Biomedical

Disclosed are compositions and methods for the biocompatible sterilization of materials, in particular, of medical devices and implants. Sterilization is achieved by deactivation of microorganisms through treatment of the material with a mixture of at least one microbiocidal additive and a high-pressure or supercritical fluid, for example, high-pressure carbon dioxide or supercritical carbon dioxide. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

This study reports the effect of exposure to liquid carbon dioxide on the mechanical properties of selected medical polymers. The tensile strengths and moduli of fourteen polymers are reported. Materials were exposed to liquid CO2, or CO2 + trace amounts of aqueous H2O2, at 6.5 MPa and ambient temperature. Carbon dioxide uptake, swelling, and distortion were observed for the more amorphous polymers while polymers with higher crystallinity showed little effect from CO2 exposure.

A process for cleaning donor soft tissue by removing contaminants by extraction using a fluid at supercritical temperature and pressures while preserving the integrity of the tissue.

A method is disclosed that produces allografts from matrices typically containing demineralized bone matrix (DBM) powder, demineralized bone matrix gel, demineralized bone matrix paste, bone cement, cancellous bone, or cortical bone and mixtures thereof. The matrices are sterilized utilizing supercritical CO2 in the presence of a sterilizing additive and an entrainer such as an alkaline earth metal compound, preferably CaCO3.

Sterilization methods and apparatus are effective to achieve a 6-log reduction in CFUs of industry standard bacteria and bacterial spores, i.e., B. stearothermophilus and B. subtilis spores, by subjecting sterilizable materials to a chemical additive-containing carbon dioxide sterilant fluid at or near its supercritical pressure and temperature conditions. Most preferably, the chemical additive-containing supercritical carbon dioxide sterilant fluid is agitated during sterilization, e.g., via mechanical agitation or via pressure cycling.

A gentle sterilisation process has been commercialised for the sterilisaition of advanced biomaterials. This article describes the technique and relevant applications.

The biocompatibility of two cyanoacrylate surgical glues (Glubran and Glubran 2), supplied by General Enterprise Marketing, Viareggio, Lucca, Italy, was tested through cytotoxicity and blood compatibility tests and the evaluation of antimicrobial activity. Cytotoxicity and blood compatibility tests were performed on the polymerized glues. Using the neutral red uptake test, the extracts from Glubran and Glubran 2 after polymerization were non-toxic to L929 cells only when diluted 1 : 10 with culture medium.

Gentle alternatives to existing sterilization methods are called for by rapid advances in biomedical technologies. Supercritical fluid technologies have found applications in a wide range of areas and have been explored for use in the inactivation of medical contaminants. In particular, supercritical CO2 is appealing for sterilization due to the ease at which the supercritical state is attained, the non-reactive nature, and the ability to readily penetrate substrates.

Disclosed are processes for sterilization of cyanoacrylate adhesive compositions, the compositions, comprising 2-cyanoacrylate ester monomers, so produced and a method for assaying the effectiveness of the sterilization process. The process comprises heating the adhesive composition to from about 70° C. to about 140° C. for an effective amount of time.

A method is provided for sterilizing materials, particularly polymers, for drug delivery and implantation, wherein the material is treated with supercritical fluid carbon dioxide at pressures in the range of 2000 to 3000 psi (140 to 210 bar) and temperatures preferably between 30 and 45.degree. C. for periods between 20 minutes and six hours, more preferably between 0.5 and 2 hours.