Development of pH-responsive porphyran-coated gold nanorods for tumor photothermal and immunotherapy.

Cancer poses a significant threat to human health, and monotherapy frequently fails to achieve optimal therapeutic outcomes. Based on this premise, porphyran (PHP), a marine polysaccharide with immunomodulatory function, was used as a framework to coat gold nanorods and construct a novel nanomedicine (PHP-MPBA-GNRs) combining photothermal therapy and immunotherapy. In this design, PHP not only maintained the dispersion stability and photothermal stability of gold nanorods but also could be released under weakly acidic conditions to activate anti-tumor immunity. In vivo studies have shown that PHP-MPBA-GNRs can effectively inhibit tumor cell proliferation and reduce metastasis under near-infrared (NIR) light irradiation. Preliminary mechanistic investigations revealed that PHP-MPBA-GNRs could increase reactive oxygen species (ROS) and induce apoptosis in cancer cells. The PHP in PHP-MPBA-GNRs can also activate dendritic cells and up-regulate the expression of co-stimulatory molecules and antigen-presenting complexes. All biological experiments, including in vivo tests, demonstrated that PHP-MPBA-GNRs achieved a combination of photothermal therapy and immunotherapy for tumors.

Construction of quercetin-fucoidan nanoparticles and their application in cancer chemo-immunotherapy treatment.

Fucoidan (FU), a natural marine polysaccharide, is an immunomodulator with great potential in tumor immunotherapy. In this work, a FU encapsulated nanoparticle named QU@FU-TS was developed, which contained the anticancer phytochemical quercetin (QU) and had the potential for cancer chemo-immunotherapy. QU@FU-TS were constructed through molecular self-assembly using green material tea saponin (TS) as the linking molecule. The molecular dynamics (MD) simulation showed that QU was bound to the hydrophobic tail of TS. At the same time, FU spontaneously assembled with the hydrophilic head of TS to form the outer layer of the QU@FU-TS. The molecular interactions between QU and TS were mainly π-stacking and hydrogen bonds. The bonding of FU and TS was maintained through the formation of multiple hydrogen bonds between the sulfate ester group and the hydroxy group. The inhibitory effects of QU@FU-TS on A549 cell proliferation were more potent than that by free QU. The antitumor activity of QU@FU-TS was mediated through various mechanisms, including the induction of oxidative stress, blocking cell cycle progression, and promoting cell apoptosis. Moreover, QU@FU-TS has been demonstrated to impede the proliferation and migration of cancer cells in vivo. The expression levels of macrophage surface markers increased under the treatment of QU@FU-TS, suggesting the potential of QU@FU-TS to serve as an immunotherapeutic agent by promoting macrophage activation.

Preparation and characterization of GNRs stabled with the thiolated lemon polysaccharide and the applications for tumor photothermal therapy.

Photothermal therapy is a novel strategy for cancer treatment, which can kill tumor cells by converting light energy into heat energy through irradiating photothermal conversion materials with laser. As a common photothermal agent, gold nanorods (GNRs) have characteristics of high conversion efficiency and long circulation time in vivo. However, improving stability and reducing toxicity of GNRs remain a significant challenge. In this research, a simple and novel strategy for the synthesis of modified GNRs was proposed. The polysaccharide CL90 was obtained from lemon, which was modified to afford thiolated lemon polysaccharide (SH-CL90). SH-CL90 was used to prepare stable GNRs and give the composite GNRs-SH-CL90, which was found to have good stability in PBS solution and possess high photothermal conversion effects and photothermal stability. The biological experiments revealed that GNRs-SH-CL90 inhibited tumor cell proliferation under near-infrared light irradiation and could induce apoptosis significantly. Furthermore, in vivo experiments supported that GNRs-SH-CL90 could inhibit the proliferation and migration of tumor cells. All the experiments demonstrated that GNRs-SH-CL90 might be promising in the field of cancer treatment.

Structure, selenization modification, and antitumor activity of a glucomannan from Platycodon grandiflorum.

Platycodon grandiflorum is consumed popularly as a nutritional and healthy plant in East Asia, which has multiple medicinal functions. As an exploration to elucidate the beneficial ingredients, an acetylated glucomannan (PGP40-1) was purified from P. grandiflorum. Structural analysis showed that PGP40-1 was composed of →4)-ß-Manp-(1→, →4)-ß-Glcp-(1→, →6)-ß-Glcp-(1→, and terminal α-Glcp-(1→. PGP40-1 was found to possess weak antitumor activity in vitro, which was thus modified to afford a selenized polysaccharide (Se-PGP40-1) by the HNO3/Na2SeO3 method. Se-PGP40-1 showed significant antitumor activity in cell and zebrafish models, which could inhibit tumor proliferation and migration by inducing cell apoptosis and blocking angiogenesis. The research not only clarifies the ingredients of P. grandiflorum with high economical value, but also affords a potential antitumor agent originating from the plant polysaccharide.

Construction of inulin-based selenium nanoparticles to improve the antitumor activity of an inulin-type fructan from chicory.

Cancer has become one of the leading causes of death worldwide. It is urgent to develop new antitumor drugs with high efficiency and low toxicity. In this study, an inulin-type fructan CIP70-1 was purified and characterized from chicory and showed weak antitumor activity. To improve its antitumor effects, inulin-based selenium nanoparticles (CIP-SeNPs) were constructed and characterized. CIP-SeNPs were spherical nanoparticles (60 nm), which remained stable in water for more than 3 months. A cellular antitumor assay revealed that CIP-SeNPs had stronger inhibitory effects on cancer cells (MCF-7, A549, and HepG2) than CIP70-1 alone. Furthermore, the in vivo antitumor effects of CIP-SeNPs were confirmed using zebrafish models. The results showed that CIP-SeNPs significantly inhibited the proliferation and migration of tumors as well as the angiogenesis of transgenic zebrafish in the concentration range of 1-4 µg/mL.