Methoxy-Poly(ethylene glycol)-block-Poly(ε-caprolactone) Bearing Pendant Aldehyde Groups as pH-Responsive Drug Delivery Carrier

2013 ◽  
Vol 66 (12) ◽  
pp. 1576 ◽  
Author(s):  
Gejun Ma ◽  
Deshan Li ◽  
Ji Wang ◽  
Xuefei Zhang ◽  
Haoyu Tang
Keyword(s):  
Drug Delivery ◽  
Block Copolymer ◽  
Ethylene Glycol ◽  
In Vitro Release ◽  
Amphiphilic Block Copolymer ◽  
Poly Ethylene Glycol ◽  
Ph Change ◽  
Poly Ethylene ◽  
Aldehyde Groups

A biodegradable amphiphilic block copolymer of methoxy poly(ethylene glycol)-block-poly(ϵ-caprolactone) bearing pendant aldehyde groups was synthesised by a combination of ring-opening polymerisation and thio-bromo ‘click’ chemistry. The free aldehyde groups on the copolymer were reacted with hydrophobic payloads (p-methoxylaniline as a model drug) by a benzoic–imine linker, which was responsive to pH change. NMR, FTIR, and gel permeation chromatography analysis confirmed the copolymer structures. In vitro release studies revealed that under acid stimulus, hydrolysis of the benzoic–imine bond resulted in a rapid drug release. This new amphiphilic block copolymer is expected to have promising applications in biodegradable controlled drug delivery systems.

scholarly journals Local Toxicity of Topically Administrated Thermoresponsive Systems: In Vitro Studies with In Vivo Correlation

2018 ◽  
Vol 47 (3) ◽  
pp. 426-432 ◽  
Author(s):  
Sivan Yogev ◽  
Ayelet Shabtay-Orbach ◽  
Abraham Nyska ◽  
Boaz Mizrahi
Keyword(s):  
Block Copolymer ◽  
Ethylene Glycol ◽  
Medical Devices ◽  
Poly Lactic Acid ◽  
Poly Ethylene Glycol ◽  
Thermoresponsive Polymers ◽  
Wide Range ◽  
Poly Ethylene

Thermoresponsive materials have the ability to respond to a small change in temperature—a property that makes them useful in a wide range of applications and medical devices. Although very promising, there is only little conclusive data about the cytotoxicity and tissue toxicity of these materials. This work studied the biocompatibility of three Food and Drug Administration approved thermoresponsive polymers: poly( N-isopropyl acrylamide), poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) tri-block copolymer, and poly(lactic acid-co-glycolic acid) and poly(ethylene glycol) tri-block copolymer. Fibroblast NIH 3T3 and HaCaT keratinocyte cells were used for the cytotoxicity testing and a mouse model for the in vivo evaluation. In vivo results generally showed similar trends as the results seen in vitro, with all tested materials presenting a satisfactory biocompatibility in vivo. pNIPAM, however, showed the highest toxicity both in vitro and in vivo, which was explained by the release of harmful monomers and impurities. More data focusing on the biocompatibility of novel thermoresponsive biomaterials will facilitate the use of existing and future medical devices.

A Tunable pH-Responsive Nanomaterials for Cancer Delivery

2013 ◽  
Vol 750-752 ◽  
pp. 1476-1479 ◽  
Author(s):  
Bin Liu ◽  
Guan Hui Gao ◽  
Peng Liu ◽  
Hu Qiang Yi ◽  
Wei Wei ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Ethylene Glycol ◽  
Potential Application ◽  
Ph Responsive ◽  
Poly Ethylene Glycol ◽  
Positive Potential ◽  
Ph Values ◽  
Drugs In Blood ◽  
Poly Ethylene

In this paper, we successfully designed a pH-responsive micelles based on hybrid polypeptide copolymers of poly (L-lysine-4-Azepan-1-yl-butyric)-b-poly (ethylene glycol)-b-poly (L-lysine-Diisopropylamide)-b-poly (L-leucine) (PLL(A)-PEG-PLL(B)-PLLeu) for efficient drug delivery. This pH-responsive nanoparticles were able to response to different pH values (pH=6.8 and 5.5). In vitro, these nanoparticles exhibited a stable and evenly distributed approximately 51 nm, a slightly positive potential about 10.3 mv at pH 7.4, which were crucial for the circulation of drugs in blood. While size and potential were about 130 nm and 34.7 mv at pH 6.8, which were good for drugs in membrane. Furthermore, the loading capability of DOX was up to 11.3%, and the pH-responsive release efficiency reached to 68.3% at pH 5.5. The results indicated that these micelles had huge potential application in cancer delivery.

A block copolymer of zwitterionic polyphosphoester and polylactic acid for drug delivery

2015 ◽  
Vol 3 (7) ◽  
pp. 1105-1113 ◽  
Author(s):  
Rong Sun ◽  
Xiao-Jiao Du ◽  
Chun-Yang Sun ◽  
Song Shen ◽  
Yang Liu ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Ethylene Glycol ◽  
Polylactic Acid ◽  
Anticancer Drug ◽  
Poly Ethylene Glycol ◽  
Anticancer Drug Delivery ◽  
Poly Ethylene

Zwitterionic polyphosphoester containing polymers are synthesized and evaluated as an alternative to poly(ethylene glycol) block copolymers for anticancer drug delivery.

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