Table 2.
Study Design and Reported Biochemical Outcomes for In Vitro Studies.
| First Author, Year | Operating Mode and Treatment Duration | Study Design | Biochemical Outcomes | ||
|---|---|---|---|---|---|
| Chondrocytes Proliferation and Activity | ECM Synthesis/Degradation | Inflammatory Markers | |||
| Sakata, 2020 18 | Pulsed mode once for the duration of 4 or 12h | Human articular chondrocyte-knee (NHAC-Kn) cell line treated with recombinant human IL-1β | NA | ↓ MMP-1 and ↓ MMP-3 after both 4 and 8 J/cm2
No effect on MMP-9 and MMP-13 after both 4 and 8 J/cm2 (gene expression by RT-PCR, protein expression by Western Blot and ELISA) |
↓ IL-1β, ↓ IL-6, ↓ TNF-α for both 4 and 8
J/cm2
(gene expression by RT-PCR and protein expression by Western blot) |
| Yang, 2020 19 | Continuous, 8 min daily for 1, 3 and 5 days | Chondrocytes isolated from New Zealand white rabbits’
cartilage and expanded C28/I2 Human Chondrocyte Cell Line for gene expression analysis only |
↑ Chondrocytes viability after 8 min of LT (MTS
assay) No effect after 11 and 13 min of LT exposure ↑ Viable cells (live and dead assay) |
No effects on GAGs production (Alcian blue assay) until
6 days but were higher than control in posttreatment
period ↑ Matrix deposition (safranin O staining) ↓ COL I for all time points and ↑ COL II after 5 days (protein expression by western blot) ↑ ACAN, ↑ COL II, ↑ SOX-9 after 5 days and ↓ COL I after 3 and 5 days (gene expression by RT-PCR) ↓ MMP-13 after IL1-β and LT stimulation (protein expression by western blot and gene expression by RT-PCR) |
↓ IL1-β after LT and ↓ TNF-α after IL1-β and LT
stimulation (protein expression by Western blot and gene expression by RT-PCR) |
| Jia, 2004 20 | Continuous, 3 times at 24-hour intervals. | Chondrocytes isolated from New Zealand rabbits´ cartilage and expanded | ↑ Chondrocytes viability after irradiation at 4
J/cm2
Irradiations at 1, 2, 3 J/cm2 did not improve this outcome After 5 and 6 J/cm2, the viability decreased (XTT assay) |
↑ GAGs expression intensity (Toluidine-blue
staining) ↑ COL II expression intensity (immunocytochemistry) |
NA |
COL I and II, collagen type I and II; MMP, matrix metalloproteinase; ACAN, aggrecan; SOX-9, SRY-box transcription factor 9; GAGs, glycosaminoglycans; IL, interleukin; TNF-α, tumor necrosis factor-α; RT-PCR, reverse transcription polymerase chain reaction; ELISA, enzyme-linked immunosorbent assay; NA, not applicable.