Modular-designed engineered bacteria for precision tumor immunotherapy via spatiotemporal manipulation by magnetic field

Magnetotactic bacteria-mediated integrated magnetic targeted hyperthermia for in-situ deep-seated tumor

Unlike hyperthermia after intratumoral injection, the method of integrated magnetic targeted hyperthermia (iMTH) guides magnetic medium to the target site and then directly performs in-situ heating, showing great potential for effective treatment of deep-seated tumors in the body. Magnetotactic bacteria (MTB), having chain-like arranged magnetic nanoparticles within its body and active movement along an external magnetic field, are considered as a very fitted material for iMTH. However, the amount of MTB concentrated on the deep-seated tumor posed a significant challenge for the successful implementation of iMTH. Herein, we aim to validate the strategy of integrating magnetic targeting and hyperthermia. An in-situ liver tumor model in mouse was developed as deep-seated tumors. After administering the polar MTB MO-1 intravenously via the tail vein, a focusing magnetic field navigated these bacteria to effectively accumulate at the deep-seated tumor site. Immediately afterwards, this targeted aggregation of MO-1 cells triggered a localized magnetic hyperthermia directly at the cancer site under an applied alternating magnetic field. Our findings demonstrated that this hyperthermia induced by the bacteria led to the death of liver cancer cells, thereby effectively curbing the progression and growth of the cancer. These promising results suggested that an iMTH approach was developed, harnessing the power of MTB. This method stands as an exciting and potential therapeutic strategy for the treatment of deep-seated tumors, offering new hope in the fight against cancer.

Unraveling the potential of bioengineered microbiome-based strategies to enhance cancer immunotherapy

The human microbiome plays a pivotal role in the field of cancer immunotherapy. The microbial communities that inhabit the gastrointestinal tract, as well as the bacterial populations within tumors, have been identified as key modulators of therapeutic outcomes, affecting immune responses and reprogramming the tumor microenvironment. Advances in synthetic biology have made it possible to reprogram and engineer these microorganisms to improve antitumor activity, enhance T-cell function, and enable targeted delivery of therapies to neoplasms. This review discusses the role of the microbiome in modulating both innate and adaptive immune mechanisms-ranging from the initiation of cytokine production and antigen presentation to the regulation of immune checkpoints-and discusses how these mechanisms improve the efficacy of immune checkpoint inhibitors. We highlight significant advances with bioengineered strains like Escherichia coli Nissle 1917, Lactococcus lactis, Bifidobacterium, and Bacteroides, which have shown promising antitumor efficacy in preclinical models. These engineered microorganisms not only efficiently colonize tumor tissues but also help overcome resistance to standard therapies by reprogramming the local immune environment. Nevertheless, several challenges remain, such as the requirement for genetic stability, effective tumor colonization, and the control of potential safety issues. In the future, the ongoing development of genetic engineering tools and the optimization of bacterial delivery systems are crucial for the translation of microbiome-based therapies into the clinic. This review highlights the potential of bioengineered microbiota as an innovative, personalized approach in cancer immunotherapy, bringing hope for more effective and personalized treatment options for patients with advanced malignancies.

Designing live bacterial therapeutics for cancer

Humans are home to a diverse community of bacteria, many of which form symbiotic relationships with their host. Notably, tumors can also harbor their own unique bacterial populations that can influence tumor growth and progression. These bacteria, which selectively colonize hypoxic and acidic tumor microenvironments, present a novel therapeutic strategy to combat cancer. Advancements in synthetic biology enable us to safely and efficiently program therapeutic drug production in bacteria, further enhancing their potential. This review provides a comprehensive guide to utilizing bacteria for cancer treatment. We discuss key considerations for selecting bacterial strains, emphasizing their colonization efficiency, the delicate balance between safety and anti-tumor efficacy, and the availability of tools for genetic engineering. We also delve into strategies for precise spatiotemporal control of drug delivery to minimize adverse effects and maximize therapeutic impact, exploring recent examples of engineered bacteria designed to combat tumors. Finally, we address the underlying challenges and future prospects of bacterial cancer therapy. This review underscores the versatility of bacterial therapies and outlines strategies to fully harness their potential in the fight against cancer.

Paving the way for bacteria-based drug delivery: biohybrid microrobots emerging from microrobotics and synthetic biology

Advances in microrobotics and synthetic biology are paving the way for innovative solutions to long-standing challenges in drug delivery. Both fields have independently worked on engineering bacteria as a therapeutic system, focusing on enhancing propulsion, cargo delivery, detection, and biocompatibility. Bacteria, with their inherent adaptability and functional versatility, serve as an ideal foundation for these efforts, enabling them to navigate complex biological environments such as the human body. This review explores the convergence of microrobotics and synthetic biology, which has catalysed the development of biohybrid bacterial microrobots that integrate the strengths of both disciplines. By incorporating external control modalities - such as light, ultrasound, and magnetic fields - these hybrid systems address the limitations of purely microrobotic or biological approaches, offering new opportunities to enhance precision and efficacy in targeted therapies. However, realising the full potential of biohybrid bacterial microrobots requires overcoming critical challenges, such as ensuring compatibility between biological and synthetic components, scaling manufacturing processes, and defining regulatory pathways tailored to living therapeutics. Addressing these hurdles through joint, interdisciplinary research efforts, can unlock the transformative possibilities of these systems in modern medicine.

Surface-functionalized bacteria: Frontier explorations in next-generation live biotherapeutics

Screening robust living bacteria to produce living biotherapeutic products (LBPs) represents a burgeoning research field in biomedical applications. Despite their natural abilities to colonize bio-interfaces and proliferate, harnessing bacteria for such applications is hindered by considerable challenges in unsatisfied functionalities and safety concerns. Leveraging the high degree of customization and adaptability on the surface of bacteria demonstrates significant potential to improve therapeutic outcomes and achieve tailored functionalities of LBPs. This review focuses on the recent laboratory strategies of bacterial surface functionalization, which aims to address these challenges and potentiate the therapeutic effects in biomedicine. Firstly, we introduce various functional materials that are used for bacterial surface functionalization involving organic, inorganic, and biological materials. Secondly, the methodologies for achieving bacterial surface functionalization are categorized into three primary approaches including covalent bonding, non-covalent interactions, and hybrid techniques, while various advantages and limitations of different modification strategies are compared from multiple perspectives. Subsequently, the current status of the applications of surface-functionalized bacteria in bioimaging and disease treatments, especially in the treatment of inflammatory bowel disease (IBD) and cancer is summarized. Finally, challenges and pressing issues in the development of surface-functionalized bacteria as LBPs are presented.

Magnetoliposomes for nanomedicine: synthesis, characterization, and applications in drug, gene, and peptide delivery

INTRODUCTION

Magnetoliposomes represent a transformative advancement in nanomedicine by integrating magnetic nanoparticles with liposomal structures, creating multifunctional delivery platforms that overcome key limitations of conventional drug carriers. These hybrid systems enable precision targeting through external magnetic fields, controlled release via magnetic hyperthermia, and real-time theranostic capabilities, offering unprecedented spatiotemporal control over therapeutic administration.

AREAS COVERED

This manuscript focused primarily on studies from 2023-2025 however, a few select older references were included to provide background and context.This review examines the fundamental design principles of Magnetoliposomes, including bilayer composition, nanoparticle integration strategies, and physicochemical properties governing their biological performance. We comprehensively assess synthesis methodologies - from traditional thin-film hydration to advanced microfluidic approaches - highlighting their impact on colloidal stability, drug encapsulation, and scaling potential. Characterization techniques essential for quality control and regulatory approval are systematically reviewed, followed by applications across oncology, gene delivery, neurology, and infectious disease treatment, supported by recent experimental evidence.

