Polymer monofilament absorbable suture

Copolymers of S-caprolactone and L-lactide are elastomeric when prepared from 25% S-caprolactone and 75% L-lactide, and rigid when prepared from 10% S-caprolactone and 90% L-lactide (47). Blends of poly-DL-lactide and polycaprolactone polymers are another way to achieve unique elastomeric properties. Copolymers of S-caprolactone and glycoHde have been evaluated in fiber form as potential absorbable sutures. Strong, flexible monofilaments have been produced which maintain 11—37% of initial tensile strength after two weeks in vivo (48). 

Monofilament Synthetic Absorbable Sutures. Ethicon iatroduced the first monofilament synthetic absorbable suture ia 1984 when it marketed PDS polydioxanone (4) sutures. The polymer is produced by the bulk polymerisation of 2,5- -dioxanone. The suture is distributed under the trade name PDS 11. It is claimed to retain approximately 50% of its strength four weeks after implantation, 25% at six weeks, and to be absorbed within six months. 

Special grade poly(p-dioxanone) synthetic absorbable polymer has been developed into monofilament PDS suture, formulated to provide wound support through an extended healing period, as well as to minimize the variability of breaking strength retention and absorption and to invoke minimal tissue reaction. These features are particularly heneficial in critical applications, such as those involving slowly healing tissues. 

However, until recently, the use of a combination of controlled branching (polyaxial chain geometry) and chain segmentation or block formation of the individual branches to produce absorbable polymers with tailored properties has been overlooked. Accordingly, for addressing this area, the synthesis and available properties of this new family of copolyesters and monofilament sutures therefrom are discussed in this chapter. 

W. Channuan, J. Siripitayananon, R. Molloy, G.R. Mitchell, Defining the physical structure and properties in novel monofilaments with potential for use as absorbable surgical sutures based on a lactide containing block terpolymer, Polymer 49 (20) (2008) 4433-4445. 

Im et al (2007) have developed a manufacturing technique to produce monofilament sutures by a conjugate spinning method. Two absorbable polymers, PDS and a copolymer of / -dioxanone, trimethylene carbonate and e-caprolactone were used in this spinning method. The resulting bicomponent monofilament suture fiber (MonoFlex ) has 97 mol% / -dioxanone and exhibits the sea/islands type cross-sectional morphology shown in Fig. 11.2. These sea/island type bicomponent materials can place many fine strands... 

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