Plant-derived
compounds incite applications virtually on every
biomedical field due to the expedient antioxidant, anti-inflammatory
and antimicrobial properties in conjunction with a natural character.
Here, quercetin (QCT), a flavonoid with therapeutic potentials relevant
to the oral environment, was encapsulated within metal–organic
frameworks (MOFs) to address the concept of on-demand release of phytochemicals
at the biointerface. We verified the applicability of a microporous
MOF (ZIF-8) as a controlled-release system for QCT, as well as investigated
the incorporation of QCT@ZIF-8 microparticles into a dental adhesive
resin for desirable therapeutic capabilities at the tooth–restoration
interface. QCT was encapsulated within the frameworks through a water-based,
one-step synthetic process. The resulting QCT@ZIF-8 microparticles
were characterized with respect to chemical composition, crystal structure,
thermal behavior, micromorphology, and release profile under acidic
and physiological conditions. A model dental adhesive formulation
was enriched with the bioactive microparticles; both the degree of
conversion (DC) of methacrylic double bonds and the polymer thermal
behavior were accounted for. The results confirm that crystalline
QCT@ZIF-8 microparticles with attractive loading capacities, submicron
sizes, high thermal stability and responsiveness to environmental
pH change were successfully manufactured. The concentration of QCT@ZIF-8
in the resin system was a key factor to maintain an optimal DC plateau
and rate of polymerization. Essentially, one-step encapsulation of
QCT in biocompatible ZIF-8 matrices can be easily achieved, and QCT@ZIF-8
microparticles proved as smart platforms to carry bioactive compounds
with potential use to prevent microbial and enzymatic degradation
of hard tissues and extracellular matrix components.