EXPERT OPINION

While magnetoliposomes show remarkable therapeutic versatility, their clinical translation requires addressing biocompatibility concerns, manufacturing scalability, and regulatory hurdles. Integration with artificial intelligence, organ-on-chip technologies, and personalized medicine approaches will likely accelerate their development toward clinical reality, potentially revolutionizing treatment paradigms for complex diseases through tailored therapeutic interventions.

Unveiling the Power of Magnetic-Driven Regenerative Medicine: Bone Regeneration and Functional Reconstruction

To improve the treatment outcomes for large bone defects and osteoporosis, researchers have been committed to reducing bone loss and accelerating bone regeneration through cell transplantation, biomaterial intervention, and biophysical stimulation over the past few decades. Magnetism, as a noninvasive biophysical stimulus, has been employed in the repair of the musculoskeletal system, achieving a series of promising results. In this review, we provide a retrospective analysis and perspective of research on magnetic-driven bone regeneration and functional reconstruction. This review aims to delineate safe and efficient magnetic application modalities and to summarize the potential mechanisms by which magnetism regulates the behavior of skeletal lineage cells, thereby providing insights for the expansion and translational application of magnetic-driven regenerative medicine.

Programmable Bacterial Architects Crafting Sonosensitizers for Tumor-Specific Sonodynamic Immunotherapy

Sonodynamic therapy (SDT) is a non-invasive cancer treatment that uses ultrasound to activate sonosensitizers for selective tumor ablation. With its superior tissue penetration compared to photodynamic therapy, SDT demonstrates the potential to stimulate antitumor immune responses by modulating the tumor microenvironment. However, its clinical application remains limited by poor tumor specificity and suboptimal sonosensitizer accumulation, which reduces efficacy and causes off-target effects. To address these challenges, an Engineered Probiotic-based Calibrated 5-ALA Supply system (SPEC5) is developed to confer tumor selectivity for SDT. Engineered non-pathogenic E. coli with recombinant plasmids enables efficient 5-ALA biosynthesis through kinetic remodeling. Homologous tumor cell membrane cloaking further enhances tumor targeting and immune evasion. Upon intravenous injection, SPEC5 selectively colonizes in the tumor, supporting the sonosensitizer protoporphyrin IX (PpIX) in situ biosynthesis via 5-aminolevulinic acid (5-ALA) continuous supply. A hypoxia-inducible promoter regulating O-acetylserine sulfhydrylase ensures the tumor specificity of PpIX production. This system achieves robust sensitizer accumulation in tumors, enhancing SDT efficacy and inducing potent antitumor immune activation with minimal systemic toxicity. Post-treatment, the bacteria are rapidly cleared to ensure safety. This study presents a novel strategy for tumor-specific sonosensitizer supply, revolutionizing 5-ALA-based SDT and paving the way for advanced tumor-targeted therapies with enhanced immunotherapeutic outcomes.

Engineering advanced bacterial therapy for tumor and inflammatory diseases

Bacteria have emerged as a promising living medicine for diseases in recent years. With rapid advancements in synthetic biology and materials science, engineered bacterial therapy has encountered new opportunities. Leveraging inherent genetic reprogramming capabilities and surface chemistry modification advantages, engineered bacterial therapy enables selective functional recombination and precise spatiotemporal control, thereby enhancing therapeutic efficacy against diseases. This review summarizes the advantages of engineered bacterial therapy and various engineering strategies employed. Moreover, it outlines representative studies of engineered bacterial therapy in the treatment of tumors and inflammatory diseases, summarizing diverse engineered approaches that enhance the efficacy for these conditions, offering novel avenues for efficient disease management. In addition, current limitations and challenges in utilizing engineered bacterial therapy are discussed, providing insights for further innovation in biomedicine. Specifically, the potential and prospects of oral engineered bacteria in treating gastrointestinal tumors and inflammatory diseases have been explored.

X-ray-Responsive Semiconducting Polymer siRNA Nanosystems for Orthotopic Glioma Treatment via Silencing the Immunosuppressive Signal

Gliomas are the most lethal types of adult brain tumors with a devastating prognosis, but many therapies have failed to exert good therapeutic benefits because of the extremely hypoxic and immunosuppressive tumor microenvironment. To address these challenges, we herein present a semiconducting polymer (SP)-based small interfering RNA (siRNA) nanosystem with the loading of oxygen self-supplying perfluorohexane (PFH) and conjugation of siRNA via a singlet oxygen (1O2)-cleavable linker. The nanosystems are further camouflaged with a macrophage membrane to obtain the final RM@SPN-siRNA. RM@SPN-siRNA displays an enhanced enrichment at the orthotopic glioma site due to surface cell membrane camouflaging. PFH provides sufficient oxygen to relieve tumor hypoxia, which boosts the production of 1O2 by the SP working as the radiosensitizer under external X-ray irradiation. The generated 1O2 destroys the 1O2-cleavable linker and disrupts the membrane structure to enable in situ siRNA release at the tumor site and subsequent activatable programmed death ligand-1 (PD-L1) silencing for tumor cells. As a consequence, an immunological effect is triggered to effectively inhibit tumor growths in an orthotopic glioma mouse model. This study offers an X-ray-responsive siRNA nanosystem for precise protein silencing and treatment of deep-seated orthotopic tumors.

Recent Advances in Spatiotemporal Manipulation of Engineered Bacteria for Precision Cancer Therapy

Solid tumours possess a hypoxic and immunosuppressive microenvironment, presenting a significant challenge to anticancer treatments. Certain anaerobic microorganisms thrive in this setting, rendering them promising candidates for targeted antitumour therapy delivery. In contrast to traditional nanodrug delivery systems, bacterial-based drug delivery systems can be engineered to produce and secrete therapeutics without the need for intricate post-purification or protective delivery methods. Nevertheless, bacteria can potentially migrate beyond their intended niche, causing off-target drug release and substantial toxicity to healthy tissues. Consequently, to enhance the effectiveness of cancer treatments while minimizing side effects, it is essential to precisely manipulate bacteria for accurate and controlled drug delivery directly to the tumour site. This can be achieved by employing inducible or repressible systems that allow for precise regulation of gene expression at specific times and locations. Ideally, engineering bacteria capable of rapidly and precisely transitioning between "on" and "off" states as required will enable them to recognize and react to targeted stimuli. While various techniques such as optical, magnetic, acoustic, and hyperbaric oxygen micromanipulation have been developed for the manipulation of particles or cells, each technique boasts its unique set of pros and cons. This review article provides an updated overview of the recent progress in the spatiotemporal control of engineered bacteria via these methods and discusses the benefits and constraints of each approach.

Photoactivated in-situ engineered-bacteria as an efficient H2S generator to enhance photodynamic immunotherapy via remodeling the tumor microenvironment

Based on the unique biological advantages of bacteria and their derivatives, biosynthetic nanomaterials have been widely used in the field of tumor therapy. Although conventional bacterial treatments demonstrate potential in activating tumor immunity, their efficacy in inhibiting tumor growth remains constrained. In this study, a photoactivated hydrogen sulfide (H2S) generator was successfully prepared by in-situ engineering of bacteria, after Pt/MoS2 nanocomposites were in-situ generated by Escherichia coli (E. coli) and loaded with photosensitizer Ce6. This engineered-bacteria has been proved to have good tumor targeting ability and can enhance the effect of photodynamic therapy in the hypoxic tumor microenvironment. While reactive oxygen species (ROS) is effectively released, the fragmentation of bacteria can accelerate the release of abundant H2S, and promote tumor-specific H2S gas therapy, which can effectively remodel the tumor microenvironment and promote the activation of anti-tumor immunotherapy. This engineered bacteria not only improves the tumor specificity and effectiveness of H2S treatment, but also provides a new idea for nanomaterials in bacterial-mediated synergistic cancer treatment.

