Material good – innovations in silicone18 May 2016
The wide use of silicone in healthcare devices shows its many applications, and means of advancing the ways in which it can be used to innovate and help patients – particularly in the field of cancer research and treatment. Andrew Putwain speaks to Richard Paxman, managing director of Paxman Scalp Cooling, about the inventive ways silicone is being reimagined to aid cancer survivors’ treatment and recovery.
Silicone has many different uses and has been a great positive influence on medical devices for several decades. Its stretchiness, resilience, light weight and synthetic pliability have seen it used in devices from syringe heads to implants and everything in between.
But what its other, more personal applications? What about the uses of advanced silicone technology to provide long-lasting support and emotional comfort to those who require it once the need for a more traditional medical device has receded? A whole new market is growing around the application of silicone in devices to help people combat the side effects and after effects of cancer treatment.
In the UK in 2012, 168.6 people per 100,000 died from cancer; that's nearly 200,000 people. There have been large increases in the incidence of many cancers linked to lifestyle, such as cancers of the kidney, liver and skin, and oral and uterine cancer.
The disease is responsible for more than one in four deaths in the UK, but recent advances mean that, for the first time in history, more people who are diagnosed with the illness will survive than die. While this is obviously great news, it throws light onto the awkward after effects of the gruelling, often life-changing procedures that go with the treatments.
According to the stats, most of us have had a loved one who has suffered the rigours of chemotherapy or other cancer treatment. These procedures can be as physically demanding as the disease itself. Advances have been made but, often, the side effects can be very damaging in other ways, with infertility and pneumonia among the most serious possibilities.
A lot of the time, though, it's the less visible effects that are the worst - those on self-esteem and self-worth. These can seriously change someone's outlook on life and sometimes even their willpower to fight the disease itself.
The new normal
Many manufacturers are now focusing on this often overlooked issue and are exploring ways to improve the quality of life for cancer patients as they go through treatment by using one material, silicone, in the most ingenious and inventive of ways.
Some treatments embrace its light weight and ease of use. It is an effective scar treatment and can be used to remedy wounds caused by skin cancer surgery. If the cancer is on the chest, back or shoulders, areas prone to excessive scar tissue development, applying silicone gel sheets after stitches are removed protects the tissue and helps it absorb moisture from surrounding healthy areas, promoting more efficient healing. This is just one of the many uses silicone has found in the development of after-cancer treatments.
Thanks to advances in silicone technology, companies around the world are making the material the central element of a more comforting take on medical devices that enable patients going through treatment to regain some sense of normality. Though not all of these are solely for cancer patients, the disease remains the focus of several of the most original takes, particularly because the effects of cancer treatment can often lead to as many medical procedures as the disease itself.
US studies have found that up to 8% of women with cancer will refuse chemotherapy because they don't want to lose their hair - an incredibly serious issue that needs to be addressed. For this, a silicone cap that lowers the scalp's temperature and constricts blood vessels can be used to help prevent chemotherapy drugs from destroying hair follicles.
Coolant circulates through the cap to keep the scalp within the optimum temperature range to prevent hair loss, but not so cold as to be truly uncomfortable or risk skin damage.
Paxman is a manufacturer based in Yorkshire, UK, that has been working on specific projects since its launch in the early 1990s. Glenn Paxman founded Paxman Scalp Cooling on the back of the experience of his own wife losing her hair during chemotherapy. At a time when she and the rest of her family were undergoing enormous emotional strain, it seemed extra cruel that she would also lose her hair - and her self-confidence.
So Paxman set about doing something to help. The use of scalp cooling or 'cold caps' is proven to be an effective way of combatting chemotherapy-induced hair loss, and can result in a high level of retention or even complete preservation of the hair, depending on the person and chemotherapy course. For patients, this means the cap offers the opportunity to regain some control, maintain their privacy and encourage a positive attitude towards treatment - something that can be beneficial in the long term.
Ahead of the game
Cold caps can be used with all solid-tumour cancers that are treated with chemotherapy drugs such as taxanes, alkylating agents and anthracyclines/DNA intercalating agents. These drugs target rapidly dividing cells and the matrix keratinocytes, which results in hair loss.
The Paxman cap has been specifically designed using lightweight silicone, and it is through in-depth research that the advances were able to help. The company has been involved in a research partnership with the nearby University of Huddersfield to allow the company to interpret data from clinical trials in order to improve the efficacy of scalp cooling. This research has been responsible for enhancing the effectiveness of the procedure and helping to alleviate any fears clinicians had about the treatment.
"The cap works by lowering scalp temperature before, during and after the administration of chemotherapy, and came from the experience the family [company] had in the chilled drinks industry," explains Richard Paxman, CEO and son of founder Glenn. The joint project with the university has also led to the design and development of a cooling cap system made from lightweight silicone tubing that offers a personalised fit to all head shapes, improving contact and temperature control. The model of the cap uses 3D-printed tooling technology and will pave the way for mass manufacture using silicone-sheet technology.
According to Paxman, when it came to the choice of material for the cap, there was no alternative. "Silicone has always been an excellent material of choice for the cooling cap," he says. "It is extremely stable, and can withstand environmental factors such as high heat and freezing conditions; and exposure to sterilisation, cleaning and disinfecting chemicals.
"It is the ideal material for medical applications: many grades of it are biocompatible, and the material is available in grades specifically developed and approved for implants and similar medical applications."
With these properties, it was an obvious choice. "In addition to resisting wear and scratching, and retaining its functionality, silicone rubber remains cosmetically attractive throughout its life."
Paxman and the manufacturers did explore alternatives, including several different polymers, as well as different grades of silicone before settling on the materials that performed as required.
"The cooling cap has always needed to be robust, flexible, user-friendly, aesthetically pleasing, watertight and [able to] conform to the patient's head shape, as well as FDA compliant and biocompatible," Paxman explains. "We also had to research rapid prototyping and what could be achieved via this relatively new technology."
Feather in the cap for silicone
The cooling cap is just one means by which silicone technology is being used to help better the lives of cancer patients. As well as the unexplored alternatives to the cap through to more traditional applications like scar-tissue dressings, there are also cosmetic applications, such as a new range of prosthetics to improve the quality of life for breast cancer patients who have had to have mastectomies. New silicone cosmeses are being used to provide a range of lifelike body parts that can restore patients' confidence.
The silicone cosmesis cover fits over a prosthetic breast and is intended to look identical to the one removed. Currently, mastectomy patients can opt for a surgical reconstruction of their breasts - which can leave scars - or wear a 'filler' prosthesis in their bra, though these are often more practical than cosmetic and do not offer the realism of some other implants. Silicone's adaptability to create a lifelike outer covering, with the bottom of the cover being adhesive so it fits securely to the skin without leaving a sticky residue, is a notable step forward.
The silicone is used to create an exact replica that sits so closely to the skin the join cannot be seen. To make the cosmesis, a mould is created, and the patient is then checked for colour-matching and skin detail to provide a better fit.
With applications like this, it's clear to see the potential of silicone for use in cancer treatment and aftercare in the future. Medical manufacturers are continuing to explore new ideas in ways that take advantage of its versatility, stretch and wearability, and these innovations could be an integral part of markedly improving the treatment and post-illness lives of cancer survivors.
"For us, the future is personalisation in every sense, and we see this in the industry," Paxman adds. The use of silicone in R&D is critical to his company, and its real potential and uses are only truly beginning to be tapped now. "Our goal is creating a huge patient benefit," he concludes - with such life-changing products starting to reach the market, it's obvious to see how.