Tumor-Associated Macrophage and Tumor-Cell Dually Transfecting Polyplexes for Efficient Interleukin-12 Cancer Gene Therapy

Self-Assembled Oligopeptoplex-Loaded Dissolving Microneedles for Adipocyte-Targeted Anti-Obesity Gene Therapy

Advancements in gene delivery systems are pivotal for gene-based therapeutics in oncological, inflammatory, and infectious diseases. This study delineates the design of a self-assembled oligopeptoplex (SA-OP) optimized for shRNA delivery to adipocytes, targeting obesity and associated metabolic syndromes. Conventional systems face challenges, including instability due to electrostatic interactions between genetic materials and cationic oligopeptides. Additionally, repeated injections induce discomfort and compromise patient well-being. To circumvent these issues, a dissolvable hyaluronic acid-based, self-locking microneedle (LMN) patch is developed, with improved micro-dose efficiency, for precise SA-OP delivery. This platform offers pain-free administration and improved SA-OP storage stability. In vitro studies in 3T3-L1 cells demonstrated improvements in SA-OP preservation and gene silencing efficacy. In vivo evaluation in a mice model of diet-induced type 2 diabetes yielded significant gene silencing in adipose tissue and a 21.92 ± 2.51% reduction in body weight with minimum relapse risk at 6-weeks post-treatment, representing a superior therapeutic efficacy in a truncated timeframe relative to the GLP-1 analogues currently available on the market. Additionally, SA-OP (LMN) mitigated insulin resistance, inflammation, and hepatic steatosis. These findings establish SA-OP (LMN) as a robust, minimally invasive transdermal gene delivery platform with prolonged storage stability for treating obesity and its metabolic comorbidities.

Inhalable extracellular vesicle delivery of IL-12 mRNA to treat lung cancer and promote systemic immunity

Lung carcinoma is one of the most common cancers and has one of the lowest survival rates in the world. Cytokines such as interleukin-12 (IL-12) have demonstrated considerable potential as robust tumour suppressors. However, their applications are limited due to off-target toxicity. Here we report on a strategy involving the inhalation of IL-12 messenger RNA, encapsulated within extracellular vesicles. Inhalation and preferential uptake by cancer cells results in targeted delivery and fewer systemic side effects. The IL-12 messenger RNA generates interferon-γ production in both innate and adaptive immune-cell populations. This activation consequently incites an intense activation state in the tumour microenvironment and augments its immunogenicity. The increased immune response results in the expansion of tumour cytotoxic immune effector cells, the formation of immune memory, improved antigen presentation and tumour-specific T cell priming. The strategy is demonstrated against primary neoplastic lesions and provides profound protection against subsequent tumour rechallenge. This shows the potential for locally delivered cytokine-based immunotherapies to address orthotopic and metastatic lung tumours.

Efficient polymeric nanoparticles for RNAi in macrophage reveal complex effects on polarization markers upon knockdown of STAT3/STAT6

Tumor associated macrophages (TAMs) are the most abundant immune cell type in the tissue microenvironment, affecting tumor progression, metastasis and therapeutic response. Different macrophage activation ("polarization") states can be distinguished: resting (M0; non-activated), pro-inflammatory/anti-tumorigenic (M1) and anti-inflammatory/pro-tumorigenic (M2). When exploring macrophages as targets in novel cancer immunotherapy approaches, TAM repolarization from the M2 into the M1 phenotype is an intriguing strategy to block their pro-tumoral and enhance their anti-tumoral properties. In the context of RNAi-based gene knockdown of M2 promoting genes, major bottlenecks include cellular siRNA delivery and correct intracellular processing. This is particularly true in case of macrophages as a cell type well-known to be notoriously hard-to-transfect. Among polymeric nanocarriers, the cationic polymer polyethylenimine (PEI) is widely explored for delivering nucleic acids. Further advanced nanocarriers are tyrosine-modified polymers based on PEI or polypropylenimine dendrimers (PPI) for highly efficient siRNA delivery in vitro and in vivo. In this paper, we explored a panel of PEI- or PPI-based nanoparticle systems for siRNA-mediated gene knockdown efficacy in macrophages and subsequent TAM repolarization. The tyrosine-modified linear 10 kDa PEI (LP10Y) or branched 5 kDa PEI (P5Y) as well as a tyrosine-modified PPI (PPI-Y) were found most efficient for gene knockdown in macrophage cell lines or primary macrophages, independent of their polarization. Knockdown of STAT6 or STAT3 led to repolarization of M2 macrophages, as indicated by alterations in various M2 and M1 marker levels. This highly specific approach also demonstrated non-redundant functions of STAT3 and STAT6. Importantly, macrophage re-polarization from M2 to M1 upon PPI-Y/siRNA-mediated STAT6 knockdown increased tumor cell phagocytosis in a co-culture model. In conclusion, we identify certain tyrosine-modified PEI- or PPI-based nanoparticles as particularly efficient for macrophage transfection, and the specific, siRNA-mediated STAT6 knockdown as a promising approach for macrophage repolarization and enhancement of their tumor cell suppressive role.

IL-12-Overexpressed Nanoparticles Suppress the Proliferation of Melanoma Through Inducing ICD and Activating DC, CD8+ T, and CD4+ T Cells

Purpose

The drug resistance and low response rates of immunotherapy limit its application. This study aimed to construct a new nanoparticle (CaCO3-polydopamine-polyethylenimine, CPP) to effectively deliver interleukin-12 (IL-12) and suppress cancer progress through immunotherapy.

Methods

The size distribution of CPP and its zeta potential were measured using a Malvern Zetasizer Nano-ZS90. The morphology and electrophoresis tentative delay of CPP were analyzed using a JEM-1400 transmission electron microscope and an ultraviolet spectrophotometer, respectively. Cell proliferation was analyzed by MTT assay. Proteins were analyzed by Western blot. IL-12 and HMGB1 levels were estimated by ELISA kits. Live/dead staining assay was performed using a Calcein-AM/PI kit. ATP production was detected using an ATP assay kit. The xenografts in vivo were estimated in C57BL/6 mice. The levels of CD80+/CD86+, CD3+/CD4+ and CD3+/CD8+ were analyzed by flow cytometry.