Restoration of TP53 strategy via specific nanoparticles for ovarian cancer therapy

The p53 tumor suppressor gene, a master regulator of diverse cellular pathways, is frequently altered in various cancers. Loss of function in tumor suppressor genes is commonly associated with the onset/progression of cancer and treatment resistance. Currently, approaches for restoration of TP53 expression, including small molecules and DNA therapies, have yielded progressive success, but each has formidable drawbacks. Here, we introduced an endogenous nanoplatform to effectively deliver the TP53 protein. Briefly speaking, the endogenous TP53 proteins were fused by the Lamp2b and loaded into extracellular vesicles-based nanoparticles, which could markedly restore the TP53 expression in natural TP53-deficient ovarian cancer (OCs) and subsequently inhibit cell proliferation as well as induce cell apoptosis. Moreover, a well-known biotin streptavidin binding strategy was used to confer the nanoplatform targeting ability. Since mesothelin (MSLN) expressed highly in ovarian cancer, the anti-MSLN nanoplatform were engineered to deliver TP53 proteins to MSLN ovarian cancer and exert the anti-tumor ability. Our findings indicated that restoration of tumor suppressors by the targeting nanoplatform could be promising nanotechnology approaches for potential ovarian cancer treatment.

Hump-inspired ingestible magnetic capsules enable circular nutrition storage and supply for short bowel syndrome treatment

Parenteral nutrition and intestinal transplantation, essential clinical interventions for short bowel syndrome (SBS) patients, are limited by various complications such as impaired intestinal barrier, metabolic disorder, catheter-associated infection, and allogenic rejection, leading to inferior therapeutic outcomes. Here, inspired by the camel hump, an ingestible magnetic capsule (IMC) consisting of thermosensitive hydrogel microparticles (MPs) based on poly(N-isopropylacrylamide) and acrylamide and a magnetic shell made of NdFeB and polyvinyl alcohol is proposed to enable circular nutrition storage and supply to optimize enteral nutrition for SBS treatment. Thermosensitive hydrogel MPs absorb excessive fluid and subsequently release nutrients in response to the heat generated by the photothermal effect of the magnetic shell under near-infrared irradiation. IMC can be localized and retained in the small intestine by the attraction between the magnetic shell and the external ferromagnet. In a SBS rat model, consistent nutrition optimization significantly relieves the weight loss, improves the nutrition-related serological markers, and facilitates the adaptation of the remnant small intestinal epithelium. This study offers a proof of principle for the use of ingestible capsules for nutrient storage and supply, providing a potential strategy for SBS treatment.

Bacteria-based biohybrids for remodeling adenosine-mediated immunosuppression to boost radiotherapy-triggered antitumor immune response

Radiotherapy (RT) can trigger immunogenic cell death (ICD) in tumor cells and release adenosine triphosphate (ATP) to activate antitumor immunity. However, the formation of immunosuppressive adenosine (ADO) mediated by ectonucleotidases including CD39 and CD73, can exacerbate the immunosuppressive effects. Herein, a radiosensitizer-based metal-organic framework (MOF) composed of bismuth (Bi) and ellagic acid (EA) was synthesized in situ on the surface of Escherichia coli Nissle 1917 (EcN) to serve as a carrier for the CD39 inhibitor sodium polyoxotungstate (POM-1). This therapeutic platform, acting as a radiosensitizer, significantly enhances cytotoxicity against tumor cells while effectively inducing ICD and releasing high concentrations of ATP. Subsequently, the released POM-1 increases the levels of pro-inflammatory extracellular ATP while preventing tumor immunosuppression caused by the accumulation of ADO. Additionally, as a natural immune adjuvant, EcN further promotes the maturation of dendritic cells (DCs) and the infiltration of cytotoxic T lymphocytes (CTLs). As a result, such treatment initiates the destruction of established tumor growth and induces strong abscopal effects, leading to a significant inhibition of tumor metastases. This strategy presents a bacterial-based biohybrid system that facilitates RT-induced ICD while simultaneously limiting the degradation of ATP into ADO, thereby achieving sustained anti-tumor immunity.

Microrobotic Swarms for Cancer Therapy

Microrobotic swarms hold great promise for the revolution of cancer treatment. The coordination of miniaturized microrobots offers a unique approach to treating cancers at the cellular level with enhanced delivery efficiency and environmental adaptability. Prior studies have summarized the design, functionalization, and biomedical applications of microrobotic swarms. The strategies for actuation and motion control of swarms have also been introduced. In this review, we first give a detailed introduction to microrobot swarming. We then explore the design of microrobots and microrobotic swarms specifically engineered for cancer therapy, with a focus on tumor targeting, infiltration, and therapeutic efficacy. Moreover, the latest developments in active delivery methods and imaging techniques that enhance the precision of these systems are discussed. Finally, we categorize and analyze the various cancer therapies facilitated by functional microrobotic swarms, highlighting their potential to revolutionize treatment strategies for different cancer types.

Empowering bacteria with light: Optogenetically engineered bacteria for light-controlled disease theranostics and regulation

Bacterial therapy has emerged as a promising approach for disease treatment due to its environmental sensitivity, immunogenicity, and modifiability. However, the clinical application of engineered bacteria is limited by differences of expression levels in patients and possible off-targeting. Optogenetics, which combines optics and genetics, offers key advantages such as remote controllability, non-invasiveness, and precise spatiotemporal control. By utilizing optogenetic tools, the behavior of engineered bacteria can be finely regulated, enabling on-demand control of the dosage and location of their therapeutic products. In this review, we highlight the latest advancements in the optogenetic engineering of bacteria for light-controlled disease theranostics and therapeutic regulation. By constructing a three-dimensional analytical framework of "sense-produce-apply", we begin by discussing the key components of bacterial optogenetic systems, categorizing them based on their photosensitive protein response to blue, green, and red light. Next, we introduce innovative light-producing tools that extend beyond traditional light sources. Then, special emphasis is placed on the biomedical applications of optogenetically engineered bacteria in treating diseases such as cancer, intestinal inflammation and systemic disease regulation. Finally, we address the challenges and future prospects of bacterial optogenetics, outlining potential directions for enhancing the safety and efficacy of light-controlled bacterial therapies. This review aims to provide insights and strategies for researchers working to advance the application of optogenetically engineered bacteria in drug delivery, precision medicine and therapeutic regulation.

Ultrasound-Energized OX40L-Expressing Biohybrid for Multidimensional Mobilization of Sustained T Cell-Mediated Antitumor Immunity and Potent Sono-Immunotherapy

Harnessing immunostimulation to reinvigorate antitumor effector immune cells represents a promising strategy for tumor eradication. However, achieving durable clinical outcomes necessitates multidimensional activation to sustain robust immune responses. Here, we present an ultrasound-empowered living biohybrid that strategically mobilizes T-cell-mediated immunity for potent tumor sono-immunotherapy. Through synthetic biology, we engineer bacteria to express a fusion protein encoding the costimulatory OX40 ligand (OX40L), and further functionalize them with a high-performance polymer sonosensitizer tethered via a reactive oxygen species-cleavable linker. Upon ultrasound irradiation, the sono-activated nanocargoes detach from the bacterial surface, facilitating cellular entry and exposing immune-stimulating OX40L. The potent sonodynamic effects, coupled with the native immunogenicity of bacteria, promotes tumor-associated antigen release, fosters a proinflammatory microenvironment, and drives dendritic cell maturation, thereby priming cytotoxic T-cell activation. The OX40L expressed by the engineered bacteria amplifies and sustains T-cell activity, orchestrating a robust and durable antitumor response. This cascade-amplified immune activation effectively suppresses tumor growth, induces long-lasting immune memory, and provides protection against tumor metastasis and recurrence, significantly enhancing survival outcomes. By integrating ultrasound-energized nanoadjuvants with costimulatory immune boosters, this hybrid living biotherapeutic platform offers a versatile and powerful strategy for multidimensional immune activation, advancing the frontier of cancer sono-immunotherapy.

