聚富马酸丙二醇酯/羟基磷灰石复合多孔水凝胶的制备及其矿化性能研究

采用二步法合成了可降解的聚富马酸丙二醇酯(poly(propylene fumarate),PPF),并和N-乙烯基吡咯烷酮(N-vinyl pyrrolidone,NVP)共聚,以1,4-二氧六环为溶剂,通过改变溶剂的量制备了溶胀性能不同的PPF水凝胶.采用万能力学测试仪和扫描电子显微镜分别表征了水凝胶的压缩模量和形貌结构.选择20％ PPF和10％ NVP的聚合体系,预掺3％的纳米羟基磷灰石(hydroxyapatite,HA),以氯化钠粒子为致孔剂,制备了孔径在280～450 μm的纳米复合多孔水凝胶,使其压缩模量提高了61％.模拟体液矿化10天的结果显示,磷灰石成核位点的存在和良好的与外界液体环境物质交换的能力,促进了多孔水凝胶表面磷灰石的沉积,说明HA的复合可以有效提高PPF多孔水凝胶的成骨活性.

FABRICATION AND MINERALIZATION OF POLY(PROPYLENE FUMARATE)/HYDROXYAPATITE POROUS HYDROGELS

Biodegradable poly(propylene fumarate)(PPF) was synthesized by a two-step method,which was then copolymerized with N-vinyl pyrrolidone(NVP) in 1,4-dioxane to fabricate PPF hydrogels.By changing the relative contents of monomers and solvent,hydrogels with different swelling property and mechanical strength were obtained.Generally,with a larger volume of solvent the hydrogel had a larger swelling ratio but a smaller compressive modulus due to the existence of pores in the matrix.Considering the balance between the hydrogel swelling and mechanical strength,a composite hydrogel with a macroporous structure was further fabricated by mixing 30% PPF and NVP,3% hydroxyapatite(HA) nanoparticles and benzoyl peroxide in 1,4-dioxane,following by casting the mixture into NaCl particles(280~450 μm as porogens),polymerization and removal of porogens.Addition of the HA particles increased the compressive modulus of porous hydrogels by 61%.Due to the sufficient exposure of the pre-loaded HA nucleation seeds and the good ability of medium exchange,significantly faster apatite growth was found in the composite macroporous hydrogel after being incubated in simulated body fluid,demonstrating that the PPF-NVP/HA macroporous hydrogel has better bone formation activity than the pure PPF-NVP macroporous hydrogel.