Nanofibers: Electrospinning and centrifugal spinning for cell biology studies

Summary form only given. A large amount of three-dimensional (3D) scaffolds will be needed for cell proliferation and tissue engineering applications. To meet the requirement of high throughput and low cost manufacturing, we have investigated a few of laboratory-scale fabrication methods, including i) micro contact thermal printing of electrospun nanofibers, ii) centrifugal melt spinning and iii) solvent assisted centrifugal spinning. Electrospinning is a well-known technique for the nanofiber production. By using a a high electric field, polymer fibers are extruded from a syringe and deposited on a collector. In order to produce well stable fiber matrix, we used a piece of polydimethylsiloxan (PDMS) to transfer electrospun fibers on to a glass substrate layer by layer with the help of a micro contact thermal printing process (μCtP). Centrifugal spinning has been studied for mass production of 3D fibre scaffolds. As the first attempt, we used centrifugal melt spinning technique to fabricate fibre matrix of poly (lactic-co-glycolic acid) (PLGA) which is a well-known biodegradable and biocompatible co-polymer. We then developed a solvent assisted centrifugal spinning technique to produce fibre matrix of polystyrene (PS) which has a relative high glass transition temperature comparing to that of PLGA. Both techniques were studied with a modified cotton candy machine, showing the possibility of process optimisation by controlling the spinning parameters. To demonstrate the feasibility of cell culture and tissue engineering of the fabricated fibre scaffolds, we performed several proof-of-concept experiments, including i) enhanced adhesion stability of embryonic stem cell colonies on aligned single nanofibres, ii) culture and formation of embryonic stem cell colonies without mouse fibroblasts, iii) cell culture and proliferation in centrifugal spun fibre scaffolds and iv) cell culture and proliferation on fiber scaffolds with protein concentrations. In conclusion,- - we have proposed a few fabrication methods for mass production of 3D scaffolds which are suitable for a number of cell biology investigations. Our methods also hold potentials for other types of applications.