Healthcare is the world’s largest service sector, and in recent years there has been a massive growth in interest in nanotechnology as a potential driver for new advances in medical technology and improved treatments for patients. Development in nanotech could have significant impact on biomedicine and life sciences in:
• disease diagnosis and monitoring;
• implants;
• regenerative medicine;
• drug delivery;
• drug discovery.
Graphene oxide (GO) has unique physiochemical properties, showing great potential in biomedical applications. The full potential of graphene is a number of away in biotech and life sciences in comparison to its impact in other sectors such as electronics and batteries. Its physical and chemical properties make it an attractive material for the following applications:
• diagnostic tools and sensors;
• support for heterogeneous and coupled biocatalytic reactions;
• vector for delivery of pharmaceuticals or genes.
As well as drug delivery and implant coatings, graphene derivatives, including pristine graphene, GO, chemically reduced GO (rGO) and doped graphene have been intensively studied for their widespread applications in biosensing and detection of biomolecules such as thrombin, ATP, oligonucleotide, amino acid, and dopamine.
Drug delivery
The pharmaceutical industry faces a number of technological and market challenges in the coming years including:
• improving solubility;
• enhancing product effectiveness and exclusivity in the face of generic competition
• active drug targeting;
• patient compliance;
• cost effectiveness (the cost of producing a new drug can be upwards of $800 million);
• product life extension.
To meet these challenges the industry has turned to nanotechnology as a viable solution. Therapeutic drug delivery is one of the main markets for nanomaterials based applications, where the recent trend has been for medical therapies tailored to specific diseases and patients, especially in cancer therapy. The unique properties of nanomaterials when combined with special high loading and controlled release provide superior performance for drugs.
Nanomaterials are being utilised for treating cancer, inflammatory disorders, infectious disease and cardiovascular disease as they help drugs reach diseased tissues and release their payload in a controlled way. Localised delivery of drug payloads to target tissues allows effective drug dosing while reducing the side effects of systemic drug delivery. Under development are graphene oxide drug delivery nanocomposite for drug delivery. The nanocomposites are with anti-inflammatories molecule. They display favourable electrical properties and in response to voltage stimulation, the nanocomposite releases the drug with a linear release profile and a dosage that can be adjusted by altering the magnitude of stimulation (‘Electrically Controlled Drug Delivery from Graphene Oxide Nanocomposite Films’, http://pubs.acs.org/doi/abs/10.1021/nn406223e).
Medical device coatings and wound care
Benefits of nanomaterials in medical device and supplies coatings include:
• long lasting anti-microbial effect;
• constant release of the active substance;
• effectiveness against bacteria and other micro-organisms;
• no chemical impurities;
• easy processing;
• no changes to the characteristics of the equipped material;
• no later discolouration of the equipped material.
Nanocoating products have already found application in life sciences & healthcare in enabling anti-bacterial surfaces for medical catheters, added to paints and lacquers used to coat operating tables, door knobs and door handles in hospitals and as ultra-hard porous coatings for surgical and orthopedic implants like screws, plates or joint implants. Anti-corrosion biomedical device nanocoatings are also investigated as although the ceramic materials used in medical implants can reduce corrosion, there are certain limitations. Applications of graphene in medical coatings at different stages of development include:
• Biocompatible protective films for biomedical metal implants. Graphene effectively inhibits Cu surface from corrosion in different biological aqueous environments.
• Coatings for cardiovascular stents with enhanced hemo-compatibility.
• Anti-bacterial wound dressings. Graphene on bandages and other dressings may promote clotting of wounds, including wounds due trauma, hemorrhaging, bleeding disorders, and some cancers.
Wound dressings represents a potentially large market opportunity, taking advantage of graphene’s anti-infective and pro-thrombotic properties. Graphene induces platelet adhesion and aggregation, promotes clotting, and has anti-infective properties. The advanced woundcare market, that utilizes additional compositions to promote healing, is a significant growth market. There is a significant need for new chronic/difficult to heal wound solutions. There are over 5 million incidents of chronic wounds in the United States each year and current advanced dressing solutions such as Quikclot are expensive. Their use is increasing, to reduce bed capacity in hospitals and particularly in homecare and long-term use facilities (e.g. nursing homes) to enhance healing and minimize hospital time.
Biosensors
In the past few years, there have been a significant number of publications on graphene-based biosensors, including functional graphene oxide (GO) and graphene hybrid nanocomposites. They are being increasingly investigated for real-time imaging and quantification of biomolecules or cells and could have a major impact on disease prognosis, diagnosis and therapy.
The exceptional intrinsic and tunable properties of graphene and its derivatives making it a leading candidate for incorporation into reliable, highly sensitive and ultra-fast biosensing platforms. Examples include label-free or fluorochrome-based nano-optical/biophotonic detection systems such as Fluorescence resonance energy transfer (FRET) and Chemiluminescence resonance energy transfer (CRET)-based biosensors.
Most research has focused on developing cost-effective and scalable approaches to improve the properties such as sensitivity, specificity/selectivity, stability, rapidity and reproducibility for biosensor application. The end goal is real-time and multiplexed imaging of biomolecules (e.g. biomarkers of disease, nucleic acid alterations) or cells (e.g. cancer cells, stem cells, bacteria or viruses).
