A Novel Approach for Treating Lipomas: Percutaneous Microwave Ablation Combined with Liposuction.

Lipomas, benign adipose tissue tumors, are a common occurrence but currently, the options for their treatment are limited, with surgical excision being the most frequently used management pathway. This scenario can often lead to unsatisfactory cosmetic results and significant patient discomfort. This paper introduces a novel technique, percutaneous microwave ablation with liposuction, to address these challenges. The innovative procedure aims to enhance patient satisfaction, minimize post-operative discomfort, and improve aesthetic outcomes. The technique involves two key steps: (1) the application of percutaneous microwave ablation to selectively disrupt the lipoma cells, followed by (2) a targeted liposuction procedure to remove the ablated lipoma tissue. Our approach optimizes the removal of the lipoma and preserves the surrounding healthy tissue, reducing the risk of local recurrence and improving the cosmetic result. The use of preoperative ultrasound imaging allows for precise localization and delineation of the lipoma, aiding in the planning and execution of the procedure. This novel approach to lipoma treatment is reliable, associated with minimal morbidity, and consistently yields effective results. Additionally, it provides a new perspective on lipoma management, potentially changing the paradigm of current treatment approaches.Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Artificial Vascular with Pressure-Responsive Property based on Deformable Microfluidic Channels.

In vitro blood vessel models are significant for disease modeling, drug assays, and therapeutic development. Microfluidic technologies allow to create physiologically relevant culture models reproducing the features of the in vivo vascular microenvironment. However, current microfluidic technologies are limited by impractical rectangular cross-sections and single or nonsynchronous compound mechanical stimuli. This study proposes a new strategy for creating round-shaped deformable soft microfluidic channels to serve as artificial in vitro vasculature for developing in vitro models with vascular physio-mechanical microenvironments. Endothelial cells seeded into vascular models are used to assess the effects of a remodeled in vivo mechanical environment. Furthermore, a 3D stenosis model is constructed to recapitulate the flow disturbances in atherosclerosis. Soft microchannels can also be integrated into traditional microfluidics to realize multifunctional composite systems. This technology provides new insights into applying microfluidic chips and a prospective approach for constructing in vitro blood vessel models.

A Multidrug Delivery Microrobot for the Synergistic Treatment of Cancer.

Multidrug combination therapy provides an effective strategy for malignant tumor treatment. This paper presents the development of a biodegradable microrobot for on-demand multidrug delivery. By combining magnetic targeting transportation with tumor therapy, it is hypothesized that loading multiple drugs on different regions of a single magnetic microrobot can enhance a synergistic effect for cancer treatment. The synergistic effect of using two drugs together is greater than that of using each drug separately. Here, a 3D-printed microrobot inspired by the fish structure with three hydrogel components: skeleton, head, and body structures is demonstrated. Made of iron oxide (Fe3 O4 ) nanoparticles embedded in poly(ethylene glycol) diacrylate (PEGDA), the skeleton can respond to magnetic fields for microrobot actuation and drug-targeted delivery. The drug storage structures, head, and body, made by biodegradable gelatin methacryloyl (GelMA) exhibit enzyme-responsive cargo release. The multidrug delivery microrobots carrying acetylsalicylic acid (ASA) and doxorubicin (DOX) in drug storage structures, respectively, exhibit the excellent synergistic effects of ASA and DOX by accelerating HeLa cell apoptosis and inhibiting HeLa cell metastasis. In vivo studies indicate that the microrobots improve the efficiency of tumor inhibition and induce a response to anti-angiogenesis. The versatile multidrug delivery microrobot conceptualized here provides a way for developing effective combination therapy for cancer.

Biodegradable Microrobots for DNA Vaccine Delivery.

The delivery of nucleic acid vaccine to stimulate host immune responses against Coronavirus disease 2019 shows promise. However, nucleic acid vaccines have drawbacks, including rapid clearance and poor cellular uptake, that limit their therapeutic potential. Microrobots can be engineered to sustain vaccine release and further control the interactions with immune cells that are vital for robust vaccination. Here, the 3D fabrication of biocompatible and biodegradable microrobots via the two-photon polymerization of gelatin methacryloyl (GelMA) and their proof-of-concept application for DNA vaccine delivery is reported. Programmed degradation and drug release by varying the local exposure dose in 3D laser lithography and further functionalized the GelMA microspheres with polyethyleneimine for DNA vaccine delivery to dendritic cell and primary cells is demonstrated. In mice, the DNA vaccine delivered by functionalized microspheres elicited fast, enhanced, and durable antigen expression, which may lead to prolonged protection. Furthermore, we demonstrate the maneuverability of microrobots by fabricating GelMA microspheres on magnetic skeletons. In conclusion, GelMA microrobots may provide an efficient vaccination strategy by controlling the expression duration of DNA vaccines.

