Exploratory Study of the Cutaneous Penetration of Biodegradable Polymeric Microparticles in Atopic Dermatitis

This proof of concept study aims to assess in patients suffering from atopic dermatitis if polymeric microparticles reach the pilosebaceous follicles of inflamed skin.

Current treatments of inflammatory skin disorders such as acne, psoriasis or atopic dermatitis are primarily topical. They have the advantage of allowing the administration of active substances directly to the skin lesions.

However local treatments may have drawbacks (complex application, local and/or systemic side effects...) and cause poor compliance.

The use of drug carriers is viewed as one of the most promising strategies to target and control the release of active substances to various skin sites. Polymeric microparticles have shown to have a better stability and a more sustained release pattern than other types of drug vehicles such as liposomes.

Based on the results obtained in our preclinical experiments, this proof of concept study aims to assess, in patients suffering from atopic dermatitis, if biodegradable polymeric microparticles reach the pilosebaceous follicles of inflamed skin which would in turn serve as a reservoir of active substance.

Eligibility Criteria:
Inclusion Criteria:

* Healthy volunteers:

  * Volunteers over 18
  * Male volunteers under 65 or women of childbearing age (with a negative pregnancy test obtained at least 3 weeks before inclusion)
  * Caucasian volunteers
  * Volunteers having never shown any type of skin lesions regardless of its origin especially any allergic skin reactions.
  * Volunteers having signed a free and informed consent form
  * Volunteers affiliated to a social security system
* Patients:

  * Patients over 18
  * Male patients under 65 or women of childbearing age (with a negative pregnancy test obtained at least 3 weeks before inclusion)
  * Caucasian patients
  * Acute phase of atopic dermatitis with a SCORAD between 15 and 40
  * Patients suffering from atopic dermatitis skin lesions ≥ 1.5 cm² on the inside of the forearm
  * Patients having been treated by class II dermocorticoids with a two-week wash-out prior to inclusion
  * Patients having signed a free and informed consent form
  * Patients affiliated to a social security system

Exclusion Criteria:

* Participants under 18
* Pregnant or Breastfeeding women
* Post-menopausal women
* Patients having skin lesions adjacent to the selected area
* Patients with complications of atopic dermatitis
* SCORAD \<15 or \>40
* Patients being treated with a topical or a systemic treatment influencing the skin penetration of the microparticles
* Patients allergics to any component of the formulation
* Patients using cosmetic products on their forearms
* Patients planning to expose themselves to the sun
* Patients with a known immune deficiency
* Patients allergic to any product or device used before, during or after the skin biopsy
* Patients suffering from known wound healing disorders
* Patients with known inherited ou acquired hemostasis disorders
* Patients unable to follow the protocol requirements
* Patients currently involved in another clinical trial (or whose participation has ended less than 2 weeks before inclusion)
* Patients who are not affiliated to a social security system
* Patients in an exclusion period following participation in another clinical trial
* Incapacitated adults
* Participants placed under tutorship or curatorship
* Participants under judicial protection