Some observations on radical yield in a γ-irradiated microbial copolyester

Huglin, Malcolm B.; Wormald, Paul Stuart

doi:10.1016/s0032-3861(97)80200-5

Cited by 8 publications

(3 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This suggests that the radical concentration decays rapidly after electron‐beam irradiation in an air environment and no further changes of molecular structure occur. Huglin and Wormald19 found similar results for γ ‐irradiated microbial copolyester. Luo and Netravali20 proposed bond cleavage on the hydroxybutyrate unit as the possible process for chain scission.…”

Section: Resultsmentioning

confidence: 57%

Melt Spinning of Poly(3‐hydroxybutyrate) for Tissue Engineering Using Electron‐Beam‐Irradiated Poly(3‐hydroxybutyrate) as Nucleation Agent

Vogel

Voigt

Tändler

et al. 2008

Macromolecular Bioscience

View full text Add to dashboard Cite

Electron-beam-irradiated poly(3-hydroxybutyrate) was used as a nucleating agent for poly(3-hydroxybutyrate) in a melt-spinning process. Molecular data and thermal properties of the irradiated samples were determined. The thermal properties of the nucleated melts were determined to assess the influence of the nucleation agents, and then spinning tests were carried out. Thermal and textile properties of the spun fibers were also determined. Estimations of the improvement of the crystallization in the spinline and of the inhibition of secondary crystallization in the fibers from the use of the described blood-compatible nucleation agents are given.

show abstract

Section: Resultsmentioning

confidence: 57%

Melt Spinning of Poly(3‐hydroxybutyrate) for Tissue Engineering Using Electron‐Beam‐Irradiated Poly(3‐hydroxybutyrate) as Nucleation Agent

Vogel

Voigt

Tändler

et al. 2008

Macromolecular Bioscience

View full text Add to dashboard Cite

show abstract

“…However, gamma-irradiation may cause a decrease in molecular weight which indicates random chain scission leading to generation of degradation products. 24 Some studies have also described that gamma-irradiation can significantly affect the mechanical properties of the biomaterial and increase the surface roughness that causes absence of biocompatibility. 6 In our study, there was a significant reduction of P(3HB-co-4HB) copolymer M w after gamma-irradiation but with no obvious surface changes of the copolymer (Fig.…”

Section: Discussionmentioning

confidence: 99%

Mutagenic and clastogenic characterization of poststerilized poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) copolymer biosynthesized by Delftia acidovorans

Siew

Rajab

Osman

et al. 2008

J Biomedical Materials Res

View full text Add to dashboard Cite

Polyhydroxyalkanoates (PHA) are naturally occurring biopolyesters that have great potential in the medical field. However, the leachables resulting from sterilization process of the biomaterials may exert toxic effect including genetic damage. Here, we demonstrate that although gamma-irradiation of poly(3-hydroxybutyrate-co-50 mol % 4-hydroxybutyrate) [P(3HB-co-4HB)] did not cause any change in the morphology by scanning electron microscopy, there was a significant degradation of this copolymer where the molecular weight was reduced by 37% after sterilization indicating the generation of leachables. Therefore, further investigation on the ability of the extract of this poststerilized copolymer to induce mutagenic effect was performed using Ames test (S. typhimurium strains TA1535 and TA1537) and umu test (S. typhimurium strain TA1535/pSK1002). Additionally, the capability of the extract to induce clastogenic effect was determined using Chinese hamster lung V79 fibroblast cells. Our results showed that with and without the presence of S9 metabolic activation, no mutagenic effects were observed in both Ames and umu tests when treated with P(3HB-co-4HB) extract. Similarly, treatment of P(3HB-co-4HB) extract in V79 fibroblast cells showed no significant production of micronuclei when compared with the positive control (Mitomycin C). Together, these results indicate that leachables of poststerilized P(3HB-co-4HB) cause no mutagenic and clastogenic effects.

show abstract

“…A re-examination of the radical yield in a g-irradiated microbial polyester, the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) leads to 1.7/100 eV r À1 , an adequately large value. 478 The production of water-soluble polymers exceeds 5Â10 6 tonnes per annum. Polyacrylamide, poly(acrylic acid), and their copolymers are the most important among them.…”

Section: Synthesismentioning

confidence: 99%

7 Radiation chemistry

Belloni

Delcourt

Houée-Levin⊥

et al. 2000

Annu. Rep. Prog. Chem., Sect. C

View full text Add to dashboard Cite

We try in this review to survey advances in all the aspects of Radiation Chemistry (the effects of high energy or ionizing radiation), both basic and applied, made during the period 1995^1999, after the last report issued at the end of 1994. 1 Classically, two main classes of studies are relevant. The ¢rst one includes the primary phenomena induced by the interaction of high-energy radiation with a chemical system. The way the energy is spatially deposited is indeed highly nonhomogeneous and depends on the type of radiation considered. Mutual reactions between the primary species produced also depend on their initial spatial distribution, and therefore on the energy absorption pattern. The kinetic aspects derive directly from the initial events following radiation absorption and thus, when observed at times as short as possible, give useful information on the early energy distribution for each of the radiation types, X-and g-photons, electrons and heavy particles, and, on the in£uence of their intensity and energy per particle.The second class of studies utilizes the background knowledge of radiation chemistry to generate and then to observe the fate of chemical transient species known to be involved in very important chemical or biochemical processes. Numerous data, such as the nature of reaction products, the absolute rate constants, the sequence of elementary reactions constituting a mechanism, and the thermodynamic and spectroscopic properties of short-lived species have been attained. This kind of study of transients and reaction mechanisms, which can be approached only by pulse techniques (essentially pulse radiolysis or laser photolysis, each with its speci¢c advantages), constitutes the new ¢eld of fast to ultrafast chemistry. It concerns extended domains of physical, organic, inorganic, and bio-chemistry. Moreover, the understanding of mechanisms is quite helpful in suggesting new ways of synthesis or degradation induced by irradiation and is now extensively used in developing various speci¢c processes in applied chemistry. The number of studies on the chemical mechanisms and in applied radiation chemistry constitutes an increased fraction of the total publications in radiation chemistry, which we estimate to be around 4000 over the period considered (almost constant compared to the preceding 5-year

show abstract

Some observations on radical yield in a γ-irradiated microbial copolyester

Cited by 8 publications

References 13 publications

Melt Spinning of Poly(3‐hydroxybutyrate) for Tissue Engineering Using Electron‐Beam‐Irradiated Poly(3‐hydroxybutyrate) as Nucleation Agent

Melt Spinning of Poly(3‐hydroxybutyrate) for Tissue Engineering Using Electron‐Beam‐Irradiated Poly(3‐hydroxybutyrate) as Nucleation Agent

Mutagenic and clastogenic characterization of poststerilized poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) copolymer biosynthesized by Delftia acidovorans

7 Radiation chemistry

Contact Info

Product

Resources

About