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Among various kinds of photothermal conversion materials, polypyrrole (PPy) has attracted ever‐increasing attention because of its good biocompatibility and excellent near‐infrared light response property. In this research, the core‐shell nanoparticles with magnetic Fe3O4 as the core and mesoporous silica (MSN) as the shell were prepared, the resulted Fe3O4@MSN nanoparticles were then surface coated with a layer of PPy and further modified with polyvinylpyrrolidone (PVP) to gain colloidal stability. The Fe2+ in Fe3O4 can catalyze the decomposition of H2O2 in tumor cells to produce cytotoxic hydroxyl radicals, thus realizing the tumor chemodynamic therapy. Meanwhile, the MSN layer gives the nanoparticles a higher drug loading capacity of chemotherapeutics (doxorubicin, DOX). Therefore, the prepared Fe3O4@MSN@PPy‐PVP nanoparticles not only have good biocompatibility, magnetism and colloidal stability but also can realize the combined tumor photothermal, chemo, and chemodynamic therapy. This study demonstrates the rational design of multifunctional nanoplatforms for biomedical applications. [ABSTRACT FROM AUTHOR]

In this paper, superparamagnetic ferric oxide (Fe 3 O 4) nanospheres were prepared by hydrothermal synthesis and Fe 3 O 4 @MSN@PPy-HA composite microspheres were prepared by coating the Fe 3 O 4 with mesoporous silica nanospheres (MSN) layer, photothermal conversion materials polypyrrole (PPy) and tumor-targeting ligand hyaluronic acid (HA). The chemotherapy drug doxorubicin (DOX) was added to the above materials to prepare the tumor-targeting Fe 3 O 4 @MSN@PPy-HA@DOX microspheres. The composite nanospheres have excellent drug loading ability, controlled drug release ability, photothermal conversion performance, and good biological safety, which can be used in the treatment of tumors. Under the irradiation of the NIR laser, the photothermal conversion efficiency of Fe 3 O 4 @MSN@PPy-HA nanospheres can reach 24.61 %, realizing the thermal ablation of tumor sites. The bivalent iron ion (Fe2+) contained in the nanospheres can have a Fenton reaction with the hydrogen peroxide (H 2 O 2) in tumor cells to form cytotoxic hydroxyl radical (·OH), thus achieving the tumor chemodynamic therapy (CDT). This study confirmed that the microspheres have a good tumor inhibition effect and provided a new idea for the design of multifunctional composite nanomaterials. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent years, the novel minimally invasive combination therapy for tumors has garnered widespread attention due to its controllable therapeutic target, effective combination therapy outcome, and minimal toxic side effects. This study integrated inorganic nanospheres of ferric oxide (Fe 3 O 4) with mesoporous silica nanoparticles (MSN), along with polymeric organic polymers—polyaniline (PANI) and hyaluronic acid (HA)—to create a multifunctional tumor treatment platform (Fe 3 O 4 @MSN@PANI@HA), aiming to enhance the efficacy of therapies that have monotherapy limitations. The Fe2+ within the Fe 3 O 4 @MSN@PANI@HA nanoparticles can react with the unique hydrogen peroxide present in the tumor microenvironment to generate hydroxyl radicals (·OH), which possess cytotoxic properties that can selectively eradicate tumor cells, thereby facilitating chemodynamic therapy (CDT). Moreover, Fe 3 O 4 @MSN@PANI@HA nanoparticles, when loaded with the chemotherapy drug doxorubicin hydrochloride (DOX), yield Fe 3 O 4 @MSN@PANI@HA-DOX nanoparticles. It has been demonstrated that these nanoparticles exhibit commendable drug-loading efficiency and controlled drug-release capabilities, contributing to the chemotherapy of tumors. The inclusion of PANI in the Fe 3 O 4 @MSN@PANI@HA nanoparticles endows them with an exceptional photothermal conversion capability. Upon exposure to an 808-nm near-infrared laser (NIR), the photothermal conversion efficiency of the composite nanomaterials reaches 42.76 %, thereby enabling photothermal therapy (PTT) through the thermal ablation of tumor cells. The HA component of the composite nanoparticles provides excellent biocompatibility and a sustained drug-release effect. Simultaneously, it could target tumor cells by recognizing specific receptors that are overexpressed on the cell surfaces, directing the transport of the composite nanoparticles to the tumor site, and selectively destroying tumor cells. This paper confirms the potent therapeutic impact of composite nanoparticles on tumors and offers a novel perspective for designing multifunctional composite nanomaterials. [Display omitted] [ABSTRACT FROM AUTHOR]