The effect of melt-processing on the degradation of selected polyhydroxyacids: polylactides, polyhydroxybutyrate, and polyhydroxybutyrate-co-valerates

Gogolewski, Sylwester; Jovanović, Miodrag; Perren, Stephan M.; Dillon, J. G.; Hughes, Minerva

doi:10.1016/0141-3910(93)90137-8

Cited by 151 publications

(83 citation statements)

References 16 publications

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“…One of the most important factors that influences the properties of aliphatic polyesters is the molecular weight, with high molecular weight materials generally having better mechanical properties. In this work, we sought to optimize the conditions for synthesizing high molar mass PLDLA-TMC 30,31 .…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of a novel terpolymer based on L-lactide, D,L-lactide and trimethylene carbonate

Motta

Duek

2014

Mat. Res.

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Terpolymers of L-lactide, D,L-lactide and trimethylene carbonate (TMC) were synthesized via the ring-opening polymerization reaction for cyclic monomers using stannous octoate as the initiator at a ratio of ~0.05 mol% (monomers/(SnOct) 2 ). Synthesis was done at 130 °C for 48 h. The inclusion of TMC, an aliphatic elastomeric polycarbonate, alongside polymer chain segments containing L-lactide and D,L-lactide, was expected to yield a material with improved properties such as increased elongation; this would overcome the limitation of copolymers consisting entirely of lactide and D,L-lactide. The terpolymer properties were assessed by Nuclear magnetic resonance spectroscopy 1 H and 13 C NMR, infrared spectroscopy, differential scanning calorimetry and thermogravimetry, with particular attention being given to the effect of TMC on the copolymer of L-lactide-co-D,L-lactide. The mixing of these polymers resulted in material with a high molar mass (10 5 g/mol). The mechanical properties of the terpolymer were assessed using pins of this material that were tested by mechanical flexion at three points. When compared with results for the copolymer PLDLA there was a decrease in Young's modulus for the TMC-containing terpolymer.

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Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of a novel terpolymer based on L-lactide, D,L-lactide and trimethylene carbonate

Motta

Duek

2014

Mat. Res.

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“…em outros estudos em coelhos, pois apresenta uma maior massa molar e isso possibilita essa melhora nos parâmetros citados [11,16,17] . O uso do polímero PLDLA-TMC como protetor da área de sutura do tendão, proporcionou uma melhor cicatrização, ou seja, melhor organização das fibras colágenas e menor aderência que foi avaliada macro e microscopicamente.…”

Section: Tabelaunclassified

Membrana de PLDLA-TMC como Protetor na Regeneração do Tendão Calcâneo. Estudo in Vivo em Coelhos

Duek¹,

Riquetto²,

Jesus³

et al. 2014

Polímeros

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Resumo: Um dos maiores problemas da cirurgia restauradora dos tendões flexores é evitar a formação de aderências, pois limita seu deslizamento. Assim, é muito desejável que a cicatrização ocorra o mais rápido possível, restaurando a capacidade de deslizamento dos tendões, sem limitações dos movimentos. O objetivo deste trabalho foi analisar a resistência do Tendão calcâneo, utilizando membrana de PLDLA-TMC como protetor da aderência dos tecidos adjacentes após implantes em coelhos New Zeland. Foram utilizados 20 coelhos, divididos em dois grupos, os quais foram submetidos à secção do tendão calcâneo e posterior sutura com técnica de Kessler modificada. No grupo A, logo após sutura o animal foi sacrificado e o tendão foi enviado para ensaio mecânico. Já no grupo B, após três semanas, os animais foram sacrificados e o material foi submetido à análise histológica. Os resultados obtidos a partir do ensaio mecânico mostraram melhora nos valores da resistência à tração dos implantes com a membrana, comparados aos apenas suturados. Na cicatrização da lesão, ocorreu melhor organização das fibras colágenas quando foi utilizado o polímero PLDLA-TMC, além de uma menor aderência cicatricial. Conclui-se que a membrana de PLDLA-TMC é promissora na reparação de lesões tendíneas. Palavras-chave: Terpolimeo, PLDLA-TMC, tendão, reparo. Membrane PLDLA-TMC as Shield Regeneration in the Calcaneal Tendon. Study in Live RabbitsAbstract: The most common problem in reconstructive surgery of the flexor tendons is prevent adhesion formation by limiting its movement. Thus, it is very desirable that healing occurs as quick as possible, restoring tendons sliding capability, without limitation of movement. The objective of this study was to analyze the strength of the Achilles tendon, using PLDLA-TMC membrane as protector of the adhesion of adjacent tissues implanted in New Zealand rabbits. Twenty rabbits were used, divided into two groups, which were submitted to the section of the Achilles tendon and posterior suture with modified Kessler technique. In group A, after suturing, the animals were sacrificed and the tendon was sent for mechanical tests. In group B, after three weeks, the animals were sacrificed and the material was subjected to histological analysis. The results of the mechanical tests showed improvement in the values of the tensile strength of the implants with the membrane, compared to the sutured ones. In the injury healing process, better organization of collagen fibers occurred when the PLDLA-TMC polymer was used, and a smaller scar tissue adhesion was developed. In conclusion, the PLDLA-TMC membrane is promising in the repair of tendon injures. Keywords: Terpolymer, PLDLA-TMC, tendon, repair. IntroduçãoOs tendões constituem a unidade do sistema musculoesquelético que transmite a força do músculo ao osso [1,2] . Sua arquitetura permite o suporte de grandes tensões, e a transmissão da força gerada durante a contração muscular ao osso, para a realização dos movimentos [3] . O tendão é constituído por fibroblastos e intermedi...

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“…Medullary augmentation devices (10 × 120 mm) were meltextruded from poly(L-lactide) (PLLA) [3,4,9,10,17]. The PMMA used cement was Palacos (Essex Chemie AG, Lucerne).…”

Section: Methodsmentioning

confidence: 99%

The use of a resorbable augmentation device to secure plating of osteoporotic bones

Mainil‐Varlet

Cordey

Landolt

et al. 1997

International Orthopaedics

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The effect of melt-processing on the degradation of selected polyhydroxyacids: polylactides, polyhydroxybutyrate, and polyhydroxybutyrate-co-valerates

Cited by 151 publications

References 16 publications

Synthesis and characterization of a novel terpolymer based on L-lactide, D,L-lactide and trimethylene carbonate

Synthesis and characterization of a novel terpolymer based on L-lactide, D,L-lactide and trimethylene carbonate

Membrana de PLDLA-TMC como Protetor na Regeneração do Tendão Calcâneo. Estudo in Vivo em Coelhos

The use of a resorbable augmentation device to secure plating of osteoporotic bones

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