Growth factor-loaded microparticles for tissue engineering: The discrepancies of in vitro characterization assays

Bock, Nathalie, Dargaville, Tim R., Kirby, Giles T.S., Hutmacher, Dietmar, & Woodruff, Maria A. (2016) Growth factor-loaded microparticles for tissue engineering: The discrepancies of in vitro characterization assays. Tissue Engineering Part C: Methods, 22(2), pp. 142-154.

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Abstract

Efficient and effective growth factor (GF) delivery is an ongoing challenge for tissue regeneration therapies. The accurate quantification of complex molecules such as GFs, encapsulated in polymeric delivery devices, is equally critical and just as complex as achieving efficient delivery of active GFs. In this study, GFs relevant to bone tissue formation, vascular endothelial growth factor (VEGF) and bone morphogenetic protein 7 (BMP-7), were encapsulated, using the technique of electrospraying, into poly(lactic-co-glycolic acid) microparticles that contained poly(ethylene glycol) and trehalose to assist GF bioactivity. Typical quantification procedures, such as extraction and release assays using saline buffer, generated a significant degree of GF interactions, which impaired accurate assessment by enzyme-linked immunosorbent assay (ELISA). When both dry BMP-7 and VEGF were processed with chloroform, as is the case during the electrospraying process, reduced concentrations of the GFs were detected by ELISA; however, the biological effect on myoblast cells (C2C12) or endothelial cells (HUVECs) was unaffected. When electrosprayed particles containing BMP-7 were cultured with preosteoblasts (MC3T3-E1), significant cell differentiation into osteoblasts was observed up to 3 weeks in culture, as assessed by measuring alkaline phosphatase. In conclusion, this study showed how electrosprayed microparticles ensured efficient delivery of fully active GFs relevant to bone tissue engineering. Critically, it also highlights major discrepancies in quantifying GFs in polymeric microparticle systems when comparing ELISA with cell-based assays.

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ID Code: 94113
Item Type: Journal Article
Refereed: Yes
Keywords: growth factor, tissue engineering, electrospraying
DOI: 10.1089/ten.tec.2015.0222
ISSN: 2152-4947
Divisions: Current > Schools > School of Chemistry, Physics & Mechanical Engineering
Current > Institutes > Institute of Health and Biomedical Innovation
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Funding:
Facilities: Central Analytical Research Facility
Deposited On: 03 Apr 2016 23:49
Last Modified: 05 Apr 2016 00:24

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