Mechanism analysis of efficient degradation of carbamazepine by chalcopyrite-activated persulfate.

In this study, natural chalcopyrite (NCP) was used to activate peroxymonosulfate (PMS) to degrade carbamazepine (CBZ) oxidatively. Before and after the NCP reaction, the physical and chemical properties were characterized by SEM-EDS, XRD, XPS, XRF, and VSM. The effects of the amount of NCP and PMS, the initial pH value, and the reaction temperature on the catalytic performance of NCP were systematically studied. The research results show that the degradation efficiency of the NCP/PMS system for CBZ can reach 82.34% under the optimal reaction conditions, and the degradation process follows a pseudo-second-order kinetic model. The results of the radical quenching experiment and EPR analysis show that the active species in the system are OH·, SO4-·, and 1O2, of which SO4-· is the main active species. In addition, this study shows that the NCP/PMS system can degrade CBZ with high efficiency of 90.73% only with the assistance of 0.15 g/L Fe0. This study determined the optimal reaction conditions for natural chalcopyrite to activate PMS to degrade CBZ and clarified the activation mechanism, which broadened the application of natural ores in the field of water treatment.

Producing Genetically Engineered Macrophages With Enhanced Immunity via Microinjection.

Many virus-mediated and chemical-based methods for delivering foreign genes into target cells, such as recombinant lentivirus transfection and cationic lipid transfection, are remarkably challenging to use on immune cells because of low efficiency and high toxicity. Microinjection is a promising method to deliver foreign gene expression plasmids into single macrophages directly. This paper reports a new method that can be used to produce a genetically engineered macrophage cell line with enhanced immunity through a home-made high-throughput microinjection system. Microinjection of the expression plasmid carrying a mouse-derived toll-like receptor 4 (Tlr4) gene into a mouse macrophage cell line (Raw264.7) can construct a new stable cell line overexpressing the target gene. The expression efficiency of the target gene in the injected Raw264.7 cells reached 90%, which was measured by injecting a particular plasmid carrying a fused enhanced green fluorescent protein (eGFP) gene fragment with the Tlr4 gene and counting the proportion of cells that emitted green fluorescence. Further assessment of the messenger RNA (mRNA) and protein produced by the Tlr4 gene indicated that its expression was up-regulated remarkably in successfully injected cells. The expression of downstream genes of Tlr4 in injected cells was higher than in untouched cells. Microinjection can avoid polarization effects, which are common when traditional transfection methods are used. A case study was conducted to verify that the injected macrophages overexpressing Tlr4 could activate downstream signaling pathways and showed enhanced inhibition effect on tumor cell migration and invasion. The success of this research will verify that microinjection can be an efficient and safe method in cell transfection applications.

Knock-In of a Large Reporter Gene via the High-Throughput Microinjection of the CRISPR/Cas9 System.

The non-viral delivery of the prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) nuclease system provides promising solutions for gene therapy. However, traditional chemical and physical delivery approaches for gene knock-in are confronted by significant challenges to overcome the drawbacks of low efficiency and high toxicity. An alternative method for directly delivering CRISPR components into single cells is microinjection. Here, we present the high-throughput robotic microinjection of CRISPR machinery plasmids to produce gene insertions. We demonstrate that the microinjection of CRISPR/Cas9 with an enhanced green fluorescent protein (eGFP) donor template into single HepG2 cells can achieve reporter gene knock-in targeting the adeno-associated virus site 1 locus. Homology-directed repair-mediated knock-in can be observed with an efficiency of 41%. Assessment via T7E1 assay indicates that the eGFP knock-in cells exhibit no detectable changes at potential off-target sites. A case study of injecting the eGFP knock-in cells into zebrafish (Danio rerio) embryos to form an in vivo tumor model is conducted. Results demonstrate the efficiency of combining microinjection with the CRISPR/Cas9 system in achieving gene knock-in.

