Recent advances for liquid metals:Synthesis,modification and bio-applications

Considering the application requirements for modern biomedicine,research into novel biomaterials with unusual functions is highly desired.As an alternative,liquid metals(LMs),a nontraditional family of metal materials,have piqued the interest of biomedical researchers and made significant advances in biomed-ical areas,owing to their shape transformability,self-healing capability,excellent electrical,and thermal conductivities.In particular,many functionalized strategies for the preparation and modification of LMs or LMs-based composites to achieve extended biomedical applications have been investigated in recent years.These findings provided inspiring while constructive reference for the fabrication and engineering of novel LMs-based composites.Herein,in this topic review,we elaborate on the recent advances of LMs-based functional materials,with particular focuses on the synthesis,modification,and bio-applications,especially in antitumor therapy,antibacterial,contrast agent for imaging,bone repair,electronic skin sen-sor,and nerve connection agent.Further on,the current challenges and future prospects of LMs-based composites are carefully discussed.

Doxorubicin-Ioaded Fe3O4@MoS2-PEG-2DG nanocubes as a theranostic platform for magnetic resonance imaging- guided chemo-photothermal therapy of breast cancer

Molybdenum disulfide （MoS2）, a typical transition-metal dichalcogenide, has attracted increasing attention in the field of nanomedicine because of its preeminent properties. In this study, magnetic resonance imaging （MRI）-guided chemo-photothermal therapy of human breast cancer xenograft in nude mice was demonstrated using a novel core/shell structure of Fe3O4@MoS2 nanocubes （IOMS NCs） via the integration of MoS2 （MS） film onto iron oxide （IO） nanocubes through a facile hydrothermal method. After the necessary PEGylation modification of the NCs for long-circulation purposes, such PEGylated NCs were further capped by 2-deoxy-D-glucose （2-DG）, a non-metabolizable glucose analogue to increase the accumulation of the as-prepared NCs at the tumor site, as 2-DG molecules could be particularly attractive to resource-hungry cancer cells. Such 2-DG- modified PEGylated NCs （IOMS-PEG-2DG NCs） acted as drug-carriers for doxorubicin （DOX）, which could be easily loaded within the NCs. The obtained IOMS-PEG（DOX）-2DG NCs exhibited a 3？2 relaxivity coefficient of 48.86 （mM）^-1·s^-1 and excellent photothermal performance. 24 h after intravenous injection of IOMS-PEG（DOX）-2DG NCs, the tumor site was clearly detected by enhanced T2-weighted MRI signal. Upon exposure to an NIR 808-nm laser for 5 rain at a low power density of 0.5 W·cm^-2 a marked temperature increase was noticed within the tumor site, and the tumor growth was efficiently inhibited by the chemo-photothermal effect. Therefore, our study highlights an excellent theranostic platform with great potential for targeted MRI-guided precise chemo-photothermal therapy of breast cancer.

Necroptosis-elicited host immunity:GOx-loaded MoS_(2) nanocatalysts for self-amplified chemodynamic immunotherapy

Nanoparticles induced potent antitumor immunotherapy plays a significant role for enhancing conventional therapeutic effectiveness.However,revealing the pathway of how nanoagents themselves trigger the host immunity or how to maximize the immunotherapy efficacy still needs further exploration.Herein,rose-like MoS2 nanoflowers modified with 2-deoxy-D-glucose(2-DG)and glucose oxidase(GOx)(MPGGFs)have been successfully fabricated via a one-pot hydrothermal reaction and following one-by-one surface modification as a multifunctional nanocatalyst for photothermal therapy enhanced self-amplified chemodynamic immunotherapy(PTT-co-CDT).By introducing GOx,the obtained MPGGFs exhibited self-amplified chemodynamic therapeutic efficacy under hypoxia tumor microenvironment(TME)because of the raised intracellular H2O2 level via enzyme-catalysis of oxygen.Furthermore,combined with the intrinsic excellent photothermal conversion efficiency of MoS2 nanoflowers,PTT-co-CDT performances by MPGGFs could effectively induce the necroptosis of tumor cells both in vitro and in vivo.Then the induced necroptosis via PTT-co-CDT by MPGGFs could directly trigger host immunity by activating the antigen-specific T-cells(CD4^(+) and CD8^(+)).Finally,the excellent in vivo safety of MPGGFs makes us believe that the successful construction of rose-like multifunctional nanocatalyst not only has great potentials for self-amplified chemodynamic immunotherapy,but also provides a paradigm for exploring necroptosis triggered host immunity for cancer treatment.

Galvanic replacement reaction for in situ fabrication of litchi-shaped heterogeneous liquid metal-Au nano-composite for radio-photothermal cancer therapy

With tremendous research advances in biomedical application,liquid metals(LM)also offer fantastic chemistry for synthesis of novel nano-composites.Herein,as a pioneering trial,litchi-shaped heterogeneous eutectic gallium indium-Au nanoparticles(EGaIn-Au NPs),served as effective radiosensitizer and photothermal agent for radio-photothermal cancer therapy,have been successfully prepared using in situ interfacial galvanic replacement reaction.The enhanced photothermal conversion efficiency and boosted radio-sensitization effect could be achieved with the reduction of Au nanodots onto the eutectic gallium indium(EGaIn)NPs surface.Most importantly,the growth of tumor could be effectively inhibited under the combined radio-photothermal therapy mediated by EGaIn-Au NPs.Inspired by this approach,in situ interfacial galvanic replacement reaction may open a novel strategy to fabricate LM-based nano-composite with advanced multi-functionalities.