The solid foundation 
of research

Traumatic brain injury often results in acute complications of the cellular metabolism.

The long-run consequences for these patients may be severe secondary complications including cerebral infarction with serious consequences for the patient’s social life. In addition to this, it was recently found that many traumatic brain injuries are, in the long run, complicated by dementia.

In 2013, a research study led by Hans von Holst was published in the Journal of Neurotrauma, (länk till publikationen). The purpose of the study was to analyze the speed and energy required to break the hydrogen bond in protein structures. And the hypothesis is that this new knowledge can help define why and when a concussion occurs. We do know that broken proteins destroy the function of the proteins in the body, which increases the risk of long-term complications. The discovery was that the hydrogen bonds are maintained up to a speed of about 4 m/s (14,4 km/h) but are broken from about 5-6 m/sec (18-21,6 km/h) and up.

In addition, it was demonstrated that hydrogen bonds are also broken on the opposite side of the brain, which was a completely new discovery within the field of research.

Table 1:

Velocity impact and percentages of potential breaking apart or hydrogen bonds in the right and left frontal lobes

Impact velocity (m/s)02468.8610
Right frontal lobe (%)00040.361.973.8
Left frontal lobe (%)00016.134.135.4
Impact velocity (m/s)Right frontal lobe (%)Left frontal lobe (%)


A number of differently designed helmets have aimed to protect the head from injury and verify their mechanical prevention of such injury. However, it is not known if existing helmets have the capacity to allow the normal cellular metabolism to also continue after the time of the accident. It has recently been shown by a team led by Hans von Holst at Karolinska University, that simulated mechanical impacts result in dysfunction or disturbance of laminin – a generally existing protein in the cells.

From these results, Propretec has extended the research to a larger number of proteins located in the brain tissue, showing that about 75% of the 5,000 analyzed brain tissue proteins were affected (fig a).

Next, we performed the same test with the use of Propretecs technology and the result showed that the unfolding or disturbance of the proteins was significantly decreased by the energy absorbing material of Propretec (fig b).

Fig a

Fig b

The test is carried out from a height of 55 cm and image a shows the fold change of the proteins without Propretec, while image b shows the effect of the proteins with Propretec. The red dots illustrate proteins that have broken and lost their function due to impact. The damage is significantly reduced when using Propretec.

Since we know that the hydrogen bonds start to break from 5-6 m/s, the solution to prevent brain injuries is to invent a material and a design that reduces the impact force so that we end up below the breaking point regardless of speed.

By using energy-absorbing material we reduce the incoming velocity of the shock, so the velocity is of such a low degree when reaching the brain tissue that protein structures are not damaged. Innovations from Propretec have the advantage of being able to secure normal cellular metabolism despite an initial severe impact.

The result is that instead of brain tissue displacement, disturbance of cellular metabolism and protein disorder with suboptimal protection, brain tissue is affected to a much lesser extent. How much velocity Propretec reduces is a question of how the product is designed. Of course, the needs are different depending on the type of impact the application should protect against. Obviously, there is a big difference in impact between a bicycle accident and a fall accident.

We believe that existing biophysical mechanical evaluation of different protection systems should be complemented by routine biochemical analysis. With the addition of a molecular dimension, such as proteins and other molecules in the human body, we would get a better picture of cell metabolism after an impact. Which would give us guidance on how to best prevent damage at a molecular level going forward.


The research and development have been successful due to combining different knowledges from clinical neurosurgery with that of biophysical or engineering experience. First of all, engineering knowledge has been supported in the development of energy absorbing material used in Propretec by HGF, Halmstad Rubber Company.

Also, mechanical expertise and testing of the material has been supported by the Research Institute of Sweden, RISE, and by the Multi Impact Protection System, MIPS, Company. Further, in the molecular aspects of protein analysis, pharmacologists and engineers from the Division of Biochemistry and Biophysics, Institution of Biomedicine at Karolinska Institutet, have all given substantial support.