Team:Exeter/Applications

The potential for new applications or improvements to current treatments across the medical world is vast.

Several polysaccharides currently show biocompatible and biodegradable properties, making them suitable for both external and internal functions [1]. Chitin and chitosan have already been studied for their effect on blood coagulation, tissue growth and wound healing [2]. They are now used in wound dressings to aid the natural healing process and chitin, because of its strength and flexibility and the fact it decomposes completely over time is used as surgical thread for stitches. We would suggest an improvement to dressing wounds would be to make an equivalent in the form of a gel, this could then be coated over an open/closed wound. A gel would offer the advantage of being able to use an open-window type dressing thus enabling the injury to be clearly visible and the healing process closely observed. Not only could a gel be used over a wound, it could also be used during extensive surgeries internally on tissue. This could potentially massively increase the rate of healing.

Hyaluronan is a polysaccharide that is present within joints and as a solution offers an interesting property. It is viscoelastic, at low strain frequencies it has viscous behaviour whilst at high strain frequencies it displays elastic tendencies [3]. These properties are what enable joints to survive on a daily basis with normal use and sudden impacts. We think that future prosthetics would benefit from research within this area and could possibly provide a replacement limb capable of rivalling, mechanically, the natural design. They may even progress to be able to withstand larger amounts of impact force making the possibilities of running faster for longer and jumping higher a possibility.

We have synthesized the gene hasA from Streptococcus pyogenes that codes for hyaluronan synthase. The enzyme hyaluronan synthase is responsible for generating hyaluronan from D-glucuronic acid and D-N-acetylglucosamine, linked via alternating β-1,4 and β-1,3 glycosidic bonds. The gene has been submitted to the registry as part BBa_K764022.†

Could we go further still? Blood types are distinguished by the presence of their surface polysaccharides [4]. Depending on which antigens are present some patients can only receive donations from their own blood group or other specific blood types according to their rarity. This drastically reduces the list of potential options.

In the future we envisage a system where donor blood could be “masked” to display the properties of its intended acceptors blood. This would be achieved by creating a polysaccharide that could bind to the surface of donor blood with one end and via the other display the same properties required for the recipient, thus passing as the host blood type. We believe this would lead to a new Universal Blood Donor Group with the potential of replacing conventional methods.

Currently polysaccharides can be found in wastewater treatment processes. Chitin has been shown to decontaminate water containing plutonium and mercury, whilst chitosan is able to remove arsenic from contaminated drinking water and petroleum from wastewater [5].

There is also the potential for polysaccharides to be used in the removal of other heavy metals from wastewater [6]. Imagine if you were able to use polysaccharides to at first detect harmful elements within water, obtain a fast signal to say exactly what was present and then also be able to extract all of the contaminant using a polysaccharide removal system!

In plants, polysaccharides such as starch are used to store energy obtained via photosynthesis. Scientists have had mixed success when using polysaccharides in the production of solid state proton-conducting polymer batteries and believe a better battery system could be accomplished with a more suitable electrode material [5].

If we could manufacture polysaccharides with specific electrical properties, could it be possible to harness some form of energy and make a fuel cell? And if it were possible could we take it one step further and create mini biological circuits with custom built polysaccharides playing the roles of diodes, resistors and capacitors?

Last year Suzanne Lee, [i], set a challenge; to spin her a bug, align it in a certain direction, grow it around a specific shape and make it hydrophobic. We believe that our project is a step in the right direction to making this a reality.

With the ability to create novel polysaccharides and build them with very specific properties, in both physical and electrical, a vast amount of new, unique, and exciting materials could present themselves.

One that may be invented could take advantage of Xylomannan found within the Alaskan Beetle, Upis ceramboides. Its anti-freeze ability enables the beetle to resist temperatures below -60°C [7]. A suit which could withstand such extreme temperatures would have many uses, perhaps predominantly in diving and space suits!

Could it be possible to produce polysaccharides that have specific hydro(phobic/phillic) domains that would self-assemble when introduced to water. We believe that not only could this be possible but multitudes of new, novel and exciting materials, [10], could one day present themselves.

The self-healing abilities of certain types of supramolecular elastomers arise due to their intermolecular interactions [10]. We think this could be improved upon using research into polysaccharides, to create a glue, gel or paint like product which could be easily sprayed or coated onto materials which need protecting. These could include covering a vehicle to make it effectively “scratch proof” or, producing a thinner film to cover screens, like those found on smart phones, which come under a constant barrage of attacks daily from keys and coins!

Perhaps one day polysaccharides with such “self-healing” abilities could be used in the production of clothes. Possibly this could make them resistant to staining from food, drink and toothpaste but also resilient to rips and tears?

Newcastle 2010 iGEM team, [ii], thought that the glue like polysaccharide levansucrase could be strong enough to be used fixing cracks in cement! Could a modified polysaccharide be embedded into climbing gear to make your very own lizard/spider suit?

Still not satisfied?

We mentioned earlier, in the medical section, the potential of building upon the uses of polysaccharides that have amazing properties when involved with impacts, but could we go further still? Could we create a material that was so finely woven and had so many layers that it could not only stop a bullet but could also distribute the energy involved so the user felt nothing? If a bullet could be stopped by this type of material could a bomb blast be absorbed too? And what about falling with a broken shoot, could a special sky diving suit be made that rendered parachutes obsolete?