and one day we hope that these tissues can serve as replacement parts for the human body but what i 'm going to tell you about today is how these tissues make awesome models
a lot of time and sometimes even when a drug hits the market it acts in an unpredictable way and actually hurts people and the later it fails
the worse the consequences it all boils down to two issues one humans are not rats
and two despite our incredible similarities to one another actually those tiny differences between you and i have huge impacts with how we metabolize drugs and how those drugs affect us so what if we had better models in the lab that could not only mimic us better than rats but also reflect our diversity
let 's see how we can do it with tissue engineering
one of the key technologies that 's really important is what 's called induced pluripotent stem cells they were developed in japan pretty recently
okay induced pluripotent stem cells they 're a lot like embryonic stem cells except without the controversy we induce cells okay say skin cells by adding a few genes to them culturing them and then harvesting them
so they 're skin cells that can be tricked kind of like cellular amnesia into an embryonic state so without the controversy that 's cool thing number one cool thing number two you can grow any type of tissue out of them brain heart liver you get the picture but out of your cells so we can make a model of your heart
your brain on a chip
going forward imagine a massively parallelversion of this with thousands of pieces of human tissue it would be like having a clinical trial on a chip
but another thing about these induced pluripotent stem cells is that if we take some skin cells let 's say from people with a genetic disease and we engineer tissues out of them we can actually use tissueengineering techniques to generate models of those diseases in the lab
here 's an example from kevin eggan 's lab at harvard he generated neurons from these induced pluripotent stem cells from patients who have lou gehrig 's disease and he differentiated them into neurons and what 's amazing is that these neurons also show symptoms of the disease
so with disease models like these we can fight back faster than ever before and understand the disease better than ever before and maybe discover drugs even faster
this is another example of patient specific stem cells that were engineered from someone with retinitis pigmentosa this is a degeneration of the retina it 's a disease that runs in my family and we really hope that cells like these will help us find a cure
so some people think that these models sound well and good but ask well are these really as good as the rat
the rat is an entire organism after all with interacting networks of organs a drug for the heart can get metabolized in the liver and some of the byproducts may be stored in the fat don 't you miss all that with these tissue engineered models
well this is another trend in the field
by combining tissueengineering techniques with microfluidics the field is actually evolving towards just that a model of the entire ecosystem of the body complete with multiple organ systems to be able to test how a drug you might take for your blood pressure might affect your liver or an antidepressant might affect your heart these systems are really hard to build
but we 're just starting to be able to get there and so watch out
but that 's not even all of it because once a drug is approved tissueengineering techniques can actually help us develop more personalized treatments this is an example
that you might care about someday and i hope you never do because imagine if you ever get that call
this is an example from karen burg 's lab where they 're using inkjet technologies to print breast cancer cells and study its progressions and treatments
and some of our colleagues at tufts are mixing models like these with tissue engineered bone to see how cancer might spread from one part of the body to the next and you can imagine those kinds of multi tissue chips to be the next generation of these kinds of studies
and so thinking about the models that we 've just discussed you can see going forward that tissueengineering is actually poised to help revolutionize drug screening at every single step of the path
disease models making for better drug formulations massively parallel human tissue models helping to revolutionize lab testing reduce animal testing and human testing in clinical trials
and individualized therapies that disrupt what we even consider to be a market at all
essentially we 're dramatically speeding up that feedback between developing a molecule and learning about how it acts in the human body our process for doing this is essentially transforming biotechnology and pharmacology into an information technology helping us discover and evaluate drugs faster
more cheaply and more effectively
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