Type I collagen/sodium alginate/hyaluronic acidcompositehydrogelforcellloadingand 3Dcultureinvasculartissueengineering

alginateand hyaluronicacid are natural-derivedpolymer materials with goodcellcompatibilityandbio-safety,whichare widelyusedincellculture,tissueengineeringand drugdelivery,andsoon.Purecollagenhaspoormechanicalproperties.Whenpreparingcollagenand sodium alginatetoform acompositehydrogelmaterial,the mechanicalpropertiesandporosityofthe hydrogelscaffoldcanbeimprovedbyadjustingthedegreeofcross-linkingofsodiumalginateandCa2+ mimickingextracellularmatrix.The Young's modulusandthesol-geltransitiontemperatureofthe hydrogelwerecharacterizedbyPIUMA nanoindenterand DHRrheometerinthisstudy.Microscopic imagesofendothelialcellsexpressingredfluorescentproteinsand mesenchymalstem cellexpressing greenfluorescentproteinswerecapturedwith Olympusfluorescencemicroscopeaftercellculturedfor 0day,3days,5daysand7daysinhybridhydrogelmicroenvironment,andtheimagesofendothelial cellspheroidgrowthdiffusionaftercellculturedfor1day,6daysand9days.Theresultsshowthat thehybridhydrogeliscytocompatible.TheYoung'smodulusofthehydrogelis(600 +/- 81)Paandits sol-geltransitiontemperatureis23.2 celcius.Inconclusion,type I collagen/sodium alginate/hyaluronic acidhydrogelhasgoodcytocompatibilityforendothelialcellsand mesenchymalstem cells,andcan beusedasanidealscaffold materialforcell3Dculture.TheYoung's modulusandsol-geltransition temperatureofthe hydrogelhave no damageto cellviability,which can be used as anin vitro modelforstudyingangiogenesis and hasimportantapplication prospectsin vasculartissue engin-eering.