合成葡聚糖-聚乳酸接枝共聚物,并以此为载体,选择盐酸阿霉素为模型药物,利用纳米沉淀法和双乳法构建出了载药纳米粒子,并通过透射电镜(scanning electron microscope,TEM)、动态光散射(dynamic light scattering,DLS)、紫外(UV-vis)对...合成葡聚糖-聚乳酸接枝共聚物,并以此为载体,选择盐酸阿霉素为模型药物,利用纳米沉淀法和双乳法构建出了载药纳米粒子,并通过透射电镜(scanning electron microscope,TEM)、动态光散射(dynamic light scattering,DLS)、紫外(UV-vis)对其形貌、粒径及包封率进行了表征,结果表明:不同共聚物/药物比例会影响载药纳米粒子的粒径、粒径分布及包封率.此外,载药纳米粒子的体外释放实验表明:在弱碱条件(pH=7.4)下的释放速度比在弱酸条件(pH=5.0)下的慢,说明释放介质的pH对其释放性能有较大影响,有利于药物在肿瘤细胞中的控释.展开更多
Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits wi...Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits with a transverse transcondylar osteotomy of the distal femur were fixed intramedullary by a HA/PDLLA rod, the duration of follow- up were 3， 6， 12, 24 and 36 weeks. Histological, scanning electron microscopic (SEM), energy dispersive X- ray (EDX) and biomechanical analyses were done. Results. Active new bone formation and direct bone- bonding were seen at the bone- implant interface. Generous apatite crystals deposited and grew on the surface of the composites at 3～ 6 weeks postoperation. The interfacial shear strength increased significantly. Conclusion. Through the incorporating of resorbable HA microparticles, specific bone- bonding and active osteogenic capacity is introduced. This kind of bioactivity, together with other properties such as sufficient mechanical strength, enhanced biocompatibility and radiopacity, which are intrinsically unobtainable in totally resorbable polymer/polymer systems, make the HA/PDLLA composites become a desirable material for the internal fixation of cancellous bone.展开更多
P（LLA-CL）（75/25） （poly（L-lactide-co-caprolactone）（75/25）） was synthesized from high purity L-lactide and e-caprolactone using tin octoate as initiator by ring-opening polymerization, and characterized by inf...P（LLA-CL）（75/25） （poly（L-lactide-co-caprolactone）（75/25）） was synthesized from high purity L-lactide and e-caprolactone using tin octoate as initiator by ring-opening polymerization, and characterized by infrared spectrum and ^1-NMR （^1H proton spectrum of nuclear magnetic resonance） spectrum. The synthesized P（LLA-CL）（75/25） is a random copolymer. The influences of polymerization temperature, polymerization time and dosage of initiator on the weight average molecular weight and the polydispersity index of P（LLA-CL）（75/25） were investigated. The optimum preparation condition of P（LLA-CL）（75/25） was： the polymerization pressure is less than 0.5 Pa, the polymerization temperature is 125℃, the n（M）/n（I） ratio is 8,000/1, the polymerization time is 36 h. Under the condition, the weight-average molecular weight of prepared P（LLA-CL）（75/25） is 45.3×10^4, and molecular weight distribution coefficient is 1.24.展开更多
A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Y...A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Yb(6)] supported by an amine-bridged bis(phenolate) ligand have been synthesized through one-pot reactions of Ln(C5H5)3(THF), LH2 with p-benzenediol and 1,4-benzenedimethanol, respectively. All complexes have been fully characterized by elemental analyses, single-crystal X-ray diffraction analysis, and IR and multi-nuclear NMR spectroscopy(in the cases of 1, 4 and 5). Study of their catalytic behavior revealed that, in general, all complexes are efficient initiators for the polymerization of rac-lactide(LA) and rac-β-butyrolactone(BBL), except for 3 and 4 in the case of BBL. The influence imposed by lanthanides of different ionic radii and initiating groups of different structures on the activity, controllability, and stereoselectivity of polymerization were systematically studied and compared. Highly heterotactic PLA(Pr up to 0.99) and syndiotactic PHB(Pr ≈ 0.81) with high molecular weight and narrow polydispersity formed and were automatically capped with hydroxyl functionality at both ends.展开更多
Objective: To elongate human nerve axon in cultu re and search for suitable support matrices for peripheral nervous system trans plantation. Methods: Human embryo cortical neuronal cells,seeded on poly ( D,L-lactide-c...Objective: To elongate human nerve axon in cultu re and search for suitable support matrices for peripheral nervous system trans plantation. Methods: Human embryo cortical neuronal cells,seeded on poly ( D,L-lactide-co-glycolide) (PLGA) membrane scaffolds,were elongated with a se lf-made neuro-axon extending device. The growth and morphological changes of n euron axons were observed to measure axolemmal permeability after elongation. Ne urofilament protein was stained by immunohistochemical technique.Results: Human embryo neuron axon could be elongated and cultur ed on the PLGA membrane and retain their normal form and function. Conclusions: Three dimensional scaffolds with elongated neuron axon have the basic characteristics of artificial nerves,indicating a fundement al theory of nerve repair with elongated neuron axon.展开更多
文摘合成葡聚糖-聚乳酸接枝共聚物,并以此为载体,选择盐酸阿霉素为模型药物,利用纳米沉淀法和双乳法构建出了载药纳米粒子,并通过透射电镜(scanning electron microscope,TEM)、动态光散射(dynamic light scattering,DLS)、紫外(UV-vis)对其形貌、粒径及包封率进行了表征,结果表明:不同共聚物/药物比例会影响载药纳米粒子的粒径、粒径分布及包封率.此外,载药纳米粒子的体外释放实验表明:在弱碱条件(pH=7.4)下的释放速度比在弱酸条件(pH=5.0)下的慢,说明释放介质的pH对其释放性能有较大影响,有利于药物在肿瘤细胞中的控释.
