| Scaffold material is one of the three elements of tissue engineering(TE),its main function is as an extracellular matrix for cell adhesion growth,and the biochemical microenvironment of fiber scaffold material can regulate cell behavior.At present,the electrospinning method is the most commonly used method for preparing micro/nanofibers,but it requires high voltage static electricity and is extremely inefficient.In response to this problem,this thesis adopts an efficient and safe centrifugal spinning method to provide polycaprolactone(PCL)with high mechanical strength,good flexibility,biosafety and biodegradability and as a natural extracellular matrix.The main structural protein collagen(COL)is combined to prepare a composite fiber scaffold material which has both excellent properties.In this paper,different polylactic acid(PLA)fibers were prepared by changing the parameters.Four factors affecting the fiber morphology during spinning were studied,including spinning solution concentration,spinning speed,spinning aperture and collection height.Scanning electron microscopy results show: When the concentration of the PLA solution becomes high,the uniformity of the fibers is deteriorated,and the average diameter of the fibers becomes large;As the rotational speed increases,the average diameter of the fiber decreases first and then increases;As the orifice diameter decreases,the fiber uniformity deteriorates;The collection height affects the time during which the jet is drawn and solidified in the air.As the height of the collection increases,the formability of the fiber becomes better,but it affects the width and thickness of the fiber;The PLA fiber with a concentration of 19 wt.% has the best thermal stability and the highest crystallinity,which is 33.58%.Secondly,different ratios of polycaprolactone/collagen composite fiber scaffolds were prepared.The sample with polycaprolactone/collagen protein ratio x:y was named PCxy.For example,PC37 indicates the quality of polycaprolactone and collagen.The ratio of 3:7)was analyzed by scanning electron microscopy,Fourier transform infrared spectroscopy,contact angle meter,thermal analyzer and X-ray diffractometer.The results show that: ?1? PCL and COL mass ratio have a greater impact on fiber morphology,PC37 group fiber uniformity,but the fiber breaks severely in the forming process cannot form a complete fiber membrane;PC55 group,fiber uniformity and forming The effect is the best,and the average fiber diameter is at least 7.64 ?m;at the beginning of the PC64 group,a large amount of entanglement begins to occur between the fibers,the fiber uniformity is extremely poor,and the fiber surface roughness is deteriorated.?2? The addition of COL improved the hydrophilicity of PCL.The contact angle test results of PC73 showed that the water droplets were stable 30 s after dropping onto the surface of the fiber membrane,and the final contact angle was 28.4°.The water droplets were added to other fiber surfaces.It was completely absorbed in a short period of time,and the PC46 group was the fastest,1 s.?3? results show that there is no chemical interaction between PCL and COL,but only physical cross-linking into a net;PC55 group has the highest crystallinity and the best thermal stability.Finally,the CCK-8 kit was used to observe the adhesion and proliferation of human renal epithelial cells 293 T with the composite fiber extract and the adhesion and proliferation on the composite scaffold.The results showed that the toxicity of the composite fiber extract was 1 grade;The fiber membrane promoted cell adhesion and proliferation.The PC46 group had the best effect and the proliferation efficiency was higher than that of the culture plate(TCP).With the increase of culture time,the number of cells on the fiber surface increased gradually.Furthermore,cells grew into the inner surface of the fibrous membrane,and this result confirmed that the cell compatibility of the PCL/COL composite fiber membrane was good. |
PDF Full Text Request