Application Of Membrane-encapsulated Biomimetic Magnetic Nanospheres In Hepatocellular Carcinoma Theranostics

Objective:Hepatocellular carcinoma（HCC）is a common malignant tumor in China,with high incidence and mortality rate.The difficulty of early diagnosis and poor prognosis of patients in advanced stages are the main problems that hinder the recovery of HCC patients.Nanodelivery systems based on homotypic cancer cell membrane（CCM）mimicry have shown unique advantages in various fields,such as endowing targeting ability,improving therapeutic efficacy,reducing toxic side effects,and preventing multiple drug resistance,et al.In this study,HCC huh-7 cell membranes have been extracted as the encapsulation films to coat nanoparticles.Utilizing the homologous targeting properties of CCM,the biomimetic nanoparticles with the ability of targeting HCC and anti-cancer,along with the capabilities of MRI,have been designed to improve the therapeutic benefit of HCC and achieve an assessment of the efficacy.Methods:In this study,poly（lactic-co-glycolic acid）（PLGA）has been used as the carrier for the synthesis of nanospheres（SFINPs）through the method of single emulsion,which carried the antitumor drug sorafenib（SF）and superparamagnetic iron oxide nanoparticles（SPIONs）.The prepared particles will be coated with CCM derived from Huh-7 to obtain biomimetic nanospheres（SFINPs@CCM）.Then,the SFINPs@CCM have been characterized to ensure that the desired preparation goals are achieved.The synthesized nano microspheres were characterized for morphology,size,chemical composition,zeta potential and protein content using transmission electron microscopy（TEM）,Fourier transform infrared spectroscopy（FTIR）,dynamic light scattering（DLS）,and sodium dodecyl sulfate poly acrylamide gel electrophoresis（SDS-PAGE）.The assays of loading efficiency（LC）and encapsulation efficiency（EE）were used to detect the content of sorafenib in SFINPs.And in vitro drug release assay was used to further analyze the drug release profile.3.0 T magnetic resonance imaging system was used to examine the T₂ signal conversion ability of SFINPs@CCM to verify the ability of imaging.At the cellular level,the targeting ability to homozygous tumor cells was observed by fluorescent staining of SFINPs and cells.Cytotoxicity assay was then used to further analyze the anti-tumor ability of SFINPs@CCM.Results:TEM results showed that SFINPs could be seen spherical structures with an average diameter of 170.7±23.3 nm,and Fe₃O₄ with a particle size of about 10 nm was uniformly distributed inside the spheres.The outer layer of membranes around 10 nm could be observed in SFINPs@CCM.The particles size of SFINPs@CCM was 175.1±28.8 nm,which was slightly larger than SFINPs.In the FTIR results,SFINPs had the same representative absorption peaks with PLGA and SF,which proved the presence of PLGA and the drug of SF.The absorption peaks of Fe₃O₄ were not obvious in SFIPNs,these may due to the encapsulation of iron particles in the interior of the microspheres.In the analysis of zeta potential,the surface charge of SFINPs@CCM was-10.7±3.04 m V,which was higher than-4.6±2.61 m V for SFINPs and close to-19.0±1.46 m V for CCM.In SDS-PAGE results,SFINPs@CCM have the same protein composition as CCM,which indicates that CCM has been encapsulated on NPs successfully.In MRI,the relaxation rate of SFINPs@CCM was25.45 m M^-1s^-1,which can effectively translate the MRI signal.The EE of SFINPs was 88.2%and the LC was 12.3%,which indicated that the nanomicrosphere have an efficient drug loading capacity.In the in vitro drug release assay,both SFINPs and SFINPs@CCM showed retarding effect of drug release,with release rates of 84.02%and 72.96%at 72h respectively.In cellular level experiments,SFINPs@CCM showed the ability to actively identify and target homotypic cells and exhibited more efficient tumor-killing effects.The survival rate of Huh-7 cells treated with SFINPs@CCM was 29.48±5.74%,which was significantly lower than that of SFINPs group（52.46±5.20%）.Conclusion:In this study,the biomimetic nanoparticles SFINPs@CCM have been successfully developed,which can be used for both targeted magnetic resonance imaging and targeted therapy,which can be used as a technical basis for preclinical studies.