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In this study, reinforced poly(L-lactic acid) (PLLA) fibers made by a dry-spinning/hot-drawing process were evaluated for use as a suture. The initial tensile strength of the PLLA fibers was lower than the initial tensile strength of the commercially available sutures: PDS, Vicryl, silk, and Ethilon. However, after 12 weeks immersion in a phosphate saline buffer at 37 degrees C, PDS sutures have lower tensile strength than PLLA sutures and the tensile strength of Vicryl was unmeasurable because of fragmentation. Initially, PLLA fibers disintegrated into fibrils during degradation triggering an inflammatory response comparable to degradable multifilament sutures. However, the intensity of the inflammatory response against the PLLA fibers decreased and after 80 weeks implantation in the muscle layer of the abdominal wall of rats it was comparable to the one against Ethilon. The inflammatory response against Ethilon, which is considered to be nondegradable, increased in the same period, probably due to the change in shape. In practice, the handling characteristics of PLLA sutures are superior to the monofilament sutures like PDS and Ethilon and comparable with the multifilament sutures like Vicryl and silk. The knot security of PLLA sutures are expected to be better than the knot security of the monofilament sutures, but this remains to be investigated. It is concluded that dry-spun/hot-drawn (reinforced) PLLA fibers have the potential for use as long-term degradable suture material.

High-speed gel-spinning of ultra-high molecular weight polyethylene Pennings, A.J.; Hooft, R.J. van der; Postema, A.R.; Hoogsteen, W.; Brinke, G. ten Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. SummaryThis communication is concerned with the gel-splnning of ultrahigh molecular weight polyethylene (UHMWPE) at speeds up to 1500 m/mln. It was found that 5 wt% solutions of UHMWPE in paraffin oil could be extruded through a conical die at a rate of 100 m/min. without the appearance of filament irregularities due to elastic solution fracture. These elastic turbulences occur at extrusion speeds of about 5 m/min. Without the addition of I wt% of Aluminlum-stearate the spinllne could be stretched at most to 60 m/min at 170~ but at 210~ it did not break at a speed of 1500 m/min. These hlgh-speed gel-splnning experiments at temperatures around 200~ yielded polyethylene fibers with a tensile strength of 3.5 GPa. It was observed that drying of the as-spun fiber containing n-hexane at constant length led to excessive crazing.