Plasma-patterned polydimethylsiloxane surface with single-step coating with a mixture of vitronectin and albumin enables the formation of small discs and spheroids of human induced pluripotent stem cells

摘要

Plasma treatment is an easy method of cleaning and hydrophilizing glass and polymer surfaces to facilitate adsorption of cell-adhesive proteins. Thus a patterned plasma treatment is useful for fabricating cell adhesion patterns. We previously succeeded in producing human induced pluripotent stem cell (hiPSC) discs (2 mm in diameter) on plasma-patterned polydimethylsiloxane (PDMS) by single-step coating of a mixture of 2 ubiquitous proteins, vitronectin and γ-globulin. Under serum-free and feeder-free conditions, without any undefined cell adhesion molecules, γ-globulin blocked hiPSC adhesion on surfaces not treated with plasma. However, γ-globulin has low cost-effectiveness and availability, and the resulting disc diameter was too large for cell-based assays. We demonstrate that bovine serum albumin (BSA) can also be used to block hiPSC adhesion on plasma-untreated PDMS surfaces coated with vitronectin. We succeeded in creating small hiPSC discs (200 μm in diameter) using single-step coating of a mixture of vitronectin and BSA. The hiPSCs proliferated without escaping from the patterned area and finally spontaneously detached from the discs to form spheroids. We believe that our method for generating hiPSC discs and spheroids will be useful for developing new bioengineering devices to enhance cell differentiation and to test drug safety for human embryonic development, contributing to future medical applications.