title: Controlled microchannelling in dense collagen scaffolds by soluble phosphate glass fibers.
abstract: A problem with tissue engineering scaffolds is maintaining seeded cell viability and function due to limitations of oxygen and nutrient transfer. An approach to maintain suitable oxygen concentrations throughout the scaffold would be to controllably incorporate microchannelling within these scaffolds. This study investigated the incorporation of unidirectionally aligned soluble phosphate based glass fibers (PGF) into dense collagen scaffolds. PGF are degradable, and their degradation can be controlled through their chemistry and dimensions. Plastic compression was used to produce composite scaffolds at three different weight percentage while maintaining greater than 80% resident cell viability. PGF-collagen scaffold composition was quantified through thermogravimetric analysis as well as being morphologically and mechanically characterized. PGF degradation was measured through ion chromatography, and channel formation was verified with ultrasound imaging and SEM. The free movement of coated microbubble agents confirmed the channels to be continuous in nature and of 30-40 microm diameter. These microchannels in dense native collagen matrices could play an important role in hypoxia/perfusion limitations and also in the transportation of nutrients and potentially forming blood vessels through dense implants.
authors.affiliation: Division of Biomaterials and Tissue Engineering and Division of Microbial Diseases, UCL Eastman Dental Institute, 256 Gray's Inn Road, London, WC1X 8LD, United Kingdom. showan.nazhat@mcgill.ca
authors.forename: Showan N
authors.initials: SN
authors.lastname: Nazhat
authors.forename: Ensanya A Abou
authors.initials: EA
authors.lastname: Neel
authors.forename: Asmeret
authors.initials: A
authors.lastname: Kidane
authors.forename: Ifty
authors.initials: I
authors.lastname: Ahmed
authors.forename: Chris
authors.initials: C
authors.lastname: Hope
authors.forename: Matt
authors.initials: M
authors.lastname: Kershaw
authors.forename: Peter D
authors.initials: PD
authors.lastname: Lee
authors.forename: Eleanor
authors.initials: E
authors.lastname: Stride
authors.forename: Nader
authors.initials: N
authors.lastname: Saffari
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Knowles
authors.forename: Robert A
authors.initials: RA
authors.lastname: Brown
mesh_terms: D000818:Animals; D002470:Cell Survival; D024042:Collagen Type I; D005347:Fibroblasts / Q000166:cytology; D005898:Glass; D006801:Humans; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods; D010710:Phosphates; D051381:Rats; D012995:Solubility; D023822:Tissue Engineering / Q000295:instrumentation* / Q000379:methods
chemical_list: D024042:Collagen Type I; D010710:Phosphates; C009753:fiberglass