In vivo degradation behavior of PDC multiblock copolymers containing poly(para-dioxanone) hard segments and crystallizable poly(epsilon-caprolactone) switching segments

2009 ◽  
Vol 1190 ◽  
Author(s):  
Bernhard Hiebl ◽  
Karl Kratz ◽  
Rosemarie Fuhrmann ◽  
Friedrich Jung ◽  
Andres Lendlein ◽  
...  
Keyword(s):  
Enzymatic Degradation ◽  
Degradation Products ◽  
In Vivo Studies ◽  
Multiblock Copolymers ◽  
Degradation Behavior ◽  
Hard Segments ◽  
In Vivo Degradation ◽  
Good Agreement

AbstractThe degradation behavior of biodegradable multiblock copolymers (PDC) containing poly(p-dioxanone) hard segments (PPDO) and crystallizable poly(epsilon-caprolactone) switching segments (PCL) synthesized via co-condensation of two oligomeric macrodiols with an aliphatic diisocyanate as junction unit was explored in in vivo and in vitro experiments. The in vitro experiments for enzymatic degradation resulted that the poly(epsilon-caprolactone) segments are degraded faster, than the poly(p-dioxanone) segments. During degradation the outer layer of the test specimen becomes porous. Finally non-soluble degradation products in form of particles were found at the surface. This observation is in good agreement with the in vivo studies, where the non-soluble degradation products in the periimplantary tissues showed a diameter of 1 – 3 micron.

Comparison between three in vitro methods to measure magnesium degradation and their suitability for predicting in vivo degradation

2018 ◽  
Vol 41 (11) ◽  
pp. 772-778 ◽  
Author(s):  
Sara R Knigge ◽  
Birgit Glasmacher
Keyword(s):  
Continuous Flow ◽  
Initial Phase ◽  
Ph Value ◽  
Degradation Products ◽  
Static Condition ◽  
Degradation Behavior ◽  
Implant Material ◽  
Static Conditions ◽  
In Vivo Degradation

A lot of research has been done in the field of magnesium-based implant material. This study is focused on finding an explanation for the large disparity in results from similar experiments in literature. The hypothesis is that many different measurement protocols are used to quantify magnesium degradation and this leads to inconsistent results. Cylindrical, pure magnesium samples were used for this study. The degradation took place in revised simulated body fluid at 37°C. Hydrogen evolution was measured to quantify the degradation. Two commonly used experimental protocols were examined: static conditions and a fluid changing method. For static testing, the samples stayed in fluid. For the fluid changing method, the fluid was changed after 2 and 5 days of immersion. In addition, a new method with continuous fluid flow was established. After an initial phase, the results confirm that for all three methods, the degradation behavior differs strongly. The static condition results in a very slow degradation rate. The fluid change method leads to a similar behavior like the static condition except that the degradation was speeded up after the fluid changes. The continuous degradation is linear for a long period after the initial phase. In comparison with in vivo degradation behavior, the degradation process in continuous flow shows the best fitting. The accumulation of degradation products, especially the increasing pH value, has a strong inhibiting effect. This cannot be observed in vivo so that a constant experimental environment realizable by continuous flow is more suitable for magnesium-based implant material testing.

scholarly journals STUDIES ON ANTIGENICITY

1964 ◽  
Vol 120 (5) ◽  
pp. 955-965 ◽  
Author(s):  
Bernard B. Levine ◽  
Baruj Benacerraf
Keyword(s):  
Immune Responses ◽  
Guinea Pigs ◽  
Enzymatic Degradation ◽  
Degradation Products ◽  
Antigenic Determinants ◽  
Low Molecular Weight ◽  
Aqueous Extracts ◽  
Molecular Fragments ◽  
In Vivo Degradation

The enzymatic degradation of fluorescein conjugates of poly-L-lysine, poly-D-lysine, and exhaustively succinylated poly-L-lysine by aqueous extracts of spleens from "responder" (guinea pigs which can develop immune responses to hapten-poly-L-lysine conjugates) and "non-responder" guinea pigs was investigated. The in vivo degradation of H3-tagged dinitrophenyl conjugates of these synthetic polyamino acids was also studied by measuring urinary excretion of radioactive low molecular weight degradation products of these conjugates after their intraperitoneal injection. It was found that both responder and non-responder guinea pigs can degrade succinylated and unsuccinylated poly-L-lysine conjugates into small molecular fragments, but they cannot degrade hapten-poly-D-lysine conjugates. These studies demonstrate that in addition to the known requirements for antigenicity of macromolecules, i.e. the presence of antigenic determinants, and their capacity to be degraded by immunological tissues, the resulting degradation products must undergo certain additional, as yet unidentified, specific metabolic steps in order to induce an immune response.

scholarly journals In vivo and in vitro degradation of peptide YY3–36 to inactive peptide YY3–34 in humans

2016 ◽  
Vol 310 (9) ◽  
pp. R866-R874 ◽  
Author(s):  
Signe Toräng ◽  
Kirstine Nyvold Bojsen-Møller ◽  
Maria Saur Svane ◽  
Bolette Hartmann ◽  
Mette Marie Rosenkilde ◽  
...  
Keyword(s):  
Half Life ◽  
Peptide Yy ◽  
Degradation Products ◽  
In Vivo Studies ◽  
Metabolic Clearance ◽  
In Vitro Degradation ◽  
Healthy Men ◽  
Amino Acid Peptide

