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

Abstract

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Chiara Gualandi ◽  
Piotr Wilczek ◽  
Maria Letizia Focarete ◽  
Gianandrea Pasquinelli ◽  
Michal Kawalec ◽  
...  

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.


2015 ◽  
Vol 81 (17) ◽  
pp. 5880-5888 ◽  
Author(s):  
C. De Maesschalck ◽  
V. Eeckhaut ◽  
L. Maertens ◽  
L. De Lange ◽  
L. Marchal ◽  
...  

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.


2015 ◽  
Vol 30 (11) ◽  
pp. 1808-1819 ◽  
Author(s):  
Xin Jing ◽  
Hao-Yang Mi ◽  
Max R. Salick ◽  
Travis Cordie ◽  
Jason McNulty ◽  
...  

Abstract


MRS Advances ◽  
2019 ◽  
Vol 5 (12-13) ◽  
pp. 633-642
Author(s):  
Jun Hon Pang ◽  
Christian Wischke ◽  
Andreas Lendlein

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.


Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 700 ◽  
Author(s):  
Alyah H. Shamsah ◽  
Sarah H. Cartmell ◽  
Stephen M. Richardson ◽  
Lucy A. Bosworth

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.


2019 ◽  
Vol 136 (33) ◽  
pp. 47887 ◽  
Author(s):  
Tiantang Fan ◽  
Wuyou Ye ◽  
Beibei Du ◽  
Qin Zhang ◽  
Li Gong ◽  
...  

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