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Objectives: To reveal the force profiles recorded by haptic autonomous robotic force feedback during the transcrestal sinus floor elevation (TSFE) process, providing a reference for the surgery strategy during TSFE., Materials and Methods: A total of 42 maxillary sinus models with different angles of the sinus floor (30°, 40°, 50°, 60°, 70°, 80°, and 90°, compared to vertical plane) were 3D printed. Implant site preparation was performed using a robotic system, and the total force (Ft) and axial force along the drill (Fz) during the surgery were recorded by the haptic robotic arm. The actual initial breakthrough point (drill contacting sinus floor) and complete breakthrough point (drill penetrating the sinus floor) were defined visually (the actual IBP and the actual CBP). The theoretical initial breakthrough point (the theoretical IBP) and the theoretical complete breakthrough point (the theoretical CBP) defined by the robot-guided system and the CBCT were determined by real-time force feedback and imaging distance measurement, respectively. The distance from the bottom of the resin model to the actual IBP and the actual CBP was defined as Di and Dt, respectively., Results: The difference in Fz began to increase significantly at 70°, while the difference in Ft became significant at 60°. When the angle was greater than 70°, there was no significant difference in the discrepancy between the actual and theoretical perforation points. Compared to judging the breakthrough point by CBCT, real-time force feedback TSFE under robotic surgery achieved more accurate initial breakthrough point detection., Conclusions: The smaller the angle, the larger the breakthrough force for the drill. The real-time force feedback of haptic robotic system during TSFE could provide reliable reference for dentists. More clinical studies are needed to further validate the application of robotic surgery assisted TSFE., (© 2024 Wiley Periodicals LLC.)

Objectives: To assess the accuracy and effectiveness among operators with different levels of experience in a robot-assisted immediate implant surgery., Materials and Methods: The study included four participants who had received dental training at the same institution but have varying levels of clinical experience in implant dentistry, denoted as undergraduate student (UG), dental resident (DR), specialist with no robot experience (IS) and specialist with robot experience (RS). Following comprehensive theoretical training in robot-assisted implant operation, each operator participated in five robotic-assisted implant procedures at 21 sites, resulting in the implant surgery of a total of 20 implants. Subsequently, the accuracy of the implants was assessed by analyzing the preoperative planning and the postoperative CBCT scans, and the time required for each procedure was also recorded., Results: Angular deviation in UG, DR, IS and RS group was 0.82 ± 0.27°, 0.55 ± 0.27°, 0.83 ± 0.27°, and 0.56 ± 0.36°, respectively. The total deviation of the implant platform point was 0.28 ± 0.10 mm, 0.26 ± 0.16 mm, 0.34 ± 0.08 mm and 0.31 ± 0.06 mm, respectively. The total deviation of the apical point was 0.30 ± 0.08 mm, 0.25 ± 0.18 mm, 0.31 ± 0.09 mm, and 0.31 ± 0.05 mm, respectively. The time spent was 10.37 ± 0.57 min, 10.56 ± 1.77 min, 9.93 ± 0.78 min, and 11.76 ± 0.78 min for each operator. As the number of operations increased, the operation time decreased, but there was no significant difference in implant accuracy between the different groups., Conclusions: Within the scope of this study, robot-assisted implant surgery demonstrated high accuracy, with no significant differences in performance between operators with varying levels of clinical experience or implant robot-user experience. Furthermore, the learning curve for robotic implant surgery is steep and consistent., Clinical Relevance: Robot-assisted implant surgery demonstrates consistent high accuracy across operators of varying clinical and robotic experience levels, highlighting its potential to standardize procedures and enhance predictability in clinical outcomes., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Recent years have witnessed a surge in the application of microrobots within the medical sector, with hydrogel microrobots standing out due to their distinctive advantages. These microrobots, characterized by their exceptional biocompatibility, adjustable physico-mechanical attributes, and acute sensitivity to biological environments, have emerged as pivotal tools in advancing medical applications such as targeted drug delivery, wound healing enhancement, bio-imaging, and precise surgical interventions. The capability of hydrogel microrobots to navigate and perform tasks within complex biological systems significantly enhances the precision, efficiency, and safety of therapeutic procedures. Firstly, this paper delves into the material classification and properties of hydrogel microrobots and compares the advantages of different hydrogel materials. Furthermore, it offers a comprehensive review of the principal categories and recent innovations in the synthesis, actuation mechanisms, and biomedical application of hydrogel-based microrobots. Finally, the manuscript identifies prevailing obstacles and future directions in hydrogel microrobot research, aiming to furnish insights that could propel advancements in this field., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Song, Li, Liu, Zhu, Yu, Wang and Wang.)