Effects of Gene Delivery Approaches on Differentiation Potential and Gene Function of Mesenchymal Stem Cells.

Introduction of a gene to mesenchymal stem cells (MSCs) is a well-known strategy to purposely manipulate the cell fate and further enhance therapeutic performance in cell-based therapy. Viral and chemical approaches for gene delivery interfere with differentiation potential. Although microinjection as a physical delivery method is commonly used for transfection, its influence on MSC cell fate is not fully understood. The current study aimed to evaluate the effects of four nonviral gene delivery methods on stem cell multi-potency. The four delivery methods are robotic microinjection, polyethylenimine (PEI), cationic liposome (cLipo), and calcium phosphate nanoparticles (CaP). Among the four methods, microinjection has exhibited the highest transfection efficiency of ∼60%, while the three others showed lower efficiency of 10-25%. Robotic microinjection preserved fibroblast-like cell morphology, stress fibre intactness, and mature focal adhesion complex, while PEI caused severe cytotoxicity. No marked differentiation bias was observed after microinjection and cLipo treatment. By contrast, CaP-treated MSCs exhibited excessive osteogenesis, while PEI-treated MSCs showed excessive adipogenesis. Robotic microinjection system was used to inject the CRISPR/Cas9-encoding plasmid to knock out PPARγ gene in MSCs, and the robotic microinjection did not interfere with PPARγ function in differentiation commitment. Meanwhile, the bias in osteo-adipogenic differentiation exhibited in CaP and PEI-treated MSCs after PPARγ knockout via chemical carriers. Our results indicate that gene delivery vehicles variously disturb MSCs differentiation and interfere with exogenous gene function. Our findings further suggest that robotic microinjection offers a promise of generating genetically modified MSCs without disrupting stem cell multi-potency and therapeutic gene function.

Sonoelectrochemical activation of peroxymonosulfate: Influencing factors and mechanism of FA degradation, and application on landfill leachate treatment.

In this work, sonoelectrochemically activated peroxymonosulfate (US-EC/PMS) was used to degrade fulvic acid (FA) in water. Compared with other technologies, the US-EC/PMS system can achieve higher FA decolorization in a short time. Moreover, the benefits of synergy are more prominent in the US-EC/PMS system. The effects of operating parameters on the sonoelectrochemical degradation of FA were investigated, including initial pH, initial FA concentration, current density, ultrasonic power, PMS dosage. The results showed the initial FA concentration and current density were critical to the degradation of FA. Under optimized parameters: initial pH of 2, 50 mg L-1 initial FA concentration, 30 mA cm-2 current density, 50 W ultrasonic power, 1 mM PMS dosage, the US-EC/PMS system can achieve 93% FA decolorization. The calculation results of current efficiency and energy consumption indicate that the introduction of PMS into the US-EC system has economic applicability. Scavenger experiments and electron paramagnetic resonance suggest that hydroxyl radicals, sulfate radicals, and singlet oxygen were the main ROS produced in the US-EC/PMS system. Accordingly, the possible mechanism of FA degradation by sonoelectrochemical activation PMS was proposed. Finally, the US-EC/PMS system was used to treat the aged landfill leachate. Three-dimensional fluorescence analysis showed that most of the humic substances (Hss) were effectively removed, and the biodegradability of the leachate was considerably improved. In addition, the effective removal of COD, chroma, and ammonia nitrogen were observed, proving that this technology is a powerful means to treat organic wastewater contaminated by Hss.

Dynamic regulation of mitochondrial-endoplasmic reticulum crosstalk during stem cell homeostasis and aging.

