Fabrication of honeycomb-structured poly(ethylene glycol)-block-poly(lactic acid) porous films and biomedical applications for cell growth

2015 ◽  
Vol 332 ◽  
pp. 287-294 ◽  
Author(s):  
Bingjian Yao ◽  
Qingzeng Zhu ◽  
Linli Yao ◽  
Jingcheng Hao
2016 ◽  
Vol 32 (3) ◽  
pp. 225-241 ◽  
Author(s):  
Alena Pavelková ◽  
Pavel Kucharczyk ◽  
Zdenka Kuceková ◽  
Jiří Zedník ◽  
Vladimír Sedlařík

Poly(lactic acid)-based polymers are highly suitable for temporary biomedical applications, such as tissue support or drug delivery systems. Copolymers of different molecular weight based on poly(lactic acid) and poly(ethylene glycol) were prepared by polycondensation, catalysed by hydrochloric acid. A chain-extension reaction with l-lysine ethyl ester diisocyanate was employed afterwards to obtain polyester urethanes with enhanced properties. The GPC results showed that the molecular weights of the products reached about 50,000 g·mol−1 and the hydrolytic progress was rapid in the first 2 weeks; the drop in Mn equalled approximately 70%. Additionally, elemental analysis of the buffer medium proved that hydrolytic degradation was more rapid in the first stage. Tensile-strength testing revealed that ductility increased alongside reduced molecular weight of poly(ethylene glycol), also suggesting that polymer branching occurred due to side reactions of isocyanate. Based on the envisaged biomedical applications for these polymers, cytotoxicity tests were carried out and the cytotoxic effect was only moderate in the case of 100% polymer extract prepared according to ISO standard 10993-12. In their research, the authors focused on preparing metal-free, catalysed synthesis of polyester urethanes, which could prove useful to numerous biomedical applications.


2015 ◽  
Vol 133 (8) ◽  
pp. n/a-n/a ◽  
Author(s):  
Weraporn Pivsa-Art ◽  
Kazunori Fujii ◽  
Keiichiro Nomura ◽  
Yuji Aso ◽  
Hitomi Ohara ◽  
...  

Author(s):  
Mihir Sheth ◽  
R. Ananda Kumar ◽  
Vipul Dav� ◽  
Richard A. Gross ◽  
Stephen P. McCarthy

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Monika Dvořáková ◽  
Eva Rollerová ◽  
Soňa Scsuková ◽  
Alžbeta Bujňáková Mlynarčíková ◽  
Lucia Laubertová ◽  
...  

Our goal was to evaluate the potential health risk of the polymeric NP, poly(ethylene glycol)-block-poly(lactic acid) (PEG-b-PLA), from the view of redox imbalance of the organism in two different life stages. Female Wistar rats were neonatally administered intraperitoneally with PEG-b-PLA NPs [20 mg/kg of b.w. (PEG20) or 40 (PEG40) mg/kg of b.w.] from postnatal day 4 (PND4) to PND7. We measured antioxidant capacity (TEAC), level of protein carbonyls and lipoperoxides in plasma, activities of catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD) in hemolysates of infantile (sacrificed on PND17) and adult (sacrificed after PND176) rats. Compared to controls, neonatal PEG40 exposure induced a significant TEAC reduction in the infantile rats. Protein carbonyls and lipoperoxide levels were not affected after any dose of PEG-b-PLA NP administration. In adult rats, PEG20 administration caused a significant decrease of protein carbonyl levels compared to controls. In infantile rats, both doses of PEG-b-PLA NP administration increased catalase, Gpx, and SOD activities compared to controls. Surprisingly, in adult rats, the activities of Gpx and SOD decreased significantly after administration of both doses of PEG-b-PLA NPs. Obtained data indicate a possible age-related association between the oxidative status and neonatal PEG-b-PLA NP administration in female rats.


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