Background The most important objective of transplant studies in the injured spinal cord has been to provide a favorable environment for axonal growth. Moreover, the continuing discovery of new grafts is providing new...Background The most important objective of transplant studies in the injured spinal cord has been to provide a favorable environment for axonal growth. Moreover, the continuing discovery of new grafts is providing new potentially interesting transplant candidates. Our purpose was to observe the morphological and functional repair effects of the co-transplantation of neural stem cell （NSC）, Schwann ceils （SCs） and poly lactide-co-glycolide acid （PLGA） on the spinal cord injury of rats.Methods A scaffold of PLGA was fabricated. NSCs and SCs were cultured, with the NSCs labeled with 5-bromodeoxyuridine, and the complex of NSC/PLGA or NSC＋SCs/PLGA were constructed. Thirty-six Wistar rats were randomly divided into three groups： group A （transplantation of PLGA）, group B （transplantation of NSC/PLGA） and group C （transplantation of NSC＋SCs/PLGA）. The 3 mm length of the right hemicord was removed under the microscope in all rats. The PLGA or the complex of PLGA-celIs were implanted into the injury site. Basso-Beattie-Bresnahan （BBB）locomotion scores, motor and somatosensory evoked potential of lower limbs were examined to learn the rehabilitation of sensory and motor function at 4 weeks, 8 weeks, 12 weeks and 24 weeks after injury. All the recovered spinal cord injury （SCI） tissues were observed with HE staining, immunohistochemistry, and transelectronmicroscopy to identify the survival, migration and differentiation of the transplanted cells and the regeneration of neural fibres at 4 weeks, 8 weeks,12 weeks and 24 weeks after injury.Results （1） From 4 weeks to 24 weeks after injury, the BBB locomotion scores of cell-transplanted groups were better than those of the non-cell-transplanted group, especially group C （P 〈0.05）. The amplitudes of the somatosensory evoked potential （SEP） and motor-evoked potential （MEP） were improved after injury in groups B and C, but the amplitude of SEP and MEP at 4 weeks was lower than that at 12 weeks and 24 weeks after injury. Com展开更多
To modify the surface property of poly lactide-co-glycolide （PLGA） by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3-diamensional （3-D） porous scaffolds hydrolyzed in alkali...To modify the surface property of poly lactide-co-glycolide （PLGA） by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3-diamensional （3-D） porous scaffolds hydrolyzed in alkaline solution were minerilized in SBF for 14 days. The morphology and composition of the mineral grown on PLGA were analyzed with SEM, FTIR and XRD. The porosity of the scaffolds was detected by using the liquid displacement method. The compressive strength of the scaffolds was detected by using a Shimadzu universal mechanic tester. An obvious mineral coating was detected on the surface of films and scaffolds. The main compqnent of the mineral was carbonated hydroxyapatite （HA） similar to the major mineral component of bone tissues. The porosity of the un-mineralized and mineralized porous scaffolds was （84.86±8.52） % and （79.70 ± 7.70） % respectively. The compressive strength was 0. 784±0. 156 N/mm^2 in un-mineralized 3-D porous PLGA and 0. 858±0. 145 N/mm^2 in mineralized 3-D porous PLGA. There were no significant differences between the mineralized and un-mineralized scaffolds （P〉0, 05） in porosity and biomechanics. Biomimetic mineralization is a suitable method to construct artificial bone.展开更多
The purposes of this research were to synthesize and characterize star-shaped poly lactide-co-glycolide-β-cyclo-dextrin (PLGA-β-CD) copolymer by reacting L-lactide, glycolide and β-cyclodextrin in the presence of s...The purposes of this research were to synthesize and characterize star-shaped poly lactide-co-glycolide-β-cyclo-dextrin (PLGA-β-CD) copolymer by reacting L-lactide, glycolide and β-cyclodextrin in the presence of stannous octoate as a catalyst. The structure of PLGA-β-CD copolymer was confirmed with 1H-NMR, 13C-NMR and FT-IR spectra. Albumin as a model peptide drug was encapsulated within nanoparticles made of PLGA-β-CD with a modified double emulsion method. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) photomicrographs showed that the nanoparticles have the mean diameter within the range of 80 - 210 nm. Also they were almost spherical in shape. Effects of the experimental parameters, such as copolymer composition, copolymer concentration, and reaction temperature, on particular size and encapsulation efficiency were investigated.展开更多
基金This work was supported by grants from the National Natural Science Foundation of China （No. 30370543, No. 30540450581）.
