Active Delivery of VLPs Promotes Anti-Tumor Activity in a Mouse Ovarian Tumor Model

Nanomotor-enhanced transport of passive Brownian particles in porous media

Artificial micro/nanomotors are expected to perform tasks in interface-rich and species-rich environments for biomedical and environmental applications. In these highly confined and interconnected pore spaces, active species may influence the motion of coexisting passive participants in unexpected ways. Using three-dimensional super-resolution single-nanoparticle tracking, we observed enhanced motion of passive nanoparticles due to the presence of dilute well-separated nanomotors in an interconnected pore space. This enhancement acted at distances that are large compared to the sizes of the particles and cavities, in contrast with the insignificant effect on the passive particles with the same dilute concentration of nanomotors in an unconfined liquid. Experiments and simulations suggested an amplification of hydrodynamic coupling between self-propelled and passive nanoparticles in the interconnected confined environment, which enhanced the effective energy for passive particles to escape cavities through small holes. This finding represents an emergent behavior of confined nanomotors and suggests new strategies for the development of antifouling membranes and drug delivery systems.

Micromotor-Enabled Active Hydrogen and Tobramycin Delivery for Synergistic Sepsis Therapy

Sepsis is a highly heterogeneous syndrome normally characterized by bacterial infection and dysregulated systemic inflammatory response that leads to multiple organ failure and death. Single anti-inflammation or anti-infection treatment exhibits limited survival benefit for severe cases. Here a biodegradable tobramycin-loaded magnesium micromotor (Mg-Tob motor) is successfully developed as a potential hydrogen generator and active antibiotic deliverer for synergistic therapy of sepsis. The peritoneal fluid of septic mouse provides an applicable space for Mg-water reaction. Hydrogen generated sustainably and controllably from the motor interface propels the motion to achieve active drug delivery along with attenuating hyperinflammation. The developed Mg-Tob motor demonstrates efficient protection from anti-inflammatory and antibacterial activity both in vitro and in vivo. Importantly, it prevents multiple organ failure and significantly improves the survival rate up to 87.5% in a high-grade sepsis model with no survival, whereas only about half of mice survive with the individual therapies. This micromotor displays the superior therapeutic effect of synergistic hydrogen-chemical therapy against sepsis, thus holding great promise to be an innovative and translational drug delivery system to treat sepsis or other inflammation-related diseases in the near future.

A drug co-delivery platform made of magnesium-based micromotors enhances combination therapy for hepatoma carcinoma cells

Combination therapy is an emerging strategy to overcome multidrug resistance (MDR) in hepatocellular carcinoma (HCC) chemotherapy treatment. However, the passive diffusion in traditional delivery systems greatly retards the approach and penetration of drugs into hepatocellular carcinoma cells and thus hinders the efficacy of combination therapy. Micro/nanomotors with autonomous locomotion in a tiny scale provide the possibility of tackling this issue. Herein, an active drug delivery micromotor platform delicately designed to load drugs with different physicochemical properties and enhance the drug permeability of cells is demonstrated for HCC chemotherapy treatment. The biocompatible micromotor platform Mg/PLGA/CHI comprised magnesium (Mg) coated with two polymer layers made of poly(lactic-co-glycolic acid) (PLGA) and chitosan (CHI), where the hydrophobic and hydrophilic drugs doxorubicin (Dox) and Curcumin (Cur) were loaded, respectively. The autonomous motion of the micromotors with velocity up to 45 μm s-1 greatly enhanced the diffusion of chemotherapeutic drugs and led to higher extracellular and intracellular drug distribution. Moreover, hydrogen produced during the motion eliminated the excess reactive oxygen species (ROS) in the human hepatocellular carcinoma (HepG2) cells. Compared with inert groups, the absorption of Dox and Cur from the active micromotors was about 2.9 and 1.5 times higher in human hepatocellular carcinoma (HepG2) cells. In addition, the anti-tumor activity also obviously improved at the micromotor concentration of 1 mg mL-1 (cell proliferation was reduced by almost 30%). Overall, this work proposes an approach based on loading different chemotherapy agents on an active delivery system to enhance drug permeability and overcome MDR and provides a potentially effective therapeutic strategy for the treatment of HCC.