Results

CPP could effectively express EGFP or IL-12 and increase ROS levels. Laser treatment promoted CPP-IL-12 induced the number of dead or apoptotic cell. CPP-IL-12 and laser could further enhance CALR levels and extracellular HMGB1 levels and decrease intracellular HMGB1 and ATP levels, indicating that it may induce immunogenic cell death (ICD). The tumors and weights of xenografts in CPP-IL-12 or laser-treated mice were significantly reduced than in controls. The IL-12 expression, the CD80+/CD86+ expression of DC from lymph glands, and the number of CD3+/CD8+T or CD3+/CD4+T cells from the spleen increased in CPP-IL-12-treated or laser-treated xenografts compared with controls. The levels of granzyme B, IFN-γ, and TNF-α in the serum of CPP-IL-12-treated mice increased. Interestingly, CPP-IL-12 treatment in local xenografts in the back of mice could effectively inhibit the growth of the distant untreated tumor.

Conclusion

The novel CPP-IL-12 could overexpress IL-12 in melanoma cells and achieve immunotherapy to melanoma through inducing ICD, activating CD4+ T cell, and enhancing the function of tumor-reactive CD8+ T cells.

Engineered Bacterial Biomimetic Vesicles Reprogram Tumor-Associated Macrophages and Remodel Tumor Microenvironment to Promote Innate and Adaptive Antitumor Immune Responses

Tumor-associated macrophages (TAMs) are among the most abundant infiltrating leukocytes in the tumor microenvironment (TME). Reprogramming TAMs from protumor M2 to antitumor M1 phenotype is a promising strategy for remodeling the TME and promoting antitumor immunity; however, the development of an efficient strategy remains challenging. Here, a genetically modified bacterial biomimetic vesicle (BBV) with IFN-γ exposed on the surface in a nanoassembling membrane pore structure was constructed. The engineered IFN-γ BBV featured a nanoscale structure of protein and lipid vesicle, the existence of rich pattern-associated molecular patterns (PAMPs), and the costimulation of introduced IFN-γ molecules. In vitro, IFN-γ BBV reprogrammed M2 macrophages to M1, possibly through NF-κB and JAK-STAT signaling pathways, releasing nitric oxide (NO) and inflammatory cytokines IL-1β, IL-6, and TNF-α and increasing the expression of IL-12 and iNOS. In tumor-bearing mice, IFN-γ BBV demonstrated a targeted enrichment in tumors and successfully reprogrammed TAMs into the M1 phenotype; notably, the response of antigen-specific cytotoxic T lymphocyte (CTL) in TME was promoted while the immunosuppressive myeloid-derived suppressor cell (MDSC) was suppressed. The tumor growth was found to be significantly inhibited in both a TC-1 tumor and a CT26 tumor. It was indicated that the antitumor effects of IFN-γ BBV were macrophage-dependent. Further, the modulation of TME by IFN-γ BBV produced synergistic effects against tumor growth and metastasis with an immune checkpoint inhibitor in an orthotopic 4T1 breast cancer model which was insensitive to anti-PD-1 mAb alone. In conclusion, IFN-γ-modified BBV demonstrated a strong capability of efficiently targeting tumor and tuning a cold tumor hot through reprogramming TAMs, providing a potent approach for tumor immunotherapy.

An Esterase-Responsive SLC7A11 shRNA Delivery System Induced Ferroptosis and Suppressed Hepatocellular Carcinoma Progression

Ferroptosis has garnered attention as a potential approach to fight against cancer, which is characterized by the iron-driven buildup of lipid peroxidation. However, the robust defense mechanisms against intracellular ferroptosis pose significant challenges to its effective induction. In this paper, an effective gene delivery vehicle was developed to transport solute carrier family 7 member 11 (SLC7A11) shRNA (shSLC7A11), which downregulates the expression of the channel protein SLC7A11 and glutathione peroxidase 4 (GPX4), evoking a surge in reactive oxygen species production, iron accumulation, and lipid peroxidation in hepatocellular carcinoma (HCC) cells, and subsequently leading to ferroptosis. This delivery system is composed of an HCC-targeting lipid layer and esterase-responsive cationic polymer, a poly{N-[2-(acryloyloxy)ethyl]-N-[p-acetyloxyphenyl]-N} (PQDEA) condensed shSLC7A11 core (G-LPQDEA/shSLC7A11). After intravenous (i.v.) injection, G-LPQDEA/shSLC7A11 quickly accumulated in the tumor, retarding its growth by 77% and improving survival by two times. This study is the first to construct a gene delivery system, G-LPQDEA/shSLC7A11, that effectively inhibits HCC progression by downregulating SLC7A11 expression. This underscores its therapeutic potential as a safe and valuable candidate for clinical treatment.

Engineering Nanosensitizer to Remodel the TME for Hypoimmunogenic "Cold"-"Hot" Tumor Transformations

α-PD-L1 therapy has shown encouraging results at harnessing the immune system to combat cancer. However, the treatment effect is relatively low due to the dense extracellular matrix (ECM) and tumor immunosuppressive microenvironment (TIME). Therefore, an ultrasound (US)-responsive nanosensitizer (URNS) is engineered to deliver losartan (LST) and polyethylenimine (PEI) to remolde the TME, driving "cold"-"hot" tumor transformation and enhancing the sensitivity of α-PD-L1 therapy. In the tumor site, noninvasive US can make MTNP generate ROS, which cleave ROS-sensitive bonds to dissociate MTNPtK@LST-PEI, shedding PEI and releasing LST from mesoporous spheres. The results demonstrated that URNS combined with α-PD-L1 therapy effectively inhibited tumor growth with an inhibition rate as high as 90%, which was 1.7-fold higher than that of the α-PD-L1 treatment in vivo. In summary, the URNS improves the sensitivity of α-PD-L1 therapy by remodeling the TME, which provides promising insights for optimizing cancer immunotherapy.

