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Materijali koji se najčešće koriste u procesu 3D tiska su sintetski polimeri, čija sve veća upotreba pridonosi trendu povećanja proizvedenog otpada u svijetu. U svrhu smanjenja proizvodnje otpada, istražuju se alternativni, biorazgradivi materijali koje je moguće primijeniti u 3D tisku. U ovom istraživanju, ekstrudiranjem taljenjem se iz granula biorazgradivih polimera, polilaktične kiseline (PLA) i polikaprolaktona (PCL), priređuju filamenti koji služe kao sirovina za 3D tisak taložnim srašćivanjem. Ispitan je utjecaj uvjeta ekstrudiranja i udjela pojedine komponente na kvalitetu dobivenog filamenta. Kao najbolji filament pokazao se onaj masenog omjera PLA : PCL = 50 : 50, ekstrudiran pri 160 °C i 10 o/min. Zbog svoje biokompatibilnosti, biorazgradivosti i netoksične prirode produkata razgradnje, polimerni materijali na bazi polilaktične kiseline često se koriste za izradu raznih medicinskih implantata. U okviru ovog istraživanja proveden je test bubrenja za čisti PLA te za mješavine PLA i PCL-a. Dobiveni rezultati pokazuju da je s porastom udjela PCL-a u filamentu bubrenje sporije. Za mješavine PLA i PCL-a, provedeno je i vlačno ispitivanje te je utvrđeno na koji način dodatak PCL-a utječe na mehanička svojstva ispitivanog materijala. Na temelju izrađenog CAD modela, isprintan je bioresorptivni stent koji se sastoji od odabranog PLA-PCL filamenta i filamenta u koji je ugrađena djelatna tvar dronedaron-hidroklorid. Provedeno je in vitro ispitivanje oslobađanja djelatne tvari čiji rezultati sugeriraju kako će otapanje filamenta koji sadrži djelatnu tvar potrajati nekoliko dana, dok će osnovna konstrukcija stenta od PLA-PCL filamenta pružati potporu stijenci krvne žile kroz duži vremenski period. Ovim je istraživanjem dokazano da se izborom odgovarajućih procesnih uvjeta i sastava polimernih mješavina mogu iz polimernih granula pripremiti filamenti pogodni za 3D tisak taložnim srašćivanjem. Uzimajući u obzir svojstva dobivenog materijala, pokazana je njegova moguća primjena u medicinskim implantatima, točnije za izradu personaliziranog stenta. Synthetic polymers are materials that are most often used in the 3D printing process. The increasing use of these polymers contributes to the trend of increasing waste produced in the world. In order to reduce waste production, alternative, biodegradable materials that can be applied in 3D printing are being researched. In this research, filaments for fused deposition modeling were prepared using hot melt extrusion, by processing biodegradable polymer granules of polylactic acid (PLA) and polycaprolactone (PCL). The influence of extrusion conditions and composition of polymer blends on the quality of the obtained filament was examined. It was found that the best filament was the one with a mass ratio of PLA : PCL = 50 : 50, extruded at 160 °C and 10 RPM. Due to their biocompatibility, biodegradability and non-toxic nature of degradation products, polymeric materials based on PLA are often used for the production of various medical implants. In this research, swelling test was performed for pure PLA and for the mixtures of PLA and PCL. The obtained results show that with increasing the mass fraction of PCL in the filament, the swelling is slower. For the mixtures of PLA and PCL, tensile tests were performed. The effect of the addition of PCL to mechanical properties of the tested material was found. Based on the created CAD model, a bioresorbable stent, consisting of a selected PLA-PCL filament and a filament in which the active substance (dronedarone hydrochloride) was embedded, was printed. In vitro studies were performed. The results suggest that the dissolution of the filament that contains the active substance will take several days, while the basic structure of the stent made from PLA-PCL filament will provide support to the blood vessel wall for a longer period of time. This research has proven that by choosing the appropriate process conditions and the composition of polymer mixtures, filaments suitable for fused deposition modeling can be prepared from polymer granules. Considering the properties of the obtained material, its possible application in medical implants, more specifically for the creation of a personalized stent, was demonstrated. |