Research progress on ultrasound in bacteria-mediated tumor treatment

Bacteria-mediated tumor treatment (BMTT) has recently garnered significant attention as a promising avenue in tumor treatment. Despite the application of various strains in animal models and clinical trials, the effectiveness of BMTT has been hindered by its toxicity and inefficiency. In recent years, it has been explored that applying the biological effects of ultrasound could further improve the precision and effectiveness of BMTT. This review briefly introduces the challenges of BMTT and summarizes how the biological effects of ultrasound improve the efficacy and safety of BMTT in strategies involving genetic engineering, visualization and targeted delivery. The potential application and limitations of ultrasound in advancing BMTT controllable strategies are also discussed.

Gut microbiota and gastrointestinal tumors: insights from a bibliometric analysis

Introduction

Despite the growing number of studies on the role of gut microbiota in treating gastrointestinal tumors, the overall research trends in this field remain inadequately characterized.

Methods

A bibliometric analysis was conducted using publications retrieved from the Web of Science Core Collection (up to September 30, 2024). Analytical tools including VOSviewer, CiteSpace, and an online bibliometric platform were employed to evaluate trends and hotspots.

Results

Analysis of 1,421 publications revealed significant geographical disparities in research output, with China and the United States leading contributions. Institutionally, the University of Adelaide, Zhejiang University, and Shanghai Jiao Tong University were prominent contributors. Authorship analysis identified Hannah R. Wardill as the most prolific author, while the International Journal of Molecular Sciences emerged as a leading journal. Rapidly growing frontiers include "proliferation," "inhibition," "immunotherapy," "drug delivery," and "tumorigenesis."

Discussion

This study provides a comprehensive overview of research trends and highlights emerging directions, aiming to advance scientific and clinical applications of gut microbiota in gastrointestinal tumor therapy.

Novel bioengineered drugs with immunotherapies for malignant pleural effusion: Remodulate tumor immune microenvironment and activate immune system

Malignant pleural effusion (MPE) remains a clinical issue since it is associated with advanced-stage cancers and dismal survival, with immunosuppressive tumor microenvironment (TME) and ineffective drug delivery. Conventional therapies such as thoracentesis and pleurodesis are for symptom relief but palliative, without inducing immunity and prolonging survival. Emerging new bioengineered drugs, synergizing with immunotherapies, offer a new paradigm by dual-targeting TME remodeling and immune activation. These technologies leverage nanotechnology, gene editing, and biomaterials to offer precise spatiotemporal control. This review illustrates the molecular mechanism of the immunosuppressive TME in MPE. It examines the newest bioengineering platforms-such as cytokine-encapsulated nanoparticles and oncolytic viruses-that can reactivate immune mechanisms. We highlight preclinical and clinical evidence of the effectiveness of combinatorial strategies in overcoming local immune tolerance and potential risks in adverse events. While the clinical transformation challenge remains, future directions necessitate cross-disciplinary convergence to engineer intelligent delivery vehicles and predictive biomarkers for patient stratification. By integrating immunotherapy with bioengineering, this strategy not only restores antitumor immunity but also portends a new epoch of precision medicine for MPE.

The therapeutic promise of probiotic Bacteroides fragilis (BF839) in cancer immunotherapy

Background

Overwhelming evidence suggests that the gut microbiota modulates tumor response to immune checkpoint inhibitors (ICIs). The probiotic Bacteroides fragilis (BF839) was extensively used in China to improve gut microbiota dysbiosis-related symptoms. We hypothesized that probiotic BF839 could enhance tumor sensitivity to ICIs.

Methods

In the preclinical studies, mice received BF839 orally, PD-1 intraperitoneal injection, or a combination therapy of the two agents. The antitumor effect of BF839 was investigated by assessing the tumor growth and tumor immune microenvironment. Mice fecal samples were collected for 16S rRNA sequencing. Fresh tumor samples were collected for 16S RNA sequencing. The data of 29 patients with advanced solid tumor who received BF839 adjuvant therapy were retrospectively evaluated. The primary endpoint was overall survival (OS).

Results

Among patients with advanced solid tumors undergoing ICIs and chemotherapy, patients in BF839 long-term adjuvant treatment group had longer OS (p = 0.0101) than the BF839 short-term adjuvant treatment group. In the preclinical studies, we found that monotherapy with BF839 or anti-PD-1 antibody significantly inhibit tumor growth. Interestingly, BF839 worked synergistically with anti-PD-1 antibody and induced tumor regression, mediated by increased CD8+T cell infiltration. Mechanistically, BF839 induced tumor suppression was regulated by the cGAS-STING pathway. 16S rRNA sequencing results of mice fecal samples showed that BF839 treatment increased gut microbiota diversity.

Conclusion

Overall, our data suggest that BF839 enhanced tumor sensitivity to ICIs through cGAS-STING signaling. In the future, the application of probiotic BF839 to regulate gut microbiota may be a new strategy to enhance the efficacy of ICIs.

Differential intracellular influence of cancer cells and normal cells on magnetothermal properties and magnetic hyperthermal effects of magnetic nanoparticles

Magnetic hyperthermia using heat locally generated by magnetic nanoparticles (MNPs) under an alternating magnetic field (AMF) to ablate cancer cells has attracted enormous attention. The high accumulation of MNPs and slow heat dissipation generated in tumors are considered the dominant factors involved in magnetic hyperthermia. However, the influence of intracellular microenvironment on magnetic hyperthermia has been ignored. This study unveiled for the first time the critical role of intracellular microenvironment on magnetic hyperthermia. The intracellular microenvironments of cancer cells and normal cells showed different influence on the magnetothermal properties and magnetic hyperthermia effects of MNPs. The MNPs in cancer cells could generate higher temperatures and induce higher rates of apoptosis than those in normal cells. Compared with that of normal cells, the intracellular microenvironment of cancer cells was more conducive to Brownian relaxation and the dynamic magnetic response of internalized MNPs. The cancerous intracellular microenvironment had a discriminative effect on the magnetic hyperthermal effect of MNPs due to the low viscoelasticity of cancer cells, which was verified by the softening or stiffening of cells and simulation models created using viscous liquids or elastic hydrogels. These findings suggest that the intracellular microenvironment should be considered another critical factor of the magnetic hyperthermal effect of MNPs.

SynBioNanoDesign: pioneering targeted drug delivery with engineered nanomaterials

Synthetic biology and nanotechnology fusion represent a transformative approach promoting fundamental and clinical biomedical science development. In SynBioNanoDesign, biological systems are reimagined as dynamic and programmable materials to yield engineered nanomaterials with emerging and specific functionalities. This review elucidates a comprehensive examination of synthetic biology's pivotal role in advancing engineered nanomaterials for targeted drug delivery systems. It begins with exploring the fundamental synergy between synthetic biology and nanotechnology, then highlights the current landscape of nanomaterials in targeted drug delivery applications. Subsequently, the review discusses the design of novel nanomaterials informed by biological principles, focusing on expounding the synthetic biology tools and the potential for developing advanced nanomaterials. Afterward, the research advances of innovative materials design through synthetic biology were systematically summarized, emphasizing the integration of genetic circuitry to program nanomaterial responses. Furthermore, the challenges, current weaknesses and opportunities, prospective directions, and ethical and societal implications of SynBioNanoDesign in drug delivery are elucidated. Finally, the review summarizes the transformative impact that synthetic biology may have on drug-delivery technologies in the future.

