Repairing the bile duct with bacterial nanocellulose

Interview with Dr. Falk Rauchfuß, Department Head of General, Visceral and Vascular Surgery, Jena University Hospital

The closure apparatus between the gallbladder and small intestine is frequently injured during gallbladder surgeries. So far, however, there has been no surgical option to bridge tissue defects. Now, a novel implant made of bacterial nanocellulose (BNC) could change this. Its nanofiber network makes it extremely robust so that it is able to take on a supporting function.


Photo: Falk Rauchfuß

Dr. Falk Rauchfuß; © UKJ

In this interview with, Dr. Falk Rauchfuß, Department Head of General, Visceral and Vascular Surgery, Jena University Hospital, explains how BNC implants can be adapted to the individual patient and what properties nanocellulose exhibits in the body.

Dr. Rauchfuß, gallbladder surgeries and liver transplants can cause problems with the closure apparatus. Can you please explain this?

Dr. Falk Rauchfuß: One serious complication that can occur during a routine gallbladder removal is the transection of the bile duct. Disturbed blood flow or tissue defects might occur during liver transplants. So far, we don’t have a surgical option to reasonably bridge major substance defects in the bile duct. That is to say, we inevitably need to connect the intestine and the part of the bile duct that faces the liver. The natural sphincter apparatus is thus rendered immobile. Especially with transplant patients, germs subsequently often ascend from the small intestine to the liver and cause inflammation. This in turn means that the patient frequently receives expensive antibiotic therapies.
Photo: white implant lying in a petri dish

© Andreas Heckel

A new bile duct implant is meant to solve this problem. How did you come up with the idea to develop a bioengineered molded hollow body made of bacterial nanocellulose to become a bile duct implant?

Rauchfuß: We have and had several task forces in Jena that have experience with this material. The local POLYMET Association Jena with Professor Dieter Klemm at its helm has already dealt with this material for several years. In addition, there are already task forces that have used the material for incisional hernias. Another group works in Cologne under Professor Jens Wippermann. They inserted everything into the vascular system so that it was obvious to insert the material in the form of a tube when it comes to the biliary tract.

What properties does the material possess?

Rauchfuß: We can produce and personalize it in different diameters or lengths and stockpile it. During surgery, the material can subsequently be trimmed to fit. The body does not reabsorb the implant and it is extremely resistant so that it is not being destroyed when exposed to bile. We have tested this in the laboratory. In theory, the material could also be produced in Y-shape to be able to support biliary duct junctions. We are currently working on this.

After four weeks, animal experiments already showed a newly formed bile duct. The implant can be removed after the bile duct regeneration. Subsequently, no foreign material remains.
Photo: white implant lying next to a German one cent piece

© Andreas Heckel

We know cellulose from facial tissues. By comparison, nanocellulose does not disintegrate in the body. What processes take place in the body?

Rauchfuß: We don’t know which exact processes take place there. We have found no explanations for how this bile duct regeneration is generated. We only see the result but still don’t know exactly how we arrive at it. However, this is also because we insert the interposition graft into large animals. We would have to conduct many experiments for a gradual review of this process to consistently look after and supervise this osseointegration. We have not done this yet. We still need to answer two to three questions in experiments until the implant is inserted in human patients.

Could the material also be used in other areas?

Rauchfuß: We also investigate its use for the ureter and esophagus. These are models of the future. However, we currently focus more on the bile duct because here we can clearly see that we can quickly begin use in patients. That is why we can expect multicentric studies in the future.
Foto: Melanie Günther; Copyright: B. Frommann

© B. Frommann

The interview was conducted by Melanie Günther and translated by Elena O'Meara.