Dennis D. Jamiolkowski

Monocryl suture, a new ultra-pliable absorbable monofilament suture.

Synthetic absorbable sutures are available as braided constructions or as monofilaments. Braided absorbable sutures are made either from 90:10 poly(glycolide-co-L(-)-lactide), sold by Ethicon, Inc. under the trade name Vicryl, or from polyglycolide, as sold, for instance, by Davis and Geck under the trade name Dexon. There are, however, some concerns with braided sutures that relate to tissue drag and the trauma this may cause, as well as the possible potentiation of infection through the interstices of the braid structure. Absorbable monofilaments, such as the monofilament sutures derived from p-dioxanone homopolymer (PDS II, an Ethicon, Inc. product), or a copolymer of trimethylene carbonate and glycolide (Maxon, a Davis and Geck product), eliminate many of these concerns, but generally monofilaments do not handle as well as braids. This paper describes the research leading to the introduction of Monocryl (poliglecaprone 25) monofilament sutures, based on segmented block copolymers of epsilon-caprolactone and glycolide. Monocryl sutures will be shown to display excellent handling properties, minimal resistance during passage through tissue and excellent tensile properties. These sutures provide an in vivo breaking strength retention of approximately 20-30% after 2 weeks, considered by many to be the critical wound healing period. Absorption data on these sutures are presented; absorption is complete between the 91st and 119th days of implantation, with slight or minimal tissue reaction.

Time-resolved crystallization study of absorbable polymers by synchrotron small-angle X-ray scattering

Changes in the lamellar morphology that occurred during the quiescent isothermal crystallization of absorbable poly(p-dioxanone) (PDS) and PDS/poly(glycolide) block copolymer were studied by synchrotron small-angle X-ray scattering. Important morphological parameters such as the lamellar long period, the thicknesses of the crystal and amorphous phases, and the scattering invariant were estimated as a function of time, and trends observed over a wide range of experimental conditions are discussed. Thicker but more perfect lamellae were detected at higher crystallization temperatures. The breadth of the normalized semilog Lorentz-corrected intensity peak systematically decreased with increasing temperature. In addition, the values of the crystallization half-time and the Avrami exponent (n = 2.5), determined from the real-time changes in the lamellar development, showed superb agreement with the bulk crystallinity data generated from other experimental techniques, such as calorimetry and dielectric relaxation spectroscopy.