Safety And Anti-tumor Cell Activity Evaluation Of The Physical Complexed HA/MLT And The Chemical Modified MLT-DMMA

Melittin has good anti-tumor activity.However,the strong hemolytic and non-specific cytotoxicity severely limit the application in clinical.Therefore,in this study physical encapsulation and chemical modification were used to construct into the stable,efficient,and safe novel treatment programs,to target the delivery of melittin to lesions and improving the efficiency of melittin delivery.Reduce its toxic side effects.The main research contents and conclusions of this paper are as follows:(1)By physical encapsulation,HA/MLT nanocomposite was prepared by the negatively charged/hydrophilic hyaluronic acid(HA)encapsulatedthe positively charged melittin(MLT).The Zeta potential and size of the composite HA/MLT nano-particles was measured by the Zeta-DLS was used to measure.The morphology of the composite HA/MLT nano-particles was measured by TEM,indicating that the nano-composite has a uniform nano-particle size,an appropriate surface negative potential,and an efficient drug.Subsequently,biocompatibility was assessed by in vitro cell assays,including hemolysis tests,using HeLa cells with high expression of CD44 on the cell surface and NIH3T3 cells with low expression of CD44 on the cell surface.Confocal microscopy(CLSM)and flow cytometry(FACS)were used to verify the cellular uptake behavior and drug efficacy evaluation.The results show that HA/MLT nanocomposites have good biocompatibility and specific anti-tumor activity.(2)By chemical modification,MLT-DMMA was prepared by introducing a pH-sensitive amide bond between 2,3-dimethylmaleimide(DMMA)and lysine(Lys)of MLT was modified by introducing pH-sensitive amide bond between the 2,3-dimethyl maleimide(DMMA)and the lysine(Lys)of MLT(MLT-DMMA).MLT and its corresponding modified peptide MLT-DMMA were used to anti-tumor and biocompatibility validation.The biomaterial characteristics were tested by MALDI-TOF MS,zeta potential and HPLC,cell viability,hemolytic and animal experiment safety evaluation.Compared with the primary MLT,the DMMA modified MLT showed decreased surface charge and low cytotoxicity in physiological conditions.Moreover,cell assays confirmed the acid-activated conversion of amide bond resulting in adequately safe during its delivery and timely antitumor activity in tumor lesions.Thus,MLT-DMMA provided a feasible strategy to improve the targeted and safe antitumor applications.