Cellular therapy exerts profound therapeutic potential for curing a broad spectrum of diseases. Adult stem cells reside within a specified dynamic niche in vivo, which is essential for continuous tissue homeostatic maintenance through balancing self-renewal with lineage selection. Meanwhile, adult stem cells may be multipotent or unipotent, and are present in both quiescent and actively dividing states in vivo of the mammalians, which may switch to each other state in response to biophysical cues through mitochondria-mediated mechanisms, such as alterations in mitochondrial respiration and metabolism. In general, stem cells facilitate tissue repair after tissue-specific homing through various mechanisms, including immunomodulation of local microenvironment, differentiation into functional cells, cell "empowerment" via paracrine secretion, immunoregulation, and intercellular mitochondrial transfer. Interestingly, cell-source-specific features have been reported between different tissue-derived adult stem cells with distinct functional properties due to the different microenvironments in vivo, as well as differential functional properties in different tissue-derived stem cell-derived extracellular vehicles, mitochondrial metabolism, and mitochondrial transfer capacity. Here, we summarized the current understanding on roles of mitochondrial dynamics during stem cell homeostasis and aging, and lineage-specific differentiation. Also, we proposed potential unique mitochondrial molecular signature features between different source-derived stem cells and potential associations between stem cell aging and mitochondria-endoplasmic reticulum (ER) communication, as well as potential novel strategies for anti-aging intervention and healthy aging.

Development of Magnet-Driven and Image-Guided Degradable Microrobots for the Precise Delivery of Engineered Stem Cells for Cancer Therapy.

Precise delivery of therapeutic cells to the desired site in vivo is an emerging and promising cellular therapy in precision medicine. This paper presents the development of a magnet-driven and image-guided degradable microrobot that can precisely deliver engineered stem cells for orthotopic liver tumor treatment. The microrobot employs a burr-like porous sphere structure and is made with a synthesized composite to fulfill degradability, mechanical strength, and magnetic actuation capability simultaneously. The cells can be spontaneously released from the microrobots on the basis of the optimized microrobot structure. The microrobot is actuated by a gradient magnetic field and guided by a unique photoacoustic imaging technology. In preclinical experiments on nude mice, microrobots carrying cells are injected via the portal vein and the released cells from the microrobots can inhibit the tumor growth greatly. This paper reveals for the first time of using degradable microrobots for precise delivery of therapeutic cells in vascular tissue and demonstrates its therapeutic effect in preclinical test.

Gravitational sedimentation-based approach for ultra-simple and flexible cell patterning coculture on microfluidic device.

Combining patterning coculture technique with microfluidics enables the reconstruction of complex in-vivo system to facilitate in-vitro studies on cell-cell and cell-environment interactions. However, simple and versatile approaches for patterning coculture of cells on microfluidic platforms remain lacking. In this study, a novel gravitational sedimentation-based approach is presented to achieve ultra-simple and flexible cell patterning coculture on a microfluidic platform, where multiple cell types can be patterned simultaneously to form a well-organized cell coculture. In contrast to other approaches, the proposed approach allows the rapid patterning of multiple cell types in microfluidic channels without the use of sheath flow and a prepatterned functional surface. This feature greatly simplifies the experimental setup, operation, and chip fabrication. Moreover, cell patterning can be adjusted by simply modifying the cell-loading tubing direction, thereby enabling great flexibility for the construction of different cell patterns without complicating the chip design and flow control. A series of physical and biological experiments are conducted to validate the proposed approach. This research paves a new way for building physiologically realistic in-vitro coculture models on microfluidic platforms for various applications, such as cell-cell interaction and drug screening.

Precise Drug Delivery by Using PLGA-Based Microspheres and Optical Manipulators.

The accurate delivery of precise amounts of drugs to a specific location can considerably affect various clinical applications. The precise control of drug amount and position is crucial to a successful drug delivery. This paper proposes the use of poly(lactide-co-glycolicacid) (PLGA)-based microspheres to contain precise amounts of drugs and an optical tweezer manipulator to transport these drug-containing microspheres to their targeted sites in vivo. The drugs were delivered by the PLGA-based microspheres to the yolk sac of zebrafish embryos, and a sustained drug release was observed to examine the anti-angiogenesis and angiogenesis activities. The PLGA-based microspheres degraded in zebrafish, thereby verifying that these microspheres can be used as drug carriers in vivo to ensure good biocompatibility and biodegradation. The proposed precise drug delivery approach can be used in protein tests and drug property characterization in vivo.

Translational and rotational manipulation of filamentous cells using optically driven microrobots.

Optical cell manipulation has become increasingly valuable in cell-based assays. In this paper, we demonstrate the translational and rotational manipulation of filamentous cells using multiple cooperative microrobots automatically driven by holographic optical tweezers. The photodamage of the cells due to direct irradiation of the laser beam can be effectively avoided. The proposed method will enable fruitful biomedical applications where precise cell manipulation and less photodamage are required.