Controllable Star Cationic Poly(Disulfide)s Achieve Genetically Cascade Catalytic Therapy by Delivering Bifunctional Fusion Plasmids

The absence of effective delivery vectors and suitable multifunctional plasmids limits cancer gene therapy development. The star cationic poly(disulfide)s with β-cyclodextrin cores (termed β-CD-g-PSSn ) for caveolae-mediated endocytosis are designed and prepared via mild and controllable disulfide exchange polymerization for high-efficacy cancer therapy. Then, β-CD-g-PSSn /pDNA complexes are transported to the Golgi apparatus and endoplasmic reticulum. Disulfides in β-CD-g-PSSn vectors are degraded by glutathione in tumor cells, which not only promotes intracellular pDNA release but also reduces in vitro and in vivo toxicity. One bifunctional fusion plasmid pCATKR, which expresses catalase (CAT) fused to KillerRed (KR) (CATKR) in the same target cell, is also proposed for genetically cascade catalytic therapy. When compared with pCAT-KR (plasmid expressing CAT and KR separately in the same cell), delivered pCATKR decomposes hydrogen peroxide, alleviates tumor hypoxia more effectively, generates stronger reactive oxygen species (ROS) capabilities under moderate irradiation, and leads to robust antitumor cascade photodynamic effects. These impressive results are attributed to fusion protein design, which shortens the distance between CAT and KR catalytic centers and leads to improved ROS production efficiency. This work provides a promising strategy by delivering a catalytic cascade functional plasmid via a high-performance vector with biodegradable and caveolae-mediated endocytosis characteristics.

Tumor Microenvironment Sequential Drug/Gene Delivery Nanosystem for Realizing Multistage Boosting of Cancer-Immunity Cycle on Cancer Immunotherapy

The antitumor immune response of cancer immunotherapy is a cascade of cancer-immunity cycles (CIC). The immunosuppression of the tumor microenvironment and low immunogenicity of tumor cells, insufficient T lymphocyte activation, trafficking, and infiltration caused the failure to initiate and run the continuous multistage CIC, leading to unsatisfactory cancer immunotherapy outcomes. A doxorubicin/interleukin-12 plasmid DNA/celecoxib (DOX/pIL-12/CXB) combination strategy was designed by targeting the cascade CIC. Then, an intratumoral CXB-detachable nanosystem, or DOX/PAC/pIL-12 micelleplexes, was developed for sequential drug/gene delivery to facilitate the multistage boosting of CIC on synergistic cancer immunotherapy. The DOX/PAC/pIL-12 micelleplexes could program intratumorally sequential release of CXB to remodulate the tumor microenvironment immunosuppression by suppressing the cyclooxygenase-2/prostaglandin E2 (COX-2/PGE2) pathway. The smaller sizes and surface charge-switched micelleplexes facilitated the codelivery and corelease of DOX and pIL-12 inside 4T1 tumor cells. These micelleplexes exerted a synergistic antitumor immune response using CIC cascade activation and amplification, providing therapeutic antitumor and antimetastasis efficacy. The drug/gene sequential delivery nanosystem provides a complete CIC-boosted combinatory strategy for developing immunotherapy against cancer.

Macrophage-Based Microrobots for Anticancer Therapy: Recent Progress and Future Perspectives

Macrophages, which are part of the mononuclear phagocytic system, possess sensory receptors that enable them to target cancer cells. In addition, they are able to engulf large amounts of particles through phagocytosis, suggesting a potential "Trojan horse" drug delivery approach to tumors by facilitating the engulfment of drug-hidden particles by macrophages. Recent research has focused on the development of macrophage-based microrobots for anticancer therapy, showing promising results and potential for clinical applications. In this review, we summarize the recent development of macrophage-based microrobot research for anticancer therapy. First, we discuss the types of macrophage cells used in the development of these microrobots, the common payloads they carry, and various targeting strategies utilized to guide the microrobots to cancer sites, such as biological, chemical, acoustic, and magnetic actuations. Subsequently, we analyze the applications of these microrobots in different cancer treatment modalities, including photothermal therapy, chemotherapy, immunotherapy, and various synergistic combination therapies. Finally, we present future outlooks for the development of macrophage-based microrobots.

Technological advances in the use of viral and non-viral vectors for delivering genetic and non-genetic cargos for cancer therapy

The burden of cancer is increasing globally. Several challenges facing its mainstream treatment approaches have formed the basis for the development of targeted delivery systems to carry and distribute anti-cancer payloads to their defined targets. This site-specific delivery of drug molecules and gene payloads to selectively target druggable biomarkers aimed at inducing cell death while sparing normal cells is the principal goal for cancer therapy. An important advantage of a delivery vector either viral or non-viral is the cumulative ability to penetrate the haphazardly arranged and immunosuppressive tumour microenvironment of solid tumours and or withstand antibody-mediated immune response. Biotechnological approaches incorporating rational protein engineering for the development of targeted delivery systems which may serve as vehicles for packaging and distribution of anti-cancer agents to selectively target and kill cancer cells are highly desired. Over the years, these chemically and genetically modified delivery systems have aimed at distribution and selective accumulation of drug molecules at receptor sites resulting in constant maintenance of high drug bioavailability for effective anti-tumour activity. In this review, we highlighted the state-of-the art viral and non-viral drug and gene delivery systems and those under developments focusing on cancer therapy.

Esterase-Labile Quaternium Lipidoid Enabling Improved mRNA-LNP Stability and Spleen-Selective mRNA Transfection

Ionizable cationic lipids are recognized as an essential component of lipid nanoparticles (LNPs) for messenger RNA (mRNA) delivery but can be confounded by low lipoplex stability with mRNA during storage and in vivo delivery. Herein, the rational design and combinatorial synthesis of esterase-triggered decationizable quaternium lipid-like molecules (lipidoids) are reported to develop new LNPs with high delivery efficiency and improved storage stability. This top lipidoid carries positive charges at the physiological condition but promptly acquires negative charges in the presence of esterase, thus permitting stable mRNA encapsulation during storage and in vivo delivery while balancing efficient mRNA release in the cytosol. An optimal LNP formulation is then identified through orthogonal optimization, which enables efficacious mRNA transfection selectively in the spleen following intravenous administration. LNP-mediated delivery of ovalbumin (OVA)-encoding mRNA induces efficient antigen expression in antigen-presenting cells and elicits robust antigen-specific immune responses against OVA-transduced tumors. The work demonstrates the potential of decationizable quaternium lipidoids for spleen-selective RNA transfection and cancer immunotherapy.

