Experts claim to have found template for bone regrowth

Researchers at the Indian Institute of Science (IIS) have claimed to have discovered a new template for bone tissue regeneration by using 3D scaffolds of graphene composites as they mimic the environment of the bone.

The field of “tissue engineering” involves the use of a synthetic material as a 3D support structure to help the cells grow and subsequently heal and restore the original tissue.

Tissues or organs of the body often undergo damage in the course of various diseases or due to external injury caused during accidents.

Most of the time, these are treated using tissue or organ transplants from healthy donors. In some cases, devices (such as pacemakers for heart) can compensate for the loss of function of these organs.

However, the focus of today’s research is on making materials that the body’s own cells can grow on and repair the damage.

Dr Kaushik Chatterjee, at the IISc’s department of Materials Engineering, and his students investigated how and why do cells respond differently to 2D versus 3D scaffolds.

Dr Chatterjee and his students attempted to make the polycaprolactone (PCL) scaffold stronger by the addition of graphene (known for its high mechanical strength). The resulting Graphene+PCL scaffold was found to be stronger than PCL alone.

“PCL is a biodegradable polymer and by itself is a very soft scaffold. This makes it unsuitable for use as a template for bone engineering,” the research paper states.

The paper “3D scaffold alters cellular response to graphene in a polymer composite for orthopedic applications” was published online in the Journal of Biomedical Materials Research.

They also investigated the response of osteoblast cells (bone precursors) to graphene based polymer nanocomposites in 2D substrates and 3D scaffolds.

Graphene based polymer nanocomposites are processed differently while making 2D substrates and 3D scaffolds. The physical and chemical properties of these scaffolds differ depending on the kind of graphene used and the nature of the processing involved.

The research also revealed that bone cell precursors (osteoblasts) behave differently depending on the nature (2D versus 3D) of the scaffold. This difference in behaviour is due to the chemical difference in the method of preparation of the scaffold and the graphene used, which in turn affects the nature of the surface generated for housing the cells.

Another disadvantage of using PCL alone as a scaffold in tissue engineering is its inherent hydrophobic (water-hating) nature, making it a difficult home for cells (cells prefer a more hydrophilic i.e. water-loving environment). A solution to this problem is to mix PCL with other substances to make it more hydrophilic.

In this study, the addition of graphene increased the wettability (the degree to which a substance absorbs or can be made to absorb moisture) of the scaffold making it a better home for osteoblasts.

They also find that cells in 3D scaffolds have a compact arrangement similar to what is seen inside bone tissue, in contrast to the random distribution seen in case of 2D substrates.

In addition to this, bone mineralisation (process needed for strengthening the bone) was found to be higher in 3D scaffolds as compared to 2D substrates.