Study On Preparation And Characterization Of Paclitaxel-imprinted Polymer Microspheres Based On POSS

Paclitaxel(PTX)is often used as a drug.It can be used alone or in combination with other drugs to have special therapeutic effects on various cancers such as lung cancer.PTX is mainly derived from taxus chinensis in nature,but its content in nature is relatively low and there are more compounds with similar chemical structure to PTX,which has caused great difficulties for enrichment and separation of PTX and its application in medicine.In order to solve the above problems,a novel paclitaxel molecularly imprinted polymer(PTX-MIPs)microsphere was successfully prepared by reversible addition-fragmentation chain transfer precipitation polymerization(RAFTPP)method using methacryl POSS cage mixture(POSS)as the basic material,paclitaxel(PTX)as the imprinting molecule and methacrylic acid(MAA)as the functional monomer,its adsorption performance and drug release performance are studied as an adsorbent and a drug release agent.The experimental results show that PTX-MIP2 prepared with MAA as functional monomer and POSS/MAA of 1/10(mol/mol)has the best performance.Under these conditions,the size of PTX-MIP6 prepared by RAFT precipitation polymerization about about 1.56?m,uniform size and regular particle size.Inorganic POSS molecules play a skeleton supporting role in the microspheres,so that the microspheres have larger specific surface area and porosity,and the specific surface area of the microspheres is 41.1 m~2/g;Under the action of POSS molecules,the microspheres showed good hydrophobicity with a static water contact angle of146°.Meanwhile,PTX-MIP microspheres have good thermal stability.The adsorption process of PTX-MIP2 is analyzed in terms of kinetics and thermodynamics by using isothermal model and kinetic model.The results showed that the adsorption process of PTX-MIP2 is more consistent with Freundlich adsorption isothermal model and Quasi-first-order kinetic model,with the correlation of linear fitting is R~2=0.9963 and R~2=0.9453 respectively.The experimental results also showed that PTX-MIP6 prepared with POSS/MAA of 1/10(mol/mol)had the highest PTX encapsulation and drug loading efficiency and the best imprinting effect.Under these conditions,the size of PTX-MIP6 prepared by RAFT precipitation polymerization about 187 nm.The specific surface area of microspheres is 76m~2/g;The static water contact angle is 146.89°.Under the condition of pH=5,the maximum PTX release rate is 12.5%,and the duration can reach more than 100 h;PTX-MIP6 microsphere is sensitive to pH.Since acids can damage hydrogen bonds,the release rate of PTX at pH=5 is faster than that at pH=7.Cytotoxicity test shows that PTX-MIP6 has no cytotoxicity.By comparing the cell activity in the solution containing different concentrations of drug carriers PTX-MIP6 microspheres or PTX,the result shows that PTX-MIP6 microspheres have sustained release behavior,which indicates the potential prospect of PTX-MIP6 microspheres as carriers of PTX in cancer treatment.