Photocurable Liquid Biodegradable Copolymers:  In Vitro Hydrolytic Degradation Behaviors of Photocured Films of Coumarin-Endcapped Poly(ε-caprolactone-co-trimethylene carbonate)

2002 ◽  
Vol 3 (2) ◽  
pp. 249-255 ◽  
Author(s):  
Manabu Mizutani ◽  
Takehisa Matsuda
Keyword(s):  
Hydrolytic Degradation ◽  
Trimethylene Carbonate ◽  
Biodegradable Copolymers ◽  
Degradation Behaviors

scholarly journals Hydrolytic Degradation of Comb-Like Graft Poly (Lactide-co-Trimethylene Carbonate): The Role of Comonomer Compositions and Sequences

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2024
Author(s):  
Xuefei Leng ◽  
Wenwen Zhang ◽  
Yiying Wang ◽  
Yanshai Wang ◽  
Xiaoqing Li ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Hydrolytic Degradation ◽  
Gel Permeation Chromatography ◽  
Random Copolymers ◽  
Degradation Behavior ◽  
Weight Retention ◽  
Trimethylene Carbonate ◽  
Degradation Rates ◽  
Degradation Behaviors ◽  
Property Changes

The effect of sequence on copolymer properties is rarely studied, especially the degradation behavior of the biomaterials. A series of linear-comb block, gradient, random copolymers were successfully achieved using hydroxylated polybutadiene as the macroinitiator by simple ring-opening polymerization of l-lactide (l-LA) and 1,3-trimethylene carbonate (TMC). The hydrolytic degradation behaviors of the copolymers were systemically evaluated by using nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), differential scanning calorimeter (DSC), and scanning electron microscopy (SEM) to illustrate the influences of comonomer compositions and sequence structures. The linear-comb block copolymers (lcP(TMC-b-LLA)) with different compositions had different degradation rates, which increased with l-LA content. Thermal property changes were observed with decreased Tm and increased ΔHm in all block copolymers during the degradation. To combine different sequence structures, unique degradation behaviors were observed for the linear-comb block, gradient and random copolymers even with similar comonomer composition. The degradation rates of linear-comb PLLA-gradient-PTMC (lcP(LLA-grad-TMC)) and linear-comb PLLA-random-PTMC (lcP(LLA-ran-TMC)) were accelerated due to the loss of regularity and crystallinity, resulting in a remarkable decrease on weight retention and molar mass. The hydrolysis degradation rate increased in the order lcP(TMC-b-LLA), lcP(LLA-ran-TMC), lcP(LLA-grad-TMC). Therefore, the hydrolytic degradation behavior of comb-like graft copolymers depends on both the compositions and the sequences dramatically.

Effects of poly(para-dioxanone-co-L-lactide) on the in vitro hydrolytic degradation behaviors of poly(L-lactide)/poly(para-dioxanone) blends

2015 ◽  
Vol 30 (6) ◽  
pp. 860-868
Author(s):  
Xulong Xie ◽  
Wei Bai ◽  
Congming Tang ◽  
Dongliang Chen ◽  
Chengdong Xiong
Keyword(s):  
Hydrolytic Degradation ◽  
Degradation Behaviors ◽  
Image Position

Abstract

Bioresorbable electrospun nanofibrous scaffolds loaded with bioactive molecules

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Chiara Gualandi ◽  
Piotr Wilczek ◽  
Maria Letizia Focarete ◽  
Gianandrea Pasquinelli ◽  
Michal Kawalec ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Degradation Kinetics ◽  
Hydrolytic Degradation ◽  
Mesenchymal Cells ◽  
Bioactive Molecules ◽  
Differential Interference Contrast Microscopy ◽  
Electrospinning Technique ◽  
Ki 67 ◽  
Nanofibrous Scaffolds

AbstractElectrospinning technology is used to fabricate sub-micrometric fiber mats made of a random equimolar poly(lactide-co-glycolide) copolymer (PLGA), whose in vitro hydrolytic degradation kinetics is investigated over a period of 49 days in phosphate buffer at 37 °C. The PLGA mats show a decrease of molecular weight (by GPC) from the very beginning of the experiment, whereas a macroscopic weight loss from the samples is appreciated (by gravimetry) only after 20 days of buffer exposure. The molar mass distribution curves remain monomodal during the degradation experiment suggesting that no acid auto-catalyzed hydrolysis, commonly observed in bulk specimens, occurs in sub-micrometric PLGA fibers. PLGA scaffolds containing Endothelial Growth Factor Supplement (ECGS) were also fabricated by electrospinning, from ECGS-containing polymer solutions. Mesenchymal cells derived from human bone marrow mononuclear cells were cultured in the presence of such ECGS-loaded PLGA scaffolds. Flow cytometry and Differential Interference Contrast microscopy were used to characterize the cell cultures over a 7 day period. The results of AnexinV/PI staining and of intranuclear Ki-67 protein expression show, together with concomitant cell morphology modifications, that growth factors released from the scaffolds support the survival, proliferation and growth of the mesenchymal cells. This result demonstrates that ECGS maintains its bioactivity upon release from the electrospun fibers and shows the versatility of the electrospinning technique.

