Metallo-alginate hydrogel can potentiate microwave tumor ablation for synergistic cancer treatment.

Microwave ablation (MWA) as a local tumor ablation strategy suffers from posttreatment tumor recurrence. Development of adjuvant biomaterials to potentiate MWA is therefore of practical significance. Here, the high concentration of Ca2+ fixed by alginate as Ca2+-surplus alginate hydrogel shows enhanced heating efficiency and restricted heating zone under microwave exposure. The high concentration of extracellular Ca2+ synergizes with mild hyperthermia to induce immunogenic cell death by disrupting intracellular Ca2+ homeostasis. Resultantly, Ca2+-surplus alginate hydrogel plus MWA can ablate different tumors on both mice and rabbits at reduced operation powers. This treatment can also elicit antitumor immunity, especially if synergized with Mn2+, an activator of the stimulation of interferon genes pathway, to suppress the growth of both untreated distant tumors and rechallenged tumors. This work highlights that in situ-formed metallo-alginate hydrogel could act as microwave-susceptible and immunostimulatory biomaterial to reinforce the MWA therapy, promising for clinical translation.

Tumor-killing nanoreactors fueled by tumor debris can enhance radiofrequency ablation therapy and boost antitumor immune responses.

Radiofrequency ablation (RFA) is clinically adopted to destruct solid tumors, but is often incapable of completely ablating large tumors and those with multiple metastatic sites. Here we develop a CaCO3-assisted double emulsion method to encapsulate lipoxidase and hemin with poly(lactic-co-glycolic acid) (PLGA) to enhance RFA. We show the HLCaP nanoreactors (NRs) with pH-dependent catalytic capacity can continuously produce cytotoxic lipid radicals via the lipid peroxidation chain reaction using cancer cell debris as the fuel. Upon being fixed inside the residual tumors post RFA, HLCaP NRs exhibit a suppression effect on residual tumors in mice and rabbits by triggering ferroptosis. Moreover, treatment with HLCaP NRs post RFA can prime antitumor immunity to effectively suppress the growth of both residual and metastatic tumors, also in combination with immune checkpoint blockade. This work highlights that tumor-debris-fueled nanoreactors can benefit RFA by inhibiting tumor recurrence and preventing tumor metastasis.

[Immunoloregulation effect of polysaccharide isolated from octopus dollfusi on mouse].

OBJECTIVE: To study the immunoloregulation effect of three polysaccharides OGI, OG2and OG3 extracted from Octopus dollfusi muscle, gonad, digestive gland, respectively. METHODS: Spleen cell proliferation was measured by MTT assay and index of immune organs were weighed and calculated. RESULTS: OGI and OG2 could increase the proliferation of mouse spleen cell of normal mice, and significantly increased the proliferation of the spleen of immunosuppression mice caused by sccyclophosphamide, while showed no cooperation with ConA; OG3 appeared suppression for the two spleens. The three polysaccharides could increase index of immune organs of normal mice and remarkably increased the indexof immunosuppression mice caused by sccyclophosphamide ; while showed obvious function on thymus index. CONCLUSION: These results suggest that OG1 and OG2 have enhancement immunity for normal and immunosuppression mice, and have better effect for the latter;OG3 has suppression proliferation the spleen cell in vitro, however it has better effect for increase index of immune organs in vivo.