Vertellus Biomaterials - Advanced Biomedical Polymers

Vertellus Biomaterials based in Herriard, near Basingstoke in Hampshire, is a business unit of Vertellus Specialties UK Ltd which is part of the health and specialty products division of Vertellus Specialties Inc.

Vertellus Specialties is a progressive company consisting of three global divisions and is a leading provider of fine and specialty chemicals for the nutrition, pharmaceutical, medical, plastics and coatings markets. The UK headquarters and manufacturing facility in Middlesbrough operates under an ISO 9001:2000 environment.

Vertellus Biomaterials was set up to exploit a range of clinically proven biocompatible materials known collectively as PC Technology™, which was exclusively in-licensed from Biocompatibles UK Ltd, in 2006.

We develop and evaluate coating methodologies to apply biocompatible polymer treatments to a range of medical devices for worldwide collaborative partners.

PC TECHNOLOGY - BIOCOMPATIBLE DRUG ELUTING COATINGS

PC is short for phosphorylcholine, the chemical name of a polar head group found in the phospholipids, that form the bi-layers that make up cell membranes. PC is zwitterionic; that is it contains both positive and negative charges but is overall electrochemically neutral within a wide pH range. The high polarity of the PC group causes water to be tightly bound by materials containing PC, and it is principally this property which results in biocompatibility.

PC Technology is a proprietary platform of methacrylate polymers incorporating phosphorylcholine. These biomimetic materials build upon the body’s own chemistry but are synthetic, allowing precise control over the purity profile. They can provide an elegant solution to biocompatibility challenges for medical devices and can be tailored to specific application needs.

PC Technology is used in the manufacture of a range of medical devices including coronary stents, contact lenses, cardiopulmonary bypass equipment and catheter systems. These innovative polymers confer enhanced biocompatibility, reducing thrombogenicity, inflammatory response and bacterial adhesion and are capable of local drug delivery. The polymers can be tailored to match the delivery requirements of a specific application. A variety of drugs have been investigated including antibiotics, anti-inflammatories, cytotoxics, hormonally active agents, nucleic acid derivatives and therapeutic proteins.

The PC Technology is licensed to a number of leading medical device manufacturers including CooperVision, Smith and Nephew (Gyrus), Abbott Laboratories and the Sorin Group. FDA claims relating to reduced thrombus formation, reduced biofilm formation and improved patient comfort have been secured for devices incorporating PC polymers.

REDUCED PROTEIN AND CELLULAR FOULING

Invariably when a foreign material is placed in the body it immediately begins to reject the object through the deposition of lipids and proteins, which denature, adopting active conformations that encourage the adhesion of cells from the surrounding environment. These cells may then promote further fouling of the surface.

In the case of blood, plasma proteins become irreversibly bound to the surface, followed by platelet adhesion and activation, leading to the release of additional activating factors and eventually the formation of blood clots, or thrombi. By inhibiting the initial adsorption of proteins, PC materials provide an inert, non-thrombogenic surface.

When used as a coating on a medical device the improved haemocompatibility can significantly suppress the usual response of the body to a foreign material. An appreciation of this property may be seen in clinical research work reporting a favourable effect on platelets and lower blood losses during cardiopulmonary bypass surgery1. In addition, when used as a coating on coronary guide-wires, it was found that PC aids in the prevention of thrombus formation on the guide wire tip during short term clinical use2.

Suppression of protein fouling can also lead to significant reductions in the adhesion of bacterial cells and to reduced giant cell adhesion and activation, thereby potentially lowering the risk of biofilm formation and inflammation.

PRODUCT DEVELOPMENT OPPORTUNITIES

Vertellus has considerable experience in applying its platform technologies in the development of novel drug eluting devices. This includes studies investigating the uptake and release of drugs.

Several combination devices have been successfully marketed, including Abbott’s Dexamet™ stent3 and Medtronic’s Endeavor stent4 eluting dexamethasone and zotarolimus respectively.

REFERENCES

1. De SF et al., Perfusion. 2002 Jan;17(1):39-44.
2. Gobeil, F. et al , Canadian J. Cardiology 2002 18(3): 263-269
3. www.touchcardiology.com/dexamet-coronary-stentstent-a490-1.html
4. www.medtronic.com/Newsroom/NewsReleaseDetails.do?itemId=1101867098954&lang=en_US