Study On PEGylated Chitosan Nanoparticle Loaded With Drug And Its Application

In this study different molecular weights of methoxy polyethylene glycol(mPEG)(Mn=750,2000,5000)were grafted to chitosan(CS)with different degrees of substitutions(DS)to prepare mPEG750-g-CS(DS=9.1%),mPEG2000-g-CS(DS=4.1%,DS=8.5%,DS=18.2%,DS=40.3%)and mPEG5000-g-CS(DS=8.7%).mPEG-g-CS was prepared as a nanocarrier for anticancer drug methotrexate(MTX)and the effects of mPEG molecular weight and degree graft on the pharmacokinetics and biodistribution of methotrexate loaded chitosan nanoparticles(MTX/mPEG-g-CS NP)were determined.Based on the natural immunity of bacterial outer membrane vesicles(OMV),ovalbumin(OVA)as a commonly used model antigen,we constructed a drug delivery system of bacterial OMV-coated OVA loaded mPEG-g-CS nanoparticles(OVA@OMV-mPEG-CS NP),which used for the study of nasal mucosal immunity in mice and laying the foundation for preparing novel nasal mucosa vaccine.One of the most important functions of nanoparticle drug delivery systems is extended drug residence time in vivo.We report a series of MTX/mPEG-g-CS NP coated with differently sized mPE?G at different surface densities.MTX was incorporated into nanoparticles(112.8?171.2 nm in diameter)prepared from the resulting mPEG-g-CS.The nanoparticles had a zeta potential of+7.4?35.0 mV and MTX loading efficiency of 17.1%?18.4%.MTX/mPEG-g-CS NP showed an initial burst release of MTX followed by a sustained-release profile in PBS at pH 7.4.The in-vitro cellular uptake study showed that MTX accumulation in J774A.1 macrophage cells decreased with increasing surface density or molecular weight of mPEG.The pharmacokinetic study on Sprague-Dawley rats revealed an increase in AUC0-72h(Area under the plasma drug concentration-time curve over a period of 72 hours)with increasing the surface density or molecular weight of mPEG and a linear correlation between the mPEG surface density and AUC0-72h.The biodistribution study on ICR mice revealed that MTX/mPEG-g-CS NP significantly enhanced blood circulation time in the body and decreased accumulation in liver,spleen,and lung.These results suggest the potential of the mPEG-g-CS nanoparticles as a promising candidate for drug delivery.The engineered OMV coated OVA loaded mPEG-CS nanoparticle was reported as a promising nasal vaccine delivery system.OMV was prepared by ultrafiltration concentration method.OVA loaded mPEG-CS nanoparticle was prepared by ionic gelation method using tripolyphosphate.OMV coated mPEG-CS nanoparticle loaded with OVA was prepared by extrusion method and it was fully characterized.Balb/c mice were intranasally immunized and specific sIgA levels in nasal wash,jejunum,and fecal pellet were determined by ELISA.Size of OVA loaded PEGylated chitosan NP was 167.8±10.3 nm.The shell-core structure of OVA loaded PEGylated chitosan NP was proved by TEM.After 14 days of administration,slgA levels in nasal wash,jejunum and fecal pellet of OVA loaded OMV-mPEG-CS NP treated group were the highest than all the other treated groups.Compared with the treated group of OMV+OVA solution,OVA-sIgA antibody level in nasal wash,jejunum and fecal pellet of OVA loaded OMV-mPEG-CS NP treated group was increased 1.5 times,1.6 times and 1.5,respectively.Compared with the treated group of OMV+OVA solution,OMV-sIgA antibody level in nasal wash,jejunum and fecal pellet of OVA loaded OMV-mPEG-CS NP treated group was increased 1.5 times,1.5 times and 1.4,respectively.These novel nanoparticle drug delivery systems can simultaneously delivery OVA and OMV to antigen presenting cells,resulting in stronger mucosal immune response in mice.These results confirm that OVA@OMV-mPEG-CS NP can be considered as a novel nano-drug delivery system,utilizing a combination of intact OMV and OVA as antigens to produce an enhanced immune response for more effective antibacterial defense.Such a strategy to use OMV in vaccine nano-drug delivery system should be also applicable to other infectious bacteria strains,thus providing a rather general approach to improve vaccine efficacy and fight against potentially deadly infections.