pH-sensitive polymersomes are produced from amphiphilic copolymers of the type mPEG-b-(PMMA-ran-PDMAEMA) obtained via ATRP, so that mPEG with molecular masses of 2k and 5kDa forms the corona of a hydrophobic double layer with 22–28% molar content in protonable DMAEMA. Vesicles obtained via dialysis were loaded with curcumin, 2-naphthole, paclitaxel (PTX) and ampicillin sodium salt, and the release kinetics of the latter studied via UV-vis spectrometry as a function of pH. Overall, the release profiles clearly indicated a dopant-sensitive kinetics and, likely, mechanism depending on molecule-copolymer interactions. Infrared spectrometry highlighted the formation of hydrogen bonds and salt bridges that may be responsible for these findings; support for the formation of the latter are obtained comparing the IR spectrum for ampicillin doped-vesicles with the anharmonic vibrational transition of model salt bridges. Importantly, DLS data indicated that our vesicles appeared to remain stable even at pH 4.4 after 48 h and completely releasing ampicillin. The release profiles of co-loaded curcumin/PTX with ampicillin also suggest that desorption rates of water-soluble species can be modulated by the presence of hydrophobic molecules in the double layer, at least at pH 7.4 and 6.4.

Impact of intermolecular drug-copolymer interactions on size and drug release kinetics from pH-responsive polymersomes

Mella, Massimo;Izzo, Lorella
2017-01-01

Abstract

pH-sensitive polymersomes are produced from amphiphilic copolymers of the type mPEG-b-(PMMA-ran-PDMAEMA) obtained via ATRP, so that mPEG with molecular masses of 2k and 5kDa forms the corona of a hydrophobic double layer with 22–28% molar content in protonable DMAEMA. Vesicles obtained via dialysis were loaded with curcumin, 2-naphthole, paclitaxel (PTX) and ampicillin sodium salt, and the release kinetics of the latter studied via UV-vis spectrometry as a function of pH. Overall, the release profiles clearly indicated a dopant-sensitive kinetics and, likely, mechanism depending on molecule-copolymer interactions. Infrared spectrometry highlighted the formation of hydrogen bonds and salt bridges that may be responsible for these findings; support for the formation of the latter are obtained comparing the IR spectrum for ampicillin doped-vesicles with the anharmonic vibrational transition of model salt bridges. Importantly, DLS data indicated that our vesicles appeared to remain stable even at pH 4.4 after 48 h and completely releasing ampicillin. The release profiles of co-loaded curcumin/PTX with ampicillin also suggest that desorption rates of water-soluble species can be modulated by the presence of hydrophobic molecules in the double layer, at least at pH 7.4 and 6.4.
2017
http://www.tandf.co.uk/journals/titles/10610278.html
drug release kinetic; intermolecular interactions; pH-sensitive copolymer; Polymersomes; Chemistry (all)
Barrella, Maria Chiara; Di Capua, Alessia; Adami, Renata; Reverchon, Ernesto; Mella, Massimo; Izzo, Lorella
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11383/2066509
 Attenzione

L'Ateneo sottopone a validazione solo i file PDF allegati

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 10
  • ???jsp.display-item.citation.isi??? 9
social impact