2.1 Materials
Annatto extract (containing the main components bixin, norbixin, and
carotenoids) was purchased from Amazonia Forest Trading (Manaus,
Brazil). Cellulose acetate (CA) in powder form, with Mn
~30,000 g/mol, density of 1.3g/ml, and 40% degree of
substitution was purchased from Sigma-Aldrich (São Paulo). The solvent
used to obtain annatto extract was ethanol, and for electrospinning
acetone and N,N-dimethylformamide (DMF), all from Labsynth (Diadema,
Brazil). For biological assays, Dulbecco’s Modified Eagle medium (DMEM),
fetal bovine serum (FBS), penicillin-streptomycin-amphotericin B
solution (anti-anti), and
3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) were
all purchased from Gibco-Invitrogen (São Paulo, Brazil).