Objectives: To compare the accuracy of immediate implant placement of cylindrical implants (CI) and tapered implants (TI) of different lengths using a robotic dental implant system., Materials and Methods: CI and TI of three lengths (8, 10, and 12 mm) each were digitally planned and placed in a three-dimensional printed extraction socket model under robotic guidance. There were six groups with three samples in each group, resulting in a total of 18 samples. Implant angular deviation, platform point deviation (total, lateral, depth), and implant apical point deviation (total, lateral, depth) were recorded and compared between the different groups., Results: The angular deviations for CI 8 mm, CI 10 mm, CI 12 mm, TI 8 mm, TI 10 mm, and TI 12 mm were 1.32° ± 0.19°, 1.03° ± 0.56°, 1.31° ± 0.38°, 1.27° ± 0.64°, 1.10° ± 0.43° and 1.05° ± 0.45°, respectively. The total deviations of platform and apical points for CI 8 mm, CI 10 mm, CI 12 mm, TI 8 mm, TI 10 mm, and TI 12 mm were 0.79 ± 0.18 mm, 0.77 ± 0.33 mm; 0.64 ± 0.21 mm, 0.55 ± 0.17 mm; 0.64 ± 0.37 mm, 0.65 ± 0.34 mm; 0.68 ± 0.26 mm, 0.71 ± 0.20 mm; 0.70 ± 0.12 mm, 0.66 ± 0.23 mm; and 0.71 ± 0.15 mm, 0.77 ± 0.29 mm, respectively, and had no significant differences., Conclusions: Within the limitation of this study, acceptable accuracy can be achieved for both TI and CI using robotic systems. Our study demonstrated that the implant shape and length did not affect the accuracy of immediate implant placement under robotic guidance in vitro. However, further trials are required to confirm their efficacy in clinical practice., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

A growing interest in the development of efficient strategies for the removal of organic pollutants from polluted water is emerging. As such, artificial micro/nano machines performing excellent water purification tasks have recently attracted more research attention of scientists. Hereby a spinous Fe 3 O 4 @PPy microrobot is presented that towards an efficient organic pollutant removal by enhancing Fenton-like reaction. The microrobot is fabricated by wrapping polypyrrole (PPy) on a spiny magnetic template prepared from sunflowers pollen. Modulating the sound pressure and frequency of the ultrasonic field enables the Fe 3 O 4 @PPy microrobot to present multimode motion, such as violent eruption-like motion caused by local cavitation (ELM), march-like unific motion (MLM), and typhoon-like rotation toward the center gathered motion (TLM). This multimode motion achieves the sufficient locomotion of microrobots in three-dimensional space and effective contact with organic pollutants in polluted water. Furthermore, a 5.2-fold increase in the degradation rate of methylene blue has been realized using Fe 3 O 4 @PPy microrobots under low-concentration hydrogen peroxide conditions. Also, the magnetically controlled recovery of microrobots from water after the completion of the degradation task has been demonstrated. The magnetic-acoustic actuated spinous microrobot can be extrapolated to other catalytic microrobot, developing a new strategy for an easier implementation and recovery of microrobot in real applications of water purification., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Backgroud: Regardless of application scenarios, proper mechanical characteristics and degradation properties are prerequisites for horizontal platelet rich fibrin (H-PRF) to manifest its ability. Among the methods used to modify PRF, thermal manipulation is promising as it is easy to handle without adding extra additives. Yet there is no consensus on optimal temperature treatment. This study aimed to investigate the effects of heating on the biological and mechanical characteristics of H-PRF and explore the optimum heating temperature for H-PRF thermal treatment., Methods: We employed a series of temperature gradients, room temperature, 50℃, 75℃, 90℃, 105℃. The microstructure and the mechanical properties were recorded by Scanning Electron Microscope (SEM) and tensile strength tests respectively. The degradation rate of H-PRF membranes was examined by digestion assay with plasmin and trypsin. The viability of cells within H-PRF membranes and the proliferation of osteoblasts cultured with extracts from different H-PRF groups was evaluated using CCK-8 assays., Results: Compared with the nonheated group, overheated manipulation beyond 90℃ can significantly prolong the degradation properties for up to 3 to 4 weeks and enhance the mass stress of H-PRF membranes. A high-temperature treatment of 105℃ accompanied by the cell activity beneath H-PRF reduced more than half, and thus, the biological effect on human osteoblasts (hFOBs) also reduced dramatically., Conclusions: High thermal manipulation can prolong the degradation properties and enhance the mechanical properties of PRF membranes accompanied by the loss of biological effect., (© 2023. The Author(s).)

