Effect of heat treatment of poly(l-lactide) on the response of osteoblast-like MC3T3-E1 cells

Ikarashi, Yoshiaki; Tsuchiya, Toshie; Nakamura, Akitada

doi:10.1016/s0142-9612(00)00008-9

Cited by 27 publications

(26 citation statements)

References 27 publications

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“…Tumor incidence was 44% (22/50) with PLLA 6 and 38% (11/29) with PU, 1 which correlates well with the in vitro malignancy incidence data in the present study. Isama and Tsuchiya, 7 and Ikarashi et al 8 reported that low-molecular-weight PLLA increases alkaline phosphatase activity and stimulates calcification of mouse osteoblast-like MC3T3-E1 cells.…”

Section: Discussionmentioning

confidence: 99%

Gene expression changes in BALB/3T3 transformants induced by poly(L‐lactic acid) or polyurethane films

Matsuoka

Tsuchiya

2003

J Biomedical Materials Res

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We performed DNA microarray analysis on two BALB/3T3 transformants (A5 and A6) induced by polyurethane (PU) film, two (L11 and L21) induced by biodegradable poly(L-lactic acid) (PLLA) film, and the parental cells. The transforming ability of the cells was in the order A5 < A6 < L21 < L11. In all, 1176 cancer-related genes were up- or down-regulated in at least one transformant. Those that were markedly up-regulated were c-fos protooncogene, FBJ osteosarcoma oncogene B, and Jun oncogene; those markedly down-regulated were pleiotrophin, histidine triad nucleotide-binding protein, protein kinase C iota, and large multifunctional protease 7. A common function of proteins encoded by genes that underwent marked expression changes was bone formation. The genes were c-fos, FBJ osteosarcoma, Jun, pleiotrophin, a disintegrin-like and metalloprotease with TS-1 motif protein 1. This finding was consistent with the tumor formation in the 2-year PLLA or PU subcutaneous implantation into rats. The number of genes that underwent marked expression change in each transformant was consistent with its malignancy. PLLA induced more malignant transformants than PU, especially in relation to osteosarcoma-like gene expression.

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Section: Discussionmentioning

confidence: 99%

Gene expression changes in BALB/3T3 transformants induced by poly(L‐lactic acid) or polyurethane films

Matsuoka

Tsuchiya

2003

J Biomedical Materials Res

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“…The main complication of these techniques is related to the tendency of PLLA to undergo thermal degradation during processing above 180 °C (Gogolewski et al, 1993;Tsuji and Fukui, 2003;Wang and Mano, 2005). The poor thermal stability of PLLA during high processing temperatures can lead to depolymerisation and water traces can cause hydrolysis, reducing the molecular weight and affecting final product properties, including physical and mechanical properties, biodegradation ki netics and biological response (Ikarashi et al, 2000;Ghosh et al, 2007). For this reason PLLA must be sufficiently dried before its melting processing and processed at the minimum suitable temperature, to avoid excessive thermal degradation and reduce the lost of physical properties.…”

Section: Introductionmentioning

confidence: 99%

Does magnesium compromise the high temperature processability of novel biodegradable and bioresorbables PLLA/Mg composites?

Cifuentes¹,

Benavente²,

González-Carrasco³

2014

REVMETAL

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This paper addresses the influence of magnesium on melting behaviour and thermal stability of novel bioresorbable PLLA/Mg composites as a way to investigate their processability by conventional techniques, which likely will require a melt process at high temperature to mould the material by using a compression, extrusion or injection stage. For this purpose, and to avoid any high temperature step before analysis, films of PLLA loaded with magnesium particles of different sizes and volume fraction were prepared by solvent casting. DSC, modulated DSC and thermogravimetry analysis demonstrate that although thermal stability of PLLA is reduced, the temperature window for processing the PLLA/Mg composites by conventional thermoplastic routes is wide enough. Moreover, magnesium particles do not alter the crystallization behaviour of the polymer from the melt, which allows further annealing treatments to optimize the crystallinity in terms of the required combination of mechanical properties and degradation rate. RESUMEN: ¿Compromete el magnesio la procesabilidad a elevada temperatura de nuevos materiales compuestos biodegradables y biorreabsorbibles de PLLA/Mg?.Este trabajo aborda la influencia de magnesio en el comportamiento a fusión y en la estabilidad térmica de nuevos compuestos de PLLA / Mg biorreabsorbibles como una forma de investigar su procesabilidad mediante técnicas convencionales, lo que probablemente requerirá una etapa en estado fundido a alta temperatura para moldear el material mediante el uso de una etapa de compresión, extrusión o inyección. Para este fin, los materiales de PLLA cargados con partículas de magnesio, de diferentes tamaños y fracción de volumen, se prepararon por la técnica de disolución y colada, evitando así el procesado a alta temperatura antes del análisis. El análisis mediante DSC, DSC modulada y termogravimetría demuestra que, aunque la estabilidad térmica de PLLA se reduce, el intervalo de temperatura para su procesado por rutas convencionales es suficientemente amplio. Además, las partículas de magnesio no alteran la cristalización del polímero a partir del fundido, lo que permitirá optimizar el grado de cristalinidad mediante tratamientos posteriores de recocido y conseguir así una adecuada combinación de propiedades mecánicas y velocidad de degradación.

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“…Stannous 2-ethylhexanoate [Sn(Oct) 2 ] is commonly used as a catalyst in the production of poly-L-lactic acid (PLLA) and other copolymers that are implanted in cranial surgery. 1 Food dishes and trays are also made of PLLA.…”

Section: Introductionmentioning

confidence: 99%

“…1 Food dishes and trays are also made of PLLA. The toxicity of Sn(Oct) 2 has been examined in in vitro and in vivo studies. 2,3 Sn(Oct) 2 is resolved into Sn and 2-ethylhexanoic acid in the stomach.…”

Section: Introductionmentioning

confidence: 99%

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Intracerebral microinjection of stannous 2‐ethylhexanoate affects dopamine turnover in cerebral cortex and locomotor activity in rats

et al. 2008

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Stannous 2-ethylhexanoate [Sn(Oct)(2)] is used as a catalyst for production of poly-L-lactic acid and copolymers that are implanted in cranial surgery, but reports on its effects on the central nervous system are few. We examined the effects of Sn(Oct)(2) on cell viability in vitro and on neurotransmission and behavior in the rat. Treatment of normal human astrocytes with 10 mg/mL Sn(Oct)(2) reduced mitochondrial activity to 16% of the control. Injection of Sn(Oct)(2) at 6.28 mg/kg BW (2 mg/kg BW Sn) into right lateral ventricle of the rat brain tended to increase the ambulation distance after 30 days when compared with the control group. The turnover of dopamine neurotransmission was increased in the cerebral cortex. These results suggest that Sn(Oct)(2) is cytotoxic to astrocytes in vitro. Injection of Sn(Oct)(2) into the brain had no or very weak immediate neurotoxicity, but long-term exposure to Sn(Oct)(2) increased dopamine neurotransmission turnover.

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Effect of heat treatment of poly(l-lactide) on the response of osteoblast-like MC3T3-E1 cells

Cited by 27 publications

References 27 publications

Gene expression changes in BALB/3T3 transformants induced by poly(L‐lactic acid) or polyurethane films

Gene expression changes in BALB/3T3 transformants induced by poly(L‐lactic acid) or polyurethane films

Does magnesium compromise the high temperature processability of novel biodegradable and bioresorbables PLLA/Mg composites?

Intracerebral microinjection of stannous 2‐ethylhexanoate affects dopamine turnover in cerebral cortex and locomotor activity in rats

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