Lgr5-overexpressing mesenchymal stem cells augment fracture healing through regulation of Wnt/ERK signaling pathways and mitochondrial dynamics.

Fracture remains one of the most common traumatic conditions in orthopedic surgery. The use of mesenchymal stem cells (MSCs) to augment fracture repair is promising. Leucine-rich repeat-containing GPCR 5 (Lgr5), a transmembrane protein, has been identified as a novel adult stem cell marker in various organs and tissues. However, the roles of Lgr5 in MSCs are not fully understood. In this study, we investigated cellular functions of Lgr5 in MSCs and its potential implications in treating fracture. Lgr5-overexpressing MSCs (MSCLgr5) were established in murine SV40 promoter-driven luciferase reporter MSC line through virus transfection. Results of real-time quantitative PCR and Western blot analysis confirmed the increased expression of Lgr5 in MSCLgr5. MSCLgr5 exhibited increased osteogenic capacity, which may result from elevated expression of ß-catenin and phosphorylated ERK1/2 within the nuclear region of cells. In contrast, inhibition of Lgr5 expression decreased the osteogenic differentiation ability of MSCs, accompanied with increased mitochondrial fragmentation and reduced expression of ß-catenin. Local transplantation of MSCLgr5 at fracture sites accelerated fracture healing via enhanced osteogenesis and angiogenesis. MSCLgr5 stimulated the tube formation capacity of HUVECs in a Matrigel coculture system in vitro significantly. Taken together, results suggest that Lgr5 is implicated in the cellular processes of osteogenic differentiation of MSCs through regulation of Wnt and ERK signaling pathways and mitochondrial dynamics in fusion and fission. Inhibition of Lgr5 expression induced increased mitochondrial fragmentation and suppression of osteogenesis. MSCLgr5 exhibited enhanced therapeutic efficacy for fracture healing, which may serve as a superior cell source for bone tissue repair.-Lin, W., Xu, L., Pan, Q., Lin, S., Feng, L., Wang, B., Chen, S., Li, Y., Wang, H., Li, Y., Wang, Y., Lee, W. Y. W., Sun, D., Li, G. Lgr5-overexpressing mesenchymal stem cells augment fracture healing through regulation of Wnt/ERK signaling pathways and mitochondrial dynamics.

Calcium Spike Patterns Reveal Linkage of Electrical Stimulus and MSC Osteogenic Differentiation.

Mesenchymal stromal/stem cells (MSCs) are easily obtained multipotent cells that are widely applied in regenerative medicine. Electrical stimulation (ES) has a promoting effect on bone healing and osteogenic differentiation of MSCs. Direct and alternating currents (AC) are extensively used to promote the osteogenic differentiation of MSCs in vivo and in vitro. However, information on conducting effective differentiation remains scarce. In this paper, we propose a method to optimize ES parameters based on calcium spike patterns of MSCs. Calcium spike frequency decreases as the osteogenic differentiation of MSC progresses. Furthermore, we tested various ES parameters through the real-time monitoring of calcium spike patterns. We efficiently initiated the process of osteogenic differentiation in MSCs by using the optimal parameters of AC, including voltage, signal shapes, frequency, and duty time. This method provides a new approach to optimize osteogenic differentiation and is potentially useful in clinical treatment such as of bone fractures.

Magnetic Force-driven in Situ Selective Intracellular Delivery.

Intracellular delivery of functional materials holds great promise in biologic research and therapeutic applications but poses challenges to existing techniques, including the reliance on exogenous vectors and lack of selectivity. To address these problems, we propose a vector-free approach that utilizes millimeter-sized iron rods or spheres driven by magnetic forces to selectively deform targeted cells, which in turn generates transient disruption in cell membranes and enables the delivery of foreign materials into cytosols. A range of functional materials with the size from a few nanometers to hundreds of nanometers have been successfully delivered into various types of mammalian cells in situ with high efficiency and viability and minimal undesired effects. Mechanistically, material delivery is mediated by force-induced transient membrane disruption and restoration, which depend on actin cytoskeleton and calcium signaling. When used for siRNA delivery, CXCR4 is effectively silenced and cell migration and proliferation are significantly inhibited. Remarkably, cell patterns with various complexities are generated, demonstrating the unique ability of our approach in selectively delivering materials into targeted cells in situ. In summary, we have developed a magnetic force-driven intracellular delivery method with in situ selectivity, which may have tremendous applications in biology and medicine.

