation for medical devices, and to gain understanding of the solid/liquid interactions between the components of the polyelectrolyte-surfactant complex (chitosan, lysine-based surfactant) as a colloidal formulation (coating) and solid surface of PDMS, with subsequent study of the detailed surface characteristics of this kind of functionalised materials and further examination of the bioactive properties of the coatings: i) Protein interactions, ii) Microbiology testing and iii) Biocompatibility assays. The interactions between positively charged biopolymer chitosan and an anionic surfactant derived from lysine (77KS) were studied with turbidity and surface tension measurements, ζ-potential and Dynamic Light Scattering. Chitosan and 77KS form complexes which reverse their charge at higher 77KS concentration, forming larger aggregates that were loaded with drugs (amoxicillin, AMOX). A QCM-D study showed irreversible adsorption of the coatings on a model silicone (polydimethylsiloxane; PDMS) surface, even after the rinsing step, while their presence and homogeneity were confirmed via surface analyses using XPS and ToF-SIMS. The effect was also examined of the ionic strength and of the ultraviolet/ozone (UVO) activation of the PDMS films on the adsorption behaviour of the formulations. An important part of this study was devoted to understanding the underlying adsorption phenomena and identifying the mechanisms associated with biofouling. The adsorption of a number of proteins was investigated, together with their mixture on PDMS surfaces. Different proteins with different physicochemical properties were tested (bovine serum albumin, fibrinogen, gamma globulin and their mixture). Adsorption experiments were performed with a quartz crystal microbalance. The adsorption properties of the test proteins were investigated. Moreover, adsorption of proteins was also followed through ζ-potential measurements, with comparison of the results of both techniques. IX The additional layer of anionic and hydrophilic hyaluronic acid as an inner layer improved protein-repelling behaviour, due to the formation of a highly hydrated layer in combination with steric hindrance. The last part of the Doctoral Dissertation deals with the preliminary assessment of real applications. For this purpose, real samples were used, i.e. materials, which are among the most commonly used as medical devices, namely, PDMS and medical stainless steel AISI 316LVM in the form of discs. The biocompatibility using mouse fibroblasts L929 and antimicrobial activity against Escherichia coli and Staphylococcus aureus were studied using PDMS and AISI 316LVM medical grade stainless steel as real materials with applied coatings, to show the applicability of the developed coatings on real, not only model surfaces. Bioactive coatings on biomaterial surfaces were confirmed by ATR-FTIR and with a change in the water contact angle. Although coatings provide antibiofilm properties in all cases, coating PDMS/Chi-77KS/HA lowered the presence of bacteria by 85% in the case of Escherichia coli, while PDMS/Chi-77KS/AMOX improved the antibiofilm behaviour by 81%. To conclude, all coatings are biocompatible, based on the criteria of ISO 10993-5 under the applied conditions.
Keywords:silicone, polysaccharides, chitosan, surfactant, biofilm, medical devices


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