Tertiary lymphoid structure formation induced by LIGHT-engineered and photosensitive nanoparticles-decorated bacteria enhances immune response against colorectal cancer

Tertiary lymphoid structures (TLSs) are known to enhance the prognosis of patients with colorectal cancer (CRC) by fostering an immunologically active tumor microenvironment (TME). Inducing TLS formation therapeutically holds promise for treating immunologically cold CRC, though it poses technical challenges. Here, we design and fabricate a photosensitive bacterial system named E@L-P/ICG. This system is engineered bacteria internally loaded with the cytokine LIGHT and surface-modified with PLGA/ICG nanoparticles (P/ICG NPs). Once accumulated in orthotopic colonic tumors in mice, E@L-P/ICG generates a mild photothermal effect under laser irradiation due to the photosensitive P/ICG NPs. This photothermal effect triggers the self-rupture of E@L-P/ICG and the death of surrounding tumor cells to release adjuvants and antigens, respectively, which in turn synergistically activate the adaptive immune responses. Furthermore, the cytokine LIGHT released from ruptured E@L-P/ICG stimulates the generation of high endothelial vessels (HEVs), promoting lymphocyte recruitment within the TME. These mechanisms lead to the TLS formation in CRC, which further boosts adaptive immune responses through effective infiltration of T cells and B cells, resulting in effectively inhibited tumor growth and extended survival of mice. Our study shows the potential of the E@L-P/ICG system in photosensitively inducing the TLS formation to treat CRC in clinic.

On-Demand Controlled Release Multi-Drugs Delivery System for Spatiotemporally Synergizing Antitumor Immunotherapy

Although cytotoxic T lymphocytes (CTLs) activation combined with programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) axis blockade have emerged as an effective strategy to improve immunotherapeutic potency, it remains challenging to realize the spatiotemporal synergy of these two components. Herein, the study reports an engineered bacterial-based delivery system that can simultaneously promote CTLs infiltration and control PD-L1 binding protein (PD-L1 trap) release on demand at tumor site. The drug release button of this tumor targeting system is the specific temperature, which is accomplished by dual-modified melanin nanoparticles with photothermal conversion capacity on the engineered bacterial. These dual-modified nanoparticles can form in situ reservoir of heat supplier and antitumor immunity activator once arriving at tumor microenvironment (TME). Importantly, the study establishes the personalized administration regimen according to TME changes, and perform local laser irradiation to trigger PD-L1 trap production only in TME when infiltrated CTLs reach the highest level. This work provides a flexible platform for optimizing cancer immunotherapy.

Advances in magnetic nanoparticles for molecular medicine

Magnetic nanoparticles (MNPs) are highly versatile nanomaterials in nanomedicine, owing to their diverse magnetic properties, which can be tailored through variations in size, shape, composition, and exposure to inductive magnetic fields. Over four decades of research have led to the clinical approval or ongoing trials of several MNP formulations, fueling continued innovation. Beyond traditional applications in drug delivery, imaging, and cancer hyperthermia, MNPs have increasingly advanced into molecular medicine. Under external magnetic fields, MNPs can generate mechano- or thermal stimuli to modulate individual molecules or cells deep within tissue, offering precise, remote control of biological processes at cellular and molecular levels. These unique capabilities have opened new avenues in emerging fields such as genome editing, cell therapies, and neuroscience, underpinned by a growing understanding of nanomagnetism and the molecular mechanisms responding to mechanical and thermal cues. Research on MNPs as a versatile synthetic material capable of engineering control at the cellular and molecular levels holds great promise for advancing the frontiers of molecular medicine, including areas such as genome editing and synthetic biology. This review summarizes recent clinical studies showcasing the classical applications of MNPs and explores their integration into molecular medicine, with the goal of inspiring the development of next-generation MNP-based platforms for disease treatment.

Magnetically driven bionic nanorobots enhance chemotherapeutic efficacy and the tumor immune response via precise targeting

We developed magnetically driven bionic drug-loaded nanorobots (MDNs) to accurately target tumors and deliver chemotherapy agents using a customized three-dimensional (3D) magnetic manipulation platform (MMP) system to precisely control their movement mode. MDNs were based on polyethylene glycol-modified homogeneous ultrasmall iron oxide nanoparticles (7.02 ± 0.18 nm). Doxorubicin (12% ± 2% [w/w]) was encapsulated in MDNs by an imide bond. MDNs could imitate the movement mode of a school of wild herrings (e.g., re-dispersion/arrangement/vortex/directional movement) to adapt to the changing and complex physiological environment through the 3D MMP system. MDNs overcame blood flow resistance and biological barriers using optimized magnetic driving properties according to in vivo imaging (magnetic resonance imaging and fluorescence) and histopathology. The performance of fabricated MDNs was verified through cells and tumor-bearing mouse models. The MDNs showed high efficiency of drug delivery and targeting at the tumor site (>10-fold), lower toxicity than free doxorubicin (5 mg/kg body weight), activated immune response in the tumor site, and significantly lengthened survival for mice. The synergistic interaction between MDNs and the 3D MMP system underscores the immense potential of this drug delivery system, indicating a potential revolution in the field of tumor chemotherapy.

In Situ Fabrication of Electrospun Magnetic Film under Laparoscopic Guidance for Preventing Postoperative Recurrence of Hepatocellular Carcinoma

Despite laparoscopic-guided minimally invasive hepatectomy emerging as the primary approach for resecting hepatocellular carcinoma (HCC), there is still a significant gap in suitable biomaterials that seamlessly integrate with these techniques to achieve effective hemostasis and suppress residual tumors at the surgical margin. Electrospun films are increasingly used for wound closure, yet the employment of prefabricated electrospun films for hemostasis during minimally invasive HCC resection is hindered by prolonged operation times, complexity in implementation, limited visibility during surgery, and inadequate postoperative prevention of HCC recurrence. In this study, montmorillonite-iron oxide sheets are integrated into the polyvinylpyrrolidone (PVP) polymer framework, enhancing the resulting electrospun PVP/montmorillonite-iron oxide (MI) film (abbreviated as PMI) with robustness, hemostatic capability, and magnetocaloric properties. In contrast to the in vitro prefabricated electrospun films, the electrospun PMI film is designed to be formed in situ on liver wounds under laparoscopic guidance during hepatectomy. This design affords superior wound adaptability, facilitating meticulous wound closure and expeditious hemostasis, thereby simplifying the operative process and ultimately alleviating the workload of healthcare professionals. Moreover, when exposed to an alternating magnetic field, the film can efficiently ablate residual tumors, significantly augmenting the treatment efficacy of HCC.

Precision tumor treatment utilizing bacteria: principles and future perspectives

Bacteria-based tumor therapy, which releases therapeutic payloads or remodels the tumor's immune-suppressive microenvironment and directly kills tumor cells or initiates an anti-tumor immune response, is recently recognized as a promising strategy. Bacteria could be endowed with the capacities of tumor targeting, tumor cell killing, and anti-tumor immune activating by established gene engineering. Furthermore, the integration of synthetic biology and nanomedicine into these engineered bacteria could further enhance their efficacy and controllability. This comprehensive review systematically elucidates the classification and mechanisms of bacterial gene expression induction systems, as well as strategies for constructing bacterial-nanomaterial nanobiohybrids. The review concludes by highlighting the challenges associated with quality control and regulation of bacteria-based tumor therapy while also providing insights into the future prospects of this therapeutic technology. KEY POINTS: • A comprehensive overview of the current status of research on bacteria-based tumor therapy. • The classification and mechanisms of bacterial gene expression induction systems are summarized. • The challenges and perspectives in clinical translation.