Peptide YY (PYY) is a 36-amino-acid peptide released from enteroendocrine cells upon food intake. The NH2 terminally truncated metabolite, PYY3–36, exerts anorexic effects and has received considerable attention as a possible antiobesity drug target. The kinetics and degradation products of PYY metabolism are not well described. A related peptide, neuropeptide Y, may be degraded from the COOH terminus, and in vivo studies in pigs revealed significant COOH-terminal degradation of PYY. We therefore investigated PYY metabolism in vitro after incubation in human blood and plasma and in vivo after infusion of PYY1–36 and PYY3–36 in eight young, healthy men. A metabolite, corresponding to PYY3–34, was formed after incubation in plasma and blood and during the infusion of PYY. PYY3–34 exhibited no agonistic or antagonistic effects on the Y2 receptor. PYY1–36 infused with and without coadministration of sitagliptin was eliminated with half-lives of 10.1 ± 0.5 and 9.4 ± 0.8 min (means ± SE) and metabolic clearance rates of 15.7 ± 1.5 and 14.1 ± 1.1 ml·kg−1·min−1 after infusion, whereas PYY3–36 was eliminated with a significantly longer half-life of 14.9 ± 1.3 min and a metabolic clearance rate of 9.4 ± 0.6 ml·kg−1·min−1. We conclude that, upon intravenous infusion in healthy men, PYY is inactivated by cleavage of the two COOH-terminal amino acids. In healthy men, PYY3–36 has a longer half-life than PYY1–36.

scholarly journals In vitro and in vivo degradation behavior of Mg–2Sr–Ca and Mg–2Sr–Zn alloys

2020 ◽  
Vol 5 (2) ◽  
pp. 275-285 ◽  
Author(s):  
Kai Chen ◽  
Xinhui Xie ◽  
Hongyan Tang ◽  
Hui Sun ◽  
Ling Qin ◽  
...  
Keyword(s):  
Degradation Behavior ◽  
In Vivo Degradation ◽  
Zn Alloys

Mucopeptidhydrolasen in Escherichia coli B

1963 ◽  
Vol 18 (11) ◽  
pp. 956-964 ◽  
Author(s):  
H. Pelzer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Enzymatic Degradation ◽  
Quantitative Method ◽  
Degradation Products ◽  
In Vivo Studies ◽  
Partial Purification ◽  
E Coli ◽  
Escherichia Coli B

A quantitative method for the estimation of cell wall mucopeptides and their enzymatic degradation products by paper chromatography is described. The procedure can be used for measuring the activities of mucopeptidehydrolases as well as for in vivo studies of the metabolism of cell wall mucopeptides.A partial purification of E. coli mucopeptidehydrolases was achieved by column chromatography on DEAE-Sephadex.

In vitro and in vivo degradation behavior of acetylated chitosan porous beads

2008 ◽  
Vol 19 (4) ◽  
pp. 453-466 ◽  
Author(s):  
Sung Mook Lim ◽  
Dae Kun Song ◽  
Se Heang Oh ◽  
Dong Sin Lee-Yoon ◽  
Eun Hee Bae ◽  
...  
Keyword(s):  
Degradation Behavior ◽  
Porous Beads ◽  
In Vivo Degradation

scholarly journals In Vitro Investigation on Degradable Mg-Based Biomaterial under the Impact of the Serum Glycoprotein Fetuin

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5005
Author(s):  
Heike Helmholz ◽  
Blessing Adejube ◽  
Bérengère Luthringer-Feyerabend ◽  
Regine Willumeit-Römer
Keyword(s):  
Serum Proteins ◽  
Degradation Products ◽  
Culture Conditions ◽  
Material Surface ◽  
Degradation Behavior ◽  
Immersion Medium ◽  
In Vitro Investigation ◽  
The Impact

Biomedical applications of magnesium (Mg) and its alloys are generally dependent on their degradation behavior in vivo. Despite its attractive properties, which make Mg suitable for orthopedic applications, the in vivo material-tissue (bone, blood, and lymph tissues) interaction is not yet fully understood. To investigate the influence of major serum proteins on the degradation, this study focused on fetuin, which is one of the major non-collagenous plasma proteins and which is essential for biomineralization. This study used a physiological setup to investigate the influence of fetuin on the degradation behavior of pure Mg in the presence of calcium (Ca). Extruded pure Mg samples were immersed under cell culture conditions in Hank’s balanced salt solution (HBSS) under defined Ca regimes. The results showed a significant decrease in the degradation rate (DR) when both fetuin and Ca were present in an immersion medium as compared to media where they were not simultaneously present. A possible reason for this behavior was the forming of a dense, protein-degradation products protection barrier at the material surface. Furthermore, the limitation of freely available Ca might be a reason for a decreased degradation. The cultivation of primary osteoblasts (pOB) was possible at the fetuin-coated Mg-surface without additional serum supplementation.

Studies on the in vitro and in vivo degradation behavior of amino acid derivative-based organogels

2016 ◽  
Vol 42 (11) ◽  
pp. 1732-1741 ◽  
Author(s):  
Zhen Li ◽  
Jinxu Cao ◽  
Beibei Hu ◽  
Heran Li ◽  
Hongzhuo Liu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Acid Derivative ◽  
Amino Acid Derivative ◽  
Degradation Behavior ◽  
In Vivo Degradation

In vitro and in vivo degradation behavior and the long-term performance of biodegradable PLCL balloon implants

2020 ◽  
Vol 574 ◽  
pp. 118870 ◽  
Author(s):  
Moran Haim Zada ◽  
Awanish Kumar ◽  
Omar Elmalak ◽  
Elana Markovitz ◽  
Ruthy Icekson ◽  
...  
Keyword(s):  
Degradation Behavior ◽  
Long Term Performance ◽  
Term Performance ◽  
In Vivo Degradation
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