- MSc, (2016-2018): Fabrication and evaluation of nanocomposite silk fibroin/laponite fibrous membrane decorated by wool keratin for guided bone regenaration
Restoration of bone defects of teeth is one of the most important challenges in the present age. Today, the use of guided bone regeneration to accelerate the process of bone defect repair in tissue engineering is increasing. Guided bone regeneration membranes should have suitable physical and chemical properties. They should be semilar to extracellular matrix also they should have mechanical properties close to natural bone and be antibacterial to prevent infection. The purpose of this research is to construct silk fibroin/laponie nanofibrous nanocomposite scaffolds through electrospinning and modify its surface by wool keratin to achieve antibacterial surface and finally characterize it. In this regard, first of all, the fibroin degummed from silk polymer. The parameters of electrospinning was optimized and nanofibrous membranes containing 0, 2, 5 and 10 %wt of laponite nanopowder were manufactured and characterized. The mechanical tests demonestred adding laponite up to 5 %wt cause to increasing the mechanical properties of membrane like elastic modulus (11.47 folds) and tensile strength (4.11 folds). According to this results the nanocomposite of silk fibroin consist 5 %wt of laponite chose as an optimum membrane. Also the biodegradation, swelling and wetting properties of nanocomposite were measured. The results showed that by adding laponite up to 10 %wt the biodegradation, swelling and wetting of membranes were increased. In addition, adding 10 %wt of laponite to the silk fibroin matrix cause to the membranes achieved to better bioactivity, MSC cells attachment and viability. In the second step, the keratin extract from wool and the parameters of electrospray were optimezed, too. Then the keratin solution were electrosprayed on nanofibrous nanocomposite at different times (2, 3 and 4 hours). The mechanical, biological and chemical properties of electrosprayed membranes were measured. The results showed that 4 hours electrospraying on nanofibrous nanocomposite membranes cause to decreaesd tensile strength (0.77 folds) and increased elongation (3.19 folds). Moreover, wetting tests showed 4 hours electrosprayed had the less contact angle (36.62±1.8 degree). Therefore, it had the best hydrophylicity. The bioactivity test showed 2 hours electrosprayed membrane had the best bioactive ability. Also, the 3 hours wool keratin electrosprayed membrene had the best cells attachment and viability of MSCs during 7 days. In addition, the antibacterial tests on electrosprayed membranes at 2 and 4 hours showed the better antibacterials reaction. Accordingly, nanofibrous nanocomposite of silk fibroin/laponite decorated by wool keratin due to proper mechanical and biological properties can be a suitable candidate for guided bone regeneration.