Photodynamic therapy for hair removal

Background: Unwanted hair is one of the most common medical problems affecting women of reproductive age inducing a lot of psychological stress and threatening their femininity and self-esteem. Old methods of removing unwanted hair include shaving, waxing, chemical epilation, and electrolysis, all of which have temporary results. However laser-assisted hair removal is the most efficient method of long-term hair removal currently available. It is desirable to develop a reduced-cost photodynamic therapy (PDT) system whose properties should include high efficiency and low side-effects. Objectives: The aim is to develop an adequate PDT system including helium-neon (He-Ne) laser and its effect on the photodynamic activity of methylene blue (Figs. 1 and 2) in biological experiments. Method: Mice skin tissues were used in this study and divided into the following six groups: controls (Fig.3), free methylene blue (MB) incubation, liposomal MB incubation, laser without MB, free MB for 3 and 4 hrs and laser, liposome MB for 3 hrs and laser. MB was applied to wax epilated areas. The areas were irradiated with CW He-Ne laser system that emits orange-red light with wavelength 632.8 nm and 10 mW at energy density of 5 J/cm2 for 10 minutes. The UV-visible spectrum was collected by Cary spectrophotometer. Results: MB is selectively absorbed by actively growing hair follicles due to its cationic property (Fig.4). MB untreated sections showed that hair follicles and sebaceous glands are intact and there is no change due to the laser exposure (Fig.5). Free MB sections incubated for 3 hrs showed that He:Ne laser induced destruction in hair follicles, leaving an intact epidermis (Fig. 6). Treated section with free MB for 4 hrs showed degeneration and necrosis in hair follicles, leaving an intact epidermis (Fig. 7). Liposomal MB sections incubated for 3 hrs showed He:Ne laser induced destruction in hair follicles with intradermal leukocytic infiltration (Fig. 8). Conclusion: Low power He:Ne laser and MB offers a successful PDT system in selectively damaging hair follicles, leaving an intact epidermis. The current PDT system provides better outcome than hair destruction through laser heat transfer procedures and laser-mediated hair removal, due to complete destruction of hair follicles.