3D-printed GelMA/CS Composite Hydrogel Scaffold For Vascularized Adipose Tissue Restoration

The high incidence of breast cancer has become the main killer of female cancer.Surgical resection is still the main treatment for breast cancer.This will not only increase the pain of patients,but also cause great psychological trauma to patients.With the increase of incidence rate of breast cancer,the excised breast urgently needs to be repaired,and the accuracy of inches is also a challenge.This requires not only good biological materials,but also precise personalized customization to meet the above requirements.3D printing technology includes computer aided design,precise regulation of biological ink,and selection of hydrogel with good biocompatibility to promote tissue regeneration and accelerate wound healing.In this study,methacrylate gelatin(Gel MA)was used as the printing biological ink,and calcium silicate(CS)bioceramics were used as the active ingredient of breast fat tissue regeneration.Through 3D printing technology,porous scaffold materials are prepared to promote fat regeneration.Firstly,Gel MA/CS composite hydrogel scaffold was prepared by 3D printing technology,and its physical and chemical properties were characterized.It was found that the composite scaffold has a high water content,a uniform pore structure,and a diameter of approximately 1mm.This provides a good microenvironment for cell adhesion and proliferation;The mechanical experiment verified that the average Young’s modulus of the composite scaffold was 2.15 ± 0.11 k Pa,which was close to 0.5-25 k Pa of normal human breast.The biological experiment found that the 3D printed Gel MA/CS composite hydrogel scaffold significantly stimulated 3T3-L1 preadipocytes,and promoted the PPAR of adipogenesis through oil red staining,cell morphology,cell migration and up regulation γ、 Cell experiments such as leptin and FABP4 genes have fully verified their good adipogenic properties.Similarly,in angiogenesis,3D printed Gel MA/CS composite hydrogel scaffold significantly stimulates human umbilical vein endothelial cells(HUVECs),including cell adhesion,migration,differentiation,and VEGFA,FGF-2,HIF-1 that upregulate angiogenesis α Genes.In addition,through subcutaneous implantation experiments on animals in vivo,subsequent section staining confirmed that the 0.4% CS+Cell group had a larger area of lipid droplet aggregation,and the PPAR of lipid forming antibodies was also observed in tissue immunofluorescence γCD31,which is associated with angiogenic antibodies,has higher expression in the 0.4%CS+Cell group.All the results confirmed that our composite hydrogel scaffold can promote the repair of vascularized adipose tissue under the skin of nude mice.In conclusion,we have successfully prepared a new 3D printed Gel MA/CS composite hydrogel scaffold with controllable structure and enhanced mechanical properties,which can effectively stimulate the repair of vascularized fat.Our research is used for breast reconstruction and adipose tissue regeneration.Its preparation cost is low and the operating technology is simple.This research result has played a phased role in future clinical transformation,and has certain commercial value.It has opened up a new path in the field of adipose tissue regeneration and has good application prospects in the biomedical field.