Genetically Engineered Bacteria as A Living Bioreactor for Monitoring and Elevating Hypoxia-Activated Prodrug Tumor Therapy

Tirapazamine (TPZ), an antitumor prodrug, can be activated in hypoxic environment. It specifically targets the hypoxic microenvironment of tumors and produces toxic free radicals. However, due to the tumor is not completely hypoxic, TPZ often fails to effectively treat the entire tumor tissue, resulting in suboptimal therapeutic outcomes. Herein, a low pathogenic Escherichia coli TOP10 is utilized to selectively colonize tumor tissues, disrupt blood vessels, and induce thrombus formation, leading to the expansion of hypoxic region and improving the therapeutic effect of TPZ. Additionally, a thermosensitive hydrogel is constructed by Pluronic F-127 (F127), which undergoes gelation in situ at the tumor site, resulting in sustained release of TPZ. To monitor the therapeutic process, it is genetically modified TOP10 by integrating the bioluminescent system luxCDABE (TOP10-Lux). The bioluminescent signal is associated with tumor hypoxia enhancement and thrombus formation, which is beneficial for therapeutic monitoring with bioluminescence imaging. In the murine colon cancer model, the TOP10-Lux combined with TPZ-loaded F127 hydrogel effectively suppressed tumor growth, and the treatment process is efficiently monitored. Together, this work employs genetically modified TOP10-Lux to enhance the therapeutic efficacy of TPZ and monitor the treatment process, providing an effective strategy for bacteria-based tumor-targeted chemotherapy and treatment monitoring.

Magneto-Thermal Hydrogel Swarms for Targeted Lesion Sealing

Magnetic microswarms capable of performing navigation to targeted lesions show great potential for in vivo medical applications. However, using the swarms for lesion cavity filling encounters challenges from precise delivery and sealing. Herein, this work develops a magneto-thermal hydrogel swarm consisting of magnetic hydrogel particles, which can perform phase transition induced by temperature change. The particles are prepared using a temperature-responsive hydrogel matrix, tissue adhesive monomers, and magnetic microparticles. The swarms can be remolded to various shapes, and it can be used to seal perforation in phantom and gastric tissue. The swarms can also serve as drug carriers, and their drug release profiles induced by temperature changes are characterized. Finally, the targeted delivery, adaptive filling, and sealing of a gastric ulcer using the swarms are achieved in ex vivo and in vivo environments.

Harnessing nanoengineered CAR-T cell strategies to advance solid tumor immunotherapy

The efficacy and safety of chimeric antigen receptor (CAR) T cell therapy is still inconclusive in solid tumor treatment. Recently, nanotechnology has emerged as a potent strategy to reshape CAR-T cell therapy with promising outcomes. This review aims to discuss the significant potential of nano-engineered CAR-T cell therapy in addressing existing challenges, including CAR-T cell engineering evolution, tumor microenvironment (TME) modulation, and precise CAR-T cell therapy (precise targeting, monitoring, and activation), under the main consideration of clinical translation. It also focuses on the growing trend of technological convergence within this domain, such as mRNA therapeutics, organoids, neoantigen, and artificial intelligence. Moreover, safety management of nanomedicine is seriously emphasized to facilitate clinical translation.

Precisely Controlling the Activation of an Iron-Locked Drug Generator in the Liver Sinusoid to Enhance Barrier Penetration and Reduction of Liver Fibrosis

Complex physical barriers and the nanomaterial's clearance mechanism in the liver greatly hinder the feasibility of using a conventional liver-targeting nanoplatform to deliver antifibrotic drugs to pathological sites for the treatment of liver fibrosis. Here, a novel drug delivery strategy was designed to overcome drug penetration barriers in a fibrotic liver and cooperated with oral nattokinase (NKase)-mediated antifibrosis therapy as a proof of concept, which relies on the coadministration of a nanosized iron-locked drug generator (named Pro-HAase) and orally absorbed iron chelator deferasirox (DFX). Such a strategy starts from the rapid accumulation of intravenously injected Pro-HAase in the microcapillaries of the fibrotic liver followed by disrupting the polyphenol-iron coordination inside Pro-HAase by DFX, liberating antifibrotic components, including procyanidine (PA) and hyaluronidase (HAase). Attractively, absorption of DFX requires the sequential processes of traversing the intestinal mucosa and targeting the liver, which enable DFX to preferentially disassemble Pro-HAase accumulated in the liver sinusoid rather than in systemic circulation or other organs, thus avoiding the off-target activation of Pro-HAase and depletion of the normal iron pool. The in situ disassembly process decreases the sequestration of Pro-HAase by cells of the mononuclear phagocyte system and promotes gradient-driven permeation of therapeutic components to surrounding liver tissues within 2 h, accompanied by biliary excretion of the inactive iron-DFX complex. As a result, the cooperation of Pro-HAase and DFX not only allows NKase-mediated therapy to completely reverse liver fibrosis but also suppresses the chronic hepatotoxicity of residual liver iron after multiple doses of Pro-HAase. The high spatiotemporal precision, unique barrier-penetration mechanism, and self-detoxification ability of this strategy will inspire the rational design of analogous iron-locked nanosystems to improve the therapeutic outcomes of liver fibrosis or other liver diseases.

DNA Nanopatch-Specific Modification of Probiotics for Ultrasound-Triggered Inflammatory Bowel Disease Therapy

Probiotics offer promising results for treating inflammatory bowel disease, yet precision therapy remains challenging, particularly in manipulating probiotics spatially and temporally and shielding them from oxidative stress. To address these limitations, herein we synthesized bacteria-specific DNA nanopatches to modify ultrasound-triggered engineered Escherichia coli Nissle 1917. These probiotics produced the anti-inflammatory cytokine interleukin-10 when stimulated by ultrasound and were fortified with DNPs for oxidative stress resistance. The DNPs were composed of rectangular DNA origami nanosheets with reactive oxygen species' scavenging ability and bacterial targeting ligands of maltodextrin molecules. We systematically demonstrated that the DNPs could selectively attach to bacterial surface but not mammalian cell surface via the maltodextrin transporter pathway. To further enhance the bioavailability of engineered probiotics in the gastrointestinal tract, we employed a self-assembly strategy to encapsulate them using chitosan and sodium alginate. In a murine model of ulcerative colitis, this system significantly improved the gut barrier integrity and reduced inflammation. Our results indicate that this DNA nanopatch-bacteria system holds substantial promise for mitigating oxidative stress, correcting microbiota dysbiosis, and enhancing the intestinal barrier function in colitis.

A hypoxia-activated and microenvironment-remodeling nanoplatform for multifunctional imaging and potentiated immunotherapy of cancer

Activatable theranostic systems combining precise diagnosis and robust immune activation have significant potential in cancer treatment. Herein, we develop a versatile nanoplatform integrating hypoxia-activatable molecular imaging with effective photoimmunotherapy for cancer treatment. Our molecular probe features turn-on near-infrared-II (NIR-II) fluorescence and photoacoustic signals in hypoxic tumor environments. It also induces hypoxia-triggered photodynamic and photothermal effects, promoting immunogenic cell death and activating the STING pathway, engaging both innate and adaptive immunity. The molecular probe is formulated with a vascular disrupting agent to amplify the hypoxia-responsive phototheranostic properties, on which M1-like macrophage membrane is camouflaged to shield against premature release while conferring cancer-targeting affinity. The activatable NIR-II fluorescence and photoacoustic imaging enable precise tumor delineation, while the enhanced phototherapy activates tumor-specific cytotoxic T cells, impeding both primary and distant tumor progression and providing protective immunity against rechallenge in 4T1 tumor-bearing female mice. This work advances activatable theranostic protocols for image-guided immunotherapy.

