scholarly journals Accelerated Degradation of polymeric surgical suture materials

2020 ◽  
Vol 6 (3) ◽  
pp. 458-460
Author(s):  
Thomas Reske ◽  
Thomas Eickner ◽  
Niels Grabow ◽  
Klaus-Peter Schmitz ◽  
Stefan Siewert
Keyword(s):  
Molecular Weight ◽  
Mass Loss ◽  
Glycolic Acid ◽  
Medical Implants ◽  
Suture Materials ◽  
Degradable Polymer ◽  
Accelerated Degradation ◽  
Surgical Suture

AbstractThe degradable polymer Polydioxanone (PDO) is used for medical implants since 1981. Manufacturers state a degradation timeframe of <180 days or an absorption duration of 182-238 days [1, 2]. Aim of this study was to find in vitro-conditions to degrade PDO films within four weeks. Therefore the degradation of PDO was performed in accelerated conditions in tempered alkaline glycine NaOH buffer. Molecular weight and mass loss were studied. PDO results were compared with poly lactic-co-glycolic acid P(LLA-co-GA).

A Novel Biodegradable Poly(Lactic-Co-Glycolic Acid) Foam for Bone Regeneration

1993 ◽  
Vol 331 ◽  
Author(s):  
Robert C. Thomson ◽  
Michael J. Yaszemski ◽  
John M. Powers ◽  
Antonios G. Mikos
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Composite Material ◽  
Bone Regeneration ◽  
Pore Size ◽  
Glycolic Acid ◽  
Average Molecular Weight ◽  
Gelatin Microspheres ◽  
Degradable Polymer ◽  
Biodegradable Poly

AbstractWe present a novel method for manufacturing three-dimensional, biodegradable poly(DL-lactic-co-glycolic acid) (PLGA) foam scaffolds for use in bone regeneration. The technique involves the formation of a composite material consisting of gelatin microspheres surrounded by a PLGA matrix. The gelatin microspheres are leached out leaving an open-cell foam with a pore size and morphology defined by the gelatin microspheres. The foam porosity can be controlled by altering the volume fraction of gelatin used to make the composite material. PLGA 50:50 was used as a model degradable polymer to establish the effect of porosity, pore size, and degradation on foam mechanical properties. The compressive strengths and moduli of PLGA 50:50 foams were found to decrease with increasing porosity but were largely unaffected by pore size. Foams with compressive strengths up to 2.5 MPa were manufactured. From in vitro degradation studies we established that for PLGA 50:50 foams the mechanical properties declined in parallel with the decrease in molecular weight. Below a weight average molecular weight of 10,000 the foam had very little mechanical strength (0.02 MPa). These results indicate that PLGA 50:50 would not be suitable as a scaffold material for bone regeneration. However, the dependence of mechanical properties on porosity, pore size, and degree of degradation which we have determined will aid us in designing a PLGA foam (with a comonomer ratio other than 50:50) suitable for bone regeneration.

IN VITRO AND IN VIVO DEGRADATION OF A TWISTED SILK FIBROIN–POLY(LACTIC-CO-GLYCOLIC ACID) FIBER COMPOSITE ROPE-LIKE SCAFFOLD AND CHANGES IN ITS MECHANICAL PROPERTIES

2016 ◽  
Vol 16 (04) ◽  
pp. 1650053
Author(s):  
WENYUAN ZHANG ◽  
YADONG YANG ◽  
KEJI ZHANG ◽  
YING LI ◽  
GUOJIAN FANG
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tissue Engineering ◽  
Mass Loss ◽  
Silk Fibroin ◽  
Glycolic Acid ◽  
Property Loss ◽  
In Vivo Degradation

