ABSTRACT:The aim of the study was to investigate the mechanical properties and biodegradability of poly(trimethylenecarbonate--caprolactone)-block-poly(p-dioxanone) [P(TMC--CL)-block-PDO] in comparison with poly(p-dioxanone) and poly(glycolide--caprolactone) (Monocryl) monofilaments in vivo and in vitro. P(TMC--CL)-block-PDO copolymer and poly(p-dioxanone) were prepared by using ringopening polymerization reaction. The monofilament fibers were obtained using conventional melt spun methods. The physicochemical and mechanical properties, such as viscosity, molecular weight, crystallinity, and knot security, were studied. Tensile strength, breaking strength retention, and surface morphology of P(TMC--CL)-block-PDO, poly(p-dioxanone), and Monocryl monofilament fibers were studied by immersion in phosphate-buffered distilled water (pH 7.2) at 37°C and in vivo. The implantation studies of absorbable suture strands were performed in gluteal muscle of rats. The polymers, P(TMC--CL)-block-PDO, poly(p-dioxanone), and Monocryl, were semicrystalline and showed 27, 32, and 34% crystallinity, respectively. Those mechanical properties of P(TMC--CL)-block-PDO were comparatively lower than other polymers. The biodegradability of poly(dioxanone) homopolymer is much slower compared with that of two copolymers.

A series of poly(trimethylenecarbonate-e-caprolactone)-block-poly(p-dioxanone) copolymers were prepared with varying feed rations by using two step polymerization reactions. Poly(trimethylenecarbonate)(e-caprolactone) random copolymer was synthesized with stannous-2-ethylhexanoate and followed by adding p-dioxanone monomer as the other block. The ring opening polymerization was carried out at high temperature and long reaction time to get high molecular weight polymers. The monofilament fibers were obtained using conventional melting spun methods. The copolymers were identified by 1 H and 13 C NMR spectroscopy and gel permeation chromatography (GPC). The physicochemical properties, such as viscosity, molecular weight, melting point, glass transition temperature, and crystallinity, were studied. The hydrolytic degradation of copolymers was studied in a phosphate buffer solution, pH ¼ 7.2, 37 8C, and a biological absorbable test was performed in rats. V V C 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: [2790][2791][2792][2793][2794][2795][2796][2797][2798][2799] 2005

Background In this study, a physical properties test and preclinical evaluation were performed on two polycaprolactone (PCL)‐based dermal filler formulas. Objective This study was performed to compare the rheological characteristics, preclinical efficacy, and safety of a new PCL filler, SF‐01, with a licensed PCL filler. Methods First, the viscoelasticity of the PCL filler was evaluated. Next, hairless mice were injected with fillers and evaluated for efficacy with a folliscope and PRIMOSLITE. Histological evaluation was conducted for 6 months to evaluate safety. Results In this evaluation, SF‐01 was superior to a licensed PCL filler in initial volume increase rate and in vivo durability, and the migration of the injected filler was not confirmed. The elasticity (G*, G′) and viscosity (G′′) are also expected to be lower than those of a licensed PCL filler, thereby resulting in less foreign body sensation in the living body. Conclusion SF‐01 (porous PCL microsphere–based dermal filler) has been confirmed to be superior in durability and shape retention compared to the licensed PCL filler (nonporous PCL microsphere–based dermal filler), and the in vivo safety is equivalent.

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Article history:Measurement of the absolute displacement of the moving machinery components in three-dimensions (3D) is of critical functional importance. This paper describes the system that measures motion associated with six degrees-of-freedom in 3D. Wire-sensors are used to estimate the positions of an object in a 3D Cartesian coordinate system, based on the values of their initial position and the measured values. For inducing the transfer function, which represents the motion of an object, the number of the minimum measurement points is determined. Also, the experimental measuring device is configured to visualize the behavior of a rectangular object in real-time. The software for measuring the six types of motions is directly programmed using a commercial software. . 단순한 거동의 경우에 는 변위센서를 이용하면 대체적인 거동측정이 가능하나