Optical lens-microneedle array for percutaneous light delivery.

The limited penetration depth of light in skin tissues is a practical bottleneck in dermatologic applications of light-induced therapies, including anti-microbial blue light therapy and photodynamic skin cancer therapy. Here, we demonstrate a novel device, termed optical microneedle array (OMNA), for percutaneous light delivery. A prototype device with a 11 by 11 array of needles at a spacing of 1 mm and a length of 1.6 mm was fabricated by press-molding poly-(lactic acid) (PLA) polymers. The device also incorporates a matched microlens array that focuses the light through the needle tips at specific points to achieve an optimal intensity profile in the tissue. In experiments done with bovine tissues, the OMNA enabled us to deliver a total of 7.5% of the input photons at a wavelength of 491 nm, compared to only 0.85% without the device. This 9-fold enhancement of light delivery was close to the prediction of 10.8 dB by ray-tracing simulation and is expected to increase the effective treatment depth of anti-microbial blue light therapy significantly from 1.3 to 2.5 mm in human skin.

Shear Brillouin light scattering microscope.

Brillouin spectroscopy has been used to characterize shear acoustic phonons in materials. However, conventional instruments had slow acquisition times over 10 min per 1 mW of input optical power, and they required two objective lenses to form a 90° scattering geometry necessary for polarization coupling by shear phonons. Here, we demonstrate a confocal Brillouin microscope capable of detecting both shear and longitudinal phonons with improved speeds and with a single objective lens. Brillouin scattering spectra were measured from polycarbonate, fused quartz, and borosilicate in 1-10 s at an optical power level of 10 mW. The elastic constants, phonon mean free path and the ratio of the Pockels coefficients were determined at microscopic resolution.

RimabotulinumtoxinB versus OnabotulinumtoxinA in the treatment of masseter hypertrophy: a 24-week double-blind randomized split-face study.

BACKGROUND: Masseter hypertrophy can be ameliorated by botulinum toxin. OBJECTIVE: To compare the efficacy and safety of RimabotulinumtoxinB (BTX-B) and OnabotulinumtoxinA (BTX-A) in the treatment of masseter hypertrophy. METHODS: Sixteen women with bilateral masseter hypertrophy received single injections of BTX-A or BTX-B at a dose ratio of 1:50 or 1:70 in a 24-week double-blind randomized split-face study. RESULTS: Both BTX-A and BTX-B produced significant improvements in masseter hypertrophy. The maximum volume reduction, as determined by computed tomography scanning, at week 12 was comparable between BTX-A and BTX-B at a dose ratio of 1:70 (15.6 and 14.2%, respectively). At week 24, only masseters treated with BTX-A maintained a significant volume reduction. Investigator ratings and patient satisfaction scores paralleled objective computed tomography measurements. CONCLUSION: Both BTX-A and BTX-B are effective in the treatment of masseter hypertrophy. BTX-B, at a dose ratio of 1:70, has a comparable efficacy but a shorter duration of action than BTX-A.

0.5% Liposome-encapsulated 5-aminolevulinic acid (ALA) photodynamic therapy for acne treatment.

BACKGROUND: Photodynamic therapy using topical 5-aminolevulinic acid (ALA) has been successful in treating acne vulgaris, but sun avoidance for at least 48 hours after treatment is necessary due to the risk of post-treatment photosensitivity. Recently, a lower concentration of liposome-encapsulated 5-ALA was introduced to minimize this risk. OBJECTIVES: To evaluate the efficacy and safety of liposome-encapsulated 0.5% 5-ALA in the photodynamic therapy of inflammatory acne and its effects on sebum secretion in Asian skin. METHODS: Thirteen Korean subjects with inflammatory acne were administered 0.5% ALA spray before photoradiation treatment. Photoradiation was performed at 3.5-6.0 J/cm(2) three times during each of two visits, performed 2 weeks apart. Improvement of acne was evaluated subjectively and objectively based on the Korean Acne Grading System. Sebum secretion was measured quantitatively at each visit. RESULTS: The mean reduction in acne grade at the end of the treatment was 43.2%. Of the patients, 69.2% reported improvements in subjective skin oiliness, but fewer showed objective reductions in sebum secretion as determined by the Sebumeter® SM10. No serious adverse events were observed. CONCLUSION: Photodynamic therapy using liposome-encapsulated 0.5% 5-ALA improved inflammatory acne with minimal side effects in Asians.