The Effect Of Doxorubicin Loaded On Nanoparticles On Targeting And Inhibiting MCF-7 Cells In Vitro And In Vivo

Breast cancer is one of the most common malignancies affecting females worldwide, and its incidence is more and more every year. The conventional chemotherapy is the main adjust treatment for breast cancer therapy. Doxorubicin is a very commonly used anthracycline compound in chemotherapy regimens for breast cancer. It can intercalate into DNA and lead to cell cycle arrest at the G2 checkpoint. Then this leads to apoptosis. Conventional chemotherapeutic agents are distributed non-specifically in the body affecting both normal and tumoral cells and leading to severe side effect due to the lack of selectivity.Tissue selectivity is a major issue.But its clinical application is greatly limited by these disadvantages. Recently, nanotechnology has been extensively studied to develop novel strategies to overcome these problems.Therefore, the development of safe and efficient treatment against breast cancer has become important and urgent. Nanoparticle drug delivery system has a great many of usefull advantages, such as low toxicity or non-toxicity, biodegradable, high biocompatibility in vivo, accumulate these nano-scaled drug delivery system at tumor site via the enhanced permeability and retention effect and so on. Based on the fact that nanoparticulate drug delivery system has shown greatly enhanced chemotherapy efficiency for cancer therapy,nanomaterials have the potential to be the new drugdelivery system for chemotherapy to improve breast cancer treatment efficacy. Importantly,the surface of nanomaterials need adequate chemical modification to obtain the active targeting.Here, we focus on studying the effect on targeting and inhibiting tumor cells in vitro and in vivo dependent on DOX-loaded reversibly crosslinked hyaluronic acid nanoparticles which has been prepared.Part Ⅰ: Study of the effect of doxorubicin loaded nanoparticles(DOX-NPs) on targeting and inhibiting MCF-7 cells in vitroObjectives: To study the effect of doxorubicin loaded reversibly crosslinked hyaluronic acid nanoparticles(DOX-NPs) on targeting and inhibiting tumor cells in vitro.Methods: The flow cytometry was adopted to determine the expression of CD44 on the human breast cancer cell line MCF-7, which could specifically recognize and combine the DOX-NPs and to measure the uptake of DOX-NPs by tumor cells in vitro. After MCF-7 cells were treated with Free DOX and DOX-NPs respectively, the proliferation, apoptosis and migration of tumor cells were respectively determined by CCK-8 assay, Hoechst staining and wound healing experiment. Using MCF-7 tumor-bearing nude mice as a model, imaging the distribution of DOX-NPs in vivo and observing the antitumor efficacy of DOX-NPs were performed.Results: The results showed that CD44 was expressed on MCF-7 cells with a high level. DOX-NPs could be uptaked by MCF-7 cells, significantly inhibit the cell proliferation and induce the apoptosis of MCF-7 cells. The results from the study performed with the tumor-bearing mice demonstrated that DOX-NPs could significantly inhibit tumor growth and prolong the survival period of tumor-bearing mice comparing with the control.Conclusion: DOX-NPs could actively target to the breast cancer cells and significantly suppress the tumor in vivo.Part Ⅱ: Part Ⅰ: Study of the effect of doxorubicin loaded nanoparticles(DOX-NPs) on targeting and inhibiting MCF-7 tumor-bearing mice in vivoObjectives: To study the effect of doxorubicin loaded reversibly crosslinked hyaluronic acid nanoparticles(DOX-NPs) on targeting and inhibiting tumor cells in vivo.Methods: The pharmacokinetics of DOX-NPs was determined by blood circulation. The fluorescence imaging in vivo was used to determine the accumulation of nanoparticles in cancer tissue. Tumor-bearing mice following 10 h in vivo injection with DOX-NPs were sacrificed, and then the tumors and several organs including the heart, liver, spleen,lung and kidney were collected. The biodistribution and amount of DOX was studied via fluorescence imaging and fluorescence measurement. Using the tumor-bearing mice as a model, in vivo antitumor efficacy and histological analysis were determined. The DCJTB labeled nanoparticles was applied to determine the biodistribution in breast cancer and organs of MCF-7 bearing mice using fluorescence imaging in vivo.Results: The results showed an obviously cumulative effect of nanoparticles in tumor site,a prolonged circulation time in blood and high amounts of retention in kidney. Moreover, DOX-NPs possess significantly improved pharmacokinetic properties than Free DOX, remarkably reduce DOX’s toxicity to normal tissues and exhibit excellent antitumor activity in vivo. DOX-NPs hold great promise to become a novel nanomedcine useful for clinics, and deserve further studies. The results of HE staining and TUNEL revealed that DOX-NPs exhibited almost no toxicity to normal organs, which was a great improvement in safeness compared with DOX.Conclusion: DOX-NPs could actively target to the breast cancer and significantly suppress the tumor growth in vivo.