The homopolymerization and copolymerization of glycolide (GA) and lactide (LA) are des-cribed. The resulting polymers are characterized by differential scanning calorimetry (DSC),thermogravimetric analysis (TGA), 300 ...The homopolymerization and copolymerization of glycolide (GA) and lactide (LA) are des-cribed. The resulting polymers are characterized by differential scanning calorimetry (DSC),thermogravimetric analysis (TGA), 300 MHz proton nuclear magnetic resonance spectroscopy(NMR), infrared spectroscopy, and X-ray diffraction. The rheological properties of PGA andPGLA 910 are evaluated by shear experiments. The biodegradation has been studied in vivo. Theresults show that the polyesters can be absorbed by the muscles of rabbits after 60 days.展开更多
Four kinds of braided yarns were produced with different proportions of polyglycolic acid( PGA) and polylactic acid( PLA)multifilaments( 2PGA /1PLA, 2PGA /2PLA, 3PGA /1PLA, and3PGA /2PLA). A novel artificial plain sti...Four kinds of braided yarns were produced with different proportions of polyglycolic acid( PGA) and polylactic acid( PLA)multifilaments( 2PGA /1PLA, 2PGA /2PLA, 3PGA /1PLA, and3PGA /2PLA). A novel artificial plain stitch scaffold reinforcement was manufactured by braiding technology and knitting technology respectively. Tendon scaffold reinforcements were investigated for 8weeks in phosphate buffered solution( PBS)( pH = 7. 4) at 37 ℃.The degradation was studied with regard to the mass loss,tensile properties,grams per square meter( g /m2),thickness,caliber,and porosity of scaffold reinforcements. The experimental showed that during the process of 8-week degradation,the mass losses of scaffold reinforcements were small in the first 3-week,but they increased rapidly after 3-week,and the speeds tended to be small gradually after 6-week; the tensile properties dropped rapidly in the first 2-week; the grams per square meter and thicknesses speeded down obviously between 3-week to 6-week. The caliber and porosity of scaffold reinforcements first decreased and then increased gradually. The porosity can reach more than 97%.展开更多
Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is...Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is not able to observe the internal structure, and there is a risk of sacrificing animals to remove the suture and damaging the materials. Therefore, we introduced optical coherence tomography (OCT) to observe and evaluate four different kinds of surgical sutures in vivo (monofilament absorbable and nonabsorbable sutures and braided absorbable and nonabsorbable sutures). As a result, while the monofilament nonabsorbable sutures showed almost no change over time, the absorbable sutures had color fading and it was also confirmed that the internal structure became chaotic due to decomposition, which improved the OCT signal intensity. For the braided sutures, both absorbable and nonabsorbable, we found that the reflection signal improved from week 0 because blood got among the filaments of sutures and dried during recovery which increased OCT signal from week 0 to week 1. We also confirmed that the braided sutures untwisted over time. All four kinds of sutures were pulled due to the movement of rats during recovery. It is expected that OCT technology will be of great help in in vivo experiments on biomaterials such as sutures.展开更多
文摘The homopolymerization and copolymerization of glycolide (GA) and lactide (LA) are des-cribed. The resulting polymers are characterized by differential scanning calorimetry (DSC),thermogravimetric analysis (TGA), 300 MHz proton nuclear magnetic resonance spectroscopy(NMR), infrared spectroscopy, and X-ray diffraction. The rheological properties of PGA andPGLA 910 are evaluated by shear experiments. The biodegradation has been studied in vivo. Theresults show that the polyesters can be absorbed by the muscles of rabbits after 60 days.
基金Hi-Tech Research and Development Program of China(863 program)(No.2012AA020507)
文摘Four kinds of braided yarns were produced with different proportions of polyglycolic acid( PGA) and polylactic acid( PLA)multifilaments( 2PGA /1PLA, 2PGA /2PLA, 3PGA /1PLA, and3PGA /2PLA). A novel artificial plain stitch scaffold reinforcement was manufactured by braiding technology and knitting technology respectively. Tendon scaffold reinforcements were investigated for 8weeks in phosphate buffered solution( PBS)( pH = 7. 4) at 37 ℃.The degradation was studied with regard to the mass loss,tensile properties,grams per square meter( g /m2),thickness,caliber,and porosity of scaffold reinforcements. The experimental showed that during the process of 8-week degradation,the mass losses of scaffold reinforcements were small in the first 3-week,but they increased rapidly after 3-week,and the speeds tended to be small gradually after 6-week; the tensile properties dropped rapidly in the first 2-week; the grams per square meter and thicknesses speeded down obviously between 3-week to 6-week. The caliber and porosity of scaffold reinforcements first decreased and then increased gradually. The porosity can reach more than 97%.
文摘Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is not able to observe the internal structure, and there is a risk of sacrificing animals to remove the suture and damaging the materials. Therefore, we introduced optical coherence tomography (OCT) to observe and evaluate four different kinds of surgical sutures in vivo (monofilament absorbable and nonabsorbable sutures and braided absorbable and nonabsorbable sutures). As a result, while the monofilament nonabsorbable sutures showed almost no change over time, the absorbable sutures had color fading and it was also confirmed that the internal structure became chaotic due to decomposition, which improved the OCT signal intensity. For the braided sutures, both absorbable and nonabsorbable, we found that the reflection signal improved from week 0 because blood got among the filaments of sutures and dried during recovery which increased OCT signal from week 0 to week 1. We also confirmed that the braided sutures untwisted over time. All four kinds of sutures were pulled due to the movement of rats during recovery. It is expected that OCT technology will be of great help in in vivo experiments on biomaterials such as sutures.
