Appold, M. ; Mari, C. ; Lederle, C. ; Elbert, J. ; Schmidt, C. ; Ott, I. ; Stühn, B. ; Gasser, G. ; Gallei, M. (2017)
Multi-stimuli responsive block copolymers as a smart release platform for a polypyridyl ruthenium complex.
In: Polymer Chemistry, 8
doi: 10.1039/C6PY02026G
Article
Abstract
A variety of applications of amphiphilic block copolymers result from the control of their self-assembled structures. Herein, the synthesis and structure formation of block copolymers (BCPs) consisting of poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) as one segment and poly(methyl methacrylate) (PMMA) or a statistical copolymer (PDMAEMA-co-PMMA) as a second segment, is described. The BCPs provide molar masses between 8.9 kg mol-1 and 35.6 kg mol-1 with low polydispersity index values, D = 1.05-1.13. BCPs are synthesized via sequential anionic polymerization strategies while structure formation in water is investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The PDMAEMA-containing micelles in water are loaded with a Ru(ii) polypyridyl complex, i.e. Ru(bipy)2-dppz-7-hydroxymethylPF62 (bipy = 2{,}2prime or minute-bipyridine; dppz = dipyridophenazine){,} which was previously shown to act as a potential photosensitizer in photodynamic therapy (PDT). Successful loading of the BCP micelles is evidenced by TEM measurements after dialysis in water. Stimulus-responsive release of the Ru(ii) complex from the BCP micelles is shown using ultrasound{,} change of pH or temperature as external triggers. The quantification and release profiles for the Ru(ii) complex are obtained by atomic absorption spectrometry (AAS). As a result{,} PDMAEMA-b-PMMA is not capable of releasing the Ru(ii) complex in a controlled manner after application of{,} for instance{,} ultrasound or temperature change as external triggers due to the shielding (stealth effect) of the BCP. On the contrary{,} micelles made of BCPs featuring PDMAEMA and PDMAEMA-co-PMMA segments reveal excellent Ru(ii) complex release profiles due to the tailored molecular composition of the underlying block segments as evidenced by temperature-dependent DLS and AAS measurements. Thus{,} these smart PDMAEMA-containing BCPs pave the way to a variety of applications for selective triggered release of small molecules.
| Item Type: | Article |
|---|---|
| Erschienen: | 2017 |
| Creators: | Appold, M. ; Mari, C. ; Lederle, C. ; Elbert, J. ; Schmidt, C. ; Ott, I. ; Stühn, B. ; Gasser, G. ; Gallei, M. |
| Type of entry: | Bibliographie |
| Title: | Multi-stimuli responsive block copolymers as a smart release platform for a polypyridyl ruthenium complex |
| Language: | English |
| Date: | 2017 |
| Publisher: | The Royal Society of Chemistry |
| Journal or Publication Title: | Polymer Chemistry |
| Volume of the journal: | 8 |
| DOI: | 10.1039/C6PY02026G |
| URL / URN: | http://dx.doi.org/10.1039/C6PY02026G |
| Abstract: | A variety of applications of amphiphilic block copolymers result from the control of their self-assembled structures. Herein, the synthesis and structure formation of block copolymers (BCPs) consisting of poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) as one segment and poly(methyl methacrylate) (PMMA) or a statistical copolymer (PDMAEMA-co-PMMA) as a second segment, is described. The BCPs provide molar masses between 8.9 kg mol-1 and 35.6 kg mol-1 with low polydispersity index values, D = 1.05-1.13. BCPs are synthesized via sequential anionic polymerization strategies while structure formation in water is investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The PDMAEMA-containing micelles in water are loaded with a Ru(ii) polypyridyl complex, i.e. Ru(bipy)2-dppz-7-hydroxymethylPF62 (bipy = 2{,}2prime or minute-bipyridine; dppz = dipyridophenazine){,} which was previously shown to act as a potential photosensitizer in photodynamic therapy (PDT). Successful loading of the BCP micelles is evidenced by TEM measurements after dialysis in water. Stimulus-responsive release of the Ru(ii) complex from the BCP micelles is shown using ultrasound{,} change of pH or temperature as external triggers. The quantification and release profiles for the Ru(ii) complex are obtained by atomic absorption spectrometry (AAS). As a result{,} PDMAEMA-b-PMMA is not capable of releasing the Ru(ii) complex in a controlled manner after application of{,} for instance{,} ultrasound or temperature change as external triggers due to the shielding (stealth effect) of the BCP. On the contrary{,} micelles made of BCPs featuring PDMAEMA and PDMAEMA-co-PMMA segments reveal excellent Ru(ii) complex release profiles due to the tailored molecular composition of the underlying block segments as evidenced by temperature-dependent DLS and AAS measurements. Thus{,} these smart PDMAEMA-containing BCPs pave the way to a variety of applications for selective triggered release of small molecules. |
| Divisions: | 05 Department of Physics > Institute for condensed matter physics (2021 merged in Institute for Condensed Matter Physics) > Experimental Condensed Matter Physics 05 Department of Physics > Institute for condensed matter physics (2021 merged in Institute for Condensed Matter Physics) 05 Department of Physics |
| Date Deposited: | 21 Nov 2017 09:03 |
| Last Modified: | 21 Nov 2017 09:03 |
| PPN: | |
| Export: | |
| Suche nach Titel in: | TUfind oder in Google |
 |
Send an inquiry |
Options (only for editors)
 |
Show editorial Details |
Drucken
Impressum