Inhibitory effect of bovine serum albumin-chitosan nanoparticles loaded with EPZ6438 on osteosarcoma / 中国组织工程研究

ABSTRACT

BACKGROUND:The most prominent transcription factor activated by tumor stem cells in osteosarcoma is EZH2,and silencing of EZH2 has been reported to inhibit osteosarcoma cell growth.Studies have confirmed that bovine serum albumin-chitosan nanoparticles are a drug delivery vector with excellent biocompatibility and biodegradability,and the albumin carrier can provide tumor-targeted drug delivery function. OBJECTIVE:To investigate the effect and mechanism of bovine serum albumin-chitosan nanoparticles loaded with EPZ6438(EZH2 inhibitor)for the treatment of osteosarcoma. METHODS:(1)Bovine serum albumin-chitosan nanoparticles loaded with and without EPZ6438 were prepared.The drug encapsulation rate and drug release rate of serum albumin-chitosan nanoparticles loaded with EPZ6438 were detected.(2)MG-63 cells were divided into four groups and added with PBS(control group),serum albumin-chitosan nanoparticle extract solution(blank nanoparticle group),EPZ6438 solution(free drug group),and serum albumin-chitosan nanoparticle extract loaded with EPZ6438(drug-loaded nanoparticle group),respectively.After 3 days of culture,cell apoptosis was detected by flow cytometry and the expression of caspase-3 mRNA was detected by RT-PCR.(3)Twelve nude mice were selected and the subcutaneous tumor-bearing mouse model was established by injecting MG-63 cell suspension under the armpit.After successful modeling,the mice were randomly divided into four groups for intervention.Normal saline(control group),serum albumin-chitosan nanoparticle solution(blank nanoparticle group),EPZ6438 solution(free drug group)and serum albumin-chitosan nanoparticle solution loaded with EPZ6438(drug-loaded nanoparticle group)were injected into tumor tissues,with three animals in each group.After 7 days of injection,the tumor volume and frozen sections of tumor tissue were observed by TUNEL staining. RESULTS AND CONCLUSION:(1)The drug encapsulation rate of the nanoparticles was about 8.8%,and the nanoparticles had a good drug release effect in pure water.The drug release amount was(34.72±1.93)μg at 24 hours,(48.58±1.10)μg at 72 hours,(49.18±1.24)μg at 120 hours,and(50.25±1.13)μg at 168 hours.The drug release reached the plateau at 120 hours,and the release rate was about 97.9%.(2)After 3 days of cell culture with MG-63,the apoptotic rate in the control group and blank nanoparticle group was lower than that in the free drug group and drug-loaded nanoparticle group(P<0.001),and the expression of caspase 3 mRNA was lower than that in the free drug group and drug-loaded nanoparticle group(P<0.000 1).(3)After 7 days of injection,the tumor volume of nude mice in the drug-loaded nanoparticle group was smaller than that in the other three groups(P<0.05),and the percentage of TUNEL-positive cells in tumor tissue was higher than that in the other three groups(P<0.000 1).(4)The results verify that serum albumin-chitosan nanoparticles loaded with EPZ6438 can inhibit the growth of osteosarcoma by inducing apoptosis of tumor cells.