Physicochemical Properties of Bromelain Adsorption on Magnetic Carbon Nanoparticles and in Vitro Cytotoxicity on Breast Cancer Cells

Background and Aim: As a proteolytic enzyme extracted from the pineapple stalk, Bromelain (Br) is known as an anticancer agent. In the first stage of this research, we studied the physicochemical factors which influence the maximum adsorption of Br on magnetic carbone nanoparticles (MCNPs) and then the anticarcinogenic activity of Br enzyme alone. Moreover, they were evaluated in combination with these particles on MCF-7 breast cancer cells. Materials and Methods: The operational determinants influencing Br adsorption such as pH, contact time (30, 60, 90, 120 and 180 min), adsorbent dosage (1 gr/L, 5 gr/L), initial Br concentration (50, 150 and 300 mg/L) and temperature (35 and 50°C) were studied in detail. Then cancer cells were exposed to various Br concentrations (0.1 μg/mL, 1 μg/mL, 10 μg/mL, and 100 μg/mL) and the cell viability was determined by methylthiazol tetrazolium (MTT) assay after 24, 48 and 72 h. Results: The highest adsorption of Br on MCNPs was 44 mg/g and was achieved at pH 5, 35°C and 120 min with 50 mg/L initial Br concentration and 1g/L MCNPs. The adsorption used the Freundlich and pseudo first-order kinetic models. The results indicated that MCNPs could be a potential effective adsorbent for the removal of Br. MTT assay indicated that a 100 μg/mL concentration of Br alone (after 24 h) and in combination with MCNPs (after 72 h) could efficiently inhibit the MCF-7 breast cancer cells. Conclusion: Although the dose of Bromelain on synthesized MCNPS is about 440 times less than Bromelain alone, it possesses a significant cytotoxicity (P<0.001). Moreover, synthesized MCNPS had a considerable advantage of slow delivery which is favorable for the treatment of cancer.