Pig's bladder restored the muscles torn off by the explosion
The result of the study, in which the US Army invested $ 70 million, was the development of a method for using growth factors and proteins of the pig bladder or small intestine to restore skeletal muscles lost by soldiers as a result of injuries.
The essence of the technique is to apply an extracellular (extracellular) matrix to the area of damage, obtained by cleaning the cells from the tissue of the pig bladder or intestine. The remaining material consists of structural components, such as collagen, and functional molecules, such as growth factors. The extracellular matrix contains hundreds of growth factors that regulate the behavior of cells, including their migration, differentiation and division. Therefore, it not only stimulates the regeneration of the damaged zone due to the division of the cells preserved in it, but also attracts other types of cells, including stem cells, to help.
According to one of the leaders of the study, Dr. Stephen F. Badylak from the McGowan Institute of Regenerative Medicine, part of the University of Pittsburgh, no one can choose a set of necessary factors better than nature itself does.
He also adds that to obtain positive results, it is not enough to simply place the extracellular matrix in the damage zone. A prerequisite is the creation of a microenvironment necessary for the growth of a full-fledged tissue. This means maintaining certain levels of acidity of the environment, oxygen content, moisture and nutrients. It is also necessary to properly direct the impact of mechanical forces. The Achilles tendon, for example, must be constantly under load, otherwise it turns into an inert connective tissue.
Due to the fact that the processes of tissue regeneration involve the basic mechanisms preserved in the process of evolution that ensure the survival of mammals, the extracellular matrix successfully copes with the task assigned to it. At the same time, the removal of pig cells from it avoids immunological rejection.
One of the first participants of the project, within the framework of which the described technique is being tested, is 19-year-old Corporal Isaias Hernandez, who lost 70% of the muscle tissue of his right thigh during military operations in Afghanistan as a result of a bomb explosion. Fortunately, the patient has preserved fragments of muscles located above the knee and in the upper thigh. This made it possible to avoid amputation and use a new method to restore the middle part of the soldier's thigh.
Initially, Hernandez took a course of physical exercises aimed at strengthening the preserved thigh muscles. After that, an extracellular matrix was injected into the damage zone. Within a few weeks, the muscles began to grow, which was accompanied by an increase in physical strength. Two months after the procedure, computed tomography showed an increase in thigh muscle mass by 12%, while the strength of the injured limb increased by 7-10%. Inspired by the results, the patient expressed a desire to repeat the procedure.
Dr. Badylyak notes that the achieved result can be considered as quite modest, but it significantly exceeds the results of all previously tried approaches.
Pig extracellular matrix implantation has already been successfully used to repair smaller injuries of another type, for example, ruptures of the rotator cuff of the shoulder joint – a group of tendons that ensure the correct position of the arm and its movements in different directions. Traditional surgical methods for such injuries are powerless, whereas the introduction of an extracellular matrix, which completely resolves within 75 days as it is replaced by the body's own cells, has already helped more than 1.5 million patients.
There is also evidence according to which the use of powder from the dried extracellular matrix allowed three patients to regrow the lost fingertips. However, according to Dr. Badylyak's comments, in some cases, especially in children, the fingertips can recover on their own, therefore, clinical studies are necessary to confirm these data. Although there is a video on YouTube, at the end of which he himself describes a case that most likely served as the basis for a few years of a tale about a severed finger that roamed the Internet. It is a pity that the journalist who first launched it in the media, hearing some ringing, retold it so stupidly that smart people did not believe him.
Evgeniya Ryabtseva
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of Medical Xpress – Pig blader cells help regenerate an army veteran's leg muscle and an interview given by Dr. Badylyak to a Newsweek correspondent.
23.06.2011