Team:Nanjing-China/Implementation

Our project uses the inorganic material polyphosphate which is widely used in chemical synthesis. Early investigations have provided us with information that it is chemically and physically stable and possesses great merit of thermal stability as well. We therefore wish to use it in our project to serve the purpose of fire prevention. Additionally, we want it to be versatile. For example, it may be possible to be adopted in spinning industry. Therefore, we come up with the idea of the combination between organic biomacromolecules and polyphosphate. For one thing, the stability of polyphosphate may improve the thermal stability of biomarcomolecules. For another, the new material still can possess its original biological function. What’s more, our project is completely environmental friendly(because polyphosphate can be synthesized through biological methods), which can fundamentally solve the problems of danger and pollutions produced by chemical synthesis. Therefore, the proposal that through combination of organic and inorganic materials we will synthesize the new materials will be of great use in the future. Additionally, it’s easy to operate and can gain a positive reputation among people.

INVESTIGATION&CONSULTATION

Polyphosphate has a wide range of applications: in animals, polyphosphate is related to coagulation, bone mineralization and cell apoptosis. Although most of them are still in the laboratory exploration stage, some results have shown that polyphosphate have hemostatic effect, and polyphosphate antagonists may act as antithrombotic / antishock agents. It has been found that the addition of polyphosphate can alleviate the decline of plasma coagulation function of platelets in patients with Hermansky Pudlak syndrome. In animal cells, only bone tissue cells need polyphosphate as a storage tool, and vertebrate bones are mainly composed of a calcium phosphate called apatite. In plants, polyphosphate can be used as a heavy metal chelator. Through producing a large amount of polyphosphate by expressing bacterial polyphosphate kinase, transgenic tobacco can resist the effects of heavy metals such as Hg2 + on plants. In microorganisms, polyphosphate plays a key role in the process of stress resistance, colonization and infection. Long chain polyphosphate can also lead to bacterial growth inhibition, pathological changes and Bacillus cereus cracking.

In the industrial field, commercial ammonium polyphosphate is often a mixture of orthophosphate and polyphosphate. Polyphosphate has been used in plant phosphate fertilizer and food additives. In addition, ammonium polyphosphate can be used as a halogen-free, efficient and non-toxic flame retardant. This is the focus of our project. Because of its simple structure, polyphosphate can form a dense structure and is very stable. At present, polyphosphate can be used as flame retardant (coating) for fiber materials (paper, wood, fiber fabrics), various polymers, fire-resistant building board, coil, epoxy resin and unsaturated resin, cable and rubber, plastic materials of electronic devices, etc.

The excellent properties and wide application prospects of polyphosphate have greatly aroused the interest of our team members. We believe that it is appropriate for us to choose it as inorganic material.

We interviewed Professor Zheng Peng from the school of chemistry and chemical engineering of Nanjing University. Professor Zheng Peng is an outstanding scholar in the field of organic-inorganic hybrid materials and protein biomacromolecules. We mainly consult about how to realize the combination of polyphosphate and complex proteins. Professor Zheng point out that polyphosphates, as inorganic linear materials with strong negative charges, should bind to proteins with more positive charges on the surface. Professor Zheng has put forward some instructive suggestions for our project. He thinks that the fire resistance property of our polyphosphate can be combined with the wearability of our potential product, and is expected to be used in fire-resistant and flame-retardant textile materials. In this regard, we can think about how to combine with spider silk protein with high strength and toughness.

After a variety of previous research and interviews, we know that the concept of organic-inorganic biosynthesis new materials not only has strong innovation value and broad application prospects, but also has high operability. With the support of certain research results, the production cost of new materials will be reduced and can enter the market.

EXPERIMENTS

Since polyphosphate is highly negatively charged, we decide to start from the proteins that possess positive charges. Therefore, we make a few improvements for the GFP, and exhibit its characteristics. After combining it with polyphosphate, what surprises us is that polyphosphate extends the fluorescence time of GFP, and we end up with the conclusion that polyphosphate can stable the fluorescence property of GFP, and this kind of stability enhances with the increasing of the concentration of polyphosphate. This result gives us a hint that polyphosphate can improve the overall characteristics of binding proteins. Therefore, we manipulate the charges of spidroin by mutating it to a more positively charged protein, which, according to our model, can combine to polyP. We also built a +36GFP-sp fusion protein part, which is absolutely able to combine to polyP, and proved it worked as expected.

NEW APPLICATION

The concept that we put up is brand new and prospective. We use the traditional electrostatic interactions and mix it with our inspirations and innovations, applying the method of synthetic biology to a whole new concept. This is an area that has been rarely touched upon by others, therefore we wish our project can provide the researchers with more ideas and inspirations: using synthetic biology to manufacture inorganic-organic new material.

PROPOSED IMPLEMENTATION

What comes together with the perspectiveness of our project is a little uncertainty. However, not only the early investigations, interviews but also the later modeling and experiments all prove that for one thing, it is imperative to develop inorganic-organic new material, and for another, our project is feasible.

There are few options for the implementation of current project:

1. a great many of experiment scientists (chemists, biologists, biophysicists, etc) can utilize the combination of polyphosphate and protein or change the conformation of protein in order to refine the chemical property of target proteins.

2. The majority of manufacturers (engineering experts, textile mills, coating factories and other flame retardant material manufacturers) can combine polyphosphate with certain biological macromolecules, and put them into production in batches, achieving the goal that novel fireproof materials can be produced by biosynthesis under the premise of comprehensive environmental protection.

3. A large number of basic theoretical researchers (inorganic chemists, physicists, mathematicians, etc.) can apply our idea to the research, develop better modeling methods and moreaccurate simulation of the combination of organic macromolecules and inorganic molecules, ultimately reducing the cost of biological synthesis, which will expand the application range of polyphosphate and improve the influence of synthetic biology.

4. The majority of medical workers (doctors, rehabilitation scientists and other medical and health workers) can learn from our ideas, and further combine polyphosphate with other biological macromolecules which are more valuable for human medical and health services, so as to obtain artificial with better properties organs (such as bones) and other medical devices.

In addition, our project has a wide market. As we have described, all kinds of pollution which cannot be ignored by fire and chemical synthesis materials are and will always devour our good life, and the development idea of this kind of fireproof and flame retardant materials just makes up for this vacancy.

SAFETY ISSUES&OTHER CHALLENGES

Since no gene sequences or engineering strains with potential biosafety risks is involved in our project, and through our unremitting efforts, we have formed a complete set of pollution-free and safe synthesis methods for polyphosphate. Nevertheless, we have had discussions with Genscript on biosafety and ethical issues.The conclusion was that our program had no biosecurity issues and was beneficial to humans.

The challenge of the project is how to make the combination of polyphosphate and biological macromolecules stable enough to play a positive role in "protecting" biological macromolecules. The method adopted in this project is to modify the electrical properties, but we also noticed that sometimes it is not easy to obtain large amount of modified proteins by traditional purification methods. However, such a challenging problem can still be solved. We are using modern computational biology methods such as modeling to find the best electrical modification scheme and the concentration ratio of molecular binding, and we try to solve this problem by connecting the positive protein with the target negative protein (making the fusion protein positive).

In conclusion, our project has a wide range of application prospects. The majority of experimental scientists, manufacturers, basic theoretical researchers, medical and health workers and other practitioners can use this idea to connect polyphosphate with different biological macromolecules, improve or even adjust their physical and chemical properties to make them more in line with their own expectations, and do so when they are put into production Zero pollution.