Therapeutic potential of gene therapy for gastrointestinal diseases: Advancements and future perspectives

Advancements in understanding the pathogenesis mechanisms underlying gastrointestinal diseases, encompassing inflammatory bowel disease, gastrointestinal cancer, and gastroesophageal reflux disease, have led to the identification of numerous novel therapeutic targets. These discoveries have opened up exciting possibilities for developing gene therapy strategies to treat gastrointestinal diseases. These strategies include gene replacement, gene enhancement, gene overexpression, gene function blocking, and transgenic somatic cell transplantation. In this review, we introduce the important gene therapy targets and targeted delivery systems within the field of gastroenterology. Furthermore, we provide a comprehensive overview of recent progress in gene therapy related to gastrointestinal disorders and shed light on the application of innovative gene-editing technologies in treating these conditions. These developments are fueling a revolution in the management of gastrointestinal diseases. Ultimately, we discuss the current challenges (particularly regarding safety, oral efficacy, and cost) and explore potential future directions for implementing gene therapy in the clinical settings for gastrointestinal diseases.

Peritoneal Gene Transfection of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand for Tumor Surveillance and Prophylaxis

Peritoneal metastasis is very common in gastrointestinal, reproductive, and genitourinary tract cancers in late stages or postsurgery, causing poor prognosis, so effective and nontoxic prophylactic strategies against peritoneal metastasis are highly imperative. Herein, we demonstrate the first gene transfection as a nontoxic prophylaxis preventing peritoneal metastasis or operative metastatic dissemination. Lipopolyplexes of TNF-related-apoptosis-inducing-ligand (TRAIL) transfected peritonea and macrophages to express TRAIL for over 15 days. The expressed TRAIL selectively induced tumor cell apoptosis while exempting normal tissue, providing long-term tumor surveillance. Therefore, tumor cells inoculated in the pretransfected peritoneal cavity quickly underwent apoptosis and, thus, barely formed tumor nodules, significantly prolonging the mouse survival time compared with chemotherapy prophylaxis. Furthermore, lipopolyplex transfection showed no sign of toxicity. Therefore, this peritoneal TRAIL-transfection is an effective and safe prophylaxis, preventing peritoneal metastasis.

Lipid-based nanoparticles for cancer immunotherapy

As the fourth most important cancer management strategy except surgery, chemotherapy and radiotherapy, cancer immunotherapy has been confirmed to elicit durable antitumor effects in the clinic by leveraging the patient's own immune system to eradicate the cancer cells. However, the limited population of patients who benefit from the current immunotherapies and the immune related adverse events hinder its development. The immunosuppressive microenvironment is the main cause of the failure, which leads to cancer immune evasion and immunity cycle blockade. Encouragingly, nanotechnology has been engineered to enhance the efficacy and reduce off-target toxicity of their therapeutic cargos by spatiotemporally controlling the biodistribution and release kinetics. Among them, lipid-based nanoparticles are the first nanomedicines to make clinical translation, which are now established platforms for diverse areas. In this perspective, we discuss the available lipid-based nanoparticles in research and market here, then describe their application in cancer immunotherapy, with special emphasis on the T cells-activated and macrophages-targeted delivery system. Through perpetuating each step of cancer immunity cycle, lipid-based nanoparticles can reduce immunosuppression and promote drug delivery to trigger robust antitumor response.

Curcumin-reduced gold nanoparticles facilitate IL-12 delivery to a cervical cancer in vitro cell model

Aim: To synthesize curcumin-reduced gold nanoparticles (AuNPs) for the efficient delivery to and expression of the IL-12 gene in cervical cancer (HeLa) cells in vitro. Methods: Curcumin-reduced AuNPs were synthesized, stabilized with poly-L-lysine and PEG, conjugated to IL-12 DNA and physicochemically characterized. Cytotoxicity and IL-12 expression were accessed in vitro. Results & discussion: Stable, spherical AuNPs effectively compacted and protected the IL-12 DNA and tolerated well in vitro. Real-time quantitative PCR and ELISA confirmed the successful delivery and expression of the IL-12 gene in HeLa cells. Conclusion: The favorable attributes of this AuNP-delivery system and the significant IL-12 expression obtained augur well for cytokine-based therapy or immunotherapy in cervical cancer.

Crosstalk between macrophages and cardiac cells after myocardial infarction

Cardiovascular diseases, such as myocardial infarction (MI), are a leading cause of death worldwide. Acute MI (AMI) inflicts massive injury to the coronary microcirculation, causing large-scale cardiomyocyte death due to ischemia and hypoxia. Inflammatory cells such as monocytes and macrophages migrate to the damaged area to clear away dead cells post-MI. Macrophages are pleiotropic cells of the innate immune system, which play an essential role in the initial inflammatory response that occurs following MI, inducing subsequent damage and facilitating recovery. Besides their recognized role within the immune response, macrophages participate in crosstalk with other cells (including cardiomyocytes, fibroblasts, immune cells, and vascular endothelial cells) to coordinate post-MI processes within cardiac tissue. Macrophage-secreted exosomes have recently attracted increasing attention, which has led to a more elaborate understanding of macrophage function. Currently, the functional roles of macrophages in the microenvironment of the infarcted heart, particularly with regard to their interaction with surrounding cells, remain unclear. Understanding the specific mechanisms that mediate this crosstalk is essential in treating MI. In this review, we discuss the origin of macrophages, changes in their distribution post-MI, phenotypic and functional plasticity, as well as the specific signaling pathways involved, with a focus on the crosstalk with other cells in the heart. Thus, we provide a new perspective on the treatment of MI. Further in-depth research is required to elucidate the mechanisms underlying crosstalk between macrophages and other cells within cardiac tissue for the identification of potential therapeutic targets. Video Abstract.

Esterase-Activated, pH-Responsive, and Genetically Targetable Nano-Prodrug for Cancer Cell Photo-Ablation

Activatable prodrugs have drawn considerable attention for cancer cell ablation owing to their high specificity in drug delivery systems. However, phototheranostic prodrugs with dual organelle-targeting and synergistic effects are still rare due to low intelligence of their structures. Besides, the cell membrane, exocytosis, and diffusional hindrance by the extracellular matrix reduce drug uptake. Moreover, the up-regulation of heat shock protein and short singlet-oxygen lifetime in cancer cells hamper photo-ablation efficacy, especially in the mono-therapeutic model. To overcome those obstacles, we prepare an esterase-activated DM nano-prodrug, which is conjugated by diiodine-substituted fluorogenic malachite green derivative (MG-2I) and phototherapeutic agent DPP-OH via hydrolyzable ester linkage, having pH-responsiveness and genetically targetable activity for dual organelles-targeting to optimize photo-ablation efficacy. The DM nanoparticles (NPs) present improved pH-responsive photothermal/photodynamic property by the protonation of diethylaminophenyl units in acidic environment. More importantly, the MG-2I and DPP-OH moieties can be released from DM nano-prodrug through overexpressed esterase; then specifically target lysosomes and mitochondria in CT-26 Mito-FAP cells. Hence, near-infrared DM NPs can trigger parallel damage in dual-organelles with strong fluorescence and effective phototoxicity, thus inducing serious mitochondrial dysfunction and apoptotic death, showing excellent photo-ablation effect based on esterase-activated, pH-responsive, and genetically targetable activities.

