Tricol Biomedical, Inc.

Hemcon Medical Technologies, Inc.

Barbara McGrath

Simon J McCarthy

Sam Kuhn

Michael Stolten

Amanda Bennett

Alysha Wold

Jess Kimball

Ervelyn Winata

Simon Mccarthy

Amanada Bennett

The present invention comprises chitosan materials and methods of using carbonic acid for aqueous solubilization of neutralized or pre-treated chitosan gels and provides, among other things, substantially acid salt free composition native final forms without requiring subsequent acid salt elution. The invention includes chitosan-based solid and semi-solid material forms, optionally reinforced with chitosan fibers, such as powders, fibers, films, matrices, sponges, implants, scaffolds, fillers, and hydrogels. Native final forms are produced from chitosan powder solubilized in an aqueous acidic solution, processed to form a high pH hydrated chitosan gel precipitate material that is then neutralized by water washing and re-solubilized substantially to chitosan solution using carbonic acid. Chitosan materials can be mixed in solution with one or more of other hydrophilic polymers to create compositional heterogeneity and pharmaceutical agents to achieve controlled release of the agent(s) from the final forms at the site of application.

Chitosan materials from carbonic acid solution

The invention relates to biocompatible, bioabsorbable derivatized non-crosslinked chitosan compositions optionally crosslinked to gelatin/collagen by 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) for biomedical use and methods of making and testing such compositions, including a modified acute systemic toxicity test. The compositions comprise derivatized chitosan reacetylated to a degree of N-deacetylation (DDA) of between about 15% and 40%. The compositions are typically bioabsorbed in about 90 days or less and can be made to bioabsorb at differing rates of speed. The compositions are initially soluble in aqueous solution below pH 6.5. The compositions have an acid content that can be adjusted between about 0% (w/w) and about 8% (w/w) to customize the composition for uses that require and/or tolerate differing levels of cytotoxicity, adhesion, composition cohesion, and cell infiltration into the composition.

Biocompatible and bioabsorbable derivatized chitosan compositions

The invention relates to biocompatible, bioabsorbable derivatized non-crosslinked chitosan compositions optionally crosslinked to gelatin/collagen by 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) for biomedical use and methods of making and testing such compositions, including a modified acute systemic toxicity test. The compositions comprise derivatized chitosan reacetylated to a degree of N-deacetylation (DDA) of between about 15% and 40%. The compositions are typically bioabsorbed in about 90 days or less and can be made to bioabsorb at differing rates of speed. The compositions are initially soluble in aqueous solution below pH 6.5. The compositions have an acid content that can be adjusted between about 0% (w/w) and about 8% (w/w) to customize the composition for uses that require and/or tolerate differing levels of cytotoxicity, adhesion, composition cohesion, and cell infiltration into the composition.

Absorbable tissue dressing assemblies are formed from hydrophilic polymer sponge structures, such as chitosan.

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Portland, OR, United States of America

Barbara McGrath