Self-Propelled Janus Nanocatalytic Robots Guided by Magnetic Resonance Imaging for Enhanced Tumor Penetration and Therapy

Biomedical micro/nanorobots as active delivery systems with the features of self-propulsion and controllable navigation have made tremendous progress in disease therapy and diagnosis, detection, and biodetoxification. However, existing micro/nanorobots are still suffering from complex drug loading, physiological drug stability, and uncontrollable drug release. To solve these problems, micro/nanorobots and nanocatalytic medicine as two independent research fields were integrated in this study to achieve self-propulsion-induced deeper tumor penetration and catalytic reaction-initiated tumor therapy in vivo. We presented self-propelled Janus nanocatalytic robots (JNCRs) guided by magnetic resonance imaging (MRI) for in vivo enhanced tumor therapy. These JNCRs exhibited active movement in H₂O₂ solution, and their migration in the tumor tissue could be tracked by non-invasive MRI in real time. Both increased temperature and reactive oxygen species production were induced by near-infrared light irradiation and iron-mediated Fenton reaction, showing great potential for tumor photothermal and chemodynamic therapy. In comparison with passive nanoparticles, these self-propelled JNCRs enabled deeper tumor penetration and enhanced tumor therapy after intratumoral injection. Importantly, these robots with biocompatible components and byproducts exhibited biosecurity in the mouse model. It is expected that our work could promote the combination of micro/nanorobots and nanocatalytic medicine, resulting in improved tumor therapy and potential clinical transformations.

Design of Disintegrable Nanoassemblies to Release Multiple Small-Sized Nanoparticles

The therapeutic and diagnostic effects of nanoparticles depend on the efficiency of their delivery to targeted tissues, such as tumors. The size of nanoparticles, among other characteristics, plays a crucial role in determining their tissue penetration and retention. Small nanoparticles may penetrate deeper into tumor parenchyma but are poorly retained, whereas large ones are distributed around tumor blood vessels. Thus, compared to smaller individual nanoparticles, assemblies of such nanoparticles due to their larger size are favorable for prolonged blood circulation and enhanced tumor accumulation. Upon reaching the targeted tissues, nanoassemblies may dissociate at the target region and release the smaller nanoparticles, which is beneficial for their distribution at the target site and ultimate clearance. The recent emerging strategy that combines small nanoparticles into larger, biodegradable nanoassemblies has been demonstrated by several groups. This review summarizes a variety of chemical and structural designs for constructing stimuli-responsive disintegrable nanoassemblies as well as their different disassembly routes. These nanoassemblies have been applied as demonstrators in the fields of cancer therapy, antibacterial infection, ischemic stroke recovery, bioimaging, and diagnostics. Finally, we summarize stimuli-responsive mechanisms and their corresponding nanomedicine designing strategies, and discuss potential challenges and barriers towards clinical translation.

In vivo applications of micro/nanorobots

Untethered robots in the size range of micro/nano-scale offer unprecedented access to hard-to-reach areas of the body. In these challenging environments, autonomous task completion capabilities of micro/nanorobots have been the subject of research in recent years. However, most of the studies have presented preliminary in vitro results that can significantly differ under in vivo settings. Here, we focus on the studies conducted with animal models to reveal the current status of micro/nanorobotic applications in real-world conditions. By a categorization based on target locations, we highlight the main strategies employed in organs and other body parts. We also discuss key challenges that require interest before the successful translation of micro/nanorobots to the clinic.

Virus-like particle-based nanocarriers as an emerging platform for drug delivery

New nanocarrier technologies are emerging, and they have great potential for improving drug delivery, targeting efficiency, and bioavailability. Virus-like particles (VLPs) are natural nanoparticles from animal and plant viruses and bacteriophages. Hence, VLPs present several great advantages, such as morphological uniformity, biocompatibility, reduced toxicity, and easy functionalisation. VLPs can deliver many active ingredients to the target tissue and have great potential as a nanocarrier to overcome the limitations associated with other nanoparticles. This review will focus primarily on the construction and applications of VLPs, particularly as a novel nanocarrier to deliver active ingredients. Herein, the main methods for the construction, purification, and characterisation of VLPs, as well as various VLP-based materials used in delivery systems are summarised. The biological distribution of VLPs in drug delivery, phagocyte-mediated clearance, and toxicity are also discussed.

Biosynthesis of a VLP-type nanocarrier specific to cancer cells using the BEVS expression system for targeted drug delivery

OBJECTIVE

Canine parvovirus (CPV) is a small virus without an envelope that consists of three viral proteins including VP1, VP2, and VP3. Exclusively, the VP2 can form a typically CPV-sized virus-like particle (CPV-VLP) that can be used as a biological nanocarrier for diagnostic and therapeutic purposes since these VLPs can target cancer cells specially through the transferrin surface receptors (TFRs). Consequently, we aimed to produce these nanocarriers to be used for specific targeting of cancer cells.

