Team:SMS Shenzhen/Design

Prototype: A piston & An APP

For our prototype, we first developed a device that only needs 4 steps to obtain the final products of a protein, thus to provide convenience for patients and factories. Then based on our investigation in hospital, we did researches to find possible materials for our products, and more importantly, to improve patients’ lives better. We found hydrocolloid dressing and hydrogel.

Steps to use:

1. Add Ecoli and IPTG in small packages with calculated amount of water to chamber A.

2. Wait for some time.

3. Press the Piston.

4. Put Part B into 50 Celcius hot water.

Explanation:

For this prototype, we devised two separate chambers with a semi-permeable membrane to obtain nanoparticles, which we want to isolate from Ecoli. Since the size of E. coli is 0.5µm x 2µm, we used a mixed cellulose ester membrane with pore sizes of 0.2µm. First, we add Ecoli and IPTG with water to chamber A and wait until OD value is 0.6, according to the previous calculations of time done in lab. Next, we press the piston so that proteins can flow through the semi-membrane while Ecoli remains. Then, we can just put the piston in water and heat to 50℃ to form nanoparticles. After that, we can use the product to heal the wounds. .

App Guide::

Aside from the prototype, we can also design an APP, which has the instruction for people to use the prototype and tells knowledge on chronic wounds as well.

Hydrocolloid dressing:

After our investigation in hospital, we knew that absorbing the exudates in time is also important. But currently most hospitals apply negative pressure, such as negative pressure drainage and gauze, to absorb exudate. Those methods will clean both exudate and medicines, so nurses need to alternatively clean exudate and apply medicines, or continue use a large amount of liquid medicines during the absorption. To improve the situation, we found hydrocolloid dressing.

The active surface of the hydrocolloid dressing is coated with a cross-linked adhesive mass containing a dispersion of gelatin, pectin and carboxy-methylcellulose together with other polymers and adhesives forming a flexible wafer. In contact with wound exudate, the polysaccharides and other polymers absorb a great amount of water and swell, forming a gel which is held within the structure of the adhesive matrix.

Hydrocolloid dressing possesses a degree of flexibility very similar to natural tissue, and thus is more comfortable and convenient than the traditional methods. At the same time, the moist conditions produced under the dressing and gel are intended to promote fibrinolysis, angiogenesis and wound healing, without causing softening and breaking down of tissue.

Moreover, hydrocolloid dressing can contain sdf-1LP proteins and antimicrobial peptides. After hydrocolloid dressing absorb the water in the exudate, the sdf-1LP protein and antimicrobial peptide on the inner surface of the dressing can dissolve and directly contact with the wounds. As a result, sdf-1LP solution in the hydrogel dressings can be largely absorbed by the wounds.

However, hydrocolloid dressing still has limitation: it cannot be appropriately applied to wound with large surface area. In this situation, larger and more dressings are needed in order to cover the wound and absorb exudate. Consequently, it is uneconomic to use hydrocolloid dressing. Instead, the traditional method, using negative pressuredrainage with continuous output of medicines, is more convenient, efficient and economic.

With this design, we can integrate promoting wound healing, preventing bacterial infection and absorbing exudates into one!

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