scholarly journals Effects of Xylo-Oligosaccharides on Broiler Chicken Performance and Microbiota

2015 ◽  
Vol 81 (17) ◽  
pp. 5880-5888 ◽  
Author(s):  
C. De Maesschalck ◽  
V. Eeckhaut ◽  
L. Maertens ◽  
L. De Lange ◽  
L. Marchal ◽  
...  
Keyword(s):  
Broiler Chickens ◽  
Degradation Products ◽  
Hydrolytic Degradation ◽  
Feed Additives ◽  
Gut Health ◽  
Feed Conversion ◽  
Content Type ◽  
Beneficial Effects ◽  
Coa Transferase

ABSTRACTIn broiler chickens, feed additives, including prebiotics, are widely used to improve gut health and to stimulate performance. Xylo-oligosaccharides (XOS) are hydrolytic degradation products of arabinoxylans that can be fermented by the gut microbiota. In the current study, we aimed to analyze the prebiotic properties of XOS when added to the broiler diet. Administration of XOS to chickens, in addition to a wheat-rye-based diet, significantly improved the feed conversion ratio. XOS significantly increased villus length in the ileum. It also significantly increased numbers of lactobacilli in the colon andClostridiumcluster XIVa in the ceca. Moreover, the number of gene copies encoding the key bacterial enzyme for butyrate production, butyryl-coenzyme A (butyryl-CoA):acetate CoA transferase, was significantly increased in the ceca of chickens administered XOS. In this group of chickens, at the species level,Lactobacillus crispatusandAnaerostipes butyraticuswere significantly increased in abundance in the colon and cecum, respectively.In vitrofermentation of XOS revealed cross-feeding betweenL. crispatusandA. butyraticus. Lactate, produced byL. crispatusduring XOS fermentation, was utilized by the butyrate-producingAnaerostipesspecies. These data show the beneficial effects of XOS on broiler performance when added to the feed, which potentially can be explained by stimulation of butyrate-producing bacteria through cross-feeding of lactate and subsequent effects of butyrate on gastrointestinal function.

In vitro Degradation Analysis of 3D-architectured Gelatin-based Hydrogels

MRS Advances ◽  
2019 ◽  
Vol 5 (12-13) ◽  
pp. 633-642
Author(s):  
Jun Hon Pang ◽  
Christian Wischke ◽  
Andreas Lendlein
Keyword(s):  
Rational Design ◽  
Loss Modulus ◽  
Hydrolytic Stability ◽  
Hydrolytic Degradation ◽  
Chemical Properties ◽  
In Vitro Models ◽  
Polypeptide Backbone ◽  
Tan Δ ◽  
Physical And Chemical

ABSTRACT:Multifunctional biopolymer-based materials are promising candidates for next generation regenerative biomaterials. Understanding the degradation behavior of biomaterials is vital for ensuring biological safety, as well as for better control of degradation properties based on rational design of a material’s physical and chemical characteristics. In this study, we decipher the degradation of a hydrogel prepared from gelatin and lysine diisocyanate ethyl ester (LDI) using in vitro models, which simulate hydrolytic, oxidative and enzymatic degradation (collagenase). Gravimetrical, morphological, mechanical and chemical properties were evaluated. Notably, the hydrogels were relatively resistant to hydrolytic degradation, but degraded rapidly within 21 days (>95% mass loss) under oxidative and collagenase degradation. Oxidative and collagenase degradation rapidly decreased the storage and loss modulus of the hydrogels, and slightly increased their viscous component (tan δ). For each degradation condition, the results suggest different possible degradation pathways associated to the gelatin polypeptide backbone, urea linkages and ester groups. The primary degradation mechanisms for the investigated gelatin based hydrogels are oxidative and enzymatic in nature. The relative hydrolytic stability of the hydrogels should ensure minimal degradation during storage and handling prior to application in surgical theatres.

scholarly journals Membranes for Modelling Cardiac Tissue Stiffness In Vitro Based on Poly(trimethylene carbonate) and Poly(ethylene glycol) Polymers

