Bacterial infection is a major health threat to patients with severe burns and other kinds of serious wounds such as traumatic bone fractures.
Insulin, however, can be used to accelerate the healing of wounds by acting as a growth hormone, encouraging skin cells to proliferate and divide, increasing blood flow to the wound, suppressing inflammation and fighting infection.
Now, using nanodiamonds, researchers at Northwestern University led by Dean Ho, an assistant professor of biomedical engineering and mechanical engineering, have demonstrated a new way to release the curative hormone at specific locations over a given period of time. The nanodiamond-insulin clusters they have developed to do this could be used in gels, ointments, bandages or suture materials.
The effectiveness of the clusters take advantage of the fact that at a wound site, skin pH levels can reach very basic levels during the repair and healing process. The insulin, bound firmly to the tiny carbon-based nanodiamonds, is released when it encounters those levels. The researchers also found that the insulin is slowly and consistently released from the nanodiamond clusters over a period of several days.
Ho’s group now plans to integrate the nanodiamond-insulin complexes into a gel and conduct preclinical studies. The researchers will also investigate other areas of medicine in which the nanodiamond-insulin clusters could be used.
Nanodiamonds have many advantages for biomedical applications, not least because a substantial amount of insulin can be loaded onto them due to their high surface area. They can be functionalised with nearly any type of therapeutic, including small molecules, proteins and antibodies. They can also be suspended easily in water – an important property in biomedicine.
The nanodiamonds, each being 4-6nm in diameter, are minimally invasive to cells, biocompatible and do not cause inflammation, which can be a serious complication. They are also scalable and can be produced in large quantities in uniform sizes.