Nowadays, global water scarcity is becoming a pressing issue, and the discharge of various pollutants leads to the biological pollution of water bodies, which further leads to the poisoning of living organisms. Consequently, traditional water treatment methods are proving inadequate in addressing the growing demands of various industries. As an effective and eco-friendly water treatment method, micro/nanorobots is making significant advancements. Based on researches conducted between 2019 and 2023 in the field of water pollution using micro/nanorobots, this paper comprehensively reviews the development of micro/nanorobots in water pollution control from multiple perspectives, including propulsion methods, decontamination mechanisms, experimental techniques, and water monitoring. Furthermore, this paper highlights current challenges and provides insights into the future development of the industry, providing guidance on biological water pollution control., Competing Interests: Author JY was employed by PetroChina Changqing Oilfield Company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wang, Jing, Yu, Ma, Sui, Zhu, Dai, Yu, Li and Wang.)

Due to their enormous potential to be navigated through complex biological media or narrow capillaries, microrobots have demonstrated their potential in a variety of biomedical applications, such as assisted fertilization, targeted drug delivery, tissue repair, and regeneration. Numerous initial studies have been conducted to demonstrate the biomedical applications in test tubes and in vitro environments. Microrobots can reach human areas that are difficult to reach by existing medical devices through precise navigation. Medical imaging technology is essential for locating and tracking this small treatment machine for evaluation. This article discusses the progress of imaging in tracking the imaging of micro and nano robots in vivo and analyzes the current status of imaging technology for microrobots. The working principle and imaging parameters (temporal resolution, spatial resolution, and penetration depth) of each imaging technology are discussed in depth.

Swimming microrobot energized by magnetic fields exhibits remotely propulsion and modulation in complex biological experiment with high precision. However, achieving high environment adaptability and multiple tasking capability in one configuration is still challenging. Here, we present a strategy that use oriented magnetized Janus spheres to assemble the microdimer robots with two magnetic distribution configurations of head-to-side configuration (HTS-config) and head-to-head configuration (HTH-config), achieving performance of multiple tasks through multimode transformation and locomotion. Modulating the magnetic frequency enables multimode motion transformation between tumbling, rolling, and swing motion with different velocities. The dual-asynchronization mechanisms of HTS-config and HTH-config robot dependent on magnetic dipole-dipole angle are investigated by molecular dynamic simulation. In addition, the microdimer robot can transport cell crossing morphological rugae or complete drug delivery on tissues by switching motion modes. This microdimer robot can provide versatile motion modes to address environmental variations or multitasking requirements., Competing Interests: The authors declare no competing interests., (© 2023 The Author(s).)

