Effect of Chitosan Coating on Properties of Polyactic Acid Thread-Embedding Material

Thread-embedding materials buried into acupuncture points to produce a long-time stimulation is a method which has been widely applied in the acupuncture and moxibustion therapies for diseases treating and they should have excellent properties of good biocompatibility,biodegradability and moderate rigidity.Polyactic acid(PLA) as the thread-embedding material had some shortcomings such as poor hydrophilicity and slowly biodegradable speed.In this paper,PLA thread-embedding material was modified by chitosan coating which could improve rigidity,hydrophilicity and moisture absorption and thus produce better stimulation effect.The variation tendency of diameter,mass,hydrophilicity,and initial modulus of the sample under the change of chitosan coating concentration,coating time and coating times were studied respectively.The results showed that the hydrophilicity,mass,and initial modulus after coating rose in a certain range when the coating time,coating times and coating concentration increased,while the changing of coating had little impact on fiber diameter.

Clinical outcomes of amniotic membrane loaded with5-FU PLGA nanoparticles in experimental trabeculectomy

AIM: To evaluate the effect of amniotic membrane loaded with 5-fluorouracil poly(lactic-co-glycolic acid)(PLGA) nanoparticles(5-FU-NPs) in the surgical outcomes of experimental trabeculectomy in rabbits.METHODS: Thirty-two New Zealand white rabbits were randomly categorized into four groups with 8 rabbits in each group. Group 1, the control group, performed traditional trabeculectomy without adjuvant treatment.While the experimental groups performed compound trabeculectomy with different implantations including amniotic membrane(group 2), 5-FU-NPs(group 3) and amniotic membrane loaded with 5-FU-NPs(group 4).Clinical evaluations including IOP measurement and filtration bleb analysis were performed in all groups postoperatively.RESULTS: There is no significant difference of mean IOP in all groups at first 7d after surgery. While at P14,mean IOPs of experimental group 2(9.8 ±2.1 mm Hg),groups 3(8.9 ±2.8 mm Hg) and group 4(7.6 ±2.3 mm Hg)were significantly reduced compared to control group(12.4 ±2.6 mm Hg; n =8, P 【0.05). At P21, mean IOPs of groups 3(11.7±3.2 mm Hg) and group 4(9.9±1.6 mm Hg)were significantly decreased compare to control group(17.9±1.6 mm Hg) and group 2(16.6 ±2.8 mm Hg; n =8,P 【0.05). At P28, mean IOPs of groups 3(13.8±3.3 mm Hg)and group 4(10.6 ±2.0 mm Hg) were also significantly reduced compare to control group(19.4±2.3 mm Hg) and group 2(18.5 ±2.4 mm Hg; n =8, P 【0.05). Meanwhile mean IOP of group 4 is significantly decreased compared to group 3 at P28(n =8, P 【0.05). Survival analysis of functional filtration blub in all groups revealed the longest survival time in group 4(24.9±5.1d) compared to that in group 3(20.6 ±4.3d), group 2(15.0 ±5.2d) and control group(10.1±5.7d).CONCLUSION: Amniotic membrane loaded with 5-FuNPs may function as an effective anti-scarring implant and provides improved long-term surgical outcomes for experimental trabeculectomy in rabbits.

Molecular and Mesoscopic Dynamics Simulations on the Compatibility of PLA/Plasticizer Blends

The compatibility of the blend systems for olyactic acid （PLA）/tributyl citrate （TBC） and PLA/glycerol has been studied by molecule and mesoscopic dynamics methods. The results from glass transition temperature simulations showed that the compatibility of PLA/TBC system was better than that of PLA/glycerol, which were consistent with the conclusion obtained from the pair correlation functions. Besides, the behaviors of phase state distribution and evolution process were investigated by mesoscopic dynamics method as well. The results indicated that citrate ester was a better plasticizer than glycerol for PLA.