Biomineralized Polydopamine Nanoparticle-Based Sodium Alginate Hydrogels for Delivery of Anti-serine/Threonine Protein Kinase B-Rapidly Accelerated Fibrosarcoma siRNA for Metastatic Melanoma Therapy.

Malignant melanoma, as a highly aggressive skin cancer, is strongly associated with mutations in serine/threonine protein kinase B-RAF (BRAF, where RAF stands for rapidly accelerated fibrosarcoma). Targeted therapy with anti-BRAF small interfering RNA (siBRAF) represents a crucial aspect of metastatic melanoma treatment. In this study, an injectable hydrogel platform based on sodium alginate (SA), with multifunctions of photothermal and Ca2+-overload cell apoptosis, was explored as a siBRAF carrier for metastatic melanoma therapy. We employed polydopamine nanoparticles (PDAs) as a photothermal core and constructed a calcium phosphate (CaP) shell via biomineralization (PDA@CaP) to load siBRAF (PDA@siBRAF/CaP). The pH-sensitive CaP shell facilitated the release of Ca2+ under the weakly acidic tumor microenvironment, triggering the gelation of PDA@siBRAF/CaP-SA to localized release siBRAF at tumor sites with the interruption of the RAS-RAF-MEK-ERK (MAPK) pathway. Besides, the continuous release of Ca2+ could also lead to Ca2+-overload cell apoptosis. Moreover, the photothermal effect of PDA regulated the release kinetics, resulting in coordinated therapeutic abilities of individual components in the PDA@siBRAF/CaP-SA hydrogels. Consequently, the effective inhibition of tumor growth and metastasis was achieved in vitro and in vivo using a highly metastatic melanoma cell line B16F10 as the model, by combining photothermal ablation, Ca2+ overload, and BRAF silencing. Our work provides a proof-of-concept for an injectable hydrogel system that simultaneously targets multiple mechanisms involved in melanoma progression and has the potential to be translated into clinical use for the metastatic melanoma therapy.

CaCO3-assistant synthesis of pH/near-infrared light-responsive and injectable sodium alginate hydrogels for melanoma synergistic treatment.

Melanoma is an aggressive tumor located in skin with high rates of recurrence and metastasis. Due to the limited traditional therapies, the development of novel strategies against melanoma is urgently quested. To reduce the side effects of traditional administration ways and amplify the killing effect, an injectable sodium alginate (SA)-based hydrogels were developed, in which CaCO3/polydopamine nanoparticles (CaCO3/PDA NPs) were embedded for the synergistic photothermal/calcium ions interference therapy of melanoma. In the study, the formation conditions and mechanical properties of CaCO3/PDA-SA hydrogels were characterized, and their antitumor efficiency and mechanism against mouse melanoma cells were investigated. Wheninjectedintratumorally, CaCO3/PDA-SA fluid was converted into hydrogel in situ through the interaction of pH-sensitive released Ca2+ and alginate chains, which increased the retention time of photothermal agents (CaCO3/PDA NPs) at tumor sites and thereby was more conducive to produce hyperthermia via photothermal conversion to combat melanoma. Moreover, in acidic tumor microenvironment, the residual CaCO3/PDA NPs in hydrogels continuously decomposed and released Ca2+ to destroy the Ca2+ buffering capacity and evoke the mitochondrial Ca2+-overloading, resulting in the inhibition of adenosine triphosphate production to accelerate cell death. Notably, besides the heat elevation, the near-infrared light (NIR) irradiation would further enhance the release of Ca2+ to promote the Ca2+-involved cell death. Therefore, a pH/NIR-responsive and injectable SA-based hydrogels were successfully established and showed enhanced treatment efficacy of melanoma through the synergism of photothermal therapy and calcium ions interference therapy.

Ferrous iron-induced formation of glycyrrhizic acid hydrogels for Staphylococcus aureus-infected wound healing.

Severe skin wound healing is mainly hindered by bacterial infection and uncontrolled inflammatory reaction. As a wound dressing, multifunctional hydrogel is expected to offer the potential possibility for overcoming current barriers in wound therapeutics. Herein, a natural drug molecule (glycyrrhizic acid, GA) and metal ion (Fe2+) were used to achieve the metal coordination-induced gelation. This as-prepared Fe2+-induced GA hydrogel showed excellent injectability, self-healing property, and sustained release behavior at a relatively lower concentration of GA, thereby reducing the high dose-caused cytotoxicity. In addition to acting as an inducer of gelation, Fe2+ promoted the antibacterial performance of hydrogel against Escherichia coli and Staphylococcus aureus through causing lipid peroxidation, membrane damage, and DNA degradation. Moreover, the released GA from hydrogel significantly accelerated cell migration and inhibited the inflammatory reaction by mediation of NF-κB signaling pathway to downregulate levels of important inflammatory cytokines in lipopolysaccharide-stimulated RAW264.7 cells. Using a mouse skin infected model, we revealed that the Fe2+/GA hydrogel applied to the wound resulted in the rapid wound healing. It is believed that the construction of natural drug molecule-derived hydrogel with antibacterial and anti-inflammatory capabilities may shed a new light to serve as a promising dressing for managing the severe skin wounds.

Metal ions/nucleotide coordinated nanoparticles comprehensively suppress tumor by synergizing ferroptosis with energy metabolism interference.

BACKGROUND: Ferroptosis holds promise as a potential tumor therapy by programming cell death with a hallmark of reactive oxygen species (ROS)-induced lipid peroxidation. However, vigorous energy metabolism may assist tumors to resist oxidative damage and thus weaken the effects of ferroptosis in tumor treatment. RESULTS: Herein, a bifunctional antitumor platform was constructed via coordinated interactions between metal ions and nucleotides to synergistically activate ferroptosis and interrupt energy metabolism for tumor therapy. The designed nanoparticles were composed of Fe2+/small interfering RNA (siRNA) as the core and polydopamine as the cloak, which responded to the tumor microenvironment with structural dissociation, thereby permitting tumor-specific Fe2+ and siRNA release. The over-loaded Fe2+ ions in the tumor cells then triggered ferroptosis, with hallmarks of lipid peroxidation and cellular glutathione peroxidase 4 (GPX4) down-regulation. Simultaneously, the released siRNA targeted and down-regulated glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression in the tumor to inhibit glycolytic pathway, which interfered with tumor energy metabolism and enhanced Fe2+-induced ferroptosis to kill tumor cells. CONCLUSIONS: This study presents a concise fabrication of a metal ion/nucleotide-based platform to integrate ferroptosis and energy metabolism intervention in one vehicle, thereby providing a promising combination modality for anticancer therapy.