Remolding the tumor microenvironment by bacteria augments adoptive T cell therapy in advanced-stage solid tumors

The intricate tumor microenvironment presents formidable obstacles to the efficacy of adoptive T cell therapy in the management of solid tumors by limiting the infiltration and inducing exhaustion of the transferred T cells. Here, we developed a bacterial-based adjuvant approach that augments the efficacy of adoptive T-cell therapy for solid tumor treatment. Our study reveals that intratumor injection of E. coli MG1655 normalizes tumor vasculatures and reprograms tumor-associated macrophages into M1 phenotype that produce abundant CCL5, together facilitating tumor infiltration of adoptively transferred T cells. The depletion of tumor-associated macrophages or CCL5 neutralization in vivo leads to the significantly decreased solid tumor infiltration of adoptive T cells in the presence of bacteriotherapy. This combinatorial therapy, consisting of E. coli adjuvant and adoptive T-cell therapy, effectively eradicates early-stage melanoma and inhibits the progression of pancreatic tumors. Notably, this dual strategy also strengthened the distal tumor control capabilities of adoptive T-cell therapy through the induction of in situ tumor vaccination. This dual therapeutic approach involving bacterial therapy targeting the interior of solid tumors and adoptive T-cell therapy attacking the tumor periphery exhibits potent therapeutic efficacy in achieving the eradication of advanced-stage tumors, including melanoma and hepatocellular carcinoma, by converging attacks from both inside and outside the tumor tissues.

Recent Advances and Challenges in Targeted Drug Delivery Using Biofunctional Coatings

Globally, clinics are overwhelmed by drugs targeting undesired cells and organs, causing adverse systemic effects on the body. This shortfall in targeting specificity, safety, and efficiency has noticeably contributed to the failure of the bench-to-bedside transition. Activation or impairment of immune activity due to a misdirected drug and its carrier fuels complications, extending the range of destruction which can convert the course of disease into a life-threatening route. To address these great challenges, advanced coatings as indispensable components of future medicine have been investigated over the last few decades for precisely targeted drug delivery to achieve favorable prognoses in the treatment of a broad spectrum of diseases. Complemented by advancements in the pharmacological parameters, these systems hold great promise for the field. This chapter aims to discuss recent progress on new coatings for targeted drug delivery and the parameters for manufacturing these platforms for their cargo based on major determinants such as biocompatibility and bioactivity. A brief overview of the various applications of targeted drug delivery with functional coatings is also provided to offer a new perspective on the field.

The Rational Engineered Bacteria Based Biohybrid Living System for Tumor Therapy

Living therapy based on bacterial cells has gained increasing attention for their applications in tumor treatments. Bacterial cells can naturally target to tumor sites and active the innate immunological responses. The intrinsic advantages of bacteria attribute to the development of biohybrid living carriers for targeting delivery toward hypoxic environments. The rationally engineered bacterial cells integrate various functions to enhance the tumor therapy and reduce toxic side effects. In this review, the antitumor effects of bacteria and their application are discussed as living therapeutic agents across multiple antitumor platforms. The various kinds of bacteria used for cancer therapy are first introduced and demonstrated the mechanism of antitumor effects as well as the immunological effects. Additionally, this study focused on the genetically modified bacteria for the production of antitumor agents as living delivery system to treat cancer. The combination of living bacterial cells with functional nanomaterials is then discussed in the cancer treatments. In brief, the rational design of living therapy based on bacterial cells highlighted a rapid development in tumor therapy and pointed out the potentials in clinical applications.

Nanomaterial combined engineered bacteria for intelligent tumor immunotherapy

Cancer remains the leading cause of human death worldwide. Compared to traditional therapies, tumor immunotherapy has received a lot of attention and research focus due to its potential to activate both innate and adaptive immunity, low toxicity to normal tissue, and long-term immune activity. However, its clinical effectiveness and large-scale application are limited due to the immunosuppression microenvironment, lack of spatiotemporal control, expensive cost, and long manufacturing time. Recently, nanomaterial combined engineered bacteria have emerged as a promising solution to the challenges of tumor immunotherapy, which offers spatiotemporal control, reversal of immunosuppression, and scalable production. Therefore, we summarize the latest research on nanomaterial-assisted engineered bacteria for precise tumor immunotherapies, including the cross-talk of nanomaterials and bacteria as well as their application in different immunotherapies. In addition, we further discuss the advantages and challenges of nanomaterial-engineered bacteria and their future prospects, inspiring more novel and intelligent tumor immunotherapy.

Non-pathogenic E. coli displaying decoy-resistant IL18 mutein boosts anti-tumor and CAR NK cell responses

The tumor microenvironment can inhibit the efficacy of cancer therapies through mechanisms such as poor trafficking and exhaustion of immune cells. Here, to address this challenge, we exploited the safety, tumor tropism and ease of genetic manipulation of non-pathogenic Escherichia coli (E. coli) to deliver key immune-activating cytokines to tumors via surface display on the outer membrane of E. coli K-12 DH5α. Non-pathogenic E. coli expressing murine decoy-resistant IL18 mutein (DR18) induced robust CD8+ T and natural killer (NK) cell-dependent immune responses and suppressed tumor progression in immune-competent colorectal carcinoma and melanoma mouse models. E. coli K-12 DH5α engineered to display human DR18 potently activated mesothelin-targeting chimeric antigen receptor (CAR) NK cells and enhance their trafficking into tumors, which extended survival in an NK cell treatment-resistant mesothelioma xenograft model by enhancing TNF signaling and upregulating NK activation markers. Our live bacteria-based immunotherapeutic system safely and effectively induces potent anti-tumor responses in treatment-resistant solid tumors, motivating further evaluation of this approach in the clinic.

Spatiotemporal Delivery of Dual Nanobodies by Engineered Probiotics to Reverse Tumor Immunosuppression via Targeting Tumor-Derived Exosomes

The anti-PD-L1 and its bispecific antibodies have exhibited durable antitumor immunity but still elicit immunosuppression mainly caused by tumor-derived exosomes (TDEs), leading to difficulty in clinical transformation. Herein, engineered Escherichia coli Nissle 1917 (EcN) coexpressing anti-PD-L1 and anti-CD9 nanobodies (EcN-Nb) are developed and decorated with zinc-based metal-organic frameworks (MOFs) loaded with indocyanine green (ICG), to generate EcN-Nb-ZIF-8CHO-ICG (ENZC) for spatiotemporal lysis of bacteria for immunotherapy. The tumor-homing hybrid system can specifically release nanobodies in response to near-infrared (NIR) radiation, thereby targeting TDEs and changing their biological distribution, remodeling tumor-associated macrophages to M1 states, activating more effective and cytotoxic T lymphocytes, and finally, leading to the inhibition of tumor proliferation and metastasis. Altogether, the microfluidic-enabled MOF-modified engineered probiotics target TDEs and activate the antitumor immune response in a spatiotemporally manipulated manner, offering promising TDE-targeted immune therapy.

NIR-II-Responsive Hybrid System Achieves Cascade-Augmented Antitumor Immunity via Genetic Engineering of Both Bacteria and Tumor Cells

The combination of nanoparticles and tumor-targeting bacteria for cancer immunotherapy can overcome the shortcomings of poor nanoparticle accumulation, limited penetration, and restricted distribution. However, it remains a great challenge for the hybrid system to improve therapeutic efficacy through the simultaneous and controllable regulation of immune cells and tumor cells. Herein, a hybrid therapeutic platform is rationally designed to achieve immune cascade-augmented cancer immunotherapy. To construct the hybrids, photothermal nanoparticles responsive to light in the second near-infrared (NIR-II) region are conjugated onto the surface of engineered bacteria through pH-responsive Schiff base bonds. Taking advantage of the hypoxia targeting and deep penetration characteristics of the bacteria, the hybrids can accumulate at tumor sites. Then nanoparticles detach from the bacteria to realize genetic engineering of tumor cells, which induces tumor cell apoptosis and down-regulate the expression of programmed cell death ligand 1 to alleviate immunosuppressive tumor microenvironment. The mild photothermal heating can not only induce tumor-associated antigen release, but also trigger sustainable expression of cytokine interleukin-2. Notably, a synergistic antitumor effect is achieved between the process of p53 transfection and NIR-II light-activated genetic engineering of bacteria. This work proposes a facile strategy for the construction of hybrid system to achieve cascade-augmented cancer immunotherapy.