Pre-Induced ICD Membrane-Coated Carrier-Free Nanoparticles for the Personalized Lung Cancer Immunotherapy

Immunotherapy is a required adjuvant method in lung cancer therapy clinically. The single immune adjuvant failed to show the expected clinical therapeutic efficacy due to its rapid drug metabolism and inability to accumulate in the tumor site efficiently. Immunogenic cell death (ICD) is a new anti-tumor strategy combined with immune adjuvants. It can provide tumor-associated antigens, activate dendritic cells, and attract lymphoid T cells into the tumor microenvironment. Here doxorubicin-induced tumor membrane-coated iron (II)-cytosine-phosphate-guanine nanoparticles (DM@NPs) are shown for efficient co-delivery of tumor-associated antigens and adjuvant. Higher expression of ICD-related membrane proteins on the surface of the DM@NPs leads to the enhanced uptake of DM@NPs by dendritic cells (DCs), thereby promoting the DCs maturation and pro-inflammatory cytokines release. DM@NPs can remarkably increase the T cell infiltrations, remodel the tumor immune microenvironment and inhibit tumor progression in vivo. These findings reveal that pre-induced ICD tumor cell membrane-encapsulated nanoparticles can enhance immunotherapy responses and provide an effective biomimetic nanomaterial-based therapeutic strategy for lung cancer.

"Intercellular Mass Transport" Mimic Enables ASO Entry Completely into the Cell Nucleus for Enhanced Ischemia Therapy

Currently, the development of a new therapeutic technology is focused on antisense oligonucleotides (ASOs), where ASOs are used to complementarily pair with DNA, messenger RNA, or long noncoding RNA (lncRNA) to regulate the cell behavior by inhibiting the target gene expression. However, the targeted regulation toward nuclear genes still faces great challenges in ASO delivery for clinical applications, i.e., two essential criteria (high nuclear entry and delivery vehicle safety/simplification) generally compromise each other and are not simultaneously satisfactory. Herein, for the first time, inspired by "intercellular-mass-transport", we report an important discovery that the cell membrane of endothelial cells (ECs) serving as the biointerface enables ASOs to rapidly and completely enter the EC nucleus. Thereby, we innovatively fabricate a nanosystem only by sequential self-assembly of natural/off-the-shelf biomaterials to well overcome the above-mentioned contradiction. The efficacy is strikingly superior to that of the previous delivery vehicles. Furthermore, our technology is applied to successfully silence lncRNA MEG3 in the EC nucleus, significantly augmenting EC morphogenesis. More importantly, this nanosystem is applicable for in vivo intramuscular injection to enhance the therapeutic outcome in a critical limb ischemia mouse model. This work brings a new hope for the technological innovation of ASO nuclear delivery and opens a new avenue to explore natural/off-the-shelf materials for cargo delivery into subcellular compartments.

Safe engineering of cancer-associated fibroblasts enhances checkpoint blockade immunotherapy

Abundant cancer-associated fibroblasts (CAFs) in highly fibrotic breast cancer constitute an immunosuppressive barrier for T cell activity and are closely related to the failure of immune checkpoint blockade therapy (ICB). Inspired by the similar antigen-processing capacity of CAFs to professional antigen-presenting cells (APCs), a "turning foes to friends" strategy is proposed by in situ engineering immune-suppressed CAFs into immune-activated APCs for improving response rates of ICB. To achieve safe and specific CAFs engineering in vivo, a thermochromic spatiotemporal photo-controlled gene expression nanosystem was developed by self-assembly of molten eutectic mixture, chitosan andfusion plasmid. After photoactivatable gene expression, CAFs could be engineered as APCs via co-stimulatory molecule (CD86) expression, which effectively induced activation and proliferation of antigen-specific CD8 + T cells. Meanwhile, engineered CAFs could also secrete PD-L1 trap protein in situ for ICB, avoiding potential autoimmune-like disorders caused by "off-target" effects of clinically applied PD-L1 antibody. The study demonstrated that the designed nanosystem could efficiently engineer CAFs, significantly enhance the percentages of CD8+ T cells (4-folds), result in about 85% tumor inhibition rate and 83.3% survival rate at 60 days in highly fibrotic breast cancer, further inducing long-term immune memory effects and effectively inhibiting lung metastasis.

Cold atmospheric plasma: Novel opportunities for tumor microenvironment targeting

With mounting preclinical and clinical evidences on the prominent roles of the tumor microenvironment (TME) played during carcinogenesis, the TME has been recognized and used as an important onco-therapeutic target during the past decade. Delineating our current knowledge on TME components and their functionalities can help us recognize novel onco-therapeutic opportunities and establish treatment modalities towards desirable anti-cancer outcome. By identifying and focusing on primary cellular components in the TME, that is, tumor-infiltrating lymphocytes, tumor-associated macrophages, cancer-associated fibroblasts and mesenchymal stem cells, we decomposed their primary functionalities during carcinogenesis, categorized current therapeutic approaches utilizing traits of these components, and forecasted possible benefits that cold atmospheric plasma, a redox modulating tool with selectivity against cancer cells, may convey by targeting the TME. Our insights may open a novel therapeutic avenue for cancer control taking advantages of redox homeostasis and immunostasis.

