Photodynamic Therapy (PDT) is a technique based on the interaction of a nontoxic and light-sensitive dye, called photosensitizer (PS), with light at an appropriate wavelength that in the presence of oxygen results in the formation of reactive species that causes cell death. Some PSs, e.g. hypericin (HY), are hydrophobic and causes aggregation in water media, affecting the PDT application. Obtaining of cyclodextrins (CD) inclusion complexes can improve some properties of PSs such as solubility and bioavailability. This study aimed to produce an inclusion complex between HY and β-Cyclodextrin (β-CD) to improve HY solubility and to study the effect of this improvement on its chemical, photochemical and biological properties for application in PDT. The inclusion complex β-CDHY formation was confirmed by FTIR and NMR-1 H spectroscopy techniques. HY solubility was improved and its photochemical properties (chemical stability, photostability, photodynamic activity, and quantum yield) were not affected after being included in the β-CD cavities. The complex β-CDHY presented an in vitro release six times faster than HY free. Besides, β-CDHY exhibited a slower cutaneous permeation profile, indicating the possibility of being applied in topic uses due to the greater retention in superficial skin layers. Intracellular accumulation of free and complexed HY, as well as the cito and phototoxicity, were evaluated in HeLa, MCF7 e Vero cell lines. In HeLa cells there was nearby two times fold improvement in accumulation, leading to an increase of 40% in the phototoxicity of β-CDHY related to free HY in 3, 6 and 10 J cm -2 . In MCF7 cells, the intracellular accumulation was the same for free and complexed HY, however, there was a decrease of about 20% in IC50 values when the complex was incubated within the cells under 3 and 6 J cm -2 . In Vero cells it was obtained a cell uptake 10 3 times lower than the values for HeLa and MCF7, suggesting that free and complexed HY accumulate selectively in carcinogenic cells.Therefore, these results suggest that the use of β-CD as a drug delivery system for HY is effective and allows its application in Photodynamic Therapy. O 2 -Oxigênio singlete AF -Atividade fotodinâmica ALAácido 5-aminolevulênico AUácido úrico β-CD -Beta-ciclodextrina β-CDHY -Complexo de inclusão entre β-CD e HY
CAQI -Central de Análises Químicas Instrumentais
CD -Ciclodextrina
CIS -Cruzamento intersistema
DLS -Dynamic Light Scattering
DMEM -Dulbecco's Modified Medium
DMSO -Dimetilsulfóxido
DP -Desvio Padrão
DPBF -1,3-Difenilisobenzofurano
ECestrato córneo
ERO -Espécies Reativas de Oxigênio
FS -Fotossensibilizador
GPX-4 -Glutationa peroxidase
HY -Hipericina
HP-β-CD -Hidroxipropil-β-Ciclodextrina
IV -Espectroscopia na região do Infravermelho Jfluxo de permeação LD -Limite de detecção LED -Light-emitting Diode LQ -Limite de quantificação