본 연구에서는, 전기방사를 위하여 알지네이트와 키토산을 이용하여 알지네이트/poly(ethylene oxide)(PEO)와 키 토산/PEO 용액을 준비하였다. 준비된 용액을 10 mL 플라스틱 주사기에 넣고 금속 노즐에 높은 전압을 공급하였다. 키토산과 알지네이트 용액은 고분자 농도, 온도, 상대습도, 인가전압, 노즐과의 거리, 그리고 용액 속도에 의해 컨트롤되었다. 제조된 나노섬유막은 전자주사현미경을 이용하여 모폴로지를 관찰하였다. 알지네이트 전기방사를 위한 나노 섬유막의 최적화된 조건 은 2 wt% 알지네이트, 2 wt% PEO, 60°C, 노즐과의 거리 15 cm, 20~24 kV, 8 μm/min이었으며, 키토산 섬유막의 최적화 조 건은 2 wt% 키토산, 2 wt% PEO, 25°C, 노즐과의 거리 15 cm, 24 kV, 8 μm/min이었다. 복합 나노섬유 제조조건은 노즐과의 거리 20 cm, 8 μm/min, 26 kV이었다.
Multilayer Poly methyl methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates were fabricated using electrospinning and in vitro investigations were carried out for pre-clinical biocompatibility studies. The initial cellular cytotoxicity of the methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay using fibroblast-like L-929 cells. Cellular adhesion and differentiation studies were carried out using osteoblast-like MG-63 cells. As simulated body fluid (SBF) contains the same ionic concentration of body fluid and any bioactive material tends to deposit bone-like apatite on the samples surfaces into the SBF, in vitro bioactivity of the multilayer bone plates were investigated using SBF. We also studied the internal organization and tensile strength of the multilayer PMMA/PVA bone plates using micro-computed topography (μ-CT) and universal testing instrument (UTI, Korea) respectively. The cellular cytotoxicity study with MTT confirmed that the cellular viability was 78 to 90% which indicates good cyto-compatibility. Scanning electron microscopic findings revealed a good attachment and adhesion phenomenon of MG-63 cells onto the surfaces of the samples. Cellular differentiation studies also showed that osteogenic differentiation was switched on in a timely manner and affirmed along with that of the control group. Bone-like apatite formation on the surfaces was confirmed within 14 days of SBF incubation. Initial organizations of the multilayer PMMA/PVA bone plates were characterized as dense and uniform. The tensile strength of the post-pressing electronspun mat was higher than that of the pre-electronspun mat. These results suggest that a multilayer PMMA/PVA bone plate system is biocompatible, bioactive and a very good alternative bone plate system.
Functional nanomaterial is expected to have improved capacities on various fields. Especially, metal nanoparticles dispersed in polymer matrix and metal nanofiber, one of the functional nanomaterials, are able to achieve improvement of property in the electric and other related fields. In this study, the fabrication of metal (Ag) nanoparticle dispersed nanofibers were attempted. The Ag nanoparticle dispersed polymer nanofiber and Ag nanofiber were fabricated by electrospinning method using electric force. First, PVP/ nanofibers were synthesized by electrospinning in voltage with the starting materials (Ag-nitrate) added polymer (PVP; poly (vinylpyrrolidone)). Then Ag nanoparticle dispersed polymer nanofibers were fabricated to reduce hydrogen reduction at for 3hr. And Ag nanofibers were synthesized by the decomposited of PVP at for 3hr. The nanofibers were analyzed by XRD, TGA, FE-SEM and TEM. The experimental results showed that the Ag nanofibers could be applied in many fields as an advanced material.
Polyethersulfone (PES)와 Bovine Serum Albumin (BSA) 용액으로 전기방사법을 이용하여 단백질 친화막을 제조하였다. 방사운전조건(방사용액의 농도, 전압, 방사속도, 방사거리)을 다양하게 조절하여 나노섬유의 크기를 관찰하였으며, 최적의 친화막 제조 조건을 확인할 수 있었다. XPS와 FT-IR로써 PES와 BSA의 결합을 확인하였으며, PES-BSA 나노섬유의 최적 방사 온도와 습도는 20~22℃와 45~55% 임을 알 수 있었다. 또한 PES 함량이 증가할수록 섬유의 크기가 증가하고, BSA의 경우 나노섬유의 크기에 큰 영향이 없음을 알았다. PES 7 wt%, BSA 0.7 wt%. Hexafluropropanol (HFP) 92.3 wt%의 용액을 이용하여 전압 10.0 kV, 방사거리 10 cm, 방사속도 1.0 mL/hr의 조건에서 방사한 경우 균일한 크기의 PES-BSA 나노섬유가 얻어졌다.
Fibers of microbial polyesters, poly(3-hydroxy butyrate) (PHB) and poly(3-hydroxy butyrate-co-3-hydroxy valerate) (HB-co-HV) were prepared by electrospinning method. The obtained fibers were evaluated by differential scanning calorimetry, scanning electron microscopy, and oil absorption. The formation of fibers was strongly dependent on a concentration of solution. At a low concentration, the fibers contained beads which is from aggregation of polymer due to short evaporation time. The fine fibers with 2-5 mm diameter were obtained at 20 wt% concentration. The contact angle measurement showed that the fiber had higher water contact angle than the film due to the lotus-like effect. Oil absorbency showed that the fiber had higher than the film. Specially, the HB-co-HV fiber which was spinned from 20 wt% absorbed 65% oil which is much higher than that of a normal polypropylene-based oil paper.