Background: Facial fat grafting for rejuvenation is one of the most popular facial aesthetic procedures in plastic surgery. It is always challenging and since there are a lot of techniques for adipose tissue (AT) harvesting, there are no standard procedures that guarantee natural and long-lasting results. We developed the selective tissue engineering photo stimulation technique (One STEP™) in which we used a novel infrared 1210-nm wavelength laser diode for fat preserved harvesting and direct fat injection that we named PicoGraft™, with no fat manipulation. Methods: This is a retrospective descriptive study in which we included all senior author’s patients that got facial fat grafting using the One STEP™ technique. We compared the AT aspirated, after laser emission (STEP-PicoGraft) and the standard assisted liposuction samples (SAL) in cultures. We study the mitochondrial activit...