The Use of Silicone in Medicine

By Susha Cheriyedath, M.Sc.Reviewed by Lexie CornerNov 22 2024

Advancements in material science and manufacturing techniques have transformed medicine, improving surgical tools, prosthetics, practices, and materials. Medical-grade silicone has been adopted across multiple applications in medicine due to its biocompatibility, mechanical properties, and ability to be sterilized and processed.

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Silicone is immunologically neutral and durable, which reduces foreign body responses and ensures optimal performance under varying physiological situations. This synthetic polymer is thermally stable and chemically inert, which ensures it remains unaffected by aggressive biofluids and pharmaceutical compounds. Silicone also exhibits dielectric strength and electrical insulation, making it suitable for several applications in medical devices, such as cardiac pacemaker leads and implantable neurostimulators.

Moreover, the low thrombogenicity of silicone reduces the likelihood of inflammatory responses or rejection when in contact with biological tissues. Its resistance to microbiological growth ensures hygiene and mitigates biofilm formation. Silicone’s resilience to oxidative degradation ensures long-term durability under exposure to oxygen, ozone, and ultraviolet (UV) light.¹

Silicone in Scar Treatment and Wound Healing 

Scar treatment and wound healing are medical procedures that widely use silicone. By creating a semi-occlusive barrier that hydrates the skin, silicone sheets and gels regulate collagen production and help soften and flatten scars while reducing symptoms like itching and redness.

Most effective in the early stages of scar maturation, silicone products can be used for multiple scar types, including keloids and hypertrophic scars. Silicone therapy enhances scar pliability while lowering pigmentation and vascularity, significantly changing scar elevation and texture.^2,3

This therapy is most effective when introduced early and applied consistently during the wound healing process. The non-invasive nature of silicone products enhances tolerance, supporting effective long-term scar management.^2,3

Using silicone sheets and gels in conjunction provides enhanced results. Silicone scar sheets are thin and comfortable for daily use. They help reduce pain during dressing removal while discreetly protecting healing wounds.

Silicone sheets conform effectively to scar contours, regardless of shape or individual characteristics. Silicone gels, meanwhile, are popular for their ease of application and wearer comfort, making both great options for scar management.^2,3

Use of Silicone in Medical Implants 

Silicone’s versatility and biocompatibility make it suitable for both temporary and long-term implants. It is commonly used in breast implants, maxillofacial prosthetics, joint prosthetics, and implantable drug delivery devices. Its flexible nature and structural similarity to carbon provide functionality in various biomedical applications.

Bioresorbable silicone composites are designed to degrade inside the body over time, eliminating secondary surgeries to remove devices. Such implants could be used for cardiovascular stents or bone scaffolds. Patients could, hence, benefit from temporary support without the long-term risk of implant-related complications.⁴

When used in contact lenses, silicone hydrogels provide high oxygen permeability, enhancing wearer comfort and reducing the risk of hypoxia in extended-use lenses. Their porous and hydrophilic nature also makes them suitable as scaffolds for cell proliferation and tissue regeneration.

Liquid silicone rubber (LSR) allows rapid prototyping and further customization of medical devices, as well as higher control over the curing process and results. The LSR SELECT^TM by Elkem Silicones is an example of new-age LSRs driving growth in the industry.⁵

A paper published in Recent Progress in Materials assesses the effects of incorporating different reinforcements on the properties of silicone rubber used in medical implants.⁶

Silicone in Medical Devices and Equipment 

The versatile properties of silicone make it adaptable to manufacturing techniques like injection molding and 3D printing, which, when coupled with digital health technologies, allows the creation of customized medical devices tailored to individual patient needs.⁷

Researchers have developed formulations that replicate the viscoelastic properties of soft tissues, achieving high anatomical accuracy by employing direct ink writing (DIW) techniques. DIW deposits silicone gels in layers, producing properties similar to those of soft tissues.⁸

Rheological optimization can be attained by carefully controlling the concentration of additives, such as Aerosil and silicone oil. This enhances the utility of surgical phantoms for practice, as the viscoelastic behavior of silicone closely mimics the characteristics of specific tissues, such as skin, fat, or muscle.

