2 research outputs found
Acid-Resistant Mesoporous Metal–Organic Frameworks as Carriers for Targeted Hypoglycemic Peptide Delivery: Peptide Encapsulation, Release, and Bioactivity
Oral administration of bioactive peptides with α-glucosidase
inhibitory activities is a promising strategy for diabetes mellitus.
The wheat germ peptide Leu–Asp–Leu–Gln–Arg
(LDLQR) has been previously proven to inhibit the activity of α-glucosidase
efficiently. However, it is still difficult to transport the peptide
to the intestine completely due to the harsh condition of the stomach.
Herein, an acid-resistant zirconium-based metal–organic framework,
NU-1000, was used to immobilize LDLQR with a high encapsulation capacity
(92.72%) and encapsulation efficiency (44.08%) in only 10 min. The in vitro release results showed that the acid-stable NU-1000
not only effectively protected LDLQR from degradation in the presence
of stomach acid and pepsin effectively but also ensured the release
of encapsulated LDLQR under simulated intestinal conditions. Furthermore,
LDLQR@NU-1000 could slow down the elevated blood sugar caused by maltose
in mice and the area under blood sugar curve decreased by almost 20%
when compared with the control group. The inflammatory factor (IL-1β,
IL-6) in vivo and cell growth in vitro were almost the same between NU-1000 treatment and normal control
groups. This study indicates NU-1000 is a promising vehicle for targeted
peptide-based bioactive delivery to the small intestine
Radiotherapy-Sensitized Tumor Photothermal Ablation Using γ‑Polyglutamic Acid Nanogels Loaded with Polypyrrole
Development
of versatile nanoscale platforms for cancer diagnosis
and therapy is of great importance for applications in translational
medicine. In this work, we present the use of Îł-polyglutamic
acid (Îł-PGA) nanogels (NGs) to load polypyrrole (PPy) for thermal/photoacoustic
(PA) imaging and radiotherapy (RT)-sensitized tumor photothermal therapy
(PTT). First, a double emulsion approach was used to prepare the cystamine
dihydrochloride (Cys)-cross-linked Îł-PGA NGs. Next, the cross-linked
NGs served as a reactor to be filled with pyrrole monomers that were
subjected to in situ oxidation polymerization in the existence of
FeÂ(III) ions. The formed uniform PPy-loaded NGs having an average
diameter of 38.9 ± 8.6 nm exhibited good water-dispersibility
and colloid stability. The prominent near-infrared (NIR) absorbance
feature due to the loaded PPy endowed the NGs with contrast enhancement
in PA imaging. The hybrid NGs possessed excellent photothermal conversion
efficiency (64.7%) and stability against laser irradiation, and could
be adopted for PA imaging and PTT of cancerous cells and tumor xenografts.
Importantly, we also explored the cooperative PTT and X-ray radiation-mediated
RT for enhanced tumor therapy. We show that PTT of tumors can be more
significantly sensitized by RT using the sequence of laser irradiation
followed by X-ray radiation as compared to using the reverse sequence.
Our study suggests a promising theranostic platform of hybrid NGs
that may be potentially utilized for PA imaging and combination therapy
of different types of tumors