For Photodynamic Therapy With Functional Side Groups Of The Amphiphilic Polymer Micro And Nano Systems

Polydepsipeptides were well-studied copolymers with excellent biocompatibility and biodegradability.In this paper,a kind of polydepsipeptides with pendant carboxyl groups used as carriers of photosensitizer for photodynamic therapy(PDT) was synthesized.The nanoparticle systems loaded with hematoporphyrin monomethyl ether(HMME) were also evaluated initially.Firstly,a six-member cyclic monomer with protected carboxyl group of 3-[(Benzyloxycarbonyl)methyl]morpholine 2,5-dione was synthesized from benzyl alcohol, L-aspartate and bromoacetyl bromideSecondly,homopolymer and copolymer of 3-[(Benzyloxycarbonyl)- methyl]morpholine 2,5-dione and L-lactide were prepared through ring opening polymerization.After the protected groups of benzyloxycarbonyl were effectively removed via Pd/C catalytic hydrogenation,the homopolymer of poly(Glc-alt-Asp) and copolymer of poly[LA-co-(Glc-alt-Asp)]with different composition and hydrophilicity were obtained.Thirdly,micro-nanoparticles at the range of 400nm and 600nm of PLA and poly[LA-co-(Glc-alt-Asp)]loaded with HMME were prepared by oil-in-water(O/W) solvent evaporation method.Apparently,the drug loading amount of HMME of copolymer was higher than PLA,and it was also enhanced by improved the composition of polydepsipeptide.Finally,fluorescence excitation and triple state studies of HMME in the nanoparticle system were investigated.As shown in the results,the structure and the fluorescence excitation of HMME were not changed and can be excitated to triple state.The initial investigation of the in vitro release behaviors of the nanoparticle system indicated that the release rate of HMME were different with different copolymer composition.