Keratinocyte Exosomes for Topical Delivery of Tofacitinib in Treatment of Psoriasis: an In Vitro/ In Vivo Study in Animal Model of Psoriasis.

INTRODUCTION

Exosomes are extracellular vesicles in the range of 40-150 nm released from the cell membrane. Exosomes secreted by keratinocytes can communicate with other keratinocytes and immune cells with specific biomarkers at their surface, which may be effective on inflammation of psoriasis and its pathogenesis.

OBJECTIVE

The present study aimed to formulate and study effectiveness of an exosomal delivery system of tofacitinib (TFC).

METHODS

TFC was loaded by different methods in exosomes and then characterized for particle size, zeta potential, drug loading efficiency, and release efficiency. By comparing these parameters, the probe sonication method was chosen to load TFC into exosomes. The MTT assay was used to compare the cytotoxicity of the free drug with the TFC-loaded exosomes (TFC-Exo), and Real-time PCR was used to determine the expression levels of several genes involved in psoriasis expressed in the A-431 keratinocyte and their suppression after treatment. Animal model of psoriasis was induced in BALB/c mice by imiquimod and the efficacy of free TFC, and TFC-Exo were studies on macroscopic appearance and histopathological symptoms.

RESULTS

Exosomes encapsulating TFC showed lower cytotoxicity in MTT assay, higher suppression the expression of TNF-a, IL-23, IL-6, and IL-15 genes in real-time PCR and better therapeutic effect on animal models compered to free TFC.

CONCLUSIONS

This method of drug delivery for TFC may be effective on enhancing its therapeutic effects and reduction its side effects favorably in chronic administration.