Drug-eluting implant

[2] The production of drug eluting implants has grown significantly in the last decade and continues to be an area of research due to their flexible nature that can be utilised for the treatment of a multitude of medical conditions.

[1] Drug-eluting stents and balloons are a common therapeutic method in the management and treatment of cardiovascular disease that to open and maintain arteries while delivering drug locally to an area of a vessel.

[9] Drug eluting implants have shown potential in the treatment of cancer through adjuvant chemotherapy that has shown to suppress tumor formation locally, overcoming side effects associated with systemic chemotherapy treatment and reduce the need for surgical resection of cancerous tumors.

[12] Drug eluting sutures can produce a prolonged local release of anaesthetic as well as heal wounds.

[15] Designs aim to provide therapeutic dosage to the target tissue while reducing negative side effects and maximizing efficacy.

These implants are classified as either degradable and able to be broken down and metabolized by the body, or non-degradable which eventually require removal.

[2] Common degradable polymer materials used in drug eluting implants include poly e-caprolactone (PCL), polylactic-co-glycolic acid (PLGA) and poly-L-lactic acid (PLLA), while non-degradable polymer materials include silicones commonly used in plastic surgery, urethanes and acrylates, and are more likely to be used in the treatment of chronic conditions in which long term implantation is to be expected.

[2][16][17] In relation to biomedical implant manufacturing, the term 'ceramic' can be used to encompass a wide variety of non-metallic substances that can be utilised in drug eluting implants due to their biocompatible properties such as resistance to corrosion and shear, low electrical conductance ability, and high melting temperatures.

[18][19] Ceramic implants can be classified as bio-inert and include materials such as aluminum, zirconia, and certain carbon and silicon derivatives which are not biodegradable.

Bioactive ceramic implants are biodegradable substances that include calcium phosphates, and a variety of oxidised minerals that mimic natural bone properties.

Ceramic drug eluting implants are therefore commonly used in hard tissue replacement surgeries such as bone.

The development of drugs that can travel from systemic circulation to a specific depot could prove a useful way to overcome the need for invasive refilling and re-implantation.

Medically implanted drug eluting devices can induce an inflammatory response as well as being rejected by the body which can cause chronic inflammation.