Preparation And Properties Of Biodegradable PLLA/PCL/PEG Blend For Artificial Lacrimal Canaliculus

Recently, with the development of tissue engineering, the researches on medicalbiodegradable material are becoming more and more significant. In order to reduce the painand inflammation during the removal of non-biodegradable artificial lacrimal canaliculus,the biodegradable ternary blends of PLLA/PCL/PEG were prepared by melt blending, andtheir microstructure, mechanical property, crystallization were discussed, the plasticizingeffect of PEG and the hydrophilicity of the ternary blends were also investigated. Finally,the biodegradable artificial lacrimal canaliculi were prepared, and their degradationbehavior in vitro was studied.For the binary blend of PLLA/PCL, it is a partially compatible system and PCLdispersed homogeneously in the blends, The notched impact strength of the PLLA/PCLblends increased compared with pure PLLA. PCL lowered the melting temperature (Tm) ofPLLA, but had little effect on the crystallinity of PLLA. PEG improved the compatibilitybetween PCL and PLLA. PEG also lowered the glass transition temperature (T_g) and themelting temperature (Tm) of PLLA. Moreover, the crystallinity of PLLA increased withincreasing the content of PEG, which testified PEG was a perfect plasticizer. Meanwhile,the hydrophilicity of the blends increased gradually with the addition of PEG.The results of the in vitro degradation of the biodegradable artificial lacrimalcanaliculi based on ternary PLLA/PCL/PEG blend showed that the pH value of phosphatebuffer solution, the number average molecular weight(Mn) and the mass of the blendsdecreased gradually during the degradation, while the crystallinity of PLLA increasedduring early degradation. It was confirmed that the introduction of PEG led to an increasein the degradation rate. For the PLLA/PCL/PEG with a mass ratio of51/34/15, the masspercentage lowered to84.2%, and the number average molecular weight Mnof the blenddecreased from5.8×10~4g/mol to3.4×10~4g/mol after three months. Consequently, the study would provide beneficial reference for the application in vivo.