title: Printing thermoresponsive reverse molds for the creation of patterned two-component hydrogels for 3D cell culture.
abstract: Bioprinting is an emerging technology that has its origins in the rapid prototyping industry. The different printing processes can be divided into contact bioprinting(1-4) (extrusion, dip pen and soft lithography), contactless bioprinting(5-7) (laser forward transfer, ink-jet deposition) and laser based techniques such as two photon photopolymerization(8). It can be used for many applications such as tissue engineering(9-13), biosensor microfabrication(14-16) and as a tool to answer basic biological questions such as influences of co-culturing of different cell types(17). Unlike common photolithographic or soft-lithographic methods, extrusion bioprinting has the advantage that it does not require a separate mask or stamp. Using CAD software, the design of the structure can quickly be changed and adjusted according to the requirements of the operator. This makes bioprinting more flexible than lithography-based approaches. Here we demonstrate the printing of a sacrificial mold to create a multi-material 3D structure using an array of pillars within a hydrogel as an example. These pillars could represent hollow structures for a vascular network or the tubes within a nerve guide conduit. The material chosen for the sacrificial mold was poloxamer 407, a thermoresponsive polymer with excellent printing properties which is liquid at 4 °C and a solid above its gelation temperature ~20 °C for 24.5% w/v solutions(18). This property allows the poloxamer-based sacrificial mold to be eluted on demand and has advantages over the slow dissolution of a solid material especially for narrow geometries. Poloxamer was printed on microscope glass slides to create the sacrificial mold. Agarose was pipetted into the mold and cooled until gelation. After elution of the poloxamer in ice cold water, the voids in the agarose mold were filled with alginate methacrylate spiked with FITC labeled fibrinogen. The filled voids were then cross-linked with UV and the construct was imaged with an epi-fluorescence microscope.
authors.affiliation: Department of Health Science & Technology, Cartilage Engineering & Regeneration.
authors.forename: Michael
authors.initials: M
authors.lastname: Müller
authors.forename: Jana
authors.initials: J
authors.lastname: Becher
authors.forename: Matthias
authors.initials: M
authors.lastname: Schnabelrauch
authors.forename: Marcy
authors.initials: M
authors.lastname: Zenobi-Wong
mesh_terms: D000464:Alginates / Q000737:chemistry; D062028:Bioprinting / Q000295:instrumentation / Q000379:methods*; D018929:Cell Culture Techniques / Q000295:instrumentation* / Q000379:methods*; D046169:Dermoscopy; D005340:Fibrinogen / Q000737:chemistry; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D006358:Hot Temperature; D020100:Hydrogels / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry; D020442:Poloxamer / Q000737:chemistry; D012685:Sepharose / Q000737:chemistry
chemical_list: D000464:Alginates; D020100:Hydrogels; D008689:Methacrylates; D020442:Poloxamer; D005340:Fibrinogen; D012685:Sepharose; D016650:Fluorescein-5-isothiocyanate
references.citation: Biomaterials. 2003 Jun;24(13):2303-8
references.pmid: 12699667
references.citation: Anat Rec A Discov Mol Cell Evol Biol. 2003 Jun;272(2):497-502
references.pmid: 12740943
references.citation: Biofabrication. 2011 Jun;3(2):025003
references.pmid: 21562366
references.citation: Curr Opin Biotechnol. 2011 Oct;22(5):667-73
references.pmid: 21419621
references.citation: Biotechnol Lett. 2013 Mar;35(3):315-21
references.pmid: 23160742
references.citation: Biorheology. 2004;41(3-4):371-5
references.pmid: 15299269
references.citation: Science. 2002 Mar 1;295(5560):1702-5
references.pmid: 11834780
references.citation: Annu Rev Biomed Eng. 2001;3:335-73
references.pmid: 11447067
references.citation: Biomaterials. 2009 May;30(14):2724-34
references.pmid: 19201462
references.citation: Regen Med. 2008 Jan;3(1):93-103
references.pmid: 18154465
references.citation: Tissue Eng. 2004 Sep-Oct;10(9-10):1316-22
references.pmid: 15588392
references.citation: Clin Plast Surg. 2012 Jan;39(1):21-32
references.pmid: 22099846
references.citation: Biomacromolecules. 2011 May 9;12(5):1831-8
references.pmid: 21425854
references.citation: Tissue Eng. 2006 Apr;12(4):631-4
references.pmid: 16674278
references.citation: Expert Opin Biol Ther. 2003 Aug;3(5):701-4
references.pmid: 12880370
references.citation: J Biomed Mater Res A. 2013 Jan;101(1):272-84
references.pmid: 22941807
references.citation: Nat Biotechnol. 1999 Feb;17(2):149-55
references.pmid: 10052350
references.citation: Biomaterials. 2003 Apr;24(8):1487-97
references.pmid: 12527290
references.citation: J Appl Biomater Funct Mater. 2012 Jun 26;10(1):55-65
references.pmid: 22562455
references.citation: J Biomech Eng. 2000 Jun;122(3):252-60
references.pmid: 10923293
references.citation: Biomacromolecules. 2009 Jul 13;10(7):1689-96
references.pmid: 19445533
references.citation: Panminerva Med. 2005 Mar;47(1):53-60
references.pmid: 15985977
references.citation: Biotechnol Bioeng. 2010 Apr 15;105(6):1178-86
references.pmid: 19953677
references.citation: Biomaterials. 2009 Apr;30(12):2164-74
references.pmid: 19176247
references.citation: Clin Plast Surg. 2012 Jan;39(1):33-58
references.pmid: 22099847
references.citation: J Mater Sci Mater Med. 2012 Sep;23(9):2267-79
references.pmid: 22639153
references.citation: Nat Mater. 2012 Sep;11(9):768-74
references.pmid: 22751181
references.citation: Acta Biomater. 2011 Jan;7(1):152-62
references.pmid: 20688198
references.citation: Nat Clin Pract Urol. 2006 Nov;3(11):588-9
references.pmid: 17088926
references.citation: Nat Mater. 2003 Apr;2(4):265-71
references.pmid: 12690401
references.citation: Biotechnol Bioeng. 2000 Feb 5;67(3):312-8
references.pmid: 10620261
references.citation: Circulation. 2006 Jul 4;114(1 Suppl):I132-7
references.pmid: 16820562
references.citation: Biomaterials. 2012 Sep;33(26):6020-41
references.pmid: 22681979
references.citation: Tissue Eng Part A. 2008 Jan;14(1):127-33
references.pmid: 18333811