No abstract

Although the fabrication of engineered organs as replacements for damaged organs has been widely studied over the past decade, practical fabrication is very difficult because the engineered organ usually has a very complex structure and cannot be fabricated simply by using a fixed scaffold. Special attention has therefore been paid to methods of making engineered organs by assembling composite parts. Since structures of these individual parts are very different, fabrication using fixed scaffolds requires a lot of effort and time. The concept of a changeable scaffold offered by “changeable cell culture (C3) mold” is proposed in this paper as a means to simplify the fabrication of these parts. Using a thin PDMS membrane as an actuator layer enables various scaffold structures to be formed and altered, in turn enabling the fabrication of many different tissue structures.C3mold consists of a 3 × 3 microactuator array with a diameter of 500 µm and spacing of 650 µm. Plant oil is used as the working fluid enabling deformation of the actuator layer. Various micropatterned gel sheets are fabricated, in order to demonstrate the possibility of usingC3molds in future tissue fabrication.

This paper presents a flexible microscaffold to facilitate the fabrication of different cellular constructs which could be used as the building units for the construction of a larger tissue with a complex structure. The device consists of a 6 × 6 array of membrane actuators, made of Polydimethylsiloxane. The superiority of membrane actuators helps preventing the leakage of culture medium and allows for the formation of various temporary scaffolds. In biological test, NIH3T3 cells were seeded on the scaffold provided. The positive pressure applied to membrane actuators enables the formation of the scaffold for construction of hole array-patterned and round flat cell sheets while the negative pressure applied enables the scaffold for construction of spherical cellular aggregates. The results after 2-day cultivation show that the micropatterned cell sheet has a thickness of about 100 μm and a hole diameter of about 200 μm. In addition, the round flat cell sheets have a diameter of about 623.87 μm, and the spherical aggregates have a diameter of about 280 μm. These suggest the possibility of using our device to prepare many different cellular constructs with more complex structures in future biological applications.

Assembling engineered tissues at the mesoscale into an engineered organ has specially attracted our attention since engineered organ usually has a very complex structure and cannot be fabricated simply by using a fixed scaffold. The fabrication of these composite tissues is, however, difficult since many different scaffolds are required. The flexible microsaffold, called "changeable cell culture (C 3 ) mold", is therefore proposed to simplify this task. C 3 mold consists of 5×5 PDMS microactuator array with a diameter of 700 m and spacing of 800 m. The fabrication of cutout-shaped gel sheet is successfully carried out where mineral oil is used as the working fluid. This experiment indeed demonstrates the possibility of using C 3 mold in future tissue fabrication.

No abstract