We have so much hope for medical innovation in the near future. Words such as nanotechnology, immune therapy, stem cells and tissue creation are becoming more and more common in the medical world, generating a current of optimism that we may soon find cures and treatments for many complex diseases and conditions.

Without a doubt, biopolymers are becoming a source of innovation, and new therapies must take advantage of them.

Throughout history, technological revolutions are typically paralleled by material revolutions behind the scenes. In recent years, for example, polymers and composite materials have given enormous technological support to innovation in the automotive and aerospace sectors. Without these materials, it could not be possible to reach the advances and technologies that we are currently enjoying.

The 21st century will inevitably be known for great medical advances and exciting therapies. With these medical innovations, biopolymers are gaining more and more importance.

When we talk about biopolymers or biomaterials in general, we are discussing materials strictly prepared to act with biological systems — whether to evaluate, treat or replace tissues, organs or diverse organic functions. As the name indicates, biomaterials are in close contact with all kinds of biological material, making that "biocompatibility" word have particular importance.

It must be a priority to avoid any kind of interaction between material and organic tissues, minimizing the risks of inflammatory processes, rejects or other problems. We must not forget that biocompatibility must be associated to some minimum requirements of sterilization. Thus, there is no point in an inert material that is polluted with bacteria and other microorganisms.

In contrast, some functional requirements also can involve the absorption/dissolution of the biomaterial in an organic medium. This process is required when the biomaterial's function is exclusively temporary, with an expiration date on its effects. In this case, these biomaterials are also called bioabsorbables.

There are a lot of types of biomaterials, usually clearly differentiated between natural (collagen, albumin, polypeptides, gelatins, proteins, PHBs, PLAs) and synthetic (methacrylate, silicones, polyethylene, polyester, polystyrene, polysulphone). In short, we're talking about a long list of materials whose objective can be summarized in two big fronts of application:

  • implants and permanent replacement of organs and tissues
  • degradable biomaterials with temporary application as a support or way to accelerate the curing or diverse processes of the recipient organism

To sum up a bit of history, the use of biomaterials came to the forefront during the wars of the 20th century and even by the end of the 19th century. Materials (usually metallic ones) were used as prosthesis for repairing fractures or directly used as implants after the loss of limbs.

With the rise of polymeric materials after World War II, these materials have been gradually displacing traditional materials such as metals and ceramics, in osseous and orthopedic applications (high-density polyethylenes), orthodontics (resins, high-performance polymers), contact lenses and artificial corneas (PMMA, PHEMA), facial reconstructions, catheters and blood vessels (teflons and silicones).

Over the years, metallic biomaterials have been replaced by polymers in hip replacements.

The future is bright. There are a lot of star materials that are going to have a huge relevance in the following years or even decades.

Hydrogels are a great example of this. They are made from biocompatible block co-polymers, with a huge bioabsorption capacity and with properties of solid/liquid phase change activated by temperature (normally body temperature is the trigger). They are especially skillful at acting as a support when regenerating injuries in really difficult-to-access areas brain damage, alimentary tract damage, orthodontic techniques, etc.

Polymers for the controlled release of drugs in nanocapsule form, nanoconjugated with molecular recognition or intelligent activation after specific external stimuli raise the grade of pharmacological effectiveness to once-unimagined levels. To sum up, they are systems that can be useful to radically improve the effectiveness of new drugs against cancer, tumoral presence, Parkinson's disease, complex infections and others.

Nanotechnology and the most innovative polymeric biomaterials converge in the development of nanocomposites with complementary properties. For instance, bioabsorbable polymers filled with hydroxyapatites are a classic example of regeneration of structures and bone cells. In this case, the polymer acts as a biodegradable holder for this growth.

Historically, nanosilver and other metallic particles have presented extraordinary antibacterial properties. Even carbon nanotubes and their particular structure have shown their especially skillful properties in order to promote neuronal growth in cases of brain damage.

The regeneration of tissues and organs is another basic pillar for medicine that is coming soon — especially if we keep in mind the huge evolution in the last few years of the growing techniques and cellular specialization techniques from stem cells. From the first and primitive solutions for corneas based on PMMA to working on materials for artificial skin generation with collagens and silicones, we have seen great evolutionary research and development.

An illustrative advance that combines material science with the highest exigency in electronics would be the development of "electronic skins," based on PMDS with "nanohair" of carbon-nanotube-like pressure sensors. Together with polyethylene fibers like artificial muscles, which reach effort capacities above the human level, this constitutes clear examples of what we call biomimicry.

Biopolymers have moved into areas like artificial skin generation (left) and the creation of 3-D skin tissue (right).

The creation of artificial 3-D tissues from porous PEG structures allows the creation of a cell-growing space, creating fully functional organs (bladders, stomachs, etc.). This current technology is as complex as it is exciting, especially if we keep in mind that growing tissues is now usually made above plane surfaces in 2-D.

It has been always said that the first step of a new medical therapy consists on knowing perfectly how things happen that is, what is the mechanism of action of the biological events. The second step would be to proportionate solutions tools for the modification, cancellation and promotion of these biological mechanisms.

In short, polymeric materials offer a wealth of possibilities in biomedical research, and they are essential for the 21st century's medical advancements. As the genie of the lamp says: "Ask for what you wish, and it will be given to you."