Preparation, Targeted Delivery And Freeze-drying Formulation Of Folate-conjugated, Paclitaxel-loaded Human Serum Albumin Nanoparticles

Targeted drug delivery system is a new drug delivery system based on the molecular biology theory. Comparing to conventional anticancer drugs it has many advantages. It can carry drugs maximum to target cells or organs, and have little impact on the nontarget cells or organs, so as to achieve treatment effect of high efficiency and low toxicity. It can be expected in the future development of cancer chemotherapy, the molecular targets of a new generation of anticancer drugs with its specificity and targeting property will become the main direction of anticancer treatment in addition to cytotoxic class traditional chemotherapy drugs continues to grow. Paclitaxel has a unique anticancer activity, shows encouraging efficacy in the treatment of breast cancer, lung cancer, gastrointestinal cancer, and advanced ovarian cancer. Due to the lack of paclitaxel and low water solubility limits its clinical application, and clinical application of paclitaxel injection has adverse reactions of allergenic, toxic. In this study, targeted delivery of paclitaxel-loaded nanoparticles was prepared by a desolvation procedure, crosslinked on the wall material of bovine serum albumin, and subsequently decorated by folic acid. For studies of the tumor targeting, cervical cancer cell were incubated with FITC-labeled nanoparticles for4h at37℃. Using single factor experiment, the three lyoprotectants be selected for studying PTX-FA-HSANPs physical, chemical characterization and stability to optimize the freeze-drying process of PTX-FA-HSANPs by vacuum freeze-drying technology.1、The drug loading efficiency of PTX-FA-HSANPs was approximately up to (10.7±1.3)%and drug encapsulation was approximately up to (47.4±6.6)%. The amount of NHS-folate conjugated with HSANPs was18.464μg/mg HSA.2、The mean particle size of PTX-FA-HSANPs was213.6±5.8nm and zeta potential was-32.6±2.69mV, the mean particle size of PTX-HSANPs was199.7±3.6nm and zeta potential was-27.24±0.62mV.The results showed that the nanoparticle had the slightly larger size and zeta potential which were negatively charged was reduced by conjugated with NHS-folate. It was revealed by SEM imaging that PTX-FA-HSANPs and PTX-HSANPs were spherical in shape with a uniform particle size distribution.3、The in vitro drug release profiles of the PTX-FA-HSANPs and PTX-HSANPs showed that an initial burst of18%and15%in the first1Oh can be observed. In the following100h, cumulative release of PTX-FA-HSANPs reached70%, while cumulative release of PTX-HSANPs reached50%. Cumulative release reached almost98%after168h, showing an almost released ability of the nanoparticle formulation, while cumulative release of PTX-HSANPs reached70%. Release curve results show that the PTX-FA-HSANPs and PTX-HSANPs both have the effect of controlled release. The capacity of drug release enhanced conjugated with NHS-folate.4、Hela cells were incubated with fluorescein isothiocyanate-labeled PTX-FA-HSANPs for four hours. Hela cells were washed after stained with DAPI. Thereafter, cells were observed by confocal laser scanning microscopy with Fluoview imaging software.The fluorescence from the nanoparticles internalized in cells is shown. It is concluded that targeting of PTX-FA-HSANPs is significant and effective.5、The three lyoprotectants was analyzed the protective effect which mannitol (MAN), bovine serum albumin (BSA) and trehalose (Tre), depended on freeze-dried coefficient (fc), polydispersity index(PDI) and Zeta pptential of PTX-FA-BSANPs with and without protection agent before and after freeze-dried. The results showed that the three lyoprotectants concentration of not less than1%, the nanoparticles have a smaller value of fc and PDI values, as well as potential difference before and after freeze-drying, having a good protective effect. Nanoparticles size of PTX-FA-BSANPs with three Lyoprotectant concentration of1%had no significant changes in eight hours, proving PTX-FA-BSANPs freeze-dried preparation is relatively stable.In this experiment, the PTX-FA-HSANPs characterization identification, target detection and the freeze-drying process had been a preliminary study. The PTX-FA-HSANPs showed small particle size, good stability and tumor targeting, and optimize the nanoparticle freeze-drying process preliminarily. Nanopreparation of PTX-FA-HSANPs targeting preparation, it is able to transport orientation to the tumor cells of the folate receptor, and release the drug to achieve the purpose of targeted therapy. Paclitaxel targeting agents for specific targeting of molecular targets in anti-cancer treatment played an important role, the main direction of the anti-cancer treatment. Folate receptor as a target to carry out early diagnosis of cancer and targeted therapy has a satisfactory clinical significance, and to provide experimental evidence for targeted therapy of tumors.