METHODS

Sf9 insect cells were transfected with constructed recombinant bacmid shuttle vector encoding an enhanced green fluorescent protein (EGFP) and CPV-VP2 by the cationic lipids of Cellfectin II. Subsequently, two recombinant baculoviruses expressing EGFP and VP2 were produced and expression of VP2 was increased under the optimal condition. In consequence, the CPV-VLP nanoparticles composed of recombinant VP2 subunits were extracted. The purity of VLPs was then evaluated by SDS-PAGE, and the structural integrity and quality of the final product were evaluated by TEM and HA methods. Eventually, the size distribution of the produced biological nanoparticles and their uniformity were determined by the DLS method.

RESULTS

The expression of EGFP protein was confirmed by fluorescent microscopy, and the expression of VP2 protein was evaluated by SDS-PAGE and western blotting. Infected Sf9 insect cells also showed cytopathic effects (CPEs), and the maximum expression of VP2 occurred at MOI of 10 (pfu/cell) at the harvest time of 72 h post-infection (hpi). After performing various stages of purification, buffer exchange, and concentration, the quality and structural integrity of the VLP product were confirmed. The results of the DLS technique showed the presence of uniform particles (PdI below 0.5) with an approximate size of 25 nm.

CONCLUSION

The results indicate BEVS as an appropriate and efficient system for generating CPV-VLPs, and the used method based on two-stage ultracentrifugation was appropriate for purifying these nanoparticles. Produced nanoparticles can be used as the biologic nano-carriers in future studies.

Targeted therapy and immunotherapy: Diamonds in the rough in the treatment of epithelial ovarian cancer

Currently, for ovarian cancer, which has the highest mortality rate among all gynecological cancers, the standard treatment protocol is initial tumor cytoreductive surgery followed by platinum-based combination chemotherapy. Although the survival rate after standard treatment has improved, the therapeutic effect of traditional chemotherapy is very limited due to problems such as resistance to platinum-based drugs and recurrence. With the advent of the precision medicine era, molecular targeted therapy has gradually entered clinicians' view, and individualized precision therapy has been realized, surpassing the limitations of traditional therapy. The detection of genetic mutations affecting treatment, especially breast cancer susceptibility gene (BRCA) mutations and mutations of other homologous recombination repair defect (HRD) genes, can guide the targeted drug treatment of patients, effectively improve the treatment effect and achieve a better patient prognosis. This article reviews different sites and pathways of targeted therapy, including angiogenesis, cell cycle and DNA repair, and immune and metabolic pathways, and the latest research progress from preclinical and clinical trials related to ovarian cancer therapy.

Nanomedicine Strategies for Heating "Cold" Ovarian Cancer (OC): Next Evolution in Immunotherapy of OC

Immunotherapy has revolutionized cancer treatment, dramatically improving survival rates of melanoma and lung cancer patients. Nevertheless, immunotherapy is almost ineffective against ovarian cancer (OC) due to its cold tumor immune microenvironment (TIM). Many traditional medications aimed at remodeling TIM are often associated with severe systemic toxicity, require frequent dosing, and show only modest clinical efficacy. In recent years, emerging nanomedicines have demonstrated extraordinary immunotherapeutic effects for OC by reversing the TIM because the physical and biochemical features of nanomedicines can all be harnessed to obtain optimal and expected tissue distribution and cellular uptake. However, nanomedicines are far from being widely explored in the field of OC immunotherapy due to the lack of appreciation for the professional barriers of nanomedicine and pathology, limiting the horizons of biomedical researchers and materials scientists. Herein, a typical cold tumor-OC is adopted as a paradigm to introduce the classification of TIM, the TIM characteristics of OC, and the advantages of nanomedicines for immunotherapy. Subsequently, current nanomedicines are comprehensively summarized through five general strategies to substantially enhance the efficacy of immunotherapy by heating the cold OC. Finally, the challenges and perspectives of this expanding field for improved development of clinical applications are also discussed.