Background: The effects of horizontal platelet-rich fibrin (H-PRF) bone block on the healing and immune response during sinus augmentation have not been fully investigated histologically at early time points., Methods: Eighteenth male New Zealand white rabbits underwent bilateral sinus augmentation and were divided into two groups: deproteinized bovine bone mineral (DBBM) alone and H-PRF + DBBM (H-PRF bone block) group. Maxilla samples were collected at 3, 7 and 14 days post sinus augmentation procedures and analyzed using histological staining for the number of inflammatory cells, new blood vessels and evidence for early osteoclast bone turnover/remodeling. Furthermore, the effects of H-PRF bone blocks on the migration of osteoblasts and THP-1 macrophages were evaluated using a Transwell assay in vitro., Results: A higher number of immune cells were found in the H-PRF bone block group at 3 and 7 days post-surgery when compared to the DBBM alone group,most notably in the regions close to the mucosal lining and bone plates. Furthermore, a significantly greater number of new blood vessel formations and early signs of osteoclast development were found in the H-PRF bone block group at 14 days. The in vitro transwell assay further confirmed that culture medium from H-PRF bone block markedly promote the migration of osteoblasts and THP-1 macrophages., Conclusions: The findings from this study have shown that H-PRF bone block is capable of increasing early immune cell infiltration leading to the acceleration of neovascularization and speeding the process of bone metabolism in vivo following maxillary sinus grafting with DBBM., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: While suggested to be effective in tissue regeneration, the effects of horizontal platelet-rich fibrin (H-PRF) bone block in sinus augmentation have not been verified in an animal model., Methods: A total of 12 male New Zealand white rabbits that underwent sinus augmentation were divided into two groups: deproteinized bovine bone mineral (DBBM) only and H-PRF bone block. H-PRF was prepared at 700 × g for 8 min using a horizontal centrifuge. The H-PRF bone block was prepared by mixing 0.1 g DBBM with H-PRF fragments and then adding liquid H-PRF. Samples were collected after 4 and 8 weeks and analyzed using microcomputed tomography (micro-CT) for vertical bone gain of the sinus, bone volume/total volume (BV/TV) percentage, trabecular number (Tb.N), trabecular thickness (Tb.Th) and trabecular separation (Tb.Sp). Then, histological analyses were performed to investigate new blood vessels, material residue, bone formation and osteoclasts., Results: Higher vertical bone gain of the sinus floor, BV/TV percentage, Tb.Th, and Tb.N and lower Tb.Sp were found in the H-PRF bone block group at both time points compared with the DBBM group. Higher amounts of new blood vessels and more osteoclasts were found in the H-PRF bone block group than in the DBBM group at both time points, especially in the regions close to the bone plate. More new bone formation and less material residue were observed in the H-PRF bone block group at 8 weeks., Conclusions: H-PRF bone block showed greater potential for sinus augmentation by promoting angiogenesis, bone formation and bone remodeling in a rabbit model., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Swimming microrobots guided in the circulation system offer considerable promise in precision medicine but currently suffer from problems such as limited adhesion to blood vessels, intensive blood flow, and immune system clearance-all reducing the targeted interaction. A swimming microrobot design with clawed geometry, a red blood cell (RBC) membrane-camouflaged surface, and magnetically actuated retention is discussed, allowing better navigation and inspired by the tardigrade's mechanical claw engagement, coupled to an RBC membrane coating, to minimize blood flow impact. Using clinical intravascular optical coherence tomography in vivo, the microrobots' activity and dynamics in a rabbit jugular vein was monitored, illustrating very effective magnetic propulsion, even against a flow of ~2.1 cm/s, comparable with rabbit blood flow characteristics. The equivalent friction coefficient with magnetically actuated retention is elevated ~24-fold, compared to magnetic microspheres, achieving active retention at 3.2 cm/s, for >36 hours, showing considerable promise across biomedical applications.

Highly effective contrast enhancer that processes targeting ability and maneuverability is in great demand in clinics for accurate diagnosis. Here a new strategy using deformable and manipulatable magnetic microswarm as MRI contrast enhancer is developed. Magnetic microswarm aggregated from nanoparticles is inherently deformable and they can be controlled with multiple programmable deform abilities. It is demonstrated that spatiotemporal programming magnetic field enables the magnetic microswarm not only to exhibit both ribbon-like and round-like behaviours but also to adaptively navigate multiple terrains. Intestinal model is conducted to explore the effect of magnetic microswarm as MRI enhancer, indicating the obvious enhancement of T 2 -weighted MRI sequences. This magnetic microswarm holds great promise for highly sensitive and accurate intestinal MRI in the clinic., (© 2022 Wiley-VCH GmbH.)

Background: Drugs based on synthetic lethality have advantages such as inhibiting tumor growth and affecting normal tissue in vivo . However, specific targets for osteosarcoma have not been acknowledged yet. In this study, a non-targeted but controllable drug delivery system has been applied to selectively enhance synthetic lethality in osteosarcoma in vitro , using the magnetic-driven hydrogel microrobots. Methods: In this study, EPZ015666, a PRMT5 inhibitor, was selected as the synthetic lethality drug. Then, the drug was carried by hydrogel microrobots containing Fe 3 O 4 . Morphological characteristics of the microrobots were detected using electron microscopy. In vitro drug effect was detected by the CCK-8 assay kit, Western blotting, etc. Swimming of microrobots was observed by a timing microscope. Selective inhibition was verified by cultured tumors in an increasing magnetic field. Results: Genomic mutation of MTAP deletion occurred commonly in pan-cancer in the TCGA database (nearly 10.00%) and in osteosarcoma in the TARGET database (23.86%). HOS and its derivatives, 143B and HOS/MNNG, were detected by MTAP deletion according to the CCLE database and RT-PCR. EPZ015666, the PRMT5 inhibitor, could reduce the SDMA modification and inhibition of tumor growth of 143B and HOS/MNNG. The hydrogel microrobot drug delivery system was synthesized, and the drug was stained by rhodamine. The microrobots were powered actively by a magnetic field. A simulation of the selected inhibition of microrobots was performed and lower cell viability of tumor cells was detected by adding a high dose of microrobots. Conclusion: Our magnetic-driven drug delivery system could carry synthetic lethality drugs. Meanwhile, the selective inhibition of this system could be easily controlled by programming the strength of the magnetic field., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Mu, Liu, Zhang, Meng, Yu, Zeng, Han, Jin, Shi, Yu, Li, Xu and Hua.)