A simplified sheathless cell separation approach using combined gravitational-sedimentation-based prefocusing and dielectrophoretic separation.

Prefocusing of the cell mixture is necessary for achieving a high-efficiency and continuous dielectrophoretic (DEP) cell separation. However, prefocusing through sheath flow requires a complex and tedious peripheral system for multi-channel fluid control, hindering the integration of DEP separation systems with other microfluidic functionalities for comprehensive clinical and biological tasks. This paper presented a simplified sheathless cell separation approach that combines gravitational-sedimentation-based sheathless prefocusing and DEP separation methods. Through gravitational sedimentation in a tubing, which was inserted into the inlet of a microfluidic chip with an adjustable steering angle, the cells were focused into a stream at the upstream region of a microchannel prior to separation. Then, a DEP force was applied at the downstream region of the microchannel for the active separation of the cells. Through this combined strategy, the peripheral system for the sheath flow was no longer required, and thus the integration of cell separation system with additional microfluidic functionalities was facilitated. The proposed sheathless scheme focused the mixture of cells with different sizes and dielectric properties into a stream in a wide range of flow rates without changing the design of the microfluidic chip. The DEP method is a label-free approach that can continuously separate cells on the basis of the sizes or dielectric properties of the cells and thus capable of greatly flexible cell separation. The efficiency of the proposed approach was experimentally assessed according to its performance in the separation of human acute monocytic leukemia THP-1 cells from yeast cells with respect to different sizes and THP-1 cells from human acute myelomonocytic leukemia OCI-AML3 cells with respect to different dielectric properties. The experimental results revealed that the separation efficiency of the method can surpass 90% and thus effective in separating cells on the basis of either size or dielectric property.

Microfluidic platform for probing cancer cells migration property under periodic mechanical confinement.

Cancer cell migration and invasion, which are involved in tumour metastasis, are hard to predict and control. Numerous studies have demonstrated that physical cues influence cancer cell migration and affect tumour metastasis. In this study, we proposed the use of a microchannel chip equipped with a number of vertical constrictions to produce periodic compression forces on cells passing through narrow channels. The chip with repeated vertical confinement was applied on adherent MHCC-97L liver cancer cells and suspended OCI-AML leukaemia cells to determine the migration ability of these cancer cells. Given the stimulation of the periodic mechanical confinement on-chip, the migration ability of cancer cells was promoted. Moreover, the migration speed increased as the stimulation was enhanced. Both AFM nanoindentation and optical stretching tests on cancer cells were performed to measure their mechanical property. After confinement stimulation, the cancer cells possessed higher deformability and lower stiffness than non-stimulating cells. The confinement stimulation altered the cell cytoskeleton, which governs the migration speed. This phenomenon was determined through gene expression analysis. The proposed on-chip cell migration assays will help characterise the migration property of cancer cells and benefit the development of new therapeutic strategies for metastasis.

Development of a magnetic microrobot for carrying and delivering targeted cells.

The precise delivery of targeted cells through magnetic field-driven microrobots/carriers is a promising technique for targeted therapy and tissue regeneration. This paper presents a microrobot designed with a burr-like porous spherical structure for carrying and delivering targeted cells in vivo under a magnetic gradient field-driven mechanism. The robot was fabricated by using three-dimensional laser lithography and coated with Ni for magnetic actuation and Ti for biocompatibility. Numerical and experimental studies demonstrated that the proposed microrobot design could enhance magnetic driving capability, promote cell-carrying capacity, and benefit cell viability. Microrobots loaded with cells could be automatically controlled to reach a desired site by using a self-constructed electromagnetic coil system, as verified by in vivo transport of cell-cultured microrobots in zebrafish embryos. The carried cells could be spontaneously released from the microrobot to the surrounding tissues; in vitro experiments showed that cells from the microrobot were directly released onto the desired site or were able to pass through the blood vessel-like microchannel to arrive at the delivery area. Further in vivo cell-releasing tests were performed on nude mice, followed by histological study. This research provides a microrobotic device platform for regenerative medicine and cell-based therapy.