Investigation of polylactic acid (PLA) nanoparticles as drug delivery systems for local dermatotherapy.
OBJECTIVE
The development of particle-based carriers for transepidermal drug delivery has become a field of major interest in dermatology. In this study, we investigated the suitability of biodegradable poly-lactic acid (PLA) particles loaded with fluorescent dyes as carriers for transepidermal drug delivery.


METHODS
The penetration profiles of PLA particles (228 and 365 nm) and the release of dye from the particles were investigated in human skin explants using fluorescence microscopy, confocal laser scanning microscopy and flow cytometry.


RESULTS
PLA particles penetrated into 50% of the vellus hair follicles, reaching a maximal depth corresponding to the entry of the sebaceous gland in 12-15% of all observed follicles. The accumulation of particles in the follicular ducts was accompanied by the release of dye to the viable epidermis and its retention in the sebaceous glands for up to 24 h. Kinetic studies in vitro as well as in skin explants revealed, that, although stable in aqueous solution, destabilization of the particles and significant release of incorporated dye occurred upon contact with organic solvents and the skin surface.


CONCLUSIONS
These results suggest that particles based on PLA polymers may be ideal carriers for hair follicle and sebaceous gland targeting.
Rancan
Fiorenza
F
Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science, Charité-Universitätsmedizin Berlin, Chariteplatz 1, 10117, Berlin, Germany.
Papakostas
Dimitrios
D
Hadam
Sabrina
S
Hackbarth
Steffen
S
Delair
Thierry
T
Primard
Charlotte
C
Verrier
Bernard
B
Sterry
Wolfram
W
Blume-Peytavi
Ulrike
U
Vogt
Annika
A
D003879:Dermatologic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D016503:Drug Delivery Systems; D006801:Humans; D019344:Lactic Acid / Q000008:administration & dosage*; D053758:Nanoparticles; D011091:Polyesters; D011108:Polymers / Q000008:administration & dosage*; D012871:Skin Diseases / Q000188:drug therapy*; D013050:Spectrometry, Fluorescence
D003879:Dermatologic Agents; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)