Hybrid scientist tangos with tissues

Biomedical engineer loves to dance, eat warm stroopwafels from the Enschede market, and listen to her native fado music. Dr. Sandra Teixeira, 28, whose recent work focused on bone-tissue engineering, describes herself as a hybrid scientist.

'Being a biomedical engineer requires me to be multidisciplinary. I have to understand physics, mathematics, animal behavior, biology, medicine, and chemistry.' All this, along with her master's degree in metallurgy and materials engineering, makes Teixeira a perfect addition to the Membrane Technology Group in their attempt to develop a bioartificial kidney.

A native of Porto, Portugal and a graduate of Porto University, Teixeira's sea-gray eyes sparkled along with her dangling silver earrings as she reminisced of home. 'Porto is the city of engineers. We have a medieval center, a river and the sea. The Spanish always look towards Europe, but we Portuguese are introspective. We are always looking towards the sea,' she said.

Teixeira first came to the University of Twente in 2005 as a PhD student, and then she returned in 2008 to work for one year in the Tissue Regeneration Lab (PBM lab). Now she has a four-year position and feels at home living in the Netherlands. 'I'm used to interacting with the Dutch directness,' she said. 'It actually makes my life much easier. Women scientists are more equal here than in Portugal. Back home, men offer you their chair and open the door for you, but here I have more respect as a scientist.'

Her area of research was in developing material that was similar to the composition of human bone. This material could then be used to fill in bone defects experienced by patients suffering from bone loss such as osteoporosis. Teixeira created her artificial bone-fillers (also called scaffolds) by first testing to see if stem-cells could survive in them. She then added bone-growth factors to her constructs as well as antibiotics. `Typically, patients take drugs orally and it takes time for the medicine to reach the affected area. By adding the drugs to the constructs, we can quickly deliver the needed drugs,' Teixeira explained. She then tested everything in an in-vivo environment.

'I did my experiments on rats,' she said. 'In Europe, we are very aware of animal rights. I had to take a two-week course by the Federation of European Laboratory Animal Science Associations (FELASA), pass an exam, and receive a credential before I was allowed to perform any animal experiments.'

While in the PBM lab, Teixeira focused on assessing the biological viability of materials that could replace blood vessels, especially for those people who have suffered a heart attack. Models of micro-capillary structures were designed with CAD software. Rapid prototype techniques were then used to build the blood vessel structure with a stereolithograph machine according to the computer design. Once the polymer blood vessel was built and processed, Teixeira then tested it for cytotoxicity.

Now she's ready to help develop a bioartificial kidney that will hopefully make kidney dialysis faster and better. The team of researchers hopes to develop a Living Membranes for an Intradialytic Biological Kidney Support Device (BioKid) to help improve the quality of life for patients who suffer cardiovascular complications associated with uremia. Uremia is caused by the retention of molecules not sufficiently cleared by hemodialysis.

'Tissue engineering,' Teixeira emphasized, 'is always about helping to improve the quality of people's lives.' Meanwhile, Teixeria tries to improve the quality of my life by inviting me along to her tango class. Her eyes are shining again along with her silvery earrings, as I try to gracefully bow out. These hybrid scientists are unstoppable!

Every two days, Teixeira replaces the solution of salt and growth factors which feed the cells she is growing in the laboratory. Photo: Gijs van Ouwerkerk