Bioresorbable Airway Splint

A two-month-old baby has saved his life upon being implanted with a splint in the trachea in a hospital in Michigan (USA), which was reproduced in a 3D printer, as published today in The New England Journal of Medicine.

The newborn suffered constant attacks caused by a syndrom called tracheobronchomalacia, which prevents oxygen from reaching the lungs due to a problem in the trachea problem, as diagnosed by doctors who have published the study. In view of the situation, doctors decided to print a kind of splint, which reproduced the tracheal tube based on a tomographic image of the child's airway.

The 3D reproduction is made with a material called polycaprolactone, bioabsorbable by the human body in three years, so the patient doesn't need another surgery to have the implant removed. The implant was reproduced on the printer in less than a day.

According to doctors, when the implant is removed naturally, the child's lungs and airways will be developed enough to stay open by themselves. After inserting the tube, doctors kept the baby on life support for 21 days, after which the baby was allowed to leave the hospital. One year after implantation, there have been no rejection or any problem with breathing.

This case demonstrates, doctors conclude in the study, that the combination of high resolution images plus the computer design and biomaterials for 3D printing can facilitate the creation of precise anatomical implants. The study has been signed by Scott Hollister and Richard Ohye from the University of Michigan, and Marc Nelson from Akron Children's Hospital.

The three-dimensional printers are making headway in medicine, but for now the applications are very limited. Initially, they were used to design conventional solid materials intended to design personalised implant prosthesis. One of the benefits is the ability to create custom models at lower prices than conventional industrial processes. The next step, as the case published today in the New England Journal of Medicine, is to design objects with a biological material such as the biodegradable polymer employed in the intervention to reproduce the trachea fragment that the patient was missing.

The ability to create these structures combined with the manipulation of stem cells could lead in the future to the creation of artificial organs. At least, scientist are working in this direction. A biological mold would be the basis to provide a three-dimensional structure to the organ. The outer casing would be scattered on cells which would colonize the structure resulting in specialized cells of the organ concerned (cardiomyocytes in the case of the heart, hepatomiocitos for the liver...).

This possibility remains part of science fiction. What is beginning to be a reality is a new generation of 3D printers that generates human tissue. The company Organovo announced last April at the Experimental Biology Conference in Boston an equipment capable of producing tiny liver tissue samples (about 20 cell layers thick). This printer uses biological ink which in this case is made of three types of cells: hepatocytes, stellate cells and cells from the walls of blood vessels, obtained from waste coming from transplants and surgical interventions. Currently, the main use of these miniature livers is to test the effectiveness and impact of new drugs, but it may be the first step in a future technology able to print of organs for transplantation.

http://www.nejm.org/doi/full/10.1056/NEJMc1206319

Medical device destroys itself leaving no trace in the body

Imagine an electronic device that releases the drug in the area where it is needed, measure your vital signs, treats a surgical wound and once done it has done its job it melts away ... All this without leaving a trace, as if it had never been in the body. A new class of devices grouped under the name of "transient electronics" is about to start a medical revolution. The first step was just taken by a group of engineers at Tufts University, in the United States, who successfully tested one of these biodegradable devices. The experiment was done with mice that were implanted with a device designed to deliver drugs and treat an infection. Not only did the treatment work, but also it barely left remmants of its presence in the organism three weeks later. With only a few tens of nanometers thick, the new circuits are easily dissolved in either water or other body fluids without causing damage.

In the same line, Abbot lab has recently introduced a new "stent", a new type of coronary implant which is also absorved when is no longer useful. It has a less sophisticated technology than that of the electronic devices, but it works similarily. Stents are a mesh-like tube of thin metal wire which are placed inside the artery to keep them open and facilitate blood flow after a heart attack has occurred. Stents have been placed permanently for years. The absorbable one, made ​​of a material used in sutures, allowes the vessel to dilate and contract in a more natural way, as your body needs it. For example when you are running and need more blood flow. At the end of ist lifetime, the stent is complety disolved and the blood vessel remains open without any other extra support.

Sources:

http://www.bbc.co.uk/news/health-19737125

http://www.abbott.com/news-media/press-releases/abbott-announces-international-launch-of-the-absorb-bioresorbable-vascular-scaffold.htm