Synthetic polymer developed by IISc scientists may be used in recyclable, biodegradable electronic components as well.
There is a large demand for multifunctional biodegradable materials in biomedical applications that can mimic the properties of various tissues in the human body for efficient repair and regeneration. A wide variety of natural and synthetic polymers are used for such applications. Although non-toxic, they may lack many desired characteristics such as mechanical and electrical properties with significant scope for improvement of their biological performance, said experts. Further, most of these materials are highly susceptible to bacterial colonisation and resultant infections, a major cause of implant failure. To address these challenges, researchers from Indian Institute of Science (IISc), Bengaluru, have now developed a synthetic polymer using nanotechnology, which could be used as substitute for bone grafting. The project was funded by the Department of Science and Technology (DST).
According to Dr Sachin Kumar, who recently completed his PhD from the Biomaterial and Tissue Engineering Laboratory at IISc, while bone is one of the most widely transplanted tissues of the human body, bone grafts currently used in clinics have several problems like high costs, occasional infections and need for multiple surgeries.
“We are working towards using plastics or synthetic polymers to solve this clinical challenge,” he said.
Natural and synthetic polymers that are non-toxic degrade in the body over time to be absorbed or excreted safely; in the case of bone, these plastics may be too soft and lack other properties to help in regeneration, said experts. This prompted the team to explore methods that can enhance the biomedical properties of these polymers so that they could have orthopaedic applications.
“In recent years, graphene decorated with metal or metal oxide nanoparticles have been synthesised and extensively applied in sensing, electrical and energy applications. The great interest in these hybrid nanoparticles arises from the synergetic effect of the constituent nanomaterials that result in unique properties,” said the paper published in the journal of “Materials & Design”.
“We propose that hybrid nanoparticles can impart multifunctional properties to widely used biomedical polymers such as PCL for biomedical applications. Graphene possesses excellent mechanical and electrical properties with extremely large specific surface area. Incorporation of graphene in a polymer matrix enhances mechanical, electrical and biological properties even at very low concentration. The enhanced mechanical properties of the composite may be utilised for load bearing orthopedic applications. An electrically conducting substrate can be used to stimulate stem cell proliferation, nerve cells and bone cells to maximise tissue regeneration,” it said.
Accordingly, the team prepared polymer composites of poly (e-caprolactone) (PCL), a biodegradable polyester incorporated with these nanoparticles. The lab found the resultant composite material to be “non-toxic as well as anti-bacterial”. Cell studies showed that the composites were not toxic and supported the differentiation of stem cells to bone cells, making this material particularly useful for orthopaedic applications, said the research team.
According to the team, further research and trials need to be conducted before one can claim that this is a “perfect” artificial bone graft.
Besides being suitable for bone grafts, the composite was observed to have electrical conductivity as well. This property could make this material useful in designing biodegradable electronic components, which can be recycled.
“The use of biomolecules such as growth factors, drugs and antibiotics can severely limit the processability of these polymers. Reinforcing the polymers with nanoparticles provides an alternative route to enhancing the desired properties. The recent emergence of hybrid nanoparticles offers exciting new opportunities for preparing multifunctional composite materials. Aside from biomedical applications, biodegradable multifunctional composites are highly attractive in many other applications such as packaging materials and electronic components that can be recycled for eco-friendly sustainable use,” said the findings.
Credits Bangalore Mirror