Electrospun biodegradable fiber mesh is a promising alternative scaffold for delivering progenitor cells for repairing damaged or diseased tissue, but its cripple mechanical stability has not met the requirement of tissue engineering yet. In this work, the well-defined poly(ε-caprolactone)-branched poly(methyl methacrylate-co-hydroxyethylmethacrylate) (PCL-PMH) has been successfully synthesized to toughen electrospun poly(L-lactide) (PLLA) fiber membrane. Characterization of the obtained nanofibrous meshes indicates that PCL-PMH and PLLA can be well blended to make smooth fibers, and fibrous diameter vary little with blending PCL-PMH. The aggregation state of two macromolecules is closely correlated with blend ratio, molecular structure, and molecular weight of PCL-PMH, and only when PCL-PMH and PLLA form good interfacial adhesion can PMH give full play to its potential for toughening the fiber membrane. The tensile strength and elongation at break of the blend are 6.20 MPa and 63.40% under the optimal conditions, respectively, and it also exhibits the representative feature of toughness materials. The blending fiber membrane is as no cytotoxic as original PLLA. This work will provide a new way for toughness of electrospun fiber membrane in practice.
KEYWORDSelectrospinning, PCL-branched P(MMA-co-HEMA), PLLA, toughness and toluene were refluxed over sodium and distilled before use. Stannous octoate (SnOct 2 ) (Aldrich Chemical Co) was dissolved in dehydrated toluene to prepare 0.1 g/mL solution prior to using. n-Hexane, light petroleum, azobisisobutyronitrile (AIBN), chloroform, and triethyl benzyl ammonium chloride (TEBAC) were commercially available and used without further purification. PLLA (M n = 70 000) was purchased from Haizheng Biomaterials Co. Table 1, with increasing the molar ratio, the polymerized products were individually designed as PCL-PMH-11, PCL-PMH-21, PCL-PMH-31, and PCL-PMH-41.
| Synthesis of PCL-PMH
| Preparation of blending fiber membranesA suitable amount of PCL-PMH-11 and PLLA were dissolved into chloroform to prepare the 8 wt% solution, and 1 wt% TEBAC with respect to the polymer was added into that solution to improve our electrospinning process. 32 Their blend ratios were changed from 5 to 10, 20, and 30 wt%, respectively.The blending solution was loaded into a 5-mL syringe with a metal needle, which was installed on digital microinjection pump (Jiashan Ruichuang Electronic Tec Co Ltd, RSP01-B). The inner diameter of the orifice was 0.9 mm; 7 kV was applied between the cathode and anode by electrostatic generator (ES30P-5w/DAM, Gamma high voltage, SCHEME 1 Synthetic route of PCL-PMH JIANG ET AL. 443Ormond Beach, FL, USA) at a distance of 15 cm to produce the fibrous meshes. A steady flow of the solution from the orifice was maintained in 6 μL/min. Our electrospinning was done under ambient conditions.The collected fiber mesh was desiccated in vacuum at 30°C for 24 h.As the above, the other blending and original PLLA fiber membranes were also prepared for comparison.
| Characteristic...
