title: Rhamnolipids form drug-loaded nanoparticles for dermal drug delivery.
abstract: Bacterial biosurfactants are nature's strategy to solubilize and ingest hydrophobic molecules and nutrients using a fully biodegradable transport system. Eight structurally defined rhamnolipids were selected and investigated as potential drug carrier systems. Depending on the molecular structures defining their packing parameters, the rhamnolipids were found to form spherical nanoparticles with precisely defined average sizes between 5 and 100nm, low polydispersity, and stability over a broad concentration range as revealed from dynamic light scattering and electron microscopy. As rhamnolipids were tolerated well by the human skin, rhamnolipid nanoparticles were considered for dermal drug delivery and thus loaded with hydrophobic drug molecules. Using the drug model, Nile red, dexamethasone, and tacrolimus nanoparticles charged with up to 30% drug loading (w/w) were obtained. Nanoparticles loaded with Nile red were investigated for dermal drug delivery in a Franz cell using human skin. Fluoresence microscopy of skin slices indicated the efficient penetration of the model drug into human skin, both into the stratum corneum and although to a lesser extent into the lower epidermis. Rhamnolipid nanocarriers were found to be non-toxic to primary human fibroblasts in a proliferation assay and thus are considered candidates for the dermal delivery of drugs.
authors.affiliation: Institute of Pharmacy, Medicinal Chemistry, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Müller
authors.affiliation: Institute of Pharmacy, Medicinal Chemistry, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hönzke
authors.affiliation: Institute of Pharmacy, Medicinal Chemistry, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany.
authors.forename: Wulf-Ole
authors.initials: WO
authors.lastname: Luthardt
authors.affiliation: Institute of Pharmacy, Medicinal Chemistry, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany.
authors.forename: Ee Lin
authors.initials: EL
authors.lastname: Wong
authors.affiliation: Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Unbehauen
authors.affiliation: Institute of Pharmacy, Medicinal Chemistry, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Bauer
authors.affiliation: Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Haag
authors.affiliation: Institute of Pharmacy, Medicinal Chemistry, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Hedtrich
authors.affiliation: Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Eckart
authors.initials: E
authors.lastname: Rühl
authors.affiliation: Institute of Pharmacy, Medicinal Chemistry, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany. Electronic address: joerg.rademann@fu-berlin.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Rademann
mesh_terms: D000279:Administration, Cutaneous; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003907:Dexamethasone / Q000008:administration & dosage / Q000737:chemistry*; D004337:Drug Carriers / Q000008:administration & dosage / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods; D006017:Glycolipids / Q000008:administration & dosage* / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*; D010078:Oxazines / Q000008:administration & dosage / Q000737:chemistry*; D010316:Particle Size; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption / Q000187:drug effects; D016559:Tacrolimus / Q000008:administration & dosage / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D006017:Glycolipids; D010078:Oxazines; C418382:rhamnolipid; D003907:Dexamethasone; C044808:nile red; D016559:Tacrolimus
keywords: Biosurfactants; Dermal drug delivery; Dexamethasone; Nanocarrier; Nanoparticles; Rhamnolipid; Tacrolimus