Preparation And Properties Of PEGDA Photo-cured Resin Based On Ene-thiol Click Reaction

Polyethylene glycol diacrylate(PEGDA)is a biocompatible polymer with C=C end groups.It has relatively higher commercial value because of their low price and high product maturity.It is widely used as crossing agents to prepare hydrogels or photocurable resins.They have potential applications in the fields of biosensors and bioengineering fields.However,the high hydrophilicity of PEGDA makes it is relatively difficult for cells adhesion to the surface of PEGDA materials.Further more,the derived hydrogel usually lacks of strong and flexible mechanical properties.And there are only few references of PEGDA focused on the application in photocuring resin,which limits the development of PEGDA in biomedical field.Therefore,it is urgent to prepare a new PEGDA photocuring resin with enhanced mechanical properties and excellent biocompatibility.In this paper,we provide a novel routine for the preparation of the PCL/PEGDA photocured material with excellent biocompatibility and enhanced mechanical property by thiol-ene “click” reaction.The mechanical properties,biocompatibility and high-precision photopatterning of photocuring resin are characterized in detail,which can be divided into two parts as follows:Firstly,we reported the fabrication of photocured material and studied the effects of mechanical properties.Brielfly,polycaprolactone-derived(PCL-derived)copolymer and PEGDA were cross-linked by pentaerythritol tetra(PETMP).The photocured material is cross-linked via UV irradiation through thiol-ene “click”chemistry.Thiol-ene polymerization can be carried out under the mild condition,and has high reaction efficiency.Besides,the mercaptan group was used as thecrosslinking agent to enhance the mechanical properties of the material and reduce the residue of small molecular initiator.The photocured material is studied regarding to its thermal property and mechanical property.And the results suggest that the flexibility and toughness of PCL-derived photocured material have improved.Accordingly,the PCL-derived photocured material achieves enhanced mechanical property(with the increase of PCL segment content from 0 to 38.0 %,the photocured samples monotonically increased their breaking strength from 0.62 to 3.10 MPa and Young's modulus from 1.39 to 9.22 MPa).Therefore,it is confirmed that the mechanical properties of the photocuring resin have been effectively improved.Combining with the work of the previous chapter,we can see that the photocuring resin with enchanced mechanical properties has been successfully prepared.However,with the rapid development of photo-curing technology,biomedical materials are asked for excellent biocompatibility and manufacturing accuracy.Therefore,further characterization of biocompatibility and high-precision photopatterning are carried in the second chapter of this paper.The results showed that the cell proliferation,cytotoxicity and hemolysis rate of PCL-derived photocured resins were significantly improved,which shows excellent biocompatibility.In addition,we successfully fabricated high-precision patterns(~5 ?m),which shows a lot of promise for its application in tissue engineering scaffolds.In this paper,the facile route for synthesis of photocured resin via thiol-ene“click” chemistry with enhanced mechanical properties,excellent bioconpability and high precision patterning has a good impact in bioengineering and tissue engineering scaffolds fields.