stimuli generate driving forces from the interaction between the micro/nanorobots and aspects of the treatment microenvironment, such as pH, enzymes, and redox potential. [4][5][6][7][8][9] However, the controllability of endogenous power-driven cell robots is limited, considering tumor heterogeneity. In addition, the cell robots may lose driving force when local lesions are cured. In contrast, driving forces generated from externally-applied fields are controllable, and can be output continuously. Micro/ nanorobots for biomedical applications, driven by optical, [9][10][11][12][13] acoustic, [14][15][16][17][18] or magnetic fields, [19][20][21][22][23] have been reported. In particular, micro/nanorobots controlled by magnetic fields have been studied extensively, because magnetic fields can penetrate tissues without attenuation of energy. [23][24][25][26] In general, magneticallycontrolled micro/nanorobot systems can be divided into two components: the magnetic manipulation platform (MMP), and the magnetized micro/nanorobot (MMR). The MMP relies primarily on the characteristics of superimposed magnetic fields, generated by different coils, that can be oriented in any desired direction. [27,28] To be biocompatible, cell membranes, [29] cell derived vesicles, [30] or natural cells [31,32] can be used to camouflage MMRs. [33] Magnetized cell-based robots (MCRs) are particularly effective in targeted treatment of tumors, owing to their homology with the patient, which not only gives the cell carrier excellent biocompatibility, but also takes advantage of the cells' specialized functions. [34,35] MCR fabrication is typically manifested as adhesion of magnetic materials to the cell membrane, or entry of magnetic materials to the cell by means, such as electrostatic adsorption or endocytosis. Examples of the latter strategy include the loading of red blood cells, [36][37][38] macrophages, [32,39] and stem cells [40,41] with iron oxide nanoparticles (NPs) containing drugs, for effective targeting of lesion locations under magnetic drive. However, with this strategy, drug loading is limited, to avoid influencing the activity of cells. An alternative strategy is to wrap the drugs in a membrane, and release them when the cell robots reach the lesion location. For example, liposome or polymer NPs can be loaded into live macrophages thanks to their natural phagocytic function, and the load-drugs can subsequently be released under endogenous or exogenous Injecting micro/nanorobots into the body to kill tumors is one of the ultimate ambitions for medical nanotechnology. However, injecting current micro/ nanorobots based on 3D-printed biocompatible materials directly into blood vessels for targeted therapy is often difficult, and mistakes in targeting can cause serious side effects, such as blood clots, oxidative stress, or inflammation. The natural affinity of macrophages to tumors, and their natural phagocytosis and ability to invade tumors, make them outstanding drug delivery vehicles for targeted tumor therapy. Hence, a mag...

Figure 6. Recent research and applications of acoustic control. A) Acoustic controlled RBC-PL-robot for removal of pathogenic bacteria and toxins.Reproduced with permission. [115] Copyright 2017, ACS. B) Acoustic controlled rotation of microbeads and oocytes. Reproduced with permission. [116] Copyright 2019, AIP. C) Acoustic controlled nanoswimmer for propulsion to maneuver micro-/nanosized objects. Reproduced with permission. [118] Copyright 2019, ACS. D) An untethered ultrasound-controlled actuator for targeted drug delivery. Reproduced with permission. [119] Copyright 2019, Springer Nature. E) Acoustic controlled micro rotor in PDMS channel for microelectromechanical systems. Reproduced with permission. [120]

Metastatic tumour recurrence caused by circulating tumour cells (CTCs) after surgery is responsible for more than 90% of tumour-related deaths. A postoperative evaluation system based on the long-term dynamic detection...

with efficient locomotion in fluids. Particularly, in fields that require biosafety, these robots need to be biofriendly, biocompatible, and multifunctional. In recent years, cell membrane-coated microrobots were designed, which provided new possibilities for researchers to easily harness native biological functions. [10,11] Additionally, biological template-based microrobots, such as bacterium-based robots, [12,13] sperm-based robots, [14] and cell-based motors, [15,16] have extraordinary properties while maintaining their original functionality. By providing these biological robots with new characteristics, they can be propelled by an external field to achieve various functions. For example, researchers have created cell-based delivery systems with the property of low toxicity and immunogenicity including the red blood cells, [17] platelets, [18] stem cells, [19] immune cells, [20] and tumor cells [21] that could be controlled to achieve precise site-specific delivery with better treatment efficacy. [22,23] Recently, magnetically propelled microrobots have gained particular attention in the bioengineering field, since magnetic fields are capable of penetrating most materials with minimal interaction and are nearly harmless. [24][25][26][27][28][29] Inspiringly, these magnetically actuated robots demonstrate flexible controllability to navigate mazes and could be used to manipulate cells precisely. [30,31] Exposed to a magnetic field, different magneticdriven microrobots can be controlled simultaneously and wirelessly with high precision. Therefore, microrobotic swarm behavior emerges when a large number of magnetic robots are activated by an external field. Although a single microrobot can achieve complex tasks, the power of an individual is always limited. In nature, swarm behavior appears everywhere. Specifically, bees collaborate to work efficiently, ant colonies work together to carry larger objects, and a school of fish swim together to resist predators. In the microworld, a magnetically driven robot swarm is promising because the swarm has a flexible morphology, [32] can travel through narrow channels, [33,34] and can even be observed in real organisms. [35] However, the implementation of biocompatible and biofriendly robot swarms is still a challenge.Immune cells are widely known as excellent carriers for targeted drug delivery, [36][37][38][39][40] owing to their capability to be decorated with functional nanoparticles. For robotics and cell manipulation, using a single cell robot to manipulate other Border-nearing microrobots with self-propelling and navigating capabilities have promising applications in micromanipulation and bioengineering, because they can stimulate the surrounding fluid flow for object transportation. However, ensuring the biosafety of microrobots is a concurrent challenge in bioengineering applications. Here, macrophage template-based microrobots (cell robots) that can be controlled individually or in chain-like swarms are proposed, which can transport various objects. The cell rob...

In this study, microsatellite markers were utilized to reveal the genetic diversity of 56 strains of Lentinula edodes grown in China. A total of 224 DNA bands were detected through 25 primer pairs, of which, 223 bands (99.6%) were polymorphic between two or more strains. The variation in SSR (Simple Sequence Repeat) DNA band patterns and average genetic similarity among the wild strains of L. edodes obtained from the same region uncovered a vast genetic diversity in the natural germplasm found in China. Compared with L. edodes strains from other areas, the genetic diversity of those from the Yunnan Plateau, Hengduanshan mountains, Taiwan, and south China was significantly greater. Based on cluster analysis and principal coordinate analysis, the results indicated that all L. edodes strains could be divided into three major groups. These results effectively displayed the differences between the strains from North and South China, and those from the same or adjoining regions could cluster preferentially into small groups in most cases, suggesting the positive correlation between the cluster results and the geographical origin for the natural germplasm of Chinese L. edodes. To our knowledge, this is a pioneering report on the utilization of the SSR marker technique in analyzing L. edodes' genetic diversity.