Synthesis Of Amino Acid-modified Porous Silica Nanoparticles For Drug Delivery

Polymer nanoparticle based drugs has played an important role in the treatment of cancer and other diseases. A large number of porous silica are widely applied in drug delivery system because of its large surface area and ease of surface functionalization.Polyaminoacid which biocompatible and nontoxic combined with porous silica can get better results in the drug delivery system.In this paper, silic microspheres is prepared by sol-gel method, then protect the microspheres surface by Polyvinyl Pyrrolidone（PVP） and porous silic microspheres can be synthesized by corrosion of NaOH. using the silane coupling agent（APTES） to modify the SiO₂ surface. 2-（2-methoxyethoxy） ethyl methacrylate（MeO₂MA）- functionalized L-glutamic acid-modified porous silica was synthesized by ring-opening polymerization（ROP） of N-carboxyanhydride（NCA） monomers and subsequent atom transfer radical polymerization of MeO₂ MA. Doxorubicin（ DOX）,a model antitumor drug,was loaded on the silic surface and release it at different pH.Results reveal that L- glutamic acid-modified porous silica not only has a high drug loading capacity and efficiency,but also an outstanding release effort.Thus, L- glutamic acid-modified porous silica microspheres can be used as a drug carrier,and with better prospects.We also prepared another system to release drug, the microgel derived from Poly（L-glutamic acid）-g-Cinnamyl alcohol（PLGA-g-CA） graft copolymers.First, Poly（γ-benzyl-L-glutamate）（PBLG） was synthesized by the ring-opening polymerization of γ-benzyl-L-glutamate-N-carboxyanhydride（BLG-NCA） using triethylamine as initiator, and then（PLGA-g-CA） was prepared by the deprotection of benzyl groups in PBLG and modified by Cinnamyl alcoho.Nanogel is prepared through the methods of UV crosslinking in citric acid-disodium hydrogen phosphate buffer solution（CPBS） of pH = 7.0 and under UV irradiation of 254 nm, then characterized its structure,morphology, particle size, etc.Then loaded DOX into microgel, and the drug loading capacity and entrapment efficiency were revealed. By calculation shows that the microgel has a higher drug loading efficiency. In drug release results revealed that the release of DOX from microgel was highly dependent on pH. which revealed the great prospect of PLGAg-CA potential antitumor drug delivery.