Graphene Oxide’s effectiveness as a nanomedicine.
Medicine is one of the highest achievements of the human species and graphene is about to play its part in the most recent and exciting developments in the discipline; that is in the emerging domain of nanomedicine. Concerns for health and well-being have inspired some of the boldest innovations in history and nanomedicine continues in the great tradition of these pioneering advances. Born of interdisciplinary work in the fields of bioengineering, physics, chemistry and medicine, nanomedicine is increasingly looking to the material properties of graphene to assist in some of its most interesting projects. With ever increasing, and deepening, knowledge of the human body and of the way in which it interacts with the external world scientists are increasingly confident about the ways in which nanotechnology can be used to monitor, repair and control human biological systems at the molecular level. The latest fruit of this investment in graphene is the finding of a group of researchers at the Koch Institute for Integrative Cancer Research at MIT who have identified Graphene Oxide as a suitable agent in new methods of drug administration.
Graphene oxide (GO) is a two-dimensional charged nanomaterial that has been shown to create barrier layers in multilayer thin films, trapping molecules of interest for controlled release. Graphene oxide’s chemical properties make it an ideal surface for the controlled sequential release of pharmaceutical macromolecules, thereby offering a unique and simple way to provide complex localized dosing in vivo. The research team involved in the development of this work suggest,
“We show that it is possible to take advantage of the structure of certain nanomaterials to control release regimes from a scale of hours to months.The ability to control the timing and order of release of different therapeutic drugs will play a pivotal role in improving patient care and simplifying treatment regimes in the clinic. Protein-loaded polyelectrolyte multilayer films were fabricated using layer-by-layer assembly incorporating a hydrolytically degradable cationic poly(β-amino ester) (Poly1) with a model protein antigen, ovalbumin (ova), in a bilayer architecture along with positively and negatively functionalized GO capping layers for the degradable protein films. Ova release without the GO layers takes place in less than 1 h but can be tuned to release from 30 to 90 days by varying the number of bilayers of functionalized GO in the multilayer architecture. We demonstrate that proteins can be released in sequence with multi-day gaps between the release of each species by incorporating GO layers between protein loaded layers. In vitro toxicity assays of the individual materials on proliferating hematopoietic stem cells (HSCs) indicated limited cytotoxic effects with HSCs able to survive for the full 10 days of normal culture in the presence of Poly1 and the GO sheets. This approach provides a new route for storage of therapeutics in a solid-state thin film for subsequent delivery in a time-controlled and sequential fashion.”
Medical uses of graphene are being developed on a daily basis and soon we could find the material being used in any number of ways, however, a note of caution must be struck. Although there are as yet no indications for concern regarding the toxicity of graphene it should be remembered that it is a new material with exceptional properties and ingestion of large amounts may have as yet undiscovered adverse effects. Professor Andrew Maynard, director of the Risk Science Centre at the University of Michigan School of Public Health has this to say about graphene’s potential dangers.
“For a material to present new health risks it must be able to get into the body, and once there cause harm in unanticipated ways. It is hard to imagine how graphene in its pure form could be ingested or inhaled in significant quantities, given the size of the sheets being used and the circumstances under which they are utilised. However, if somehow it could get into the body, its unusual properties may cause harm in ways that are currently hard to predict. On the other hand, it may be relatively benign – it’s hard to tell without the relevant research.”
Clearly more research is required and any product development will have to allow for the stringent testing protocols of the global health community, however, an investment in companies researching graphene’s potential as a nanomedicine could well net the kind of profits that ethical investors crave. As with every new medicine brought to market the possibility of failing at the trial stage is high, however the rewards may just be worth the risk.