A recent paper published in IntechOpen covers the application of silicone hollow fibers to develop a membrane oxygenator. It explored how silicone can be customized to obtain increasingly efficient results for applications requiring selective permeability and biocompatibility, highlighting its versatility as a material.⁹

Surface modification methods like plasma treatment enhance adhesion to substrates like glass or metals. Silicone is hydrophobic and forms watertight seals, making it ideal for medical tubing, gaskets, and implantable devices.

Future Applications and Innovations in Silicone Medical Technology 

Innovations in silicone-based medical products have strengthened their role in medical devices, prosthetics, and monitors. The versatility and performance of these technologies have established silicone as a key material in the industry for the foreseeable future.

Some recent advancements in the use of silicone in medicine include:

• Silicone in Diagnostics: Silicon-based point-of-care testing (POCT) devices, which can be used for rapid, on-site testing, make on-site medical diagnoses possible. This technology enables analytical procedures such as sample preparation, reaction, and detection to be carried out on a single chip.
  • Drug Delivery Systems: Silicone exhibits high gas permeability at room temperature (25 °C), aiding in oxygen-permeable membranes and controlled drug delivery systems. Nanoparticles can be incorporated into silicone to improve drug delivery systems, offering better control over the release of pharmaceuticals.
• Adhesion in Silicone-Based Medical Devices: BioAdheSil is a silicone-based bio-adhesive providing robust adhesion in wet tissue environments. BioAdheSil biodegrades over time, affecting permeability and encouraging cell migration and tissue integration. It can be used in tracheal stents, left ventricular assist device lines, and other implants.¹¹
• Advanced Wound Care: Silicone's moisture-retentive properties make it ideal for dressings to promote faster healing by maintaining an optimal moisture environment, accelerating tissue repair, and reducing scarring.¹²
• Wearable Health Monitors: Heart rate sensors, glucose monitors, and continuous blood pressure systems collect health data in real time, providing patients and healthcare providers with detailed and actionable insights. Silicone’s mechanical flexibility and resilience aid the cardiac and respiratory systems. Its fatigue resistance allows it to endure cyclic loading in wearable devices and implants exposed to continuous motion.

Silicone has expedited progress in medical devices and instruments, with its applications spanning many medical niches.

Key Market Players and Drivers

The size of the medical-grade silicone market is projected to reach USD 2.7 billion by 2032.^13. This growth is attributed to the increasing demand for medical-grade silicone in prosthetics, orthopedics, and dentistry.

Market leaders like BioPlexus, LLC, Primasil Silicones Limited, Stockwell Elastomerics, Inc., DuPont, Shin-Etsu Chemical Co., Ltd., and Wacker Chemie AG are advancing the industry through innovative products and research. BioPlexus's SpectraFilm Adhesive Gel Sheets help treat hypertrophic scars, while its flexible silicone elastomers are used in reconstruction and prostheses.

Implantable devices and precision components can be fabricated using products like Liveo™ BioMedical Grade Liquid Silicone Rubbers (LSRs) by DuPont. The SILPURAN® and ELASTOSIL® series by Wacker Chemie AG can be injection molded and are soft and durable. These are used in resuscitator bags and soft nasal prongs.

Conclusion 

Silicone-based products have significantly impacted various medical applications, including—but not limited to—wound care, drug delivery systems, medical devices, prosthetics and implants, wearable health monitors, and dentistry. Thanks to its versatility and safety profile, silicone has become indispensable in modern medicine, significantly improving patient care and outcomes.

The future of silicone in medicine seems promising. Biochemistry and material science advancements have made silicone an indispensable part of medical technology, offering the potential for advanced healthcare and research globally.

The development of silicone medical technology is driven by ongoing research and advancements aimed at improving its properties and broadening its applications. Key areas of innovation include improved biocompatibility, progress in 3D printing and nanotechnology, and its use in emerging fields such as soft robotics and advanced wound care.

Although the medical silicone industry shows significant promise, the high cost of raw materials remains a challenge to further innovation. With ongoing cutting-edge research, further breakthroughs in medical silicone technology are expected to make it more affordable and broaden its impact in healthcare.

