1 / 39

Skin barrier function, skin conductivity

Skin barrier function, skin conductivity. Michal Jurajda. Terminology. Keratos = horn in Greek Cornu = horn in Latin. Skin is the body organ. epidermis. skin adnexa. +. dermis. tela subcutanea. Skin functions. Barrier functions (phys., chem. and biol.)

jeslyn
Télécharger la présentation

Skin barrier function, skin conductivity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Skin barrier function,skin conductivity Michal Jurajda

  2. Terminology • Keratos = horn in Greek • Cornu = horn in Latin

  3. Skin is the body organ epidermis skin adnexa + dermis tela subcutanea

  4. Skin functions • Barrier functions (phys., chem. and biol.) • metabolic functions (vit.D activation, excretion) • immune function, APC (Langerhansovy buňky) • Senzoring of temperatute and pain • Thermoregulation

  5. Stratum corneum Skin barrier - epidermis • Epidermal layers Stratum dysjunktum Stratum compactum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale

  6. Skin barrier • System of two compartments • „ bricks and mortar “ • keratinocytes (corneocytes) • intersticium

  7. Skin barrier • „Bricks“ • Keratinized cells • „Mortar“ • Produced by keratinocytes (Odland bodies, lamellar bodies) • Excretions of skin glands • FFA, ceramids, cholesterol

  8. Skin barrier – cellular component • Mechanic function • Hydratation • UV protection • Inflammatory response (APC)

  9. Keratin • Epithelial cells almost always coexpress pairs of type I and type II keratins, and the pairs that are coexpressed are highly characteristic of a given epithelial tissue. • In human epidermis, 3 different pairs of keratins are expressed: keratins 5 (type II) and 14 (type I), characteristic of basal or proliferative cells; keratins 1 (type II) and 10 (type I), characteristic of suprabasal terminally differentiating cells; and keratins 6 (type II) and 16 (type I) and keratin 17 (type I), characteristic of cells induced to hyperproliferate by disease or injury, and epithelial cells grown in cell culture.

  10. Filaggrin • Protein from corneocytes • In the deeper layers of epidermis connected to keratin • In the upper layers of epidermis is hydrolyzed. Free aminoacids are released. • Acidic pH and osmotic activity

  11. UCA urocanic acid • Originates from filaggrin. • Acidic pH of the epidemmis • Natural sunscreen • Cis-UCA immunosupression

  12. Skin damage by UV rays • direct • pyrimidin dimers formation – mostly thymin (UVB) • photoageing – induction/inhibition of gene expression (↓colagen, ↑MMPs, ↑elastase) • indirect • ROS formation (following excitation of „chromophores“ – molecules containing conjugated double bonds and/or aromatic circles) • retinoid depletion in skin • imunosupression (esp. UVA) • folate degradation – systemic effects

  13. Melanin – protection against ultraviolet radiation

  14. Interstitial compartment • Permeability • Deskvamation • Antimicrobial effect • Absorption of drugs or poisons • Hydratation

  15. Lamellar bodies (LB) • Lipids + enzymes producing FFA cholesterol a ceramids - permeability • Structural proteins (corneodesmin), serine proteases, proteases inhibitors – regulation of skin desquamation • Antimicrobial peptides (βdefensins, cathelicidiny – evolutionary old proteins)

  16. Cosmetics and the skin barrier • Cosmetics x pharmaceuticals • Different sale regulations • Different declaration of ingredients • Cosmetics: according to % in content • Pharmaceuticals: according to active component

  17. INCI • International Nomenclature Cosmetics Ingredients – unified nomenclature for cosmetics • Cosmetics, Toiletries & Fragrance Association (CTFA) – author of INCI

  18. Examples

  19. Skin cleanser cosmetics

  20. The importance of skin barrier function – why we are interested in? • Protection against environment • Professional exposure • Skin diseases influence skin barrier • Atopic or contact dermatitis • Drugs absorption

  21. How to test skin barrier • Resistence against given chemical compound • Stripping tests • Transparency test • Transepidermal water loss • Chemical analysis of skin eluates

  22. Transparency test

  23. Atopic dermatitis • Sensibilization • Allergic reaction

  24. Atopic dermatitis

  25. Prick test

  26. Contact dermatitis • Haptens • nickel

  27. Skin barrier tests • Burckhardt test • Locher test, nitrazolium yellow • Skin conductivity

  28. Measuring of skin conductivity by Dermotest • AC 32Hz; 0-500 μS. • standard load iontophoresis 1.5 mA, with NaCl (physiological saline).

  29. The device measures 5 characteristic values (V1-V5): 1min after the start (V1) 30 a 60s after the start of electrophoresis (V2, V3) 30 a 60s after switching off the electrophoresis(V4, V5)

  30. Normal values • V1 less than 30 μS • V3 up to 200-300 μS • V5 return to initial values • Test might be repeated after 15 minutes with the same result

  31. desquamation

  32. occlusion

  33. Course of atopic dermatitis therapy

More Related