In this study, we propose a highly efficient robot platform for pollutant adsorption. This robot system consists of a flapping-wing micro aircraft (FWMA) for long-distance transportation and delivery and cost-effective multifunctional Janus microrobots for pollutant purification. The flapping-wing micro air vehicle can hover for 11.3 km with a flapping frequency of approximately 15 Hz, fly forward up to 31.6 km/h, and drop microrobots to a targeted destination. The Janus microrobot, which is composed of a silica microsphere, nickel layer, and hydrophobic layer, is used to absorb the oil and process organic pollutants. These Janus microrobots can be propelled fast up to 9.6 body lengths per second, and on-demand speed regulation and remote navigation are manageable. These Janus microrobots can continuously carry oil droplets in aqueous environments under the control of a uniform rotating magnetic field. Because of the fluid dynamics induced by the Janus microrobots, a highly efficient removal of Rhodamine B is accomplished. This smart robot system may open a door for pollutant purification., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wang, Yu, Liao, Qing, Sun, Ji, Song, Wang and Li.)

With the rapid development of nanotechnology, nanoparticles (NPs) are widely used in all fields of life. Nowadays, NPs have shown extraordinary antimicrobial activities and become one of the most popular strategies to combat antibiotic resistance. Whether they are equally effective in combating bacterial persistence, another important reason leading to antibiotic treatment failure, remains unknown. Persister cells are a small subgroup of phenotypic drug-tolerant cells in an isogenic bacterial population. Here, various types of NPs are used in combination with different antibiotics to destroy persisters. Strikingly, rather than eradicating persister cells, a wide range of NPs promote the formation of bacterial persistence. It is uncovered by PCR, thermogravimetric analysis, intracellular potassium ion staining, and molecular dynamics simulation that the persister promotion effect is achieved through exerting a hyperosmotic pressure around the cells. Moreover, protein mass spectrometry, fluorescence microscope images, and SDS-PAGE indicate NPs can further hijack cell osmotic regulatory circuits by inducing aggregation of outer membrane protein OmpA and OmpC. These findings question the efficacy of using NPs as antimicrobial agents and raise the possibility that widely used NPs may facilitate the global emergence of bacterial antibiotic tolerance., (© 2022 Wiley-VCH GmbH.)

Photothermal nanoparticles are thought to be the most suitable candidates against infectious disease by disrupting the cell membrane or inhibiting cellular metabolism. However, cells with low-metabolic activity states may be endowed with greater ability against harsh environments including antibiotic treatment. For now, it remains unexplored whether and how photothermal therapy (PTT) gives rise to bacterial antibiotic tolerance. In this study, we showed that although it exhibits excellent bactericidal ability, PTT with typical photothermal nanoparticle gold nanocages (AuNCs) can give rise to a subpopulation of cells with great ability of antibiotic tolerance. The subpopulation exhibits delayed growth and decreased cellular ATP levels, indicating a low metabolic state. Specifically, after AuNCs attach to the surface of a bacterial cell, photothermal manipulation can induce cell membrane shrinkage and block the bacterial respiratory chain. Besides, heat shock induces protein aggregation and leads to the dysfunction of a number of important proteins. The heat shock protein DnaK is closely associated with protein aggregation and plays a vital role in modulating antibiotic tolerance, providing a potential therapeutic target.

