Evaluation of releasing of an aqueous extract of propolis from Huila (Colombia) asociate in collagen type Ⅰ scaffolds with microparticles of gelatin-collagen

摘要

Introduction: Our group has developed collagen type Ⅰ scaffolds containing microparticles of gelatin-collagen (CS-GC) as a controlled release delivery system of bioaclive metabolites. Propolis has antioxidant, anli-infiarnmatory and healing activities derived from the presence of flavonoids and phenolic compounds. In this work, a non-cytotoxic concentration of an aqueous extract of propolis was loaded into CS-GC. Then, an evaluation of in vitro release of secondary metabolites, antioxidant activity of the loaded scaffolds and growth of fibroblasts seeded into them was carried out. Methods: Fragments (1 cm2) of CS-GC loaded with a propolis extract were immersed in acetate buffer solution and samples of this solution were taken at different times (6,12, 24,48,72,96 and 120 hours). The content of total phenols and flavonoids was determined using the Folin-Ciocalteu and aluminum chloride methodologies, respectively. The antioxidant activity of the samples was determined by ORAC and the FRAP tests. For Cell proliferation assay, circular scaffolds 8mm diameter of CS-GC with propolis and CS-GC without propolis were seeded with 3T3 fibroblasts cellular line and incubated for seven days, samples of the medium (with rezasurine) were taken on days 1,3 and 7. All assays were performed three times by triplicate. Results and Discussion: Data indicate that the CS-GC loaded with the aqueos propolis extract controlled the release of total phenols and flavonoids for five days. The results also show that the antioxidant activity of the loaded scaffolds increases exponentially during the same period of time. It was also found that growth of 3T3 fibroblasts was lower in CS-GC loaded with propolis extract than in the unloaded CS-GC (Figure 3). In vivo assays are requiered to demonstrate the pharmacological significance of these findings.