Study On Biotinylation Pullulan Derivation As Nano-drug Delivery Carrier

Recently, targeted cancer nanotherapy has attracted growing interest. Nanoparticle canchange drug biodistribution in the body and target drug to tumor tissue. Drug can beprolongeed the time in circulation, reduced the toxic effect and increased therapeuticactivity by loaded in nanoparticles. So, the nanoparticles are promising in cancer therapyand diagnostics.Although, nanoparticles have been applied in clinic, they still face a few problems: 1),the alternative materials are limited; 2),the technologies for target nanoparticlesformulation and characterization need developed; 3),the stablility of nanodispersion. So, itis facing challenge in choosing the appropriate materials to prepare stably nanoparticles.In this study, to provide a novel drug delivery carrier, a kind of polymer-biotinylatedpullulan were synthesized and characterized. The formulation condition, stability test andin vitro cellular experiments of biotinylated pullulan nanoparticles were performed.Following studies were included:1),Synthesization of biotinylated pullulan derivation 2),Characterization of biotinylatedpullulan by IR, H-HMR and ICP .3),Preparation of nanoparticles, determined particle size,distribution and morphology of nanoparticles by DLS and TEM; The amount of biotin onsurface of nanoparticle was determined by Quant Tag Biotin kit; investigating the effects ofpreparation parameters on formulation of nanoparticles. 3),Determining the size ofnanoparticles for 28 d at room temperature to investigate the dispersion and stability ofnanoparticles 4),As model drug, MTX loaded into nanoparticles, the drug loadingefficiency and in vitro release character were determined. 5),To determine cytotoxicity andgrowth inhibition of nanoparticle to MCF-7 cell by MTT. 6),The cellular uptake ofFITC-Dex/nanoparticle were observed by diverted fluorescentce microscope.In the study, three samples of biotinylated pullulan (BP), comprising 21(BP₁), 46(BP₂)and 81(BP₃) biotin groups per 100 anhydroglucose units of pullulan were synthesized.Novel cancer target nanoparticles (BPNs) were prepared by nanoprecipitation. BP₂ and BP₃were named LBP and HBP. The particle size of LBPNs and HBPNs were about100-200nm, had smooth surface with narrow size distribution. The preparation parameters affected thenanoparticles formulation, such as polymer concentration, ratio of organic solvent toaqueous phase, PVA concentration et al, especially the polarity of two phases. The size didnot increase during 28d, the results shown nanoparticles were stably. Ratio of biotin onsurface of LBPNs and HBPNs to polymer was all about 2%. As a model drug, MTX loadedinto BPNs, the drug loading content and loading entrapment were 1-3% and10-20%. Thesample displayed a release pattern with two components, about 30%drug diffused at thefirst 2h, followed by a slower release profile. Blank nanoparticles were almost nocytotoxicity. The in vitro cells studies,the activity in inhibiting the growth of MCF-7 cellsof MTX was enhanced when MTX was delivered from BPNs .The cellular uptake assayshown that BPNs were internalized by cells. These results indicated that BPNs may have aspecific interaction with the MCF-7 cells via receptor-mediated endocytosis. Therefore, thebiotinylated pullulan nanoparticles may be used as a potential drug delivery system fortargeted delivery to cancer cells.Additionally, in this study, microparticles of pullulan were prepared by water-in-oilemulsion and the effect of different parameters on the microparticles formation and the sizewere Observed. Results indicated pullulan microparticles as a drug delivery vehicle wereprepared by a w/o emulsion crosslink technique, many factors control the morphology ofparticles.