Engineered ionizable lipid nanoparticles mediated efficient siRNA delivery to macrophages for anti-inflammatory treatment of acute liver injury

Small interfering RNA (siRNA) mediating specific gene silencing provides a promising strategy for anti-inflammatory therapy. However, the development of potent carriers for anti-inflammatory siRNA to macrophages remains challenging. With the aim of realizing potent delivery of siRNA to macrophages, we engineered ionizable lipid nanoparticles (LNPs) with the key component of synthetic lipid-like materials. By varying the amine molecules in the structure of synthetic lipid-like materials, a potent LNP (1O₁₄-LNP) was identified, which exhibited efficient transfection of macrophages by facilitating efficient internalization and endosomal escape. The 1O₁₄-LNP successfully delivered anti-inflammatory siRNA against interleukin-1β (siIL-1β) with more than 90% downregulation of IL-1β expression in LPS-activated macrophages. From in vivo studies, systemic administrated 1O₁₄-LNP/siRNA mainly distributed in liver and efficiently captured by hepatic macrophages without notable sign of toxicity. Furthermore, LPS/d-GalN-induced acute liver injury model treated with 1O₁₄-LNP/siIL-1β resulted in significant suppression of IL-1β expression and amelioration of liver tissue damage. These results demonstrate that the engineered ionizable LNP provides a powerful tool for siRNA delivery to macrophages and that the strategy of silencing of pro-inflammatory cytokines holds great potential for treating inflammatory diseases.

Photoswitchable Microgels for Dynamic Macrophage Modulation

Dynamic manipulation of supramolecular self-assembled structures is achieved irreversibly or under non-physiological conditions, thereby limiting their biomedical, environmental, and catalysis applicability. In this study, microgels composed of azobenzene derivatives stacked via π-cation and π-π interactions are developed that are electrostatically stabilized with Arg-Gly-Asp (RGD)-bearing anionic polymers. Lateral swelling of RGD-bearing microgels occurs via cis-azobenzene formation mediated by near-infrared-light-upconverted ultraviolet light, which disrupts intermolecular interactions on the visible-light-absorbing upconversion-nanoparticle-coated materials. Real-time imaging and molecular dynamics simulations demonstrate the deswelling of RGD-bearing microgels via visible-light-mediated trans-azobenzene formation. Near-infrared light can induce in situ swelling of RGD-bearing microgels to increase RGD availability and trigger release of loaded interleukin-4, which facilitates the adhesion structure assembly linked with pro-regenerative polarization of host macrophages. In contrast, visible light can induce deswelling of RGD-bearing microgels to decrease RGD availability that suppresses macrophage adhesion that yields pro-inflammatory polarization. These microgels exhibit high stability and non-toxicity. Versatile use of ligands and protein delivery can offer cytocompatible and photoswitchable manipulability of diverse host cells.

Comprehensive evaluation of breast cancer immunotherapy and tumor microenvironment characterization based on interleukin genes-related risk model

Breast cancer (BRCA) is the most prevalent malignancy and the leading cause of death in women. Interleukin (IL) genes are critical in tumor initiation and control. Nevertheless, the prognosis value of the IL in BRCA remains unclear. We collected data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), and 94 IL genes were identified from GeneCard. Based on the random forest (RF), least absolute shrinkage and selection operator (LASSO) analysis, and multivariate Cox regression analysis, we constructed an IL signature. GSE22219, GSE25065, and GSE21653 were derived as validation sets. The expression differences in the tumor microenvironment (TME), immunotherapy, and chemosensitivity of BRCA between the high- and low-risk groups were evaluated. Overall, 21 IL genes were selected to construct an IL risk model, of which IL18BP, IL17D, and IL23A were the first time identified as prognostic genes in BRCA. IL score could distinguish BRCA patients with inferior outcomes, and AUC of it was 0.70, 0.76, and 0.72 for 1-,3- and 5- years, respectively, which was also verified in GSE22219, GSE25065, and GSE21653 cohorts. Meanwhile, compared to luminal A and luminal B, HER2-positive and TNBC had significantly higher IL score. Besides, the high-risk group had a significantly higher prevalence of TP53 and TTN but a lower prevalence of PIK3CA, as well as higher tumor mutation burden (TMB) and neoantigen level. High- and low-risk groups exhibited notable differences in immunomodulators and tumor infiltrates immune cells (TIICs), and the high-risk group had significantly lower Tumor Immune Dysfunction and Exclusion (TIDE) score. Additionally, the high-risk group has more responders to immune or anti-HER2 combination therapy, whereas the low-risk group has higher sensitivity to docetaxel and paclitaxel. Consequently, we constructed a reliable risk model based on the IL genes, which can provide more information on both the risk stratification and personalizing management strategies for BRCA.

Origin, activation, and targeted therapy of glioma-associated macrophages

The glioma tumor microenvironment plays a crucial role in the development, occurrence, and treatment of gliomas. Glioma-associated macrophages (GAMs) are the most widely infiltrated immune cells in the tumor microenvironment (TME) and one of the major cell populations that exert immune functions. GAMs typically originate from two cell types-brain-resident microglia (BRM) and bone marrow-derived monocytes (BMDM), depending on a variety of cytokines for recruitment and activation. GAMs mainly contain two functionally and morphologically distinct activation types- classically activated M1 macrophages (antitumor/immunostimulatory) and alternatively activated M2 macrophages (protumor/immunosuppressive). GAMs have been shown to affect multiple biological functions of gliomas, including promoting tumor growth and invasion, angiogenesis, energy metabolism, and treatment resistance. Both M1 and M2 macrophages are highly plastic and can polarize or interconvert under various malignant conditions. As the relationship between GAMs and gliomas has become more apparent, GAMs have long been one of the promising targets for glioma therapy, and many studies have demonstrated the therapeutic potential of this target. Here, we review the origin and activation of GAMs in gliomas, how they regulate tumor development and response to therapies, and current glioma therapeutic strategies targeting GAMs.

Multi-Modal Imaging Monitored M2 Macrophage Targeting Sono-Responsive Nanoparticles to Combat MRSA Deep Infections

Background

MRSA with high morbidity and mortality is prone to cause serious infection, SDT has become a new antibiotic-free modality for bacterial infection treatment. Switching from proinflammatory M1 macrophages to anti-inflammatory M2 macrophages dominant could activate the immune system to generate an anti-infection immune response.

Methods

Herein, we developed M2 macrophages derived cell membranes coated PLGA nanoparticles with IR780 encapsulation (M2/IR780@PLGA) for antibacterial SDT and subsequent M2 macrophage polarization to enhance the therapeutic efficacy of MRSA myositis. For in situ visualization of antibacterial SDT, both diagnostic high-frequency US and magnetic resonance imaging (MRI) were introduced to monitor the sono-therapeutic progression of M2/IR780@PLGA nanoparticles in mice with bacterial myositis.

