Abstract
A photoresponsive
molecular-gated drug delivery system (DDS) based
on silicone-hydrogel (poly(HEMA-co-PEGMEA)) interpenetrating
polymer networks (IPNs) functionalized with carboxylated spiropyran
(SPCOOH) was designed and demonstrated as an on-demand DDS. The triggered-release
mechanism relies on controlling the wetting behavior of the surface
by light, exploiting different hydrophobicities between the “closed”
and “open” isomers of spiropyran as a photoswitchable
molecular gate on the surface of IPN (SP-photogated IPN). Light-triggered
release of doxycycline (DOX) as a model drug indicated that the spiropyran
(SP) molecules provide a hydrophobic layer around the drug carrier
and have a good gate-closing efficiency for IPNs with 20–30%
hydrogel content. Upon UV light irradiation, SP converts into an open
hydrophilic merocyanine state, which triggers the release of DOX.
These results were compared with a previously developed SP-bulk modified
IPN using the same hydrogel as a control, proving the efficiency of
the gated IPN system. The covalent attachment of SPCOOH to the alcohol
groups of the hydrogel and the structural change caused by UV light
was indicated with FTIR analysis. XPS results also confirm the presence
of SP by indicating the atomic percentage of nitrogen with respect
to the hydrogel content.
Original language | English |
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Journal | ACS Applied Bio Materials |
Volume | 4 |
Issue number | 2 |
Pages (from-to) | 1624-1631 |
Number of pages | 8 |
ISSN | 2576-6422 |
DOIs | |
Publication status | Published - 2021 |
Keywords
- Spiropyran
- IPN
- Molecular switch
- Light-triggered release
- Hydrophobicity switch