title: Pneumatic pressure bioreactor for cyclic hydrostatic stress application: mechanobiology effects on periodontal ligament cells.
abstract: A bioreactor system was developed to provide high-amplitude cyclic hydrostatic compressive stress (cHSC) using compressed air mixed commercially as needed to create partial pressures of oxygen and carbon dioxide appropriate for the cells under investigation. Operating pressures as high as 300 psi are achievable in this system at cyclic speeds of up to 0.2 Hz. In this study, ligamentous fibroblasts from human periodontal ligaments (n = 6) were compressed on two consecutive days at 150 psi for 3 h each day, and the mRNA for families of extracellular matrix protein and protease isoforms was evaluated by real-time PCR array. Several integrins were significantly upregulated, most notably alpha-3 (6.4-fold), as was SPG7 (12.1-fold). Among the collagens, Col8a1 was highly upregulated at 53.5-fold, with Col6a1, Col6a2, and Col7a1 also significantly upregulated 4.4- to 8.5-fold. MMP-1 was the most affected at 122.9-fold upregulation. MMP-14 likewise increased 17.8-fold with slight reductions for the gelatinases and a significant increase of TIMP-2 at 5.8-fold. The development of this bioreactor system and its utility in characterizing periodontal ligament fibroblast mechanobiology in intermediate-term testing hold promise for better simulating the conditions of the musculoskeletal system and the large cyclic compressive stresses joints may experience in gait, exertion, and mastication.
authors.affiliation: Department of Orthopaedic Surgery, Georgia Health Sciences University, Augusta, GA 30912, USA. kwenger@georgiahealth.edu
authors.forename: Karl H
authors.initials: KH
authors.lastname: Wenger
authors.forename: Ahmed R
authors.initials: AR
authors.lastname: El-Awady
authors.forename: Regina L W
authors.initials: RL
authors.lastname: Messer
authors.forename: Mohamed M
authors.initials: MM
authors.lastname: Sharawy
authors.forename: Greg
authors.initials: G
authors.lastname: White
authors.forename: Carol A
authors.initials: CA
authors.lastname: Lapp
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D019149:Bioreactors; D002478:Cells, Cultured; D003094:Collagen / Q000235:genetics / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D018093:Gelatinases / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D006874:Hydrostatic Pressure; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D011312:Pressure; D012333:RNA, Messenger / Q000235:genetics; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics / Q000378:metabolism
chemical_list: D016326:Extracellular Matrix Proteins; D012333:RNA, Messenger; D019716:Tissue Inhibitor of Metalloproteinase-2; D003094:Collagen; D010447:Peptide Hydrolases; D018093:Gelatinases; D008666:Metalloendopeptidases; C112889:SPG7 protein, human; D020781:Matrix Metalloproteinase 1; D053511:Matrix Metalloproteinase 14; D000074183:ATPases Associated with Diverse Cellular Activities