Effects of LED Photobiomodulation Therapy on the Proliferation of Chondrocytes

The present study aimed to evaluate the effects of PBMT by LED on chondrocyte culture derived from articular cartilage of rats. All cell culture procedures were performed under stringent aseptic conditions in a biological safety cabinet. For this, the chondrocytes were extracted from the femoral articular cartilage of rats using 0.25% type I collagenase. After extraction, the cells were seeded at 5.10⁴ cells and divided into 4 groups: Control (chondrocytes that did not receive PBMT); PBMT 70 mW (chondrocytes that received PBMT with a power of 70 mW); PBMT 150 mW (chondrocytes that received PBMT with a power of 150 mW); PBMT 300 mW (chondrocytes that received PBMT with a power of 300 mW). After 12 h of the cells being seeded, PBMT by LED (850 nm) was started and performed every 24 h, totaling 3 sessions. After this period, the viability and cell proliferation were analyzed. The results showed that all experimental groups were able to maintain cell viability. However, when cell proliferation was evaluated, only the 150 mW PBMT group was able to increase chondrocyte proliferation. In addition, the PBMT 70 mW and 300 mW groups presented lower cell proliferation when compared to the control group. Thus, it can be suggested that PBMT by LED induced a dose response effect and 150 mW power was able to maintain cell viability and proliferation.