Preparation Of Visible Light Crosslinkable Bioink And Studies On Its Biocompatiability

In recent years,with the increasing demand for disease treatment and medical research,3D bioprinting technology has received extensive attention and research in the fields of tissue engineering,drug screening,and in vitro pathological model construction.Because 3D bioprinting technology can combine cells and bioactive factors with materials,which using additive manufacturing to build tissue engineering scaffolds,artificial diseases or organ models with good biological activity.In the manufacturing process,the design and development of bioink has become more and more important.Because bioink not only provides suitable microenvironment and functional support for the growth of cells,but also protects the survival of cells during the printing process without affecting the structural resolution and stability of the printed structure.Therefore,bioink is the bridge between the cell and the printing method.Although there has been published a lot of reports in this area and a series of bioinks have been developed,the current bioinks still have the a series of problems,like complex using process and insufficient biocompatibility.Therefore,developing a bioink that is easy to use,with good biocompatibility,fast curing under mild condition,has great potential in current medical research.In this subject,in order to solve the cell damage caused by ultraviolet light during the photo-curing process,insufficient biocompatibility and complex using process,we developed a kind of visible light crosslinkable bioink which is easy to mix and with excellent biocompatibility.The bioink is a composite hydrogel of methacrylated hyaluronic acid and decellularized extracellular matrix,which can be printed into grid structure and ensures a high cell viability while support cell adhesion and proliferationFirstly,in this study,the reaction of methacrylic anhydride with hyaluronic acid successfully prepared methacrylated hyaluronic acid with a substitution degree of 41.37%.Then the enzyme treatment method was used to decellularize the intervertebral disc cartilage.And we successfully prepared a decellularized extracellular matrix with no obvious nucleus,dsDNA content of 16.62± 3.1 ng/mg and collagen content of 660.4±5.338 ug/mg.Secondly,methacrylated hyaluronic acid and lyophilized decellularized extracellular matrix powder could dissolved in 5min.And in the presence of the visible light initiator EosinY and its co-initiators TEOA and NVP,the rapid gelation of the methacrylated hyaluronic acid / decellularized extracellular matrix hydrogel under 515 nm green light irradiation can be achieved.After compositing decellularized extracellular matrix,the compressive strength and modulus of the hydrogel is significantly improved.The compressive strength of the 3% methacrylated hyaluronic acid / 1% acellular matrix hydrogel was 102.38±5.27 kPa.The compressive modulus is 782± 20.36 kPa at 80% strain.With the increase of the content of decellularized extracellular matrix in the composite hydrogel,the pore size and swelling rate of the hydrogel both decrease,indicating the formation of a double network structure between the two components of the hydrogel.After encapsulated MC3T3-E1 cells in composite hydrogel,through 7 days culture,the composited structure shows more than 95% cell viability and normal 3D morphology.At last,Through pneumatic extrusion-based 3D bioprinting technology,MeHA/dECM composite hydrogel can be used to print diverse two-dimensional patterned construction of polyline shape,snail shape and multi-layer mesh structure.At the same time,we successfully realized to bioprinting bioink containing MC3T3-E1 cells.The bioink significantly avoid cell damage during the printing process,and the cell viability was nearly 100% after printing.And the cell remained cell viability close to 100% and great state after 1 day of culture.In summary,the methacrylated hyaluronic acid / decellularized extracellular matrix composite hydrogel exhibits extremely excellent cell compatibility.And the prepared raw materials are easy to mix,convenient to use,and can be applied to biological 3D printing field.The composite bioink can provide a new strategy for the construction of in vitro disease models or drug screening models,and is expected to be used in the field of tissue engineering scaffolds in the future.