Synthesis, characterization and association of gold nanoparticles with bromelain

The extract of the stem and green fruits from plants of the Bromeliaceae family (mainly pineapple - Ananas comosus) contains a complex of proteolytic enzymes generically known as Bromelain (thiol endopeptidases), to which several pharmacological activities are attributed, such as blood coagulation, fibrinolysis healing and anti-inflammatory action. Nanotechnology has several forms of use in the pharmaceutical field, including the use of nanoparticles that act as vehicles for the distribution of derivative compounds. This study aimed to obtain bromelain, prepare gold nanoparticles (AuNPs) associated with these enzymes and perform characterization tests to observe the stability, size, polydispersion index, morphology and enzymatic activity of this association. Considering the above, gold nanoparticles associated with bromelain were prepared. Before the association, they showed a moderate stability of 27.8 mV, size of 47.6 nm, polydispersion index of 0.391. After the association, they reached values of 12 mV, 1,240 nm and 0.536, respectively. Microscopy showed that the produced nanoparticles were spherical and had an average diameter of 20 nm after association. The association reached about 77%, with an enzymatic activity of 23.36 U/ml, confirming the efficiency of the adsorption. Therefore, the complex formed by nanoparticles of gold and bromelain presented good physical characteristics and excellent proteolytic activity when compared to scientific literature, and therefore can be used for later application in curative films through new works.