Team:Groningen/Template/MODULE/project/bandage/summary

From 2014.igem.org

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Latest revision as of 02:59, 18 October 2014

Summary

Most people would think it is a bad thing to have a bacteria inside a bandage. And in many ways this makes a lot of sense, since most will damage wounds more then heal them. But this one won't! One of the biggest problems in hospitals right now, are drug resistant bacteria. However, despite the hesitation of a large group of people we think we can change a lot in bandages by having a inducible secreting system. In order to achieve a safe and easy solution a lot had to be discussed. This is our idea: Bacteria inside a hydrogel.

Lactococcus lactis would be the perfect candidate as a chassis for our engineered construct mainly because the unlikeliness of infecting humans and its ability to produce lactic acid. Of course there is a lot of expertise of L. lactis in our building which enables us to get acces to a lot of information. Before we started it was already proven that L. lactis cells can survive the harsh conditions of freeze drying¹. What also counted is that this bacteria is already used in production process in the dairy industry². These caracteristics make ourproduct more approachable to the public.

Although it is a relatively save bacteria, it is still a risk to have bacteria this close to the wound. That is why we designed the bandage, a containment device to store and activate bacteria at the right time. This bandage consists of 3 layers. A top membrane that diffuses gases like oxygen and carbon dioxide, a middle layer (a hydrogel) containing freeze dried bacteria and a bottom membrane that makes sure our bacteria stay inside the bandage. This last membrane also allows diffusion of several molecules/peptides.

Although the needs for this bandage were pretty clear from the start, finding the specific materials was harder than expected. For our top membrane a polymer from the iGEM 2012 team could be used. This is called TPX or polymethylpentene. TPX is available as a thin, transparent sheet, while it still stays strong. For our middle membrane tests with polyacrylamide gels are carried out. Although acrylamide is toxic when unpolymerized, it will no longer be toxic when polymerized and properly washed. Polyacrylamide was chosen because it is a cheap and easy to handle material. For our final product we could use a different hydrogel named PMBVF/PVA. This material is harder to handle and more expansive, but it has been tested before with bacteia inside³. Our last part is the bottom membrane. A Cellulose Nitrate membrane with a pore size of 0.2µm could be used. This is small enough to keep the bacteria inside and large enough for the molecules to diffuse freely through the membrane.

More information about the bandage design and the experiments are stated below.

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-Most people would think it’s bad to have a bacteria inside a bandage. And in many ways this makes a lot of sense, the hardest problem in hospitals right now is drug resistant bacteria. However, despite the hesitation for a large group of people we know we can change a lot in bandages by having a constant secreting system. In order to achieve a very safe and easy solution we had a lot of discussions and this is our idea:
+Most people would think it is a bad thing to have a bacteria inside a bandage. And in many ways this makes a lot of sense, since most will damage wounds more then heal them. But this one won't!
-<i>Lactococcus lactis</i> would be the perfect candidate as a chassis for our engineered construct because of its unlikely hood to infect humans and its ability to create lactic acid. Of course there is a lot of expertise of <i>L. lactis</i> in our building which gives us a lot of information. Before we started it was already proven that <i>L. lactis</i> cells can survive the freeze drying easily. What also counted is that this bacteria is one of the few that people ever heard of because of it’s production in the cheese industry.
+One of the biggest problems in hospitals right now, are drug resistant bacteria. However, despite the hesitation of a large group of people we think we can change a lot in bandages by having a inducible secreting system. In order to achieve a safe and easy solution a lot had to be discussed. This is our idea: Bacteria inside a hydrogel.
-Although it’s a very save bacteria this still doesn’t solve the problem of having bacteria next to a wound. That’s why we designed the bandage, a containment device to store and activate bacteria at the right time. This bandage contains of 3 layers. A top membrane that diffuses oxygen and carbon dioxide, a middle membrane (gel layer) that contains freeze dried bacteria and a bottom membrane that makes sure our bacteria stay inside the bandage. This last membrane also allows diffusion of several molecules/peptides.
-Although the needs for this bandage were pretty clear from the start, finding the specific materials was harder than we expected. For our top membrane we can make use of a polymer that the 2012 team used called TPX or polymethylpentene. This is available as thin, transparent sheets while it does keep its strength. For our middle membrane we were doing tests with polyacrylamide. While we know acrylamide is cancerous we needed a material that is easy to test with and quite cheap. For a final product we were thinking of PMBVF/PVA. Our last part is the bottom membrane, and for this part a lot of research has been done already. We thought of using a Cellulose Nitrate membrane with a pore size of 0.2µm for this. This is small enough to keep the bacteria inside and large enough for the molecules to diffuse
+</div>
+<div class="hspacer">&nbsp;</div>
+<!-- PARAGRAPH SNIPPET END-->
+<!-- PARAGRAPH SNIPPET START-->
+<div class="text">
+<i>Lactococcus lactis</i> would be the perfect candidate as a chassis for our engineered construct mainly because the unlikeliness of infecting humans and its ability to produce lactic acid. Of course there is a lot of expertise of <i>L. lactis</i> in our building which enables us to get acces to a lot of information. Before we started it was already proven that <i>L. lactis</i> cells can survive the harsh conditions of freeze drying<sup>1</sup>. What also counted is that this bacteria is already used in production process in the dairy industry<sup>2</sup>. These caracteristics make ourproduct more approachable to the public.
+</div>
+<div class="hspacer">&nbsp;</div>
+<!-- PARAGRAPH SNIPPET END-->
+<!-- PARAGRAPH SNIPPET START-->
+<div class="text">
+Although it is a relatively save bacteria, it is still a risk to have bacteria this close to the wound. That is why we designed the bandage, a containment device to store and activate bacteria at the right time. This bandage consists of 3 layers. A top membrane that diffuses gases like oxygen and carbon dioxide, a middle layer (a hydrogel) containing freeze dried bacteria and a bottom membrane that makes sure our bacteria stay inside the bandage. This last membrane also allows diffusion of several molecules/peptides.
+</div>
+<div class="hspacer">&nbsp;</div>
+<!-- PARAGRAPH SNIPPET END-->
+<!-- PARAGRAPH SNIPPET START-->
+<div class="text">
+Although the needs for this bandage were pretty clear from the start, finding the specific materials was harder than expected. For our top membrane a polymer from the iGEM 2012 team could be used. This is called TPX or polymethylpentene. TPX is available as a thin, transparent sheet, while it still stays strong. For our middle membrane tests with polyacrylamide gels are carried out. Although acrylamide is toxic when unpolymerized, it will no longer be toxic when polymerized and properly washed. Polyacrylamide was chosen because it is a cheap and easy to handle material. For our final product we could use a different hydrogel named PMBVF/PVA. This material is harder to handle and more expansive, but it has been tested before with bacteia inside<sup>3</sup>. Our last part is the bottom membrane. A Cellulose Nitrate membrane with a pore size of 0.2µm could be used. This is small enough to keep the bacteria inside and large enough for the molecules to diffuse freely through the membrane.
+</div>
+<div class="hspacer">&nbsp;</div>
+<!-- PARAGRAPH SNIPPET END-->
+<!-- PARAGRAPH SNIPPET START-->
+<div class="text">
 More information about the bandage design and the experiments are stated below.