Retinyl palmitate polymeric nanocapsules as carriers of bioactives.
Nanocapsules containing poly(d,l-lactide) shell and retinyl palmitate core have been prepared by the pre-formed polymer interfacial deposition method. Dynamic light scattering measurements yielded an average hydrodynamic diameter of ∼220nm and a polydispersity index of ∼0.12. Small-angle neutron scattering experiments revealed the presence of two populations of nanocapsules of core diameters ∼192 and 65nm. Freeze fracture transmission electron microscopy showed a polydisperse population of nanocapsules (NC), with a poly(d,l-lactide) shell thickness between 11 and 3nm. For comparison purposes, nanoemulsions (NE, no polymer) and nanospheres (NS, polymer matrix) were also prepared. Each type of nanoparticles exhibited a different morphology (when examined by electron microscopy), in particular NC showed deformability by capillary adhesion. All three types of nanoparticles successfully encapsulated the poorly water-soluble molecules baicalein and benzophenone-3. The thermal behavior of the various nanoparticles was different to a physical mixture of its individual components. Cytotoxicity and phototoxicity assays, performed in human keratinocytes (HaCaT) and murine fibroblasts (BALB/c 3T3), showed that the NC were only cytotoxic at high concentrations. In vitro release studies of benzophenone-3, by the dialysis bag method using NC and NS, showed a sustained release; however, permeation studies using plastic surgery human abdominal skin in Franz diffusion cells showed that a higher amount of benzophenone-3 from NC penetrated into the skin, most probably due to the deformable nature of these nanoparticles.
Instituto de Química, Universidade Estadual de Campinas, P.O. Box 6154, Brazil. zaineteixeira@ufs.br
Zaine
Z
Teixeira
Cécile A
CA
Dreiss
M J
MJ
Lawrence
Richard K
RK
Heenan
Daisy
D
Machado
Giselle Z
GZ
Justo
Sílvia S
SS
Guterres
Nelson
N
Durán
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage* / Q000493:pharmacokinetics; D041702:BALB 3T3 Cells; D001577:Benzophenones / Q000008:administration & dosage / Q000493:pharmacokinetics; D002460:Cell Line; D004224:Diterpenes; D044950:Flavanones / Q000008:administration & dosage / Q000493:pharmacokinetics; D006801:Humans; D051379:Mice; D053769:Nanocapsules / Q000737:chemistry* / Q000633:toxicity; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry* / Q000633:toxicity; D000084562:Retinyl Esters; D012867:Skin / Q000166:cytology / Q000378:metabolism; D012869:Skin Absorption; D013473:Sunscreening Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D014801:Vitamin A / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
D000975:Antioxidants; D001577:Benzophenones; D004224:Diterpenes; D044950:Flavanones; D053769:Nanocapsules; D011091:Polyesters; D000084562:Retinyl Esters; D013473:Sunscreening Agents; D014801:Vitamin A; C014794:retinol palmitate; C033616:poly(lactide); C006680:baicalein; C005290:oxybenzone