oregon-green-488-carboxylic-acid and 4-4-difluoro-4-bora-3a-4a-diaza-s-indacene

In skin and hair research drug targeting to the hair follicle is of great interest. Therefore the influence of permeant lipophilicity and vehicle composition on local accumulation has been examined using confocal laser scanning microscopy (CLSM). Formulations saturated with either Oregon Green 488, Bodipy FL C(5) or Bodipy 564/570 C(5) were prepared. The dyes were applied in citric acid buffer, 8% (w/v) surfactants in citric acid buffer or 8% (w/v) surfactants/20% (w/v) propylene glycol in citric acid buffer. Flow-through diffusion experiments were performed with fresh human scalp skin, after which the skin was imaged using CLSM. Diffusion studies showed for Oregon Green 488 (low lipophilicity) a higher flux when applied in citric acid buffer compared to surfactants. In contrast the fluxes of the more lipophilic dyes (Bodipy FL C(5) and Bodipy 564/570 C(5)) are highest when applied in surfactants/propylene glycol. CLSM studies revealed that follicular accumulation increased with (i) a lipophilic dye and (ii) application of lipophilic dyes in surfactants-propylene glycol. Therefore we conclude that targeting to the hair follicle can be increased by the use of lipophilic drugs in combination with surfactant solutions and propylene glycol.

Topics: Boron Compounds; Carboxylic Acids; Chemistry, Pharmaceutical; Diffusion; Hair Dyes; Hair Follicle; Humans; Microscopy, Confocal; Pharmaceutical Vehicles; Propylene Glycol; Scalp; Skin Absorption; Surface-Active Agents; Tissue Distribution

Fluorescent model substances of increasing lipophilicity (Oregon Green) 488, Bodipy, FL C5 and Bodipy 564/570 C5) were selected to enable the visualization in the skin using confocal laser scanning microscopy. After measuring the penetration for 18 h, the nonfixed human scalp skin was imaged from the bottom parallel to the stratum corneum and in a cross-section view perpendicular to the skin surface. The images were evaluated by calculating relative accumulation values for different penetrants. The studies indicate that the penetrated amount is highest for Bodipy FL C5 (medium lipophilicity) and lowest for Bodipy 564/570 C5 (high lipophilicity) whereas Bodipy 564/570 C5 (high lipophilicity) reveals the highest relative accumulation in parts of the hair follicle compared to Oregon Green 488 (low lipophilicity). The addition of 30% (v/v) ethanol to the donor phase of substance with a low lipophilicity increases the follicular delivery. From our results we conclude that delivery to the hair follicle can be improved by increasing the drugs lipophilicity and optimizing the composition of the donor phase. However, no conclusion can be drawn about the actual route of transport to the hair follicle.

Topics: Boron Compounds; Carboxylic Acids; Citric Acid; Drug Delivery Systems; Ethanol; Hair Follicle; Humans; In Vitro Techniques; Liposomes; Skin; Skin Absorption

A two-color fluorescence detection method is described based upon covalently coupling the succinimidyl ester of BODIPY FL-X to proteins immobilized on poly(vinylidene difluoride) (PVDF) membranes, followed by detection of target proteins using the fluorogenic substrate 9H-(1,3-dichloro-9,9-dimethylacridin-2-one-7-yl(DDAO)-phosphate in combination with alkaline-phosphatase-conjugated reporter molecules. This results in all proteins in the profile being visualized as green signal while those detected specifically with the alkaline-phosphatase conjugate appear as red signal. The dichromatic detection system is broadly compatible with a wide range of analytical imaging devices including UV epi- or transilluminators combined with photographic or charge-coupled device (CCD) cameras, xenon-arc sources equipped with appropriate excitation/emission filters, and dual laser gel scanners outfitted with a 473 nm second-harmonic generation or 488 nm argon-ion laser as well as a 633 nm helium-neon or 635 nm diode laser. The dichromatic detection method permits detection of low nanogram amounts of protein and allows for unambiguous identification of target proteins relative to the entire protein profile on a single electroblot, obviating the need to run replicate gels that would otherwise require visualization of total proteins by silver staining and subsequent alignment with chemiluminescent or colorimetric signals generated on electroblots.

Topics: Acridines; Alkaline Phosphatase; Animals; Blotting, Western; Boron Compounds; Brain Chemistry; Carboxylic Acids; Cattle; Egg Proteins; Electrophoresis; Fibroblasts; Fluorescent Dyes; Glycoproteins; Indicators and Reagents; Phosphates; Polyvinyls; Proteins; Rats; Spectrometry, Fluorescence; Tubulin