Preparation Of Environmental Sensitive Nanocarriers For 5-Fuorourecil Loading And Controlled Release

In this work, the grafted polymers CS-g-PNIPAM, SA-g-PNIPAM, CS-g-PVP and SA-g-PVP were synthesized via traditional radical polymerizations with NIPAM as temperature sensibility monomer, NVP as hydrophilic monomer, CS and SA as the natural polymers. The polyelectrolyte nanoparticles were obtained via electrostatic self-assembly after these grafted polymers dissolved in aqueous solution. On the other hand, environmental responsive polymer vesicles were obtained using the metal ions and β-CD grafting onto the SA-g-PNIPAM. The load capacity and responsive release of 5-fuorourecil as the drug model were also investigated in detail. The preparation of environmental responsive polymer vesicles solves bottle-neck that encounter in the traditional chemotherapy. It provides the guiding significance in the application of natural polymers in drug controlled release.Synthesis of grafted polymers CS-g-PNIPAM, SA-g-PNIPAM, CS-g-PVP and SA-g-PVP was initiated by oxidizing agent and oxidizing-reducing agent via "grafting onto" method with combination with active sites of CS and SA, respectively, using NIPAM as temperature sensibility monomer and NVP as hydrophilic monomer. The results showed that the temperatures have made profound effect on solution transmittance of CS-g-PNIPAM and SA-g-PNIPAM. The solution phase owned temperature sensibility.The self-assembly polyelectrolyte nanoparticles with multiple environment responsiveness CS-g-PNIPAM/SA-g-PNIPAM(PEC1), CS-g-PVP/SA-g-PVP(PEC2) and CS-g-PNIPAM/SA-g-PVP(PEC3) were obtained via electrostatic attraction of CS-g-PNIPAM, CS-g-PVP and SA-g-PNIPAM, SA-g-PVP, respectively. The results showed that polyelectrolyte nanoparticles PEC1, PEC2 and PEC3 were regular spherical structure and the distribution of partical size was narrow. All of them owned temperature sensibility. 5-fuorourecil was selected to be the hydrophilic anticancer drugs. The results showed that PEC1. PEC2 and PEC3 could response to pH, temperatures and ion strength. The release rates were efficient decreased at the early stage of 5-fuorourecil release. The use of glutaraldehyde could improve the coating function of 5-fuorourecil. Hence achieve of decrease in the release capacity and rates. The release capacity and rates increased with the increasing temperatures and ion strength. The maximum release capacity reached when the pH was 5.2. As a result, the three self-assembly polyelectrolyte nanoparticles have a promising application due to their inherent properties.The polymeric vesicles Ca2+/SA-g-PNIPAM(PV1) was prepared via electrostatic interaction with Ca2+ after deprotonation of SA-g-PNIPAM in aqueous solution. The results showed that temperatures had enormous effect on the transmittance of PV1 solution. It exhibited well temperature responsive properties. The regular vesicle structure and cross-linked vesicle wall could be obviously observed via TEM technique. The controllable release of PV1 was investigated using 5-fuorourecil as the water-soluble anti-cancer drug. The polymer vesicle showed a obviously slow release rate of 5-fuorourecil. The release capacity of 5-FU-PV1 increased with the increasing temperatures and ion strength. These demonstrated that as the anti-cancer carrier, PV1 was a promising material.The self-assembly polymer vesicle β-CD/SA-g-PNIPAM(PV2) was prepared via host-guest interaction, i.e. β-CD as the host and SA-g-PNIPAM as the guest. The results showed that temperatures had enormous effect on the transmittance of PV2. It exhibited well temperature responsive properties. It could be seen that vesicle structure was regular and the thickness of vesicle wall changed with alteration of molar ratios. The distribution of partical size was narrow and uniform. To investigate the released property of PV2, the water-soluble anti-cancer drug 5-fuorourecil was selected to be the drug model. The release of 5-fuorourecil can be efficient controlled using PV2 as the polymer vesicle. The release capacity increased with the increasing temperatures and usage of SA-g-PNIPAM. The maximum release capacity reached in the acidic surroundings. These demonstrated that PV2 possessed practical values as a novel agent carrier.