Results

Our developed M2/IR780@PLGA nanoparticles exhibited excellent antibacterial effects due to the IR780 under low-frequency US irradiation in vitro. In an MRSA-infected mice model, a great deal of M2/IR780@PLGA nanoparticles accumulated at the site of inflammation due to M2 macrophage coating. The infected legs in the M2/IR780@PLGA nanoparticles-based SDT group were significantly smaller, fewer blood flow signals, a slight muscular edema without obvious intermuscular abscesses under high-frequency US and MR images guidance. Histopathology proved the infected legs in the M2/IR780@PLGA nanoparticles-mediated SDT group had less clumped bacteria infiltration, more M2 macrophage expression and less M1 macrophage expression. The percentage of mature dendritic cells in spleens was much higher in the group of mice with M2/IR780@PLGA nanoparticles-based SDT.

Conclusion

This study provides a promising nanoparticles-based SDT anti-bacterial strategy, which could effectively enhance the antibacterial SDT and subsequent promote M2 macrophage polarization to boost the therapeutic efficacy of MRSA myositis.

Submolecular Ligand Size and Spacing for Cell Adhesion

Cell adhesion occurs when integrin recognizes and binds to Arg-Gly-Asp (RGD) ligands present in fibronectin. In this work, submolecular ligand size and spacing are tuned via template-mediated in situ growth of nanoparticles for dynamic macrophage modulation. To tune liganded gold nanoparticle (GNP) size and spacing from 3 to 20 nm, in situ localized assemblies of GNP arrays on nanomagnetite templates are engineered. 3 nm-spaced ligands stimulate the binding of integrin, which mediates macrophage-adhesion-assisted pro-regenerative polarization as compared to 20 nm-spaced ligands, which can be dynamically anchored to the substrate for stabilizing integrin binding and facilitating dynamic macrophage adhesion. Increasing the ligand size from 7 to 20 nm only slightly promotes macrophage adhesion, not observed with 13 nm-sized ligands. Increasing the ligand spacing from 3 to 17 nm significantly hinders macrophage adhesion that induces inflammatory polarization. Submolecular tuning of ligand spacing can dominantly modulate host macrophages.

Ultrasonication, immune activity, and photocrosslinked microgel formation of pectic polysaccharide isolated from root bark of Ulmus davidiana var. japonica (Rehder) Nakai

The root bark of Ulmus davidiana var. japonica (Rehder) Nakai (Japanese elm) has been used for inflammatory disease treatments. In this work, we isolated pectic polysaccharides from the root bark of U. davidiana (UDP) and explored the immune activities of intact and ultrasonicated UDP on human macrophages. The UDP-treated macrophages showed a proinflammatory response, indicating classical activation via Toll-like receptor-mediated recognition. For hydrogel formation, the ultrasonicated UDP was modified with methacrylate groups, then subjected to photocrosslinking. The formed bulk hydrogel was pulverized into microgels by homogenization, and the microgel size was modulated for macrophage phagocytosis. The UDP microgel-treated macrophages displayed microgel internalization and classical activation that involved upregulation of M1 polarization markers (IL6, TNF-α, and CCR7), indicating that the microgel can be used as a carrier for macrophage-targeted drug delivery.

Dealing with Macrophage Plasticity to Address Therapeutic Challenges in Head and Neck Cancers

The head and neck tumor microenvironment (TME) is highly infiltrated with macrophages. More specifically, tumor-associated macrophages (TAM/M2-like) are one of the most critical components associated with poor overall survival in head and neck cancers (HNC). Two extreme states of macrophage phenotypes are described as conducting pro-inflammatory/anti-tumoral (M1) or anti-inflammatory/pro-tumoral (M2) activities. Moreover, specific metabolic pathways as well as oxidative stress responses are tightly associated with their phenotypes and functions. Hence, due to their plasticity, targeting M2 macrophages to repolarize in the M1 phenotype would be a promising cancer treatment. In this context, we evaluated macrophage infiltration in 60 HNC patients and demonstrated the high infiltration of CD68+ cells that were mainly related to CD163+ M2 macrophages. We then optimized a polarization protocol from THP1 monocytes, validated by specific gene and protein expression levels. In addition, specific actors of glutamine pathway and oxidative stress were quantified to indicate the use of glutaminolysis by M2 and the production of reactive oxygen species by M1. Finally, we evaluated and confirmed the plasticity of our model using M1 activators to repolarize M2 in M1. Overall, our study provides a complete reversible polarization protocol allowing us to further evaluate various reprogramming effectors targeting glutaminolysis and/or oxidative stress in macrophages.

Roles for macrophage-polarizing interleukins in cancer immunity and immunotherapy

Macrophages are the most abundant and one of the most critical cells of tumor immunity. They provide a bridge between innate and adaptive immunity through releasing cytokines into the tumor microenvironment (TME). A number of interleukin (IL) cytokine family members is involved in shaping the final phenotype of macrophages toward either a classically-activated pro-inflammatory M1 state with anti-tumor activity or an alternatively-activated anti-inflammatory M2 state with pro-tumor activity. Shaping TME macrophages toward the M1 phenotype or recovering this phenotypic state may offer a promising therapeutic approach in patients with cancer. Here, we focus on the impact of macrophage-polarizing ILs on immune cells and IL-mediated cellular cross-interactions within the TME. The key aim of this review is to define therapeutic schedules for addressing ILs in cancer immunotherapy based on their multi-directional impacts in such a milieu. Gathering more knowledge on this area is also important for defining adverse effects related to cytokine therapy and addressing them for reinforcing the efficacy of immunotherapy against cancer.