With the development of designed materials and structures, a wide array of micro/nanomachines with versatile functionalities are employed for specific sensing applications. Here, we demonstrated a magnetic propelled microdimer-based point-of-care testing system, which can be used to provide the real-time data of plasma glucose and lipids relying on the motion feedback of mechanical properties. On-demand and programmable speed and direction of the microdimers can be achieved with the judicious adjustment of the external magnetic field, while their velocity and instantaneous postures provide estimation of glucose, cholesterol, and triglycerides concentrations with high temporal accuracy. Numerical simulations reveal the relationship between motility performance and surrounding liquid properties. Such technology presents a point-of-care testing (POCT) approach to adapt to biofluid measurement, which advances the development of microrobotic system in biomedical fields., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Yu, Sun, Zhang, Sun, Liu, Wang, Li, Zhao and Li.)

Platelet-rich fibrin (PRF) has been utilized as a substitute for resorbable membranes during guided bone regeneration therapy as it is a more bioactive biomaterial with living cells and growth factors than resorbable membranes. Nevertheless, PRF poses obvious disadvantages in its mechanical strength since its rapid degradability has been shown to typically resorb within a 2-week time period. In the present study, the barrier function and biological and mechanical properties of PRF were investigated both as standard therapy and after thermal processing. Two heating processes were applied: both single-side heating and double-side heating at 90°C for 10 s using a metal plate heater. The appearance and weight of PRF membranes were documented after heating, along with their morphological and mechanical properties evaluated by scanning electron microscope and tensile strength tests. The viability of cells found within PRF membranes was also evaluated using live/dead cell viability and CCK-8 (cell counting kit-8) assays. To comprehensively evaluate the barrier function of PRF membranes, Hoechst staining of human gingival fibroblasts, which can be distinguished from cells within the PRF membrane by emitting blue light at an excitation wavelength of 488 nm, was seeded onto the surface of PRF membranes. Furthermore, osteoblasts were cultured with extracts from different PRF groups to evaluate the biocompatibility of PRF membranes. The degradation rate of PRF membranes was examined by digestion assay. Compared with the nonheated PRF control, the size and weight of PRF membranes led to a significant decrease with a denser PRF microstructure following heating. In summary, the double-sided heating of PRF membranes not only demonstrated an improvement in mechanical and degradation properties but also led to a decrease in cell viability and proliferation.

Micro- and nanomachines as feasible agents to exploit the microworld have attracted extensive research interest, particularly in the manipulation of soft nanorobots at small scales. Herein, we propose a model for regulating the motion of a swinging flexible nanomotor (SFN) driven by an oscillating magnetic field. Multisegments of an SFN are synthesized from nickel, gold, and porous silver. The coupling of magnetic actuation and the swinging pattern of SFNs are studied to reveal their mobility. Additionally, an optimal frequency occurs from the coupling of magnetic torque and structural deformation, rather than the simply considered step-out phenomenon. Meanwhile, a fluidic trapping region is formulated alongside the SFN. Such a trapping region is demonstrated by trapping a living neutrophil and accomplishing in vitro transportation using fluidic mediation. On-demand cargo delivery can be realized using a programmable magnetic field, and SFNs can be recycled with ease after manipulation owing to environmental concerns. In this study, we demonstrated the properties of SFNs that are useful bases for their customization and control. These flexible nanomotors may have the potential to promote drug delivery and biomedical operations in noncontact modes.

Platelet-rich fibrin (PRF) has been widely used owing to its ability to stimulate tissue regeneration. To date, few studies have described the antibacterial properties of PRF. Previously, PRF prepared by horizontal centrifugation (H-PRF) was shown to contain more immune cells than leukocyte- and platelet-rich fibrin (L-PRF). This study aimed to compare the antimicrobial effects of PRFs against Staphylococcus aureus and Escherichia coli in vitro and to determine whether the antibacterial effects correlated with the number of immune cells. Blood samples were obtained from eight healthy donors to prepare L-PRF and H-PRF. The sizes and weights of L-PRF and H-PRF were first evaluated, and their antibacterial effects against S. aureus and E. coli were then tested in vitro using the inhibition ring and plate-counting test methods. Flow-cytometric analysis of the cell components of L-PRF and H-PRF was also performed. No significant differences in size or weight were observed between the L-PRF and H-PRF groups. The H-PRF group contained more leukocytes than the L-PRF group. While both PRFs had notable antimicrobial activity against S. aureus and E. coli, H-PRF demonstrated a significantly better antibacterial effect than L-PRF. Furthermore, the antimicrobial ability of the PRF solid was less efficient than that of wet PRF. In conclusion, H-PRF exhibited better antibacterial activity than L-PRF, which might have been attributed to having more immune cells.

