Japanese researchers have developed a new method for growing cylinders of living cells.

Cells used the gel microtubes as scaffolds for growth. Green fluorescence indicates viable cells.

Many tissues in the human body, such as muscle or nerve fibres, are cylinders, so growing cylindrical clumps of cells is a necessity for tissue engineering and cell transplantation.

Shinji Sugiura at the National Institute of Advanced Industrial Science and Technology, Tsukuba, and colleagues made micrometre-scale tubular gels by controlling the flow of two miscible fluids in a microchannel. The interaction between the two fluids led to the formation of droplets and gels. Sugiura showed that the gels can act as scaffolds for growing cylindrical tissues.

'In previous studies, immiscible two-phase flow in a microchannel has been successfully applied for the preparation of spherical materials,' says Sugiura. 'We thought similar technology with miscible fluids could be applied to cylindrical and tubular tissues.'

Professor Teruo Fujii, an expert in microfluidics at the University of Tokyo, Japan, describes the work as 'interesting' but cautions: 'They don't show any quantitative data on the activity or function of the cultivated cells. It is a bit difficult to draw a concrete conclusion from the photos of the cells shown in the figures.'

Sugiura acknowledges this: 'We have to investigate the cellular functions of the cylindrical tissue formed in detail. We hope it will have higher cellular activity than cells cultured conventionally in monolayers.'

'Another future challenge is fabricating tubular tissues. Unlike cylindrical tissues, tubular tissues, such as blood vessels or organ ducts, are hollow. We think the gel will be useful for making these types of tissue too,' Sugiura adds.

Colin Batchelor