In this work, we developed multifunctional hydrogel nanoparticles (NPs) that can encapsulate
anticancer drugs and imaging contrast agents as well. Mitomycin C (MMC) and rhodamine
B (RB) were selected as models for anticancer drugs and imaging contrasting agents,
respectively. Both MMC and RB were linked to the succinated polyvinyl alcohol polymer
(PVA-SA). The selected labeled hydrogel NPs ((0.5% RB)-PVA-SA NPs and (1.5% RB)-PVA-SA
NPs) improved the RB quantum yield from 29.8% to a minimum of 42.7%. Moreover, they
showed higher emission stability compared to free RB when they were repeatedly excited
at 554 nm for 2 h. Furthermore, the dye polymeric interactions significantly increased
the RB fluorescence lifetime by approximately twofold. All these optical properties
pave the way for our labeled hydrogel NPs to be used in imaging-guided therapy. For
the labeled MMC-loaded NPs, the MMC-binding efficiency was found to be exceedingly
high in all synthesized samples: a minimum of 92% was achieved. In addition, the obtained
pH-dependent drug release profiles as well as the cytotoxicity evaluation demonstrated
the high potential of releasing MMC under acidic cancerous conditions. Moreover, the
in vitro cellular uptake experiment confirmed the accumulation of MMC NPs throughout
the cytoplasm.
