Laser biostimulation of cartilage: in vitro evaluation.

An in vitro study was performed to evaluate the laser biostimulation effect on cartilage using a new gallium-aluminium-arsenic diode laser. Chondrocyte cultures were derived from rabbit and human cartilage. These cells were exposed to laser treatment for 5 days, using the following parameters: 300 joules, 1 watt, 100 (treatment A) or 300 (treatment B) hertz, pulsating emission for 10 minutes, under a sterile laminar flow. Control cultures (no treatment) received the same treatment with the laser device off. Cell viability was measured by MTT assay at the end of the laser treatment and then after 5 days. Neither rabbit nor human cultured chondrocytes showed any damage under a light microscope and immunostaining control following laser treatment. The MTT test results indicated a positive biostimulation effect on cell proliferation with respect to the control group. The increase in viability of irradiated chondrocytes was maintained for five days following the end of the laser treatment. The results obtained with the Ga-Al-As diode laser using the above tested parameters for in vitro biostimulation of cartilage tissues provide a basis for a rational approach to the experimental and clinical use of this device.