Table 2 Results on changes in cellular, signaling and/or mechanical response to chondrocyte-seeded meshes for hydrostatic and direct compression (Fig. 2). PGA is polyglycolic acid; PEGT/PBT is polyethylene glycol terephthalate/polybutylene terephthalate; Sox9 is the gene that regulates chondrogenic differentiation; # is number; h is hours; h/day is hours per day; − is decrease or inhibition; = is no change or status quo; + is increase; ++ is highest increase. *-symbol implies pressure converted from strain, which is added in brackets; **loading was performed every other day for 1 h twice a day with 8 h rest in between
From: What quantitative mechanical loading stimulates in vitro cultivation best?
Study | Cell source, cultivated construct, additive(s) | Magnitude (MPa) | Freq (Hz) | Loading (h/day) | Loading (# days) | Loading (total h) | Culture composition (change -, =, +) | mRNA response (change -, =, +) | Other findings (change -, =, +) |
|---|---|---|---|---|---|---|---|---|---|
Hydrostatic compression | |||||||||
Carver 1999a (Carver and Heath 1999a) | Young equine Mesh nonwoven PGA 10 % Fetal bovine serum; 50 μg/mL ascorbic acid | 3.4 | 0.25 | 2 | 35 | 70 | + GAG |  | GAG increase strongest at 6.9 MPa for young |
= collagen II | |||||||||
= # of chondrocytes | |||||||||
6.9 | + GAG | Â | |||||||
+ collagen II | |||||||||
= # of chondrocytes | |||||||||
Adult equine Mesh nonwoven PGA 10 % Fetal bovine serum; 50 μg/mL ascorbic acid | 3.4 | + GAG |  | Collagen II increase strongest at 6.9 MPa for young and adult | |||||
+ collagen II | |||||||||
= # of chondrocytes | |||||||||
6.9 | = GAG | Â | |||||||
+ collagen II | |||||||||
= # of chondrocytes | |||||||||
Carver 1999b (Carver and Heath 1999b) | Young equine Mesh nonwoven PGA 10 % Fetal bovine serum; 50 μg/mL ascorbic acid | 3.44 | 0.25 | 2 | 35 | 70 | + GAG |  | + E- modulus |
+ collagen | |||||||||
= # of chondrocytes | |||||||||
Direct compression | |||||||||
Démarteau 2003 (Démarteau et al. 2003) | Human Mesh PEGT/PBT Foam 10 % Fetal bovine serum; growth factor TGF-β1, FGF-2, PDGFbb | 0.3-0.6* (5 %) | 0.1 | 4 | 3 | 12 | + GAG | = Sox9 | Measured peak loading 0.018 MPa |
= aggrecan | |||||||||
= collagen II | |||||||||
Hilz 2014 (Hilz et al. 2014) | Bovine, Mesh Polyurethane 25 % Fetal calf serum;50 μg/mL L-ascorbic acid | 1.2-2.4* (20 %) | 1 | 2** | 21 | 16 | + GAG | =Sox9 |  |
+ aggrecan | +collagen II | ||||||||
+ collagen II | |||||||||
El-ayoubi 2011 (El-Ayoubi et al. 2011) | Canine, Mesh poly-L-Lactide 10Â % Fetal bovine serum | 0.6-1.2* (10Â %) | 1 | 3 | 14 | 42 | + # of cells | Â | Â |