Natural silk fibroin fiber is slowly degraded, which makes it difficult to be replaced quickly by regenerating tissues of tissue engineering. We used poly(lactic-co-glycolic acid) (PLGA, lactic acid:glycolic acid [Formula: see text] 10:90) fibers to adjust the overall degradation rate of the scaffolds. This study fabricated a three-strand helical composite rope-like scaffold from silk fibroin and PLGA fibers (silk fibroin:PLGA [Formula: see text] 36:64) using a twisting method. In vitro and in vivo degradation experiments were performed over 16 weeks. Results suggest that the in vitro and in vivo degradation tendencies of the scaffold were similar, with mass loss lagging behind mechanical property loss. The speed of degradation in vivo was faster than that in vitro. Mechanical property loss of the scaffold was fast during the first three weeks, when mass loss was slow. Mass loss rate accelerated from weeks 3 to 8. The mass and mechanical properties were relatively stable from 8 to 16 weeks. After 16 weeks of degradation, the scaffold still had considerably strong mechanical properties. The scaffold showed a reasonable and suitable degradation speed with good histocompatibility for ligament tissue engineering.

scholarly journals More Precise Control of the In Vitro Enzymatic Degradation via Ternary Self-Blending of High/Medium/Low Molecular Weight Poly(trimethylene carbonate)

2021 ◽  
Vol 8 ◽  
Author(s):  
Guiyang Cai ◽  
Zhipeng Hou ◽  
Peng Li ◽  
Wei Sun ◽  
Jing Guo ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Mass Loss ◽  
Enzymatic Degradation ◽  
Degradation Rate ◽  
Low Molecular Weight ◽  
Mass Ratio ◽  
Trimethylene Carbonate ◽  
Precise Control ◽  
Degradation Rate Constant

To more precisely control the degradation rate of poly(trimethylene carbonate) (PTMC), self-blending films were prepared via the ternary self-blending of pure PTMC with a molecular weight of 334, 152, and 57 kg/mol. The in vitro enzymolysis degradation of the ternary self-blending films was performed in lipase solutions. The results showed that ternary self-blending could control the degradation of PTMC by adjusting the mass ratio of high/medium/low molecular weight PTMC in the composition, and the PTMC334/PTMC152/PTMC57 films with a mass ratio of 1/4/16 showed mass loss of 85.96% after seven weeks of degradation, while that of PTMC334/PTMC152/PTMC57 films with a mass ratio of 1/1/1 was 96.39%. The former and latter’s degradation rate constant was 13.263 and 23.981%/w, respectively, and the former presented better morphology stability than the latter. The strategy of ternary self-blending could simultaneously bestow PTMC with a lower degradation rate and good morphology stability, indicating that ternary self-blending is an efficient way to control the degradation performance of PTMC more precisely.

scholarly journals N-Acetyl-D-Glucosamine-Loaded Chitosan Filaments Biodegradable and Biocompatible for Use as Absorbable Surgical Suture Materials

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1807 ◽  
Author(s):  
Milena Costa da Silva ◽  
Henrique Nunes da Silva ◽  
Rita de Cássia Alves Leal Cruz ◽  
Solomon Kweku Sagoe Amoah ◽  
Suédina Maria de Lima Silva ◽  
...  
Keyword(s):  
Uniaxial Tensile ◽  
Mechanical Resistance ◽  
Prolonged Release ◽  
Absorbable Suture ◽  
Suture Materials ◽  
Release Process ◽  
Uniaxial Tensile Testing ◽  
Surgical Suture ◽  
Cytotoxicity Studies

