At present, the use of substances to glue tissue together is only an idea, but it might eventually mean that surgeons will no longer need to use a needle and thread. The cellular and molecular biologist Rainer Wittig from the Ulm-based ILM hopes to develop such substances using a photochemical process. He is also planning to test substances that not only adhere to tissue but which will also be able to initiate the wound healing process.
Rainer Wittig has been given a grant of 50,000 euros from the Baden-Württemberg Ministry of Science, Research and the Arts for a period of nine months. The grant was awarded to Wittig under the Biotechnology and Medical Technology idea competition. If everything goes to plan, the ILM will protect the innovation with a patent and enter product development in cooperation with interested medical technology companies. If the new method proves to be suitable for joining tissue together, it will be expanded into a platform technology for the customised adaptation of a broad range of different tissues.
Surgeons use needle and thread for joining together a broad range of tissue types, for example for repairing intestinal anastomoses or for bridging tissue defects in nerves or blood vessels. However, the suture materials used for this purpose are materials that do not occur naturally in the human body, and may therefore lead to undesired adverse reactions. Despite the considerable improvements in making foreign materials more biocompatible, currently used materials can still lead to thread abscesses, thread fistulas and thread granulomas, said Wittig.Alternative methods to prevent the development of abscesses, fistulas and granulomas involve adhesives (e.g., fibrin glue), high-frequency current or laser light used for photothermal tissue welding, laser-assisted tissue sealing or photochemical tissue bonding.However, Rainer Wittig has discovered that none of the currently used methods and none of the new developments in the field of experimental medicine are optimally suited for repairing tissue. The limitations of such methods include problems with connection stability, histo- and biocompatibility, product safety and infection protection. This is why Wittig believes that many academic and industrial programmes are focusing on research into new biocompatible materials and methods that fulfil specific functional requirements related to the adaptation of different target tissues.
Photochemical procedures have the potential to stabilise biological target structures through the generation of light-induced bonds without leading to thermal damage. If neither the photochemical agents nor their reaction products are associated with toxic effects, photochemical procedures have considerable advantages over other tissue adaptation methods. This is because they do not lead to iatrogenic (editor's note: iatrogenic: inadvertent adverse effects or complications caused by or resulting from medical treatment) effects.The substances used in this pilot project have proven their biocompatibility in the field of experimental medicine. The only thing still missing is a mechanically stabilising property, which Wittig now hopes to develop using minor chemical modifications and light.
Wittig hopes that the planned experiments will help him and his team to clarify whether their chemical modification is effective. Wittig is supported in these investigations by a chemist and former colleague at the German Cancer Research Center (DKFZ). The researchers will also have to find out how much light is required to enable an efficient photochemical reaction and bind target tissue together. This area of research is the core competence of the ILM. Wittig also needs to find out whether the planned method is able to confer tensile strength, and is therefore able to reinforce or replace sutures. If the ILM researcher succeeds in obtaining “proof of concept”, it could then be possible to use photochemical tissue adaptation in microsurgery for treating tissue that is under limited mechanical strain. It might then also become possible to connect torn vessels together, something that is often difficult to achieve with other methods. The method could also be used to connect nerves that are cut during surgery or as a result of traumas. Organs such as ureters, spermatic ducts or bladders are usually not exposed to mechanical strain following surgery, which is why it may well be possible to partially or completely replace sutures with the method under development.
If the pilot project goes to plan and if industrial partners for product development can be found, the German healthcare system, which is currently confronted with huge costs, could also benefit from the method.
The non-invasive photochemical method might reduce or totally prevent the kind of post-operative complications that are frequently associated with high costs and a significant reduction in patients’ quality of life. In any case, the quantity of material such as thread, clips and brackets that is used can certainly be reduced.
However, as Wittig is well aware, it will take many more years before their method becomes clinical reality. The project will receive funding until November 2011 and by then it will be possible to tell whether the idea can be patented and turned into a product.