Thermal properties of electrospun scaffolds on the base of polycaprolactone and fibroin

Fibroin svile stoljećima se koristi u tekstilnoj industriji kao vlakno te već desetljećima u biomedicinske svrhe kao kirurški materijal za šivanje. Zbog svojih dobrih mehaničkih svojstava, biokompatibilnosti i biorazgradljivosti dalje se razvija njegova primjena u različite svrhe. U ovom radu pripremljeni su elektroispredeni nosači na osnovi polikaprolaktona (PCL) i fibriona svile (FS) postupkom elektroispredanja. Istražen je utjecaj FS na morfološku stukturu, kemijski sastav, toplinska svojstva, toplinsku stabilnost i hidrofobnost elektroispredenih PCL/FS vlaknastih nosača SEM analizom, infracrvenom spektroskopijom (FTIR), diferencijalnom pretražnom kalorimetrijom (DSC), termogravimetrijskom analizom (TGA) te određivanjem kontaktnog kuta. Postupkom elektroispredanja dobivena je jednolična struktura PCL/FS vlaknastog nosača s tanjim promjerom vlakana i homogenom raspodjelom SF unutar vlakana. Dobiveni rezultati FTIR analize pokazuju da je fibroin svile uspješno ugrađen u elektroispredeni PCL vlaknasti nosač. Dodatkom FS povećala se hidrofilnost elektroispredenog PCL vlaknastog nosača. Rezultati dobiveni DSC tehnikom pokazali su da se dodatkom fibroina svile temperatura staklastog prijalaza povećava, dok se talište i stupanj kristalnosti smanjuje, zbog nastajanja slabije uređene kristalne strukture nastale dodatkom fibroina svile. Toplinska stabilnost određena je termogravimetrijskom analizom iz koje se vidi da se dodatkom fibroina svile smanjuje toplinska stabilnost.For centuries silk fibroin has been used as a textile fiber. Beyond textiles, silk fibroin has also been used in biomedical applications as a surgical material for decades. Because of his good mechanical properties, biocompatibility and biodegradability silk fibroin is being further developed for various emerging. In this work, electrospun scaffolds composed of polycaprolactone (PCL) and silk fibroin (SF) were prepared by electrospinning technique. Morphology, chemical composition, thermal properties, thermal stability and hydrofobicity of the PCL/SF scaffolds were characterized to evaluate the effect of SF by means of scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and contact angle. Electrospinning resulted in uniform fiber morphology with thinner fibers in PCL/SF scaffolds and a homogeneous SF distribution throughout the fibers. The FTIR results showed that the silk fibroin was successfully introduced to PCL scaffolds. The hydrophilicity of PCL modified scaffolds were enhanced. Results obtained with DSC showed that with addition of silk fibroin, glass transition temperature increases, while melting temperature and degree of crystallity decreases, because of the less organized crystal structure with addition of silk fibroin. Thermal stability is determined by TGA which shows that with addition of silk fibroin thermal stability decreased