Construction of self-assembled nanogel as mulitenzyme mimics for bioresponsive tandem-catalysis imaging

Abstract

The self-assembled phospholipid-or cytosolassociated multienzyme complexes constitute necessary components of the foundation of life. As a proof of concept, metalcoordinated supramolecular nanogels (MCSGs) have been designed, with the self-assembly of di-lysine coordinated iron (Fe(Lys) 2 )-functionalized peptide gelators on the interface by an in situ amidation-induced protonation process. The monoatomic and highly dispersed active centers of Fe(Lys) 2 offered the nanogel mimics with excellent reaction rates due to the high density and nano compartmental structure similar to the natural matrix-associated multienzyme complex. SiO 2 @ MCSGs show both superoxide dismutase (SOD) activity and peroxidase (POD) activity, and the higher activities compared with the activity of free Fe(Lys) 2 molecules can be detected. After loading the substrate 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS), SiO 2 @MCSGs ABTS can responsively convert O 2 − • in the tumor microenvironment into H 2 O 2 intermediates and then tandem catalyzed the oxidization of ABTS for contrast photoacoustic (PA) imaging of tumor by the SOD-POD mimic activity, showing their great potential as the efficient enzymatic agents for pathological theranostics.

Recent advances in stimuli-responsive tailored nanogels for cancer therapy; from bench to personalized treatment

“…40 Several studies on the physical self-assembly of NGs for drug delivery have also been published. [41][42][43] Polymerization in a heterogeneous environment Self-assembled NGs tend to become unstable during blood circulation, which is one of its issues. Various methods can This journal is © The Royal Society of Chemistry 2024 be used for polymerization techniques including dispersion polymerizations, precipitation, nanoprecipitation, and inverse mini-emulsion.…”

“…40 Several studies on the physical self-assembly of NGs for drug delivery have also been published. 41–43…”

Molecularly Stimuli-Responsive Self-Assembled Peptide Nanoparticles for Targeted Imaging and Therapy

“…In addition to the NIR dye-based probe, PAI can also be achieved using responsive precursors. Wang et al 175 designed a self-assembled nanogel in which SiO 2 nanoparticles were used as an inorganic core. The protonation process was induced by in situ amidation, and a self-assembled dilysine coordination iron (Fe(Lys) 2 ) functionalized polypeptide gel (SiO 2 @ MCSGs) was constructed on the nanointerface.…”

Small Peptide–Based Nanodelivery Systems for Cancer Therapy and Diagnosis

“…The addition of 2,2′azinobis (3-ethylbenzthiazoline-6-sulfonate) (ABTS) as a substrate to the above nanogel led to the conversion of O 2 to H 2 O 2 in the tumor microenvironment, and then ABTS changed to its oxidized state. This was absorbed in the NIR region and thus helped in photoacoustic imaging (Xia et al, 2021).…”