Highly Oriented Electrospun Fibers of Self-Assembled Inclusion Complexes of Poly(ethylene oxide) and Urea

2006 ◽  
Vol 39 (26) ◽  
pp. 8886-8888 ◽  
Author(s):  
Yang Liu ◽  
Christian Pellerin
2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yong Liu ◽  
Xia Yu ◽  
Jia Li ◽  
Jie Fan ◽  
Meng Wang ◽  
...  

High-content keratin/poly (ethylene oxide) (PEO) (90/10) blend nanofibers were prepared by electrospinning combined with a two-step cross-linking process. The keratin/PEO aqueous solution was firstly mixed with ethylene glycol diglycidyl ether (EGDE) as cross-linker and then electrospun into nanofibers. The resulting nanofibrous mats were cross-linked with EGDE vapor to decrease the solubility of nanofibers in water. The morphologies and properties of electrospun fibers were investigated by SEM, FTIR, TG, XRD, and contact angle testing, respectively. The results showed that the morphologies of nanofibers were uniform at the fiber average diameter of 300 nm with negligible bead defects by adding EGDE to keratin/PEO solutions. The cross-linking results showed that EGDE vapor could improve the hydrophobic property of blended nanofibers. The crystallinity of the keratin/PEO blend nanofiber mat increased from 13.14% for the uncross-linked sample to 21.54% and 35.15% for the first cross-linked and second cross-linked samples, respectively. Free defect nanofiber mats with high keratin content producing from this two-step cross-linking process are particularly promising for tissue engineering and cell-seeded scaffold.


2019 ◽  
Vol 136 (19) ◽  
pp. 47479 ◽  
Author(s):  
Jaderson de A. B. Barbosa ◽  
Chirles A. de França ◽  
João José de S. Gouveia ◽  
Gisele V. Gouveia ◽  
Mateus M. da Costa ◽  
...  

2016 ◽  
Vol 133 (44) ◽  
Author(s):  
Samira Aslanzadeh ◽  
Behzad Ahvazi ◽  
Yaman Boluk ◽  
Cagri Ayranci

1991 ◽  
Vol 237 ◽  
Author(s):  
Kevin L. Prime ◽  
George M. Whttesides

ABSTRACTSelf-assembled monolayers (SAMs) of functionalized alkanethiolates on gold are a well-characterized system for studying the interfacial properties of organic materials. We have used SAMs as models for the surfaces of organic polymers and used mem to study the adsorption of proteins onto organic materials. We have formed SAMs from mixtures of alkanethiols in which one alkanethiol is hydrophobic and the other is terminated by a short (2 ≤ n ≤ 17) oligomer of poly(ethylene oxide). These “mixed” SAMs effectively resist the adsorption of fibrinogen from moderately concentrated (1 mg/mL) solutions. Protein adsorption begins when < 5% of the accessible area of the surface consists of hydrophobic groups. These findings suggest that real protein-resistant monolayers must present an almost defect-free surface of oligo(ethylene oxide) groups in order to eliminate adsorption.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1033
Author(s):  
Sams M. A. Sadat ◽  
Mohammad Reza Vakili ◽  
Igor M. Paiva ◽  
Michael Weinfeld ◽  
Afsaneh Lavasanifar

The clinical use of 7-ethyl-10-hydroxy-camptothecin (SN-38), which is the active metabolite of irinotecan, has been hampered because of its practical water-insolubility. In this study, we successfully synthesized two self-associating SN-38-polymer drug conjugates to improve the water-solubility of SN-38, while retaining its anticancer activity. The polymeric micellar SN-38 conjugates were composed of either methoxy-poly(ethylene oxide)-block-poly(α-benzyl carboxylate-ε-caprolactone) conjugated to SN-38 at the PBCL end (mPEO-b-PBCL/SN-38) or mPEO-block-poly(α-carboxyl-ε-caprolactone) attached to SN-38 from the pendent-free carboxyl site (mPEO-b-PCCL/SN-38). The chemical structure of block copolymers was confirmed by 1H NMR. The physicochemical characterizations of their self-assembled structures including size, surface charge, polydispersity, critical micellar concentration, conjugation content and efficiency, morphology, kinetic stability, and in vitro release of SN-38 were compared between the two formulations. In vitro anticancer activities were evaluated by measuring cellular cytotoxicity and caspase activation by MTS and Caspase-Glo 3/7 assays, respectively. The hemolytic activity of both micellar structures against rat red blood cells was also measured. The results showed the formation of SN-38-polymeric micellar conjugates at diameters < 50 nm with a narrow size distribution and sustained release of SN-38 for both structures. The loading content of SN-38 in mPEO-b-PBCL and mPEO-b-PCCL were 11.47 ± 0.10 and 12.03 ± 0.17 (% w/w), respectively. The mPEO-b-PBCL/SN-38, end-capped micelles were kinetically more stable than mPEO-b-PCCL/SN-38. The self-assembled mPEO-b-PBCL/SN-38 and mPEO-b-PCCL/SN-38 micelles resulted in significantly higher cytotoxic effects than irinotecan against human colorectal cancer cell lines HCT116, HT-29, and SW20. The CRC cells were found to be 70-fold to 330-fold more sensitive to micellar SN-38 than irinotecan, on average. Both SN-38-incorporated micelles showed two-fold higher caspase-3/7 activation levels than irinotecan. The mPEO-b-PBCL/SN-38 micelles were not hemolytic, but mPEO-b-PCCL/SN-38 showed some hemolysis. The overall results from this study uphold mPEO-b-PBCL/SN-38 over mPEO-b-PCCL/SN-38 micellar formulation as an effective delivery system of SN-38 that warrants further preclinical investigation.


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