Characterization And Preparation Of Modified Poly(ε-caprolactone)Fibrous Membranes

Poly(-caprolactone)(PCL) was a promising biomaterial for tissue engineering results from itsinteresting characteristics, like easy processing property, good mechanical property, excellentbiocompatibility, degradation into natural metabolites, and low cost. However, its furtherapplications in tissue engineering are largely limited due to its hydrophobic nature. As we allknow, the scaffolds should have moderate hydrophilicity, which can enhance the expressions ofphenotypic markers and promote cell attachment and proliferation. Then it is very important tofind a way to overcome this problem. In this thesis, poly(ethylene glycol)(PEG) was added intothe spinning solution of PCL. Blending PCL with PEG can substantially modify its inherenthydrophobic property. The PCL/PEG composite nanofibrous membranes were prepared byelectrospinning. Moreover, the effect of different PCL/PEG mass ratios on the composite fibermorphology, structure, hydrophilicity, mechanical properties and phase separation wascharacterized and tested. It can be found that the hydrophilicity of these fibrous membranes wassignificantly improved by the addition of PEG. Besides, PEG was mainly deposited on thesurfaces of these composite fibers, which could be easily dissolved in deionized water.Thereby, PCL-PEG-PCL (PCEC) triblock copolymers were fabricated and became PCECnanofibrous membranes via electrospinning. The composition of PCEC copolymer wascharacterized by1H-NMR and FTIR methods. Moreover, morphologies and properties of PCECfibrous membranes were systematically investigated by corresponding instruments. The resultsshowed that the water contact angles of PCEC nanofibrous membranes were declined with theincrease of PEG content, turning from hydrophobicity to hydrophilicity. Moreover, the fracturestress decreased and fracture strain increased with the enhancement of PEG content.In addition, the PCEC/SF composite nanofibrous membranes were prepared via hybridelectrospinning, which could improve the biocompatibility of PCEC nanofibrous membranes.Subsequently, the biological properties of these electrospun composite nanofibrous membraneswere investigated by in vitro NIH3T3cell culture experiment. It can be seen from results that NIH3T3cells could adhere and proliferate successfully on these electrospun fibrous membranes.Further more, the PCEC2/SF fibrous membrane had a better effect on the adhesion andproliferation of NIH3T3cells, which illustrated that PCEC2/SF fibrous membrane has goodbiocompatibility. The hydrophilic PEG segments could improve the hydrophilicity of fibrousmembranes to increase cell adhesion and proliferation, moreover, SF could improve thebiocompatibility of fibrous membranes, which was conducive to cell adhesion and growth.In this thesis, the modified PCL fibrous membranes were fabricated by electrospinningtechnology. It could enlarge the application field of PCL fibrous membranes, but also provided anew method for the design of advanced biological materials.