| Two-dimensional(2D)cell culture has been the predominant practice for cell biology and pharmaceutical research for more than 50 years,such as biomedical research,tissue engineering,regenerative medicine,and industrial practices.While it is well established that 2D culture poorly replicates in vivo function,such as growing environment,cell morphology,resistance to anti-cancer drug and so on.Consequently,there is considerable activity to develop three-dimensional(3D)cell culture scaffolds and cell culture systems,which recently grabbed great attention since the promotion of cell differentiation and tissue organization levels that are not possible in conventional 2D culture systems.We took advantage of microchip industry skills and microfluidics approaches to recreate 3D cell culture microenvironments that supports tissue differentiation and recapitulate the living fat tissues.We developed a microfluidic "fat-on-a-chip" made of polydimethylsiloxane that closely mimics the physiology of a functional adipose tissue.Using this platform,we modeled both visceral white adipose tissue(VAT)and subcutaneous white adipose tissue(SAT)by differentiating 3T3-L1 cells seeded at an initial concentration of 1M/mL and cultured in a tissue-specific 3D microenvironment with different extracellular matrix(ECM)from mice.After 10-day culturing of the mixture system,an increasing amount of cells and 3D distribution were observed.With another 10-day “cocktail” stimulation treatment,3T3-L1 were differentiated to adipocytes and can be used to grow distinct and functional adipose tissues that recapitulate depot specific metabolic differences.For a further step,we compared the cell morphology difference between 2D culture and 3D culture,also tested and validated the function of this fat chip using quantitative and functional analyses by using real-time fluorescent detection of metabolites secreted by adipose tissue and microscopy analysis of cell morphology.This adipose tissue chip will provide a novel and critical research tool for studying adipose physiology and pathophysiology.We intend to design this chip such that it can be easily applied to other tissue biology and easily integrated as part of a more complex multi organ microsystem.This will ultimately enable future studies of tissue cross-talk,metabolism and human disease modeling. |