文摘Background The most important objective of transplant studies in the injured spinal cord has been to provide a favorable environment for axonal growth. Moreover, the continuing discovery of new grafts is providing new potentially interesting transplant candidates. Our purpose was to observe the morphological and functional repair effects of the co-transplantation of neural stem cell （NSC）, Schwann ceils （SCs） and poly lactide-co-glycolide acid （PLGA） on the spinal cord injury of rats.Methods A scaffold of PLGA was fabricated. NSCs and SCs were cultured, with the NSCs labeled with 5-bromodeoxyuridine, and the complex of NSC/PLGA or NSC＋SCs/PLGA were constructed. Thirty-six Wistar rats were randomly divided into three groups： group A （transplantation of PLGA）, group B （transplantation of NSC/PLGA） and group C （transplantation of NSC＋SCs/PLGA）. The 3 mm length of the right hemicord was removed under the microscope in all rats. The PLGA or the complex of PLGA-celIs were implanted into the injury site. Basso-Beattie-Bresnahan （BBB）locomotion scores, motor and somatosensory evoked potential of lower limbs were examined to learn the rehabilitation of sensory and motor function at 4 weeks, 8 weeks, 12 weeks and 24 weeks after injury. All the recovered spinal cord injury （SCI） tissues were observed with HE staining, immunohistochemistry, and transelectronmicroscopy to identify the survival, migration and differentiation of the transplanted cells and the regeneration of neural fibres at 4 weeks, 8 weeks,12 weeks and 24 weeks after injury.Results （1） From 4 weeks to 24 weeks after injury, the BBB locomotion scores of cell-transplanted groups were better than those of the non-cell-transplanted group, especially group C （P 〈0.05）. The amplitudes of the somatosensory evoked potential （SEP） and motor-evoked potential （MEP） were improved after injury in groups B and C, but the amplitude of SEP and MEP at 4 weeks was lower than that at 12 weeks and 24 weeks after injury. Com
文摘To modify the surface property of poly lactide-co-glycolide （PLGA） by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3-diamensional （3-D） porous scaffolds hydrolyzed in alkaline solution were minerilized in SBF for 14 days. The morphology and composition of the mineral grown on PLGA were analyzed with SEM, FTIR and XRD. The porosity of the scaffolds was detected by using the liquid displacement method. The compressive strength of the scaffolds was detected by using a Shimadzu universal mechanic tester. An obvious mineral coating was detected on the surface of films and scaffolds. The main compqnent of the mineral was carbonated hydroxyapatite （HA） similar to the major mineral component of bone tissues. The porosity of the un-mineralized and mineralized porous scaffolds was （84.86±8.52） % and （79.70 ± 7.70） % respectively. The compressive strength was 0. 784±0. 156 N/mm^2 in un-mineralized 3-D porous PLGA and 0. 858±0. 145 N/mm^2 in mineralized 3-D porous PLGA. There were no significant differences between the mineralized and un-mineralized scaffolds （P〉0, 05） in porosity and biomechanics. Biomimetic mineralization is a suitable method to construct artificial bone.
文摘The purposes of this research were to synthesize and characterize star-shaped poly lactide-co-glycolide-β-cyclo-dextrin (PLGA-β-CD) copolymer by reacting L-lactide, glycolide and β-cyclodextrin in the presence of stannous octoate as a catalyst. The structure of PLGA-β-CD copolymer was confirmed with 1H-NMR, 13C-NMR and FT-IR spectra. Albumin as a model peptide drug was encapsulated within nanoparticles made of PLGA-β-CD with a modified double emulsion method. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) photomicrographs showed that the nanoparticles have the mean diameter within the range of 80 - 210 nm. Also they were almost spherical in shape. Effects of the experimental parameters, such as copolymer composition, copolymer concentration, and reaction temperature, on particular size and encapsulation efficiency were investigated.