基金This project was supported by the National Scientific Committee(969202011), the Natural Science Foundation of Hubei Province(99J
文摘Aim. To investigate the bioactivity of the self- designed biodegradable osteosynthetic devices made of resorbable hydroxyapatite microparticles/ poly- DL- lactide (HA/PDLLA) composites. Method. Forty- three rabbits with a transverse transcondylar osteotomy of the distal femur were fixed intramedullary by a HA/PDLLA rod, the duration of follow- up were 3， 6， 12, 24 and 36 weeks. Histological, scanning electron microscopic (SEM), energy dispersive X- ray (EDX) and biomechanical analyses were done. Results. Active new bone formation and direct bone- bonding were seen at the bone- implant interface. Generous apatite crystals deposited and grew on the surface of the composites at 3～ 6 weeks postoperation. The interfacial shear strength increased significantly. Conclusion. Through the incorporating of resorbable HA microparticles, specific bone- bonding and active osteogenic capacity is introduced. This kind of bioactivity, together with other properties such as sufficient mechanical strength, enhanced biocompatibility and radiopacity, which are intrinsically unobtainable in totally resorbable polymer/polymer systems, make the HA/PDLLA composites become a desirable material for the internal fixation of cancellous bone.
文摘P（LLA-CL）（75/25） （poly（L-lactide-co-caprolactone）（75/25）） was synthesized from high purity L-lactide and e-caprolactone using tin octoate as initiator by ring-opening polymerization, and characterized by infrared spectrum and ^1-NMR （^1H proton spectrum of nuclear magnetic resonance） spectrum. The synthesized P（LLA-CL）（75/25） is a random copolymer. The influences of polymerization temperature, polymerization time and dosage of initiator on the weight average molecular weight and the polydispersity index of P（LLA-CL）（75/25） were investigated. The optimum preparation condition of P（LLA-CL）（75/25） was： the polymerization pressure is less than 0.5 Pa, the polymerization temperature is 125℃, the n（M）/n（I） ratio is 8,000/1, the polymerization time is 36 h. Under the condition, the weight-average molecular weight of prepared P（LLA-CL）（75/25） is 45.3×10^4, and molecular weight distribution coefficient is 1.24.
基金financial supported by the National Natural Science Foundation of China (20972108, 21174095, 21132002)a project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the Qing Lan Project is gratefully acknowledged
文摘A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Yb(6)] supported by an amine-bridged bis(phenolate) ligand have been synthesized through one-pot reactions of Ln(C5H5)3(THF), LH2 with p-benzenediol and 1,4-benzenedimethanol, respectively. All complexes have been fully characterized by elemental analyses, single-crystal X-ray diffraction analysis, and IR and multi-nuclear NMR spectroscopy(in the cases of 1, 4 and 5). Study of their catalytic behavior revealed that, in general, all complexes are efficient initiators for the polymerization of rac-lactide(LA) and rac-β-butyrolactone(BBL), except for 3 and 4 in the case of BBL. The influence imposed by lanthanides of different ionic radii and initiating groups of different structures on the activity, controllability, and stereoselectivity of polymerization were systematically studied and compared. Highly heterotactic PLA(Pr up to 0.99) and syndiotactic PHB(Pr ≈ 0.81) with high molecular weight and narrow polydispersity formed and were automatically capped with hydroxyl functionality at both ends.
文摘Objective: To elongate human nerve axon in cultu re and search for suitable support matrices for peripheral nervous system trans plantation. Methods: Human embryo cortical neuronal cells,seeded on poly ( D,L-lactide-co-glycolide) (PLGA) membrane scaffolds,were elongated with a se lf-made neuro-axon extending device. The growth and morphological changes of n euron axons were observed to measure axolemmal permeability after elongation. Ne urofilament protein was stained by immunohistochemical technique.Results: Human embryo neuron axon could be elongated and cultur ed on the PLGA membrane and retain their normal form and function. Conclusions: Three dimensional scaffolds with elongated neuron axon have the basic characteristics of artificial nerves,indicating a fundement al theory of nerve repair with elongated neuron axon.
