Combining a sugar derived from crab and shrimp shells with nanomaterials may lead to biomedical applications that enhance bone regeneration, wound healing, and targeted drug delivery, reports a recent review study.

The review, published in the journal Science and Technology of Advanced Materials, provides an overview of the different nanomaterials that are being tested in combination with chitosan, the methods used to prepare the composite materials, and the resultant properties that make them suitable for biomedical applications.

What is useful from crab shell?

Chitosan is a sugar that is typically derived from shrimp and crab shell waste and is known for its biocompatible, biodegradable, antibacterial, antifungal, analgesic and haemostatic (stops bleeding) properties.

These characteristics make it an excellent candidate for a number of biomedical applications. Except that it only has limited mechanical strength.

Researchers are working to develop composites that combine chitosan with “nanofillers”, which will make the resulting material stronger. A successful composite is one in which the filler is well-dispersed within the composite material, so that it can interact strongly with chitosan.

Developing biomedical applications

Scientists are finding some success in combining bioactive glass nanoparticles with chitosan to develop synthetic bone grafts. Bioactive glass is a glass-ceramic biomaterial that binds well to physiological structures such as bone. Bone cells were found to grow relatively quickly and cover grafts made of bioactive glass and chitosan.

Graphene oxide (material with extraordinary electronic properties) has been used in combination with chitosan to develop “nanocarriers” that can deliver drugs to target tissues. This helps to avoid the negative side effects of conventional drugs on other tissues of the body.

Silver nanoparticles are being tested as nanofillers in combination with chitosan to develop wound dressings with antibacterial properties.

Also, hemoglobin (the protein in red blood cells that carries oxygen through the body), silver nanoparticles and graphene have been combined with chitosan to develop a biosensor that can detect hydrogen peroxide, a dangerous by-product of some industrial processes.

Further research is needed on: improving the dispersion of nanofillers within the chitosan matrix, how composite materials degrade, how they interact with host tissues in the body, and they can be sterilized using conventional methods in clinical practice.