Bioactive metal–organic frameworks (bio‐MOFs) built from biofunctional metal ions and linkers show a new strategy to construct multifunctional theranostic platforms. Herein, a bio‐MOF is synthetized via the self‐assembling of Fe3+ ions and doxorubicin hydrochloride (DOX) molecules. Then, through a stepwise assembly strategy, another bio‐MOFs structure consisting of Gd3+ ions and 1,3,5‐benzenetricarboxylic acid (H3BTC) is wrapped on the surfaces of Fe‐DOX nanoparticles, followed by adsorbing photosensitizer indocyanine green (ICG). Specifically, the Gd‐MOF shell structure can not only act as a contrast agent for magnetic resonance imaging (MRI), but also provides protection for Fe‐DOX cores, controlling the release of DOX. The photoacoustic and photothermal imaging (PAI and PTI) methods are successfully introduced to the platform by loading ICG, providing potential applications for multimodal biological imaging. The in vitro and in vivo outcomes indicate that the Fe‐DOX@Gd‐MOF‐ICG nanoplatform exhibits outstanding synergistic antitumor performance via MR/PA/PT imaging guided chemotherapy, photothermal and photodynamic combination therapy. The work may encourage further exploration of bio‐MOFs based multifunctional theranostic platforms for multimodal imaging guided compound antitumor therapy, which will open an avenue of MOFs toward biological applications.

Following spinal cord injury (SCI), the transmission of electrical signals is interrupted, and an oxidative microenvironment is generated, hindering nerve regeneration and functional recovery. The strategies of regulating oxidative pathological microenvironment while restoring endogenous electrical signal transmission hold promise for SCI treatment. However, challenges are still faced in simply fabricating bioactive scaffolds with both antioxidation and conductivity. Herein, aiming to construct an antioxidative and conductive microenvironment for nerve regeneration, the difunctional polypyrrole (PPy) nanoparticles were developed and incorporated into bioactive collagen/hyaluronan hydrogel. Owing to the embedded PPy in hydrogel, the encapsulated bone marrow mesenchymal stem cells (BMSCs) can be protected from oxidative damage, and their neuronal differentiation was promoted by the synergy between conductivity and electrical stimulation, which is proved to be related to PI3K/Akt and the mitogen-activated protein kinase (MAPK) pathway. In SCI rats, the BMSC-laden difunctional hydrogel restored the transmission of bioelectric signals and inhibited secondary damage, thereby facilitating neurogenesis, resulting in prominent nerve regeneration and functional recovery. Overall, taking advantage of a difunctional nanomaterial to meet two essential requirements in SCI repair, this work provides intriguing insights into the design of biomaterials for nerve regeneration and tissue engineering.

The construction of a Gd–PDA-Ce6@Gd-MOF (GPCG) theranostic nanosystem which shows enhanced MR/PA imaging performance with great cancer photothermal/photodynamic synergistic therapeutic efficiency under 808/660 nm double laser irradiation.

Traditional tumor treatments suffer from severe side effects on account of their invasive process and inefficient outcomes. Featuring a unique physical microenvironment, the tumor microenvironment (TME) provides a new research direction for designing more efficient and safer treatment paradigms. In this study, we fabricated a polydopamine (PDA)-based TMEresponsive nanosystem, which successfully integrates glucose degradation, the Fenton reaction, and photothermal therapy for efficient cancer therapy. Through a convenient hydrothermal method, Fe 2+ -doped Fe(II)−PDA nanoparticles were successfully fabricated, which show an excellent photothermal effect and interesting reactivity for the Fenton reaction. Instead of introducing toxic anticancer agents, natural glucose oxidase (GOD) was grafted on Fe(II)−PDA, forming a cascade catalytic nanomedicine for a specific response to the glucose in TME. GOD grafted on Fe(II)−PDA−GOD is ought to catalyze abundant glucose in TME into gluconic acid and H 2 O 2 . The concomitant generation of H 2 O 2 can enhance the efficiency of the sequential Fenton reaction, producing abundant hydroxyl radicals ( • OH) for cancer therapy. Besides, the overconsumption of intratumoral glucose also could inhibit tumor growth by reducing the energy supply. Taken together, the in vitro and in vivo antitumor studies of such TME-based Fe(II)−PDA−GOD nanosystems displayed a favorable synergistic potency of glucose degradation, the Fenton reaction, and photothermal therapy against tumor growth. Our design expands the biological application of multifunctional PDA while providing novel strategies toward effective antitumor treatment with minimal side effects.