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 274 ◽  
Author(s):  
Iris Allijn ◽  
Marcelo Ribeiro ◽  
André Poot ◽  
Robert Passier ◽  
Dimitrios Stamatialis
Keyword(s):  
Ethylene Glycol ◽  
Human Heart ◽  
Cardiac Tissue ◽  
Heart Tissue ◽  
Trimethylene Carbonate ◽  
Tissue Stiffness ◽  
Poly Ethylene Glycol ◽  
Young’S Moduli ◽  
Poly Ethylene

Despite the increased expenditure of the pharmaceutical industry on research and development, the number of drugs for cardiovascular diseases that reaches the market is decreasing. A major issue is the limited ability of the current in vitro and experimental animal models to accurately mimic human heart disease, which hampers testing of the efficacy of potential cardiac drugs. Moreover, many non-heart-related drugs have severe adverse cardiac effects, which is a major cause of drugs’ retraction after approval. A main hurdle of current in vitro models is their inability to mimic the stiffness of in vivo cardiac tissue. For instance, poly(styrene) petri dishes, which are often used in these models, have a Young’s modulus in the order of GPa, while the stiffness of healthy human heart tissue is <50 kPa. In pathological conditions, such as scarring and fibrosis, the stiffness of heart tissue is in the >100 kPa range. In this study, we focus on developing new membranes, with a set of properties for mimicry of cardiac tissue stiffness in vitro, based on methacrylate-functionalized macromers and triblock-copolymers of poly(trimethylene carbonate) and poly(ethylene glycol). The new membranes have Young’s moduli in the hydrated state ranging from 18 kPa (healthy tissue) to 2.5 MPa (pathological tissue), and are suitable for cell contraction studies using human pluripotent stem-cell-derived cardiomyocytes. The membranes with higher hydrophilicity have low drug adsorption and low Young’s moduli and could be suitable for drug screening applications.

The in vitro enzymatic degradation of poly(trimethylene carbonate-co-2, 2′-dimethyltrimethylene carbonate)

2019 ◽  
Vol 112 ◽  
pp. 51-59 ◽  
Author(s):  
Zhipeng Hou ◽  
Wei Zhang ◽  
Jing Guo ◽  
Zhangpei Chen ◽  
Jianshe Hu ◽  
...  
Keyword(s):  
Enzymatic Degradation ◽  
Trimethylene Carbonate

scholarly journals Material Characterization of PCL:PLLA Electrospun Fibers Following Six Months Degradation In Vitro

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 700 ◽  
Author(s):  
Alyah H. Shamsah ◽  
Sarah H. Cartmell ◽  
Stephen M. Richardson ◽  
Lucy A. Bosworth
Keyword(s):  
Tissue Regeneration ◽  
Annulus Fibrosus ◽  
Hydrolytic Degradation ◽  
Electrospun Nanofibers ◽  
Polymer Chains ◽  
Poly Lactic Acid ◽  
Fiber Morphology ◽  
Phosphate Buffered Saline

The annulus fibrosus—one of the two tissues comprising the intervertebral disc—is susceptible to injury and disease, leading to chronic pain and rupture. A synthetic, biodegradable material could provide a suitable scaffold that alleviates this pain and supports repair through tissue regeneration. The transfer of properties, particularly biomechanical, from scaffold to new tissue is essential and should occur at the same rate to prevent graft failure post-implantation. This study outlines the effect of hydrolytic degradation on the material properties of a novel blend of polycaprolactone and poly(lactic acid) electrospun nanofibers (50:50) over a six-month period following storage in phosphate buffered saline solution at 37 °C. As expected, the molecular weight distribution for this blend decreased over the 180-day period. This was in line with significant changes to fiber morphology, which appeared swollen and merged following observation using Scanning Electron Microscopy. Similarly, hydrolysis resulted in considerable remodeling of the scaffolds’ polymer chains as demonstrated by sharp increases in percentage crystallinity and tensile properties becoming stiffer, stronger and more brittle over time. These mechanical data remained within the range reported for human annulus fibrosus tissue and their long-term efficacy further supports this novel blend as a potential scaffold to support tissue regeneration.

Effect of segment structures on the hydrolytic degradation behaviors of totally degradable poly(L‐lactic acid)‐based copolymers

2019 ◽  
Vol 136 (33) ◽  
pp. 47887 ◽  
Author(s):  
Tiantang Fan ◽  
Wuyou Ye ◽  
Beibei Du ◽  
Qin Zhang ◽  
Li Gong ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Hydrolytic Degradation ◽  
Degradation Behaviors
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