At UNAM's Materials Research Institute (IIM), physicist María Cristina Piña Barba and her collaborators are developing third-generation biomaterials that can be inserted into patients and help in the regeneration of human bones and tissues.
These projects are part of regenerative medicine, which has gone from replacing and repairing materials from two generations ago, to regenerating and replacing bones and liver, skin, biliary, and urinary tract tissues.
Using small porous structures called molecular scaffolds, which are produced in the laboratory and manufactured from collagen, bovine bone, and biopolymers, Piña Barba and her group can also repair or replace (partially or totally) cartilage, heart valves, and bladder. They have also tested them in the trachea, liver, and heart.
So far, they are making "collagen sponges" to replace liver, biliary and urinary tract, and skin and for use as cellular scaffolds. For the molecular type, they use 3D printing and carry out tests in collaboration with the National Institutes of Rehabilitation and Respiratory Diseases, to test them on humans.
The university lecturer participated in a distance lecture at the Seminar of the Physics Department of the Faculty of Sciences of the National University, where she explained that the repair of the human body has two ways:
The bionic approach uses first and second-generation biomaterials to manufacture prostheses and implants useful for all clinical specialties, and the regenerative medicine approach includes tissue engineering and uses third-generation biomaterials.
Tissue engineering, also known as regenerative medicine or cell therapy, is the branch of bioengineering that employs the combination of cells, materials science, engineering methods, biochemistry, and physiochemistry to improve or replace biological functions.
At the IIM Biomaterials Laboratory, scaffolds are designed to be in contact with living tissues, taking into account that their surface properties are fundamental to achieving a positive response.
Therefore, a biomaterial needs to be biocompatible (the organism must accept it), chemically stable (it must not degrade over time), mechanically resistant (it must not fracture), and non-toxic (it must not damage other parts of the body).
In the third generation, said Piña Barba, we have gone from using inert materials to replace living tissues to the design of bioactive and biodegradable ones for tissue repair. "Thus, we have gone from replacing to repairing and now to regenerating living tissues.
Molecular scaffolds are developed, for example, from collagen; there is no living cell in them, only the porous structure. In the laboratory, cells from the patient's area are regenerated, and growth factors and culture media are added.
Once the culture period has elapsed, the patient's cells, grow inside the biomaterial and can be introduced into the body in the area to be regenerated. "The easiest way is to implant the scaffold directly, with the only requirements being that it be biocompatible, porous, biodegradable or resorbable, and with minimal mechanical properties".
Another option is to place it in which the patient's cells have been previously seeded, which is known as tissue engineering.
The specialist pointed out that there are two other options: to implant the scaffold functionalized with signals, or in an area of the body where signals and cells are included.
These three-dimensional artifacts must have porosity to allow the entry of cells, which it needs to house. If implanted directly in vivo, the person's cells must be able to enter and lodge in its pores. And if the cells are previously seeded in vitro, the progenitors must colonize the scaffold to subsequently implant it, she explained.
Source: UNAM Press Buletin