From pathogenesis to treatment: the impact of bacteria on cancer

The intricate relationship between cancer and bacteria has garnered increasing attention in recent years. While traditional cancer research has primarily focused on tumor cells and genetic mutations, emerging evidence highlights the significant role of microbial communities within the tumor microenvironment in cancer development and progression. This review aims to provide a comprehensive overview of the current understanding of the complex interplay between cancer and bacteria. We explore the diverse ways in which bacteria influence tumorigenesis and tumor behavior, discussing direct interactions between bacteria and tumor cells, their impact on tumor immunity, and the potential modulation of the tumor microenvironment. Additionally, we delve into the mechanisms through which bacterial metabolites and extracellular products May affect cancer pathways. By conducting a thorough analysis of the existing literature, we underscore the multifaceted and intricate relationship between bacteria and cancer. Understanding this complex interplay could pave the way for novel therapeutic approaches and preventive strategies in cancer treatment.

The application of bacteria-nanomaterial hybrids in antitumor therapy

Adverse effects and multidrug resistance remain significant obstacles in conventional cancer therapy. Nanomedicines, with their intrinsic properties such as nano-sized dimensions and tunable surface characteristics, have the potential to mitigate the side effects of traditional cancer treatments. While nanomaterials have been widely applied in cancer treatment, challenges such as low targeting efficiency and poor tumor penetration persist. Recent research has shown that anaerobic bacteria exhibit high selectivity for primary tumors and metastatic cancers, offering good safety and superior tumor penetration capabilities. This suggests that combining nanomaterials with bacteria could complement their respective limitations, opening vast potential applications in cancer therapy. The use of bacteria in combination with nanomaterials for anticancer treatments, including chemotherapy, radiotherapy, and photothermal/photodynamic therapy, has contributed to the rapid development of the field of bacterial oncology treatments. This review explores the mechanisms of bacterial tumor targeting and summarizes strategies for synthesizing bacterial-nanomaterial and their application in cancer therapy. The combination of bacterial-nanomaterial hybrids with modern therapeutic approaches represents a promising avenue for future cancer treatment research, with the potential to improve treatment outcomes for cancer patients.

Genetic Engineering Bacillus thuringiensis Enable Melanin Biosynthesis for Anti-Tumor and Anti-Inflammation

Collaboration between cancer treatment and inflammation management has emerged as an integral facet of comprehensive cancer care. Nevertheless, the development of interventions concurrently targeting both inflammation and cancer has encountered significant challenges stemming from various external factors. Herein, a bioactive agent synthesized by genetically engineering melanin-producing Bacillus thuringiensis (B. thuringiensis) bacteria, simultaneously achieves eco-friendly photothermal agent and efficient reactive oxygen/nitrogen species (RONS) scavenger benefits, perfectly tackling present toughies from inflammation to cancer therapies. The biologically derived melanin exhibits exceptional photothermal-conversion performance, facilitating potent photonic hyperthermia that effectively eradicates tumor cells and tissues, thereby impeding tumor growth. Additionally, the RONS-scavenging properties of melanin produced by B. thuringiensis bacteria contribute to inflammation reduction, augmenting the efficacy of photothermal tumor repression. This study presents a representative paradigm of genetic engineering in B. thuringiensis bacteria to produce functional agents tailored for diverse biomedical applications, encompassing inflammation and cancer therapy.

Path to bacteriotherapy: From bacterial engineering to therapeutic perspectives

The major reason for the failure of conventional therapies is the heterogeneity and complexity of tumor microenvironments (TMEs). Many malignant tumors reprogram their surface antigens to evade the immune surveillance, leading to reduced antigen-presenting cells and hindered T-cell activation. Bacteria-mediated cancer immunotherapy has been extensively investigated in recent years. Scientists have ingeniously modified bacteria using synthetic biology and nanotechnology to enhance their biosafety with high tumor specificity, resulting in robust anticancer immune responses. To enhance the antitumor efficacy, therapeutic proteins, cytokines, nanoparticles, and chemotherapeutic drugs have been efficiently delivered using engineered bacteria. This review provides a comprehensive understanding of oncolytic bacterial therapies, covering bacterial design and the intricate interactions within TMEs. Additionally, it offers an in-depth comparison of the current techniques used for bacterial modification, both internally and externally, to maximize their therapeutic effectiveness. Finally, we outlined the challenges and opportunities ahead in the clinical application of oncolytic bacterial therapies.

Intratumoral Microbiota as a Target for Advanced Cancer Therapeutics

In recent years, advancements in microbial sequencing technology have sparked an increasing interest in the bacteria residing within solid tumors and its distribution and functions in various tumors. Intratumoral bacteria critically modulate tumor oncogenesis and development through DNA damage induction, chronic inflammation, epigenetic alterations, and metabolic and immune regulation, while also influencing cancer treatment efficacy by affecting drug metabolism. In response to these discoveries, a variety of anti-cancer therapies targeting these microorganisms have emerged. These approaches encompass oncolytic therapy utilizing tumor-associated bacteria, the design of biomaterials based on intratumoral bacteria, the use of intratumoral bacterial components for drug delivery systems, and comprehensive strategies aimed at the eradication of tumor-promoting bacteria. Herein, this review article summarizes the distribution patterns of bacteria in different solid tumors, examines their impact on tumors, and evaluates current therapeutic strategies centered on tumor-associated bacteria. Furthermore, the challenges and prospects for developing drugs that target these bacterial communities are also explored, promising new directions for cancer treatment.

Toward Practical Applications of Engineered Living Materials with Advanced Fabrication Techniques

Engineered Living Materials (ELMs) are materials composed of or incorporating living cells as essential functional units. These materials can be created using bottom-up approaches, where engineered cells spontaneously form well-defined aggregates. Alternatively, top-down methods employ advanced materials science techniques to integrate cells with various kinds of materials, creating hybrids where cells and materials are intricately combined. ELMs blend synthetic biology with materials science, allowing for dynamic responses to environmental stimuli such as stress, pH, humidity, temperature, and light. These materials exhibit unique "living" properties, including self-healing, self-replication, and environmental adaptability, making them highly suitable for a wide range of applications in medicine, environmental conservation, and manufacturing. Their inherent biocompatibility and ability to undergo genetic modifications allow for customized functionalities and prolonged sustainability. This review highlights the transformative impact of ELMs over recent decades, particularly in healthcare and environmental protection. We discuss current preparation methods, including the use of endogenous and exogenous scaffolds, living assembly, 3D bioprinting, and electrospinning. Emphasis is placed on ongoing research and technological advancements necessary to enhance the safety, functionality, and practical applicability of ELMs in real-world contexts.

Microbe-material hybrids for therapeutic applications

As natural living substances, microorganisms have emerged as useful resources in medicine for creating microbe-material hybrids ranging from nano to macro dimensions. The engineering of microbe-involved nanomedicine capitalizes on the distinctive physiological attributes of microbes, particularly their intrinsic "living" properties such as hypoxia tendency and oxygen production capabilities. Exploiting these remarkable characteristics in combination with other functional materials or molecules enables synergistic enhancements that hold tremendous promise for improved drug delivery, site-specific therapy, and enhanced monitoring of treatment outcomes, presenting substantial opportunities for amplifying the efficacy of disease treatments. This comprehensive review outlines the microorganisms and microbial derivatives used in biomedicine and their specific advantages for therapeutic application. In addition, we delineate the fundamental strategies and mechanisms employed for constructing microbe-material hybrids. The diverse biomedical applications of the constructed microbe-material hybrids, encompassing bioimaging, anti-tumor, anti-bacteria, anti-inflammation and other diseases therapy are exhaustively illustrated. We also discuss the current challenges and prospects associated with the clinical translation of microbe-material hybrid platforms. Therefore, the unique versatility and potential exhibited by microbe-material hybrids position them as promising candidates for the development of next-generation nanomedicine and biomaterials with unique theranostic properties and functionalities.