SURFACE TREATMENT OF SILICONE MATERIAL

Silikon z kemijskim imenom poli(dimetilsiloksan) ali krajše PDMS je eden izmed pomembnih polimerov uporabnih v številnih industrijskih panogah. Zelo pomemben je na področju medicine, kjer se največkrat uporablja za proizvodnjo različnih implantatov, saj izkazuje dobre kemijske in strukturne lastnosti. Kot implantat je široko uporabljen za proizvodnjo katetrov. Žal je še vedno cca. 80% uroinfekcij posledica uporabe urološkega katetra, ki vpliva na prenos patogenih bakterij v sečnico in posledično v mehur, zaradi česar se uroinfekt tudi pojavi. Vzroke uroinfekta zaradi uporabe katetra je moč pripisati premalo hidrofobni površini, neučinkoviti protimikrobnosti ter nastanku biofilma na površini le tega. Zaradi tega so trendi pri izdelavi uroloških katetrov usmerjeni v oplaščanje njihovih površin s sredstvi, ki znižujejo prisotnost patogenih bakterij v sečnici in s tem preprečujejo nastanek biofilma na njihovi površini. Zaradi vse večje zdravstvene in ekološke ozaveščenosti ljudi se je zato izkazala potreba po uporabi naravnih, biorazgradljivih, netoksičnih spojin za funkcionalizacijo površin katetrov. Iz tega razloga je diplomsko delo usmerjeno v obdelavo površin silikona, kot najpogosteje uporabljenega materiala za izdelavo uroloških katetrov. Površine silikonskega materiala smo funkcionalizirali s pomočjo uporabe kisikove plazme. Sledil je tudi nanos protimikrobnega in biorazgradljivega polisaharida hitozana za dosego protimikrobnih lastnosti. Uporabili smo različne tehnike nanosa. Najprej smo uporabili tehniko namakanja neaktiviranih silikonskih ploščic v različno koncentrirane raztopine hitozana, vendar se je ta tehnologija izkazala za nefunkcionalno. Nato smo silikonske ploščice predhodno aktivirali s kisikovo plazmo in ponovili postopek namakanja v raztopine hitozana. Elementno sestavo in morfologijo funkcionaliziranih kot tudi nefunkcionaliziranih materialov smo določali z FTIR, XPS in AFM, omočljivost vzorca pa smo analizirali z goniometrijo.Silicone, also known as poly (dimethylsiloxane) or shorter PDMS is one of several important polymers used in many industries. It is very important in the field of medicine, where it is mostly used to produce a variety of implants, as it demonstrates good chemical and structural properties. As an implant it is widely used for the manufacturing of catheters. Unfortunately, there is still approximately 80% of urinary tract infection resulting from the use of urologic catheter, which affects the transmission of pathogenic bacteria’s in the urethra and consequently into the bladder, thereby causing the urinary tract infection to appear. Due to the usage of the catheter, causes of infection can be attributed to the lack of hydrophobic surfaces, ineffective antimicrobics and the formation of biofilm on its surfaces. Trends in the manufacturing of urological catheters are consequently aimed at wrapping its surfaces by means which reduce the presence of pathogenic bacteria in the urethra, thus preventing the biofilm formation on their surfaces. Due to growing health and environmental awareness among people it has proved the need for the use of natural, biodegradable, non-toxic compounds for surface functionalization of catheters. Therefore the study focuses on the silicone surfaces as the most commonly used materials for the manufacturing of urological catheters. We functionalized surfaces of silicon materials by using oxygen plasma. This was followed by the application of antimicrobial and biodegradable chitosan to achieve antimicrobial properties. We have used various techniques of application. First we used the method of irrigating inactivated silicone pads in different concentrated solutions of chitosan, however this technology has proven to be non-functional. Then we activated silicone pads by using oxygen plasma and repeated the process of irrigation. Elemental composition and morphology of functionalized and unfunctionalized materials were determined by FTIR, XPS and AFM, while the wettability of the sample was analyzed using a goniometry