Research Of Dopamine-containing Tissue Adhesive Based On Citrate

Tissue adhesive is getting more and more attention due to its advantages like efficientlystopping bleeding, avoiding needling, easy to use and no need to remove. Mussel-inspired tissuebioadhesive is one important branch of tissue adhesives. Blue mussel mytilus edulis, which is oneof maritime creatures, has strong adhesion ability due to the presence of L-3,4-dihydroxyphenylalanine (DOPA) in the structure of mussels adhesive foot proteins. Inspired bythe adhesion strategy of mussels adhesive foot proteins, tissue adhesive with good adhesiveproperty can be obtained by incorporating catechol-containing species into the structure ofpolymers.In this paper, two kinds of dopamine containing tissue adhesives were obtained by meltpolycondensation of1,8-octadiol, citric acid, dopamine, and/or polyethyleneglycol(PEO). Thestructure, adhesion strength and biocompatibility of adhesives were evaluated after exploration ofsynthesis and crosslinking conditions. Main researches are listed as follows:(1) A new kind of dopamine containing tissue adhesive(POC-d) was obtained by meltpolycondensation of1,8-octadiol, citric acid and dopamine. The optimal reaction time, dopamineloading and crosslinking condition were explored. The test results of FT-IR,1H-NMR, GPC, andUV-Vis showed that POC-d bioadhesive with higher dopamine content was perpared when thereaction time was105min and the feeding mole ratio of1,8-octanediol, citric acid and dopaminewas1:1.1:0.5. Results of lap shear strength test showed that the adhesive strength of POC-dbioadhesive was99.3KPa, which was40%of adhesive strength of commercial α-cyanoacrylateadhesive, with equal volume of20wt%NaIO4solution and70wt%POC-d adhesive solution. Andthe crosslinked POC-d adhesive exhibit elasticity. L929fibroblast cells was used for in vitro biocompatibility tests. MTT test results suggested that the leachable content and degradationproducts of crosslinked POC-d adhesive did not induce significant cytotoxicity. SEM resultsshowed that cells can survive on POC-d adhesive in good state.(2) Since POC-d adhesive was water insoluble, PEO was added to improve water solubilityof the adhesive. Poly(1,8-octadiol-co-PEO-co-citric acid) based adhesive(POEC-d) was preparedby melt polycondensation of citric acid,1,8-octadiol, PEO and dopamine. The structure,mechanical property and adhesive strength were characterized using FT-IR,1H-NMR, UV-Vis,mechanical property test and lap shear strength test. Results showed that water solubility ofPOEC-d bioadhesive was improved obviously when the feeding mole ratio of1,8-octanediol, PEO,citric acid and dopamine was0.3:0.7:1.1:0.5. POEC-d bioadhesive with better adhesive strengthwas obtained when the volume of NaIO4solution(10wt%) and POEC-d adhesive solution(50wt%)were equal. The MTT test and SEM was performed to assess in vitro biocompatibility of POEC-dadhesive. Testing results showed that crosslinked POEC-d adhesive did not induce significantcytotoxicity and cells were well-grown on it.