Compositions and methods for coating medical devices

Abstract

The present invention provides compositions and methods for coating medical devices with pharmaceutical agents and devices coated with the compositions. The coated devices provide controlled or sustained release of pharmaceutical agents for the treatment of wounds or disease.

Description

1.INTRODUCTION [0001] The present invention relates to compositions for coating medical devices with a polymeric matrix containing pharmaceutical agents, methods for coating the medical devices and medical devices coated therewith. The coated devices are useful for targeted local delivery of pharmaceutical agents at a site of medical intervention for the treatment of wounds and disease. 2. BACKGROUND OF THE INVENTION [0002] The desirability of coating medical devices such as, inter alia, surgical implants, sutures and wound dressings with pharmaceutical agents is well documented in the art. Such coated devices could theoretically provide a means for locally delivering pharmaceutical or therapeutic agents at the site of medical intervention to treat a variety of diseases. For example, surgical implants or sutures coated with antibiotics can provide local delivery of antibiotic directly at an implantation or suture site, thereby decreasing the onset of infection following the surgical...

AI Technical Summary

Benefits of technology

[0042] In another illustrative embodiment, the polymeric matrix coating is in the form of microspheres and / or nanospheres, as previously described. When used in a medical procedure, body fluids contact the polymeric matrix coating causing the microspheres and / or nanospheres to biodegrade and release pharmaceutical agents into the local area surrounding the site of medical intervention. In addition, microspheres and / or nanospheres detach from the device. The spheres may be taken up by surrounding cells where they provide controlled or sustained intracellular release of pharmaceutical agents as the spheres biodegrade within the cell.

[0044] In a particularly preferred embodiment, the nucleic acid is a nucleic acid that stimulates or promotes wound healing. Such coated medical devices exhibit improved wound healing characteristics.

Problems solved by technology

However, prior art methods for coating sutures and implants have typically been limited with respect to the types of pharmaceutical agents that can be incorporated into the coating sheath.

While methods have been developed to coat implants with water soluble pharmaceutical agents, especially anti-bacterial agents, these methods are not readily adaptable to easily and efficiently coat medical devices with a wide variety of pharmaceutical agents, especially nucleic acids, as they either require complex, expensive machinery or suffer from other undesirable limitations.

These methods are also not suitable for providing coatings exhibiting controlled or sustained release of pharmaceutical agents.

In addition to requiring expensive equipment, this method also suffers from the limitation that the pharmaceutical agent to be administered must be readily ionizable.

Furthermore, the coated implants do not provide controlled or sustained release of bactericidal agent.

While relatively simple, this method requires several manipulations and does not allow for sustained delivery of bactericidal agents.

As is readily apparent, this method is not suitable for coating devices that do not readily take up, or become impregnated with, the desired pharmaceutical agent.

Furthermore, because the suture is top-coated with polyurethane, this method is not useful for the controlled delivery of pharmaceutical agents at the site of surgical intervention.

Perhaps one of the greatest problems associated with current gene therapy strategies, whether ex vivo or in vivo, is the inability to transfer nucleic acids efficiently into a targeted cell population and to achieve a high level of expression of the gene product in vivo.

While highly efficient at gene transfer, the major disadvantages associated with the use of viral vectors include the inability of many viral vectors to infect non-dividing cells; problems associated with insertional mutagenesis; problems associated with the ability to “turn on” gene expression over time in the few cells that are transfected; potential helper virus production and / or production and transmission of harmful virus to other human patients.

In addition to the low efficiency of most cell types to uptake and expression of foreign nucleic acids, many targeted cell populations are found in such low numbers in the body that the efficiency of transformation of these specific cell types is even further diminished.

However, transfer of nucleic acids into wounded tissue need not be mediated via microspheres and / or nanospheres.

In addition, it is well-known that many fragile tissue types, such as normal and diseased liver tissue, tissues in patients suffering from certain metabolic disorders such as diabetes, and tissues that have been irradiated such as tissues following cancer surgery, have difficulty holding sutures.

A number of problems are associated with the use of therapeutic proteins in wound healing therapies.

For example, the purification and / or recombinant production of therapeutic proteins is often an expensive and time-consuming process.

Once purified, most protein preparations are unstable making storage and use cumbersome.

Therefore, such proteins cannot be administered in such a way as to be taken up and properly localized inside the cell.

As is readily apparent from the above discussion, presently there are no methods and / or compositions available which allow medical devices to be easily and efficiently coated with a wide variety of pharmaceutical agents, especially water-soluble or hydrophilic pharmaceutical agents, that permit local controlled or sustained release of such agents at a site of medical intervention for the treatment of wounds or disease.

There are also presently no methods or compositions available for coating medical devices with microsphere and / or nanosphere pharmaceutical formulations that permit easy and efficient intracellular as well as extracellular local delivery of pharmaceutical agents that do not readily traverse or penetrate cell membranes for the treatment of wounds or disease.

Furthermore, there are currently no compositions or methods available for coating medical devices with nucleic acids, especially nucleic acids that stimulate wound healing, that permit easy and efficient targeted local delivery of nucleic acids in vivo.

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