The aim of this study was to prepare chitosan (CS) filaments incorporated with N-acetyl-D-Glucosamine (GlcNAc), using the wet spinning method, in order to combine the GlcNAc pharmacological properties with the CS biological properties for use as absorbable suture materials. The filaments were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), uniaxial tensile testing, in vitro biodegradation, and through in vitro drug release and cytotoxicity studies. It was observed that the addition of GlcNAc did not alter the morphology of the filaments. The CS and CS/GlcNAc filaments presented diameters 145 µm and 148 µm, respectively, and the surfaces were homogeneous. Although the mechanical resistance of the chitosan filaments decreased with the incorporation of the GlcNAc drug, this property was greater than the mean values indicated in the U.S. Pharmacopeia (1.7 N) for suture number 6-0 (filament diameter of 100–149 μm). The biodegradation of the CS filaments was accelerated by the addition of GlcNAc. After 35 days, the CS/GlcNAc filaments degradability was at its total, and for the CS filaments it was acquired in 49 days. The in vitro kinetic of the release process was of the zero-order and Hopfenberg models, controlled by both diffusion and erosion process. The in vitro cytotoxicity data of the CS and CS/GlcNAc filaments toward L929 cells showed that these filaments are nontoxic to these cells. Thus, the GlcNAc-loaded CS filaments might be promising as absorbable suture materials. In addition, this medical device may be able to enhance healing processes, relieve pain, and minimize infection at the surgery site due the prolonged release of GlcNAc.

MECHANICAL PROPERTIES OF ELECTROSPUN PCL SCAFFOLD UNDER IN VITRO AND ACCELERATED DEGRADATION CONDITIONS

2014 ◽  
Vol 26 (03) ◽  
pp. 1450043 ◽  
Author(s):  
Alexandra Løvdal ◽  
Jakob Vange ◽  
Lene Feldskov Nielsen ◽  
Kristoffer Almdal
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Molecular Weight ◽  
Elastic Modulus ◽  
No Reduction ◽  
Biodegradable Scaffold ◽  
Accelerated Degradation ◽  
Degradation Time ◽  
Over Time

Within recent years, researchers have looked into using polycaprolactone (PCL) as a synthetic biodegradable scaffold for tissue engineering purposes. This study investigated the mechanical properties of an electrospun PCL, while being exposed to physiological fluids at 37°C (in vitro conditions) with and without the influence of cell in-growth. The molecular weight and mechanical properties were monitored during the degradation. Incubation in physiological fluids for 3–16 weeks showed an improvement in mechanical properties and no reduction in molecular weight. It was also shown that cells did not deteriorate the mechanical properties of PCL after 16 weeks. The viability of the cells decreased over time, however, without influencing the mechanical properties of the scaffold. A relation between reduction in molecular weight and the mechanical properties of electrospun PCL was seen between 2–29 days in buffer (pH 12). The accelerated study showed a linear decrease in both elastic modulus and yield stress as a function of degradation time.

In vitro cytotoxic and immunomodulative activities of low molecular weight ι-carageenans partially methylated and pyruvated

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
S Bondu ◽  
E Deslandes ◽  
MS Fabre ◽  
C Berthou ◽  
G Yu
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Partially Methylated

Dermatan Sulfate and LMW Heparin Enhance the Anticoagulant Action of Activated Protein C

1999 ◽  
Vol 82 (11) ◽  
pp. 1462-1468 ◽  
Author(s):  
José Fernández ◽  
Jari Petäjä ◽  
John Griffin
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Protein C ◽  
Dermatan Sulfate ◽  
Anticoagulant Activity ◽  
Activated Protein C ◽  
Factor V ◽  
Factor Va ◽  
Anticoagulant Action

SummaryUnfractionated heparin potentiates the anticoagulant action of activated protein C (APC) through several mechanisms, including the recently described enhancement of proteolytic inactivation of factor V. Possible anticoagulant synergism between APC and physiologic glycosaminoglycans, pharmacologic low molecular weight heparins (LMWHs), and other heparin derivatives was studied. Dermatan sulfate showed potent APC-enhancing effect. Commercial LMWHs showed differing abilities to promote APC activity, and the molecular weight of LMWHs correlated with enhancement of APC activity. Degree of sulfation of the glycosaminoglycans influenced APC enhancement. However, because dextran sulfates did not potentiate APC action, the presence of sulfate groups per se on a polysaccharide is not sufficient for APC enhancement. As previously for unfractionated heparin, APC anticoagulant activity was enhanced by glycosaminoglycans when factor V but not factor Va was the substrate. Thus, dermatan sulfate and LMWHs exhibit APC enhancing activity in vitro that could be of physiologic and pharmacologic significance.

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