Abstract: ObjectiveTo investigate the effect of linear polarized infrared light irradiation on the proliferation of primary
cultured rabbit articular chondrocytes irradiation.MethodsPrimary cultured rabbit articular chondrocytes were irradiated
with linear polarized infrared light irradiation (Super Lizer) at the power intensity of20% (360mW) to100% (1800mW) for5
min per day for5 days, and CCK-8 assay was used to measure the proliferative activity of the chondrocytes after the
exposures.ResultsThe D450 values of the cells irradiated at the power intensity of60% (1080mW) and80% (1440mW) (1.88±
0.11and1.99±0.05, respectively) were significantly greater than that of the control cells (0.95±0.38, P<0.05). The irradiation with
Super Lizer at lower (20%,360mW and40%,720mW) or higher (100%,1800mW) power intensities did not cause significant
increases of the D450 values. Compared with the control group, Super Lizer irradiation at the power intensities of20% ,40% ,
60% , and80% resulted in increment ratios of chondrocyte viability of (48.75±15.4)% , (67.02±29.61)% , (97.93±11.57)% , and
(108.52±5.81)% , respectively, but at 100% power intensity (1800mW), the irradiation caused a lowered chondrocyte viability
increment ratio of (62.84±31.12)% . ConclusionLinear polarized infrared light irradiation can promote the proliferation of
chondrocytes in an intensity-dependent manner, and the strongest effect occurs with the irradiation power intensity of80%
(1440mW).