Q&A
- Q. Do the main ingredients, poly(acrylic acid) (PAA) and poly(vinylpyrrolidone) (PVP), chemically bind to each other?
A. No, they don't. They are just attracted to each other in water through physical forces, just like a sugar molecule with water in an aqueous solution. Both PAA and PVP are long chain-like molecules. They are attracted to each other, and form a three-dimensional network. In the case of our device, they become a soft gel absorbing water. It's like a formation of jelly by cooling the hot gelatin solution.
- Q. Does the PAA/PVP gel become separated into individual molecules?
A. Yes it does. PAA and PVP do not binds chemically. They are readily separated into each PAA and PVP molecules, as a jelly becomes a viscous solution by warming.
- Q. How can the PAA/PVP gel be separated into each molecules?
A. PAA in pure water makes a weak acidic atmosphere, and attract PVP molecule to form a gel. If the gel is put inside the body or in the mouth, surrounding body fluid (pH 7.4) will neutralize the gel. Then PAA and PVP will not attract each other, and dissolved into a water.
- Q. Is bleeding arrested by such a dissolvable device?
A. Yes it is. Blood has a mechanism to form a plug or clot to stop the bleeding. If the bleeding is too much, pouring blood makes it hard to form a plug. Our device will form a jelly-like gel and cover the bleeding site, allowing the plug or clot formation. In the mouth, the gel will be slowly dissolved out. But, hemostasis is achieved before the gel dissolves.
- Q. Why bleeding is arrested? Is there any adverse side effect?
A. No, there isn't an adverse side effect. As mentioned above, the mechanism is just to plug the bleeding spot. On gel forming, our device will absorb water. It makes blood concentrated, to make it easier to from a clot. But, no bioactive agent is contained in the device. No unfavorable side effect is expected.
- Q. Is it safe to swallow the materials being dissolved out of the gel?
A. Yes it is. All the ingredients has long been accepted as very safe, and used as pharmaceutical tablet- or sweets-additives.
- Q. How will the device become after stop bleeding?
A. On the skin, it will be dried up to be easily peeled off. Invisible small scab may be left. In the mouth, after 5 - 15 min, the patient can rinse the mouth to remove the excess materials. The remaining gel will be slowly dissolved out. It is no problem to swallow the dissolved materials.
- Q. Is there any delay of recovely?
A. No there is not. In many clinical trials, no delay was observed. This device could avoid suturing, and rather faster healing could be observed.