Combinational application of metal-organic frameworks-based nanozyme and nucleic acid delivery in cancer therapy

The rapid development of nanotechnology has generated numerous ideas for cancer treatment, and a wide variety of relevant nanoparticle platforms have been reported. Metal-organic frameworks (MOFs) have been widely investigated as an anti-cancer drug delivery vehicle owing to their unique porous hybrid structure, biocompatibility, structural tunability, and multi-functionality. MOF materials with catalytic activity, known as nanozymes, have applications in photodynamic and chemodynamic therapy. Nucleic acids have also attracted increasing research attention owing to their programmability, ease of synthesis, and versatility. A variety of functional DNAs and RNAs have been applied both therapeutically (gene-targeting drugs for cancer treatment) and nontherapeutically (used as modified materials to enhance the therapeutic effects of other nanomedicines). The combined use of MOFs and functional nucleic acids have been extensively investigated and has been associated with excellent tumor-suppressor activity in various treatment methods. In this review, we summarize the progress in the research and development of tumor therapy based on MOFs and nucleic acid delivery over recent years, focusing on the combinational use of different delivery and design strategies for MOF/therapeutic nucleic acid platforms. We further summarize the strategies for combining MOFs (universal carrier, functional carrier) and nucleic acids (therapeutic nucleic acids, nontherapeutic nucleic acids) and discuss the corresponding therapeutic effects in cancer treatment. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Reprogramming the tumor microenvironment by genome editing for precision cancer therapy

The tumor microenvironment (TME) is essential for immune escape by tumor cells. It plays essential roles in tumor development and metastasis. The clinical outcomes of tumors are often closely related to individual differences in the patient TME. Therefore, reprogramming TME cells and their intercellular communication is an attractive and promising strategy for cancer therapy. TME cells consist of immune and nonimmune cells. These cells need to be manipulated precisely and safely to improve cancer therapy. Furthermore, it is encouraging that this field has rapidly developed in recent years with the advent and development of gene editing technologies. In this review, we briefly introduce gene editing technologies and systematically summarize their applications in the TME for precision cancer therapy, including the reprogramming of TME cells and their intercellular communication. TME cell reprogramming can regulate cell differentiation, proliferation, and function. Moreover, reprogramming the intercellular communication of TME cells can optimize immune infiltration and the specific recognition of tumor cells by immune cells. Thus, gene editing will pave the way for further breakthroughs in precision cancer therapy.

Non-coding RNAs and macrophage interaction in tumor progression

The macrophages are abundantly found in TME and their M2 polarization is in favor of tumor malignancy. On the other hand, non-coding RNAs (ncRNAs) can modulate macrophage polarization in TME to affect cancer progression. The miRNAs can dually induce/suppress M2 polarization of macrophages and by affecting various molecular pathways, they modulate tumor progression and therapy response. The lncRNAs can affect miRNAs via sponging and other molecular pathways to modulate macrophage polarization. A few experiments have also examined role of circRNAs in targeting signaling networks and affecting macrophages. The therapeutic targeting of these ncRNAs can mediate TME remodeling and affect macrophage polarization. Furthermore, exosomal ncRNAs derived from tumor cells or macrophages can modulate polarization and TME remodeling. Suppressing biogenesis and secretion of exosomes can inhibit ncRNA-mediated M2 polarization of macrophages and prevent tumor progression. The ncRNAs, especially exosomal ncRNAs can be considered as non-invasive biomarkers for tumor diagnosis.

The Intracellular and Extracellular Microenvironment of Tumor Site: The Trigger of Stimuli-Responsive Drug Delivery Systems

The tumor microenvironment (TME), including intracellular and extracellular microenvironment, contains many biochemical indicators (such as acidity/alkalinity, oxygen content, and enzymatic activity) that are different from the normal physiological environment. These abnormal biochemical indicators can accelerate the heterogeneity of tumors, but on the other hand, they also provide opportunities for the design of intelligent drug delivery systems (DDSs). The TME-responsive DDSs have shown great potential in reducing the side effects of chemotherapy and improving the curative effect of tumors. In this review, the abnormal biochemical indicators of TME are introduced in detail from both the extracellular and intracellular aspects. In view of the various physiological barriers encountered during drug delivery, the strategy of constructing TME-responsive DDSs is discussed. By summarizing the typical research progress, the authors prospect the development of TME-responsive DDS in the future.

Engineered Mesenchymal Stem Cells as a Biotherapy Platform for Targeted Photodynamic Immunotherapy of Breast Cancer

Interleukin-12 (IL12) is a pleiotropic cytokine with promising prospects for cancer immunotherapy. Though IL12 gene-based therapy can overcome the fatal hurdle of severe systemic toxicity, targeted delivery and tumor-located expression of IL12 gene remain the challenging issues yet to be solved. Photo-immunotherapy emerging as a novel and precise therapeutic strategy, which elaborately combines immune-activating agents with light-triggered photosensitizers for potentiated anticancer efficacy. Herein, an engineered stem cell-based biotherapy platform (MB/IL12-MSCs) incorporating immune gene plasmid IL12 (pIL12) and photosensitizer methylene blue (MB) is developed to realize tumor-homing delivery of therapeutic agents and photo-immunotherapy efficacy enhancement. The biotherapy platform retained tumor-tropic migration and penetration functions, which improved the intratumoral distribution of therapeutic agents, thereby promoting photodynamic effects and reinforcing immune responses. Importantly, MB/IL12-MSCs restricted the expression and distribution of IL12 at tumor site, which minimized potential toxicity while eliciting sufficient anticancer immunity. In noteworthy, activation of immunity induced by MB/IL12-MSCs established long-term systemic immunologic memory to prevent tumor relapse. The MB/IL12-MSCs outperform their monotherapy counterparts in breast tumor models, and the growth of tumor significantly arrested as well as re-challenging abscopal tumor growth slowdown. Collectively, this work reveals that MSCs-based strategy may advance more efficient, durable, and safer cancer photo-immunotherapy.

Glutamine Metabolism-Regulated Nanoparticles to Enhance Chemoimmunotherapy by Increasing Antigen Presentation Efficiency

Although the strategies to induce dendritic cells (DCs) maturation and promote their antigen presentation can stimulate the tumor immune response, the endogenous deficiency and immunosuppression of DCs reduce antigen utilization, which limits antigen presentation efficiency and reduces immunotherapy effectiveness. Here, we report an endogenous stimulus-responsive nanodelivery system (DOX@HFn-MSO@PGZL). On the one hand, doxorubicin (DOX) promoted antigen presentation by DCs after the immunogenic death of tumor cells. On the other hand, l-methionine sulfoximine (MSO) regulated the glutamine metabolism of tumor-associated macrophages (TAMs) to induce a shift toward the M1-type. M1-TAMs synergistically presented antigens with mature DCs and were more frequently produced to destroy the tumor suppressive immune microenvironment, resulting in the alleviation of DCs functional inhibition. Ultimately, the antigen presentation efficiency was improved, completely activating tumor immunity and exhibiting powerful antitumor effects.

Engineered a dual-targeting biomimetