title: Alpha1,3-galactosyltransferase knockout does not alter the properties of porcine extracellular matrix bioscaffolds.
abstract: Extracellular matrix (ECM) bioscaffolds, such as porcine small intestine submucosa (SIS) and urinary bladder matrix (UBM), have been successfully used to improve soft tissue healing. Yet they contain plenty of galactose α1,3 galactose (αGal) epitopes, which cause rejection responses in pig organ transplantation to human. Recently, ECM bioscaffolds derived from genetically modified pigs that are αGal-deficient (αGal(-)) have become available. To ensure that the ECM bioscaffolds from these pigs can be used as alternatives, we examined their morphological, bioactive and biomechanical properties and compared them with those from the wild-type pigs (n=5 per group). Morphologically, the αGal(-) ECMs were found to be similar to the wild-type ECMs in gross observation and matrix appearance with hematoxylin and eosin staining. Growth factors commonly known to be present in ECM bioscaffolds, including FGF-2, TGF-β1, VEGF, IGF-1 and PDGF-BB, also showed no significant differences in terms of quantity (p>0.05) and distribution in tissue from the results of enzyme-linked immunosorbent assay, Western blot analysis and immunohistochemistry. Furthermore, a bromodeoxyuridine cell proliferation assay confirmed the bioactivity of the extracts from the αGal(-) bioscaffolds to be similar to the wild-type bioscaffolds. Under uniaxial tensile testing, no significant differences were found between the αGal(-) and wild-type bioscaffolds in terms of their viscoelastic and mechanical properties (p>0.05). These multidisciplinary results suggest that genetic modification to eliminate the αGal epitopes in the ECM bioscaffolds had not altered the properties of these ECM bioscaffolds and, as such, they should retain their performance in tissue engineering in humans.
authors.affiliation: Musculoskeletal Research Center, Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15219, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Liang
authors.forename: Matthew
authors.initials: M
authors.lastname: Fisher
authors.forename: Guoguang
authors.initials: G
authors.lastname: Yang
authors.forename: Christine
authors.initials: C
authors.lastname: Hall
authors.forename: Savio L-Y
authors.initials: SL
authors.lastname: Woo
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000378:metabolism / Q000473:pathology; D001696:Biomechanical Phenomena; D015153:Blotting, Western; D001973:Bromodeoxyuridine / Q000378:metabolism; D049109:Cell Proliferation; D005109:Extracellular Matrix / Q000378:metabolism* / Q000473:pathology; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D005700:Galactosyltransferases / Q000172:deficiency* / Q000378:metabolism; D055786:Gene Knockout Techniques; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000473:pathology; D015203:Reproducibility of Results; D034421:Sus scrofa; D054457:Tissue Scaffolds / Q000737:chemistry*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D001743:Urinary Bladder / Q000473:pathology
chemical_list: D053773:Transforming Growth Factor beta1; D016222:Fibroblast Growth Factor 2; D005700:Galactosyltransferases; C047006:N-acetyllactosaminide alpha-1,3-galactosyltransferase; D001973:Bromodeoxyuridine