Abstract: A method is disclosed for improving the efficiency of producing chitin and chitosan, particularly biocompatible chitosan. Crustacean shells are maintained at a high temperature for a sufficient time to convert most of the chitin in the shells to an amorphous form. The shells are then rapidly cooled, for example by plunging into liquid nitrogen, so that most of the chitin in the shells remains in the amorphous form. These “quenched” shells are then deproteinized and demineralized to produce chitin. The chitin may be deacetylated to produce chitosan. High purity chitin or chitosan is thereby produced at a lower cost than has been possible using previous methods. Biocompatible chitosan produced by this process may be used for the delivery of cells or bioactive agents, or for other applications.

Abstract: A method is disclosed for improving the efficiency of producing chitin and chitosan, particularly biocompatible chitosan. Crustacean shells are maintained at a high temperature for a sufficient time to convert most of the chitin in the shells to an amorphous form. The shells are then rapidly cooled, for example by plunging into liquid nitrogen, so that most of the chitin in the shells remains in the amorphous form. These “quenched” shells are then deproteinized and demineralized to produce chitin. The chitin may be deacetylated to produce chitosan. High purity chitin or chitosan is thereby produced at a lower cost than has been possible using previous methods. Biocompatible chitosan produced by this process may be used for the delivery of cells or bioactive agents, or for other applications.

Abstract: An improved process for manufacturing a molded prosthetic device from a synthetic bioabsorbable polymer is disclosed. The process includes placing a solid amount of the polymer in a molding machine; melting the polymer by subjecting it to a temperature of from about 240.degree. to 255.degree. C. for about 2 to 5 minutes; transporting the polymer melt to an orifice; injecting the polymer melt from the orifice into a closed mold cavity at a pressure of from about 8000 to 9000 lbs per square inch (562 to 633 kg per sq. cm.); holding the polymer in the mold cavity for less than about one minute at a temperature of about 70.degree. to 90.degree. C.; removing a molded prosthetic device from the mold cavity; and posttreating the molded prosthetic device. The posttreating can be, e.g., annealing and then/or sterilizing.