More from AZoM: The Role of Silicon Anodes in Batteries

References and Further Reading

1. Vicky B., et al. (2016), Developments in silicone material for biomedical applications- A review, International Conference on Humanizing Work and Work Environment HWWE-2016. https://www.researchgate.net/profile/Vicky-Sardar/publication/312125805_Development_in_Silicone_Material_for_Biomedical_Applications/links/5870987308ae329d6216336b/Development-in-Silicone-Material-for-Biomedical-Applications.pdf
2. An, JK., Kim, YH (2024), Clinical Application of Self-Adherent Scar Care Silicone Sheet and Silicone Gel in Postoperative Scar Management. Journal of Wound Management and Research.  https://doi.org/10.22467/jwmr.2023.02789 https://www.jwmr.org/upload/pdf/jwmr-2023-02789.pdf
3. Mustoe, TA. (2008), Evolution of Silicone Therapy and Mechanism of Action in Scar Management, Aesthetic Plastic Surgery, DOI: 10.1007/s00266-007-9030-9 https://www.drthomasmustoe.com/content/uploads/2020/03/Scar-Management-Evolution.pdf
4. Kasemsiri, P., et al. (2024)Bioresorbable polymers: Challenges and opportunities for development and applications of medical devices, DOI: https://doi.org/10.1016/B978-0-443-18915-9.00011-2, https://www.sciencedirect.com/science/article/abs/pii/B9780443189159000112
5. Lin, F. (2019). Silicone materials for long-term medical implants: Innovate for the future. [Online] Mass Device. Available at https://www.massdevice.com/silicone-materials-for-long-term-medical-implants-innovate-for-the-future/ (Accessed on 18^th November 2024)
6. Dehnou, KH., Hadianfard, MJ. (2024), Enhancing Thermal, Viscoelastic, and Mechanical Properties of Silicone Rubber Matrix through Reinforcements for Use as a Medical Implant, Recent Progress in Materials. DOI:10.21926/rpm.2402011., https://www.lidsen.com/journals/rpm/rpm-06-02-011
7. Hosseinzadeh, E., et al. (2024), Fabrication of Soft Transparent Patient-Specific Vascular Models with Stereolithographic 3D Printing and Thiol-Based Photopolymerizable Coatings, Macromolecular Rapid Communications. DOI: https://doi.org/10.1002/marc.202300611 , https://onlinelibrary.wiley.com/doi/full/10.1002/marc.202300611
8. Nieva-Esteve, G., et al. (2024) Developing tuneable viscoelastic silicone gel-based inks for precise 3D printing of clinical phantoms, Materials Advances. DOI: 10.1039/D4MA00011K, https://pubs.rsc.org/en/content/articlehtml/2024/ma/d4ma00011k
9. Yokoi, R., et al. (2024), Development of a Membrane Oxygenator for Long-Term ECMO Support Using Fine Silicone Hollow Fiber, Evolving Therapies and Technologies in Extracorporeal Membrane Oxygenation. DOI: 10.5772/intechopen.1004358, https://www.intechopen.com/online-first/1175722
10. Rahimi, A., Mashak, A. (2013), Review on rubbers in medicine: natural, silicone and polyurethane rubbers, Plastics, Rubber and Composites.. DOI:10.1179/1743289811Y.0000000063
11. Singh, M., et al. (2024), A Tunable Soft Silicone Bioadhesive for Secure Anchoring of Diverse Medical Devices to Wet Biological Tissue, Advanced Materials. DOI: https://doi.org/10.1002/adma.202307288, https://onlinelibrary.wiley.com/doi/10.1002/adma.202307288
12.  Yailian, A-L., et al. (2024), Effectiveness and safety of an innovative silicone extender in suture reinforcement or dermatotraction: a retrospective study, Journal of Wound Care. DOI: https://doi.org/10.12968/jowc.2021.0137
13. Global Market Insights. (2023). Medical Grade Silicone Market Size - By Form (Gel,  Rubber, Foam, Sheet, Block), By Application (Respiratory Devices, Medical Device Components, Implants, Orthopedic Forms)- Global Forecast (2023-2032). [Online] Global Market Insights. Available at https://www.gminsights.com/industry-analysis/medical-grade-silicone-market (Accessed on 16^th November, 2024)

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