Coaxial core-shell structured fibers

Jiang HL et al (2006) Modulation of protein release from biodegradable core-shell structured fibers prepared by coaxial electrospinning. J Biomed Mater Res B Appl Biomater 79B(1) 50-57... 

A coaxial setup uses a multiple solution feed system that allows for the injection of one solution into another at the tip ofthe spinneret. The sheath fluid act as a carrier drawing in the inner fluid at the Taylor cone ofthe electrospinning jet. If the solutions are immiscible then a core-shell structure is usually observed. Miscible solutions, however, can result in porosity or a fiber with distinct phases due to phase separation during solidification ofthe fiber. 

Another robust technique for one-step encapsulation of fragile hydrophilic agents like peptides and proteins in PLA is coaxial electrospinning. This method is an innovative extension of electrospinning, which uses two concentrically aligned capillaries to enforce the formation of fibers or particles with a core-shell structure [49]. Basically this process removes the damaging effects resulting from the direct contact of the proteins... 

Chen HY, Wang N, Di JC, Zhao Y, Song YL, Jiang L (2010) anowire-in-microtube structured Core/Shell fibers via multifluidic coaxial electrospinning. Langmuir 26 11291-11296... 

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