Direct Electrospinning Writing

Transcription

1 Biofabrication Workshop Biomaterials Lab and Center for Engineering Complex Tissues Anthony J. Melchiorri, Ph.D. Associate Director, Biomaterials Lab Rice University Hochleitner, et al. Biofabrication Muerza-Cascante, et al. Tissue Engineering Part B: Reviews

2 Pressure Direct-Write Electrospinning Spinneret High voltage power supply Captures electrospinning techniques to fabricate patterned nanofibrous mats Electric fields used to confine and steer deposition of nanofibers Solvent-free technique Side-wall electrode Dielectric thin-plate collector Sharp-pin electrode Capable of producing fibers with diameters from microns to nanometers range Polymer properties and process parameters can affect fiber morphology and quality Necessitates more careful machine and process designs to produce quality, uniform fibers Muerza-Cascante, et al. Tissue Engineering Part B: Reviews Wunner, et al. Jove

3 Wunner, et al. Jove Advantages: Disadvantages: Can fabricate basic scaffolds for tissue engineering applications Submicron fiber size and feature size Multimaterial fabrication available Can be incorporated into other printing modalities Capable of directly writing onto cell layer Materials must have low enough viscosity to be deposited Cannot directly include cells or bioactive components Limited to thermoplastics 3

4 Materials: Applications: Synthetic and natural materials Thermoplastics (PCL commonly used) Tissue engineering scaffolds without cells High resolution architecture of cell environments S c = Velocity of collector S J = Velocity of Jet Criticial translation speed = S c > S J Turns and curves are better accommodated when S c is closer to critical translation speed Not all direct write applications involve collector Muerza-Cascante, et al. Tissue Engineering Part B Uneven jets can occur due to differences in mass flow rate Smaller fibers required higher critical translation speeds or risk collapse Direct write spinning errors propagate similarly to other extrusion methods, but smaller fiber size means lower height limits Hochleitner, et al. Biofabrication

5 Conclusions High-resolution biofabrication procedure capable of nanometer resolution More controlled than electrospinning; more technically challenging, too Errors propagate easily due to minimal layer height Great for acellular scaffolds necessitating micro/nanoarchitecture and can be combined with other fabrication modalities Resources Hochleitner G, Jungst T, Brown TD, Hahn K, Moseke C, Jakob F, Dalton PD, Groll J. Additive manufacturing of scaffolds with submicron filaments via melt electrospinning writing. Biofabrication. 2015;7(3). ( Muerza-Cascante ML, Haylock D, Hutmacher DW, Dalton PD. Melt electrospinning and its technologization in tissue engineering. Tissue Engineering Part B: Reviews. 2014;21(2): ( Wunner FM, Bas O, Saidy NT, Dalton PD, Pardo EM, Hutmacher DW. Melt eletrospinning of three-dimensional poly(ε-caprolactone) scaffolds with controllable morphologies for tissue engineering applications. J. Vis. Exp. 2017;130. ( 5