A sonochemical reactor was developed to study the ultrasound-assisted cyanide extraction of gold from gold ore at low temperature. The effects of ultrasound on gold leaching in low temperature and conventional conditions were investigated. At the low temperature of 10 °C, ultrasound-assisted extraction increased extraction rate of gold by 0.6%-0.8% and reduced the gold content of cyanide tailings to 0.28 g/t in the leaching of gold concentrate and cyanide tailings, respectively. At the conventional temperature of 25 °C, ultrasound-assisted extraction obtained a 0.1% higher extraction rate of gold compared with conventional extraction, with the unit consumption of NaCN reduction of 15%. The analysis of kinetic model also demonstrated that sonication indeed improved the reaction of gold leaching greatly. The mineralogy and morphology of ore were further analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and particle size analyzer to explore the strengthening mechanism of gold leaching. The results showed that the ore particles were smashed, the ore particle surface was peeled, the passive film was destroyed and the reaction resistance decreased under ultrasonic processing. Therefore, the extraction rate of gold was improved and the extraction time was shortened significantly in ultrasound-assisted cyanide extraction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The effect of the Prandtl number ( Pr ) on the flow and heat transfer from a porous circular cylinder with internal heat generation in the mixed convection regime is numerically investigated. The steady flow regime is considered over the ranges of the Reynolds number ( Re ), Darcy number ( Da ), and Richardson number ( Ri ), varying from 5 to 40, 10 -6 to 10 -2 , and 0 to 2, respectively. The wake structure, the temperature distribution, and the heat transfer rate are discussed. Besides precipitating the growth of the recirculating wake, the Prandtl number is found to have a significant impact on the thermal characteristics. The concave isotherms, resembling a saddle-shaped structure, occur behind the cylinder at larger Pr , resulting in swells of the isotherms pairing off at the lateral sides. These swells are found to have a negative effect on heat transfer owing to a relatively smaller temperature gradient there. Then, the heat transfer rate in terms of the local Nusselt number ( Nu ) and enhancement ratio ( Er ) is calculated, which is closely related to Pr , Re , Da , and Ri. The local minimum heat transfer rate along the cylinder surface is found at the position where the swells of the isotherms form.

Recent strides in micro- and nanofabrication technology have enabled researchers to design and develop new micro- and nanorobots for biomedicine and environmental monitoring. Due to its non-invasive remote actuation and convenient navigation abilities, magnetic propulsion has been widely used in micro- and nanoscale robotic systems. In this article, a highly efficient Janus microdimer swimmer propelled by a rotating uniform magnetic field was investigated experimentally and numerically. The velocity of the Janus microdimer swimmer can be modulated by adjusting the magnetic field frequency with a maximum speed of 133 μm·s -1 (≈13.3 body length s -1 ) at the frequency of 32 Hz. Fast and accurate navigation of these Janus microdimer swimmers in complex environments and near obstacles was also demonstrated. This efficient propulsion behavior of the new Janus microdimer swimmer holds considerable promise for diverse future practical applications ranging from nanoscale manipulation and assembly to nanomedicine.

Neddylation of the Cullin-RING E3 ligases (CRLs) regulates the homeostasis of approximately 20% of cellular proteins. Defective in cullin neddylation 1 (DCN1), as a co-E3 ligase, interacts with UBE2M to enhance the activation of CRLs, and this interaction is emerging as a therapeutic target for human diseases. Here, we present a series of pyrimidin-based small molecular inhibitors targeting DCN1-UBE2M interaction. After finding a novel inhibitor DC-1 with IC 50 = 1.2 μM, we performed a series of chemical optimizations, which finally led to the discovery of a potent thiazole containing 5-cyano-6-phenylpyrimidin-based inhibitor DC-2 (IC 50 = 15 nM). Next, using protein and cellular thermal shift assays, coimmunoprecipitation, molecular docking, and site-specific mutation experiments, we further proved that DC-2 specifically inhibited the interaction of UBE2M and DCN1 at molecule and cellular levels, resulting in the decrease of cullin3 neddylation and accumulation of its substrate, NRF2. Our findings indicate that DC-2 may serve as a novel lead compound for specific derivatives targeting DCN1-UBE2M interaction.