Cancer is the number one cause of premature death in the UK. A recent study conducted by Ahmad et al. (2015) found that,

“Over half of people who are currently adults under the age of 65 years will be diagnosed with cancer at some point in their lifetime” [1]

While predictions from The World Health organisation estimate a rise in global cancer diagnoses from 14 million to 22 million over the next 20 years with the total costs of cancer now reaching over £162 billion per year. You only have to read the headlines to find new scientific advances being made every week, each one aiming to either promote earlier diagnosis or develop a new method of treatment.

Some of the most exciting recent developments are within controlled-release drug delivery systems, with hydrogels taking centre-stage. These 3-D networks of hydrophilic polymers have received growing attention in recent years because of the possibility of scale-up synthesis and demonstrated low toxicity.

Past Drug Delivery Systems

According to Cassano et al. (2016) previously common methods of administrating drugs have been shown to be both ineffective and unreliable, especially those taken orally . Cost-effectiveness is also a common issue- when a drug cannot be delivered directly to the intended site of action, it often has little effect on the tumour and therefore requires a higher dose.

This means that any negative side-effects left the specialist having to compromise between the effectiveness of a higher dose and the possible harm caused by it. In cases such as these the harmful effects often limit the long-term use of many drugs or require a ‘cooling-off’ period between each course of treatment.

Avoiding these complications are essential to the further advancement of numerous areas within the healthcare and pharmaceutical industry, leading to the development of controlled-release drug delivery systems.

A Recent Discovery?

Although the synthesis and understanding of hydrogels is not even a remotely recent pursuit (with appearances of the term dating back to 1894 ), their full potential within the medical industry seems to have only been recognised within recent years.

Acting as an elastic solid, hydrogels possess the ability to remember and return to a specified shape following deformation. This shape can be determined or altered by scientists, allowing hydrogels to be used in a number of applications requiring complex forms. Utilising hydrogels as drug delivery systems within anti-cancer treatments has not only proven to deliver the necessary dosage directly to the tumour, but also minimise the number of healthy cells affected (and so reduce side effects). The use of hydrogels within these treatments is fast reducing the number of barriers between where we are now, and a world in which cancer can be treated quickly and effectively.

Latest Advancements

Research into hydrogels has received growing attention in recent years as progress is made rapidly; MIT hit the headlines as recently as July 2016 with their latest advancement - a Patch That Targets Colorectal Cancer, which has shown Promising Results.

Hoping to eliminate the need for damaging whole-body treatments, this research team (led by Natalie Artzi) has focussed their efforts on developing a suitable anti-cancer drug delivery system using hydrogels. For this particular application the hydrogel has been designed in the form of a patch placed at the site of the tumour. Here it not only acts as a drug-delivery system, but also facilitates the treatment of the cancer with gene and light based therapy. This can be achieved through the use of gold nanorods held within the hydrogel that, when exposed to near-infrared radiation, heat up to destroy the tumour and surrounding cells. Increasing the temperature of the nanorods also causes them to release a chemotherapeutic agent, ensuring that the effects of these harmful drugs are localised to the site of the cancer.

Alongside this, gold nanospheres (also suspended within the hydrogel) transport RNA to the site before undergoing gene therapy – silencing specific oncogenes that may lead to the growing or recurrence of the cancer. This triple therapy combination ensures that not only the main tumour is targeted, and minimises any risk of recurrence caused by metastases left untreated.

The project has not yet reached the stage of testing on humans however early results from these tests are positive. Initially designed to work alongside the surgical removal of a tumour, the patch alone has shown to entirely destroy the tumour without the need for surgery. This could be the next step forward for tackling cancers that cannot be surgically removed. With hopes for progressing this technology to combat other forms of cancer, discoveries such as this could be the next life-saving step towards winning the war on cancer.

The Characterisation of Hydrogels

Although there is no one universal method of synthesising hydrogels, all must undergo full characterisation so that the macroscopic properties responsible for their unique function are identified. For example, these functions range from absorbing urine in diapers to being used in water gel explosives (two applications that are best not mixed!).

When characterising hydrogels for use in drug delivery systems the procedure must be robust and reliable in order to ensure that the hydrogel with identical properties and function is produced every time. Failure to achieve uniformity in hydrogel production means their function is no longer accurately predictable. This not only puts the tested subjects at risk but effectively decreases the validity of any tests. With this in mind, any equipment that is used in the synthesis or characterisation of materials intended for human use must enable the user to have full control over the multiple variables that influence the obtained data. To limit or decrease the multitude of typical human errors, such instruments must offer some degree of automatization and high level of accuracy and reliability – the perfect application for a Ther-Mix.