“Motile-targeting” drug delivery platforms based on micro/nanorobots for tumor therapy

Traditional drug delivery systems opened the gate for tumor-targeted therapy, but they generally took advantage of enhanced permeability and retention or ligand-receptor mediated interaction, and thus suffered from limited recognition range (<0.5 nm) and low targeting efficiency (0.7%, median). Alternatively, micro/nanorobots (MNRs) may act as emerging “motile-targeting” drug delivery platforms to deliver therapeutic payloads, thereby making a giant step toward effective and safe cancer treatment due to their autonomous movement and navigation in biological media. This review focuses on the most recent developments of MNRs in “motile-targeting” drug delivery. After a brief introduction to traditional tumor-targeted drug delivery strategies and various MNRs, the representative applications of MNRs in “motile-targeting” drug delivery are systematically streamlined in terms of the propelling mechanisms. Following a discussion of the current challenges of each type of MNR in biomedical applications, as well as future prospects, several promising designs for MNRs that could benefit in “motile-targeting” drug delivery are proposed. This work is expected to attract and motivate researchers from different communities to advance the creation and practical application of the “motile-targeting” drug delivery platforms.

Suitability of potyviral recombinant virus-like particles bearing a complete food allergen for immunotherapy vaccines

Virus-like particles (VLPs) have been gaining attention as potential platforms for delivery of cargos in nanomedicine. Although animal viruses are largely selected due to their immunostimulatory capacities, VLPs from plant viruses constitute a promising alternative to be considered. VLPs derived from Turnip mosaic virus (TuMV) have proven to present a tridimensional structure suited to display molecules of interest on their surface, making them interesting tools to be studied in theragnostic strategies. Here, we study their potential in the treatment of food allergy by genetically coupling TuMV-derived VLPs to Pru p 3, one of the most dominant allergens in Mediterranean climates. VLPs-Pru p 3 were generated by cloning a synthetic gene encoding the TuMV coat protein and Pru p 3, separated by a linker, into a transient high-expression vector, followed by agroinfiltration in Nicotiana benthamiana plants. The generated fusion protein self-assembled in planta to form the VLPs, which were purified by exclusion chromatography. Their elongated morphology was confirmed by electron microscopy and their size (~400 nm), and monodispersity was confirmed by dynamic light scattering. Initial in vitro characterization confirmed that they were able to induce proliferation of human immune cells. This proliferative capability was enhanced when coupled with the natural lipid ligand of Pru p 3. The resultant formulation, called VLP-Complex, was also able to be transported by intestinal epithelial cells, without affecting the monolayer integrity. In light of all these results, VLP-Complex was furtherly tested in a mouse model of food allergy. Sublingual administration of VLP-Complex could effectively reduce some serological markers associated with allergic responses in mice, such as anti-Pru p 3 sIgE and sIgG2a. Noteworthy, no associated macroscopic, nephritic, or hepatic toxicity was detected, as assessed by weight, blood urea nitrogen (BUN) and galectin-3 analyses, respectively. Our results highlight the standardized production of allergen-coated TuMV-VLPs in N. benthamiana plants. The resulting formula exerts notable immunomodulatory properties without the need for potentially hazardous adjuvants. Accordingly, no detectable toxicity associated to their administration was detected. As a result, we propose them as good candidates to be furtherly studied in the treatment of immune-based pathologies.

Micro/Nanorobots for Medical Diagnosis and Disease Treatment

Micro/nanorobots are functional devices in microns, at nanoscale, which enable efficient propulsion through chemical reactions or external physical field, including ultrasonic, optical, magnetic, and other external fields, as well as microorganisms. Compared with traditional robots, micro/nanorobots can perform various tasks on the micro/nanoscale, which has the advantages of high precision, strong flexibility, and wide adaptability. In addition, such robots can also perform tasks in a cluster manner. The design and development of micro/nanorobots and the integration of surface functionalization, remote drive system, and imaging tracking technology will become a key step for their medical applications in organisms. Thus, micro/nanorobots are expected to achieve more efficient and accurate local diagnosis and treatment, and they have broad application prospects in the biomedical field. This paper aims to introduce relevant driving methods of micro/nanorobots preparation in detail, summarizes the progress of research in medical applications, and discusses the challenges it faces in clinical applications and the future direction of development.

Physical Disruption of Solid Tumors by Immunostimulatory Microrobots Enhances Antitumor Immunity

The combination of immunotherapy with other forms of treatment is an emerging strategy for boosting antitumor responses. By combining multiple modes of action, these combinatorial therapies can improve clinical outcomes through unique synergisms. Here, a microrobot-based strategy that integrates tumor tissue disruption with biological stimulation is shown for cancer immunotherapy. The microrobot is fabricated by loading bacterial outer membrane vesicles onto a self-propelling micromotor, which can react with water to generate a propulsion force. When administered intratumorally to a solid tumor, the disruption of the local tumor tissue coupled with the delivery of an immunostimulatory payload leads to complete tumor regression. Additionally, treatment of the primary tumor results in the simultaneous education of the host immune system, enabling it to control the growth of distant tumors. Overall, this work introduces a distinct application of microrobots in cancer immunotherapy and offers an attractive strategy for amplifying cancer treatment efficacy when combined with conventional therapies.

Precise Control of Customized Macrophage Cell Robot for Targeted Therapy of Solid Tumors with Minimal Invasion

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 magnetically controlled cell robot (MCR) based on a macrophage drug carrier is proposed. Here, living macrophages are converted into MCRs through endocytosis of specially-designed magnetic nanoparticles loaded with doxorubicin and indocyanine green. Following this, the MCRs can be transported to tumors through the blood vessels using external magnetic fields, and penetrate the blood vessels into the interior of the tumor due to their deformability. With the MCR's cascaded drug release, targeted killing of tumors in mice is demonstrated, with minimal effects on the normal surrounding tissue. The ability to impart precise drug doses onto natural cells, such as macrophages, and load various functional components into the MCRs, offers an efficient method for precise targeted therapy.

Nanotechnology-Assisted RNA Delivery: From Nucleic Acid Therapeutics to COVID-19 Vaccines

In recent years, the main quest of science has been the pioneering of the groundbreaking biomedical strategies needed for achieving a personalized medicine. Ribonucleic acids (RNAs) are outstanding bioactive macromolecules identified as pivotal actors in regulating a wide range of biochemical pathways. The ability to intimately control the cell fate and tissue activities makes RNA-based drugs the most fascinating family of bioactive agents. However, achieving a widespread application of RNA therapeutics in humans is still a challenging feat, due to both the instability of naked RNA and the presence of biological barriers aimed at hindering the entrance of RNA into cells. Recently, material scientists' enormous efforts have led to the development of various classes of nanostructured carriers customized to overcome these limitations. This work systematically reviews the current advances in developing the next generation of drugs based on nanotechnology-assisted RNA delivery. The features of the most used RNA molecules are presented, together with the development strategies and properties of nanostructured vehicles. Also provided is an in-depth overview of various therapeutic applications of the presented systems, including coronavirus disease vaccines and the newest trends in the field. Lastly, emerging challenges and future perspectives for nanotechnology-mediated RNA therapies are discussed.

Biosafety, Functionalities, and Applications of Biomedical Micro/nanomotors

Due to their unique ability to actively move, micro/nanomotors offer the possibility of breaking through the limitations of traditional passive drug delivery systems for the treatment of many diseases, and have attracted the increasing attention of researchers. However, at present, the realization of many advantages of micro/nanomotors in disease treatment in vivo is still in its infancy, because of the complexity and particularity of diseases in different parts of human body. In this Minireview, we first focus on the biosafety and functionality of micro/nanomotors as a biomedical treatment system. Then, we address the treatment difficulties of various diseases in vivo (such as ophthalmic disease, orthopedic disease, gastrointestinal disease, cardiovascular disease, and cancer), and then review the research progress of biomedical micro/nanomotors in the past 20 years, Finally, we propose the challenges in this field and possible future development directions.

Recent progress in targeted delivery vectors based on biomimetic nanoparticles

Over the past decades, great interest has been given to biomimetic nanoparticles (BNPs) since the rise of targeted drug delivery systems and biomimetic nanotechnology. Biological vectors including cell membranes, extracellular vesicles (EVs), and viruses are considered promising candidates for targeted delivery owing to their biocompatibility and biodegradability. BNPs, the integration of biological vectors and functional agents, are anticipated to load cargos or camouflage synthetic nanoparticles to achieve targeted delivery. Despite their excellent intrinsic properties, natural vectors are deliberately modified to endow multiple functions such as good permeability, improved loading capability, and high specificity. Through structural modification and transformation of the vectors, they are pervasively utilized as more effective vehicles that can deliver contrast agents, chemotherapy drugs, nucleic acids, and genes to target sites for refractory disease therapy. This review summarizes recent advances in targeted delivery vectors based on cell membranes, EVs, and viruses, highlighting the potential applications of BNPs in the fields of biomedical imaging and therapy industry, as well as discussing the possibility of clinical translation and exploitation trend of these BNPs.

Interactions between Biomedical Micro-/Nano-Motors and the Immune Molecules, Immune Cells, and the Immune System: Challenges and Opportunities

Mobile micro- and nano-motors (MNMs) emerge as revolutionary platforms for biomedical applications, including drug delivery, biosensing, non-invasive surgery, and cancer therapy. While for applications in biomedical fields and practical clinical translation, the interactions of these untethered tiny machines with the immune system is an essential issue to be considered. This review highlights the recent approaches of surpassing immune barriers to prevent foreign motors from triggering immune responses. In addition to trials focusing on the function preservation of MNMs, examples of versatile MNMs working with the immune components (immune molecules, immune cells and the whole system) to achieve cancer immunotherapy, immunoassay, and detoxification are outlined. The immune interference part provides researchers an idea about what is the limit presented by the immune components. The coworking part suggests ways to bypass or even utilize the limit. With interdisciplinary cooperation of nanoengineering, materials science, and immunology field, the rationally designed functional MNMs are expected to provide novel opportunities for the biomedical field.

The pharmacology of plant virus nanoparticles

The application of nanoparticles for medical purposes has made enormous strides in providing new solutions to health problems. The observation that plant virus-based nanoparticles (VNPs) can be repurposed and engineered as smart bio-vehicles for targeted drug delivery and imaging has launched extensive research for improving the therapeutic and diagnostic management of various diseases. There is evidence that VNPs are promising high value nanocarriers with potential for translational development. This is mainly due to their unique features, encompassing structural uniformity, ease of manufacture and functionalization by means of expression, chemical biology and self-assembly. While the development pipeline is moving rapidly, with many reports focusing on engineering and manufacturing aspects to tailor the properties and efficacy of VNPs, fewer studies have focused on gaining insights into the nanotoxicity of this novel platform nanotechnology. Herein, we discuss the pharmacology of VNPs as a function of formulation and route of administration. VNPs are reviewed in the context of their application as therapeutic adjuvants or nanocarrier excipients to initiate, enhance, attenuate or impede the formulation's toxicity. The summary of the data however also underlines the need for meticulous VNP structure-nanotoxicity studies to improve our understanding of their in vivo fates and pharmacological profiles to pave the way for translation of VNP-based formulations into the clinical setting.

Virus-mimetic systems for cancer diagnosis and therapy

Over past decades, various strategies have been developed to enhance the delivery efficiency of therapeutics and imaging agents to tumor tissues. However, the therapeutic outcome of tumors to date have not been significantly improved, which can be partly attributed to the weak targeting ability, fast elimination, and low stability of conventional delivery systems. Viruses are the most efficient agents for gene transfer, serving as a valuable source of inspiration for designing nanoparticle-based delivery systems. Based on the properties of viruses, including well-defined geometry, precise composition, easy modification, stable construction, and specific infection, researchers attempt to design biocompatible delivery vectors by mimicking virus assembly and using the vector system to selectively concentrate drugs or imaging probes in tumors with mitigated toxicity and improved efficacy. In this review, we introduce common viruses features and provide an overview of various virus-mimetic strategies for cancer therapy and diagnosis. The challenges faced by virus-mimetic systems are also discussed. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Research Progress of Micro/Nanomotors for Cancer Treatment

Nanomaterials have been widely used in cancer treatment and have achieved remarkable results. However, the specificity of the tumor microenvironment and a series of biological barriers (such as blood flow, cell membrane, dense tissue, etc.) have caused many obstacles faced by nanomaterials after entering the human body, which makes traditional drug delivery vehicles have insurmountable difficulties, such as low delivery efficiency, poor permeability, etc. The micro/nanomotors with autonomous movement capabilities provide the possibility to solve the above problems. Therefore, this review summarizes the current researches of micro/nanomotors strategies to overcome the different biological barriers of nanomaterials in cancer treatment. The advantages and disadvantages of three typical micro/nanomotors (biological, physical and chemical micro/nanomotors) in cancer treatment are summarized separately, and the future design of micro/nanomotors more suitable for tumor environment was discussed.

Medical Micro/Nanorobots in Precision Medicine

Advances in medical robots promise to improve modern medicine and the quality of life. Miniaturization of these robotic platforms has led to numerous applications that leverages precision medicine. In this review, the current trends of medical micro and nanorobotics for therapy, surgery, diagnosis, and medical imaging are discussed. The use of micro and nanorobots in precision medicine still faces technical, regulatory, and market challenges for their widespread use in clinical settings. Nevertheless, recent translations from proof of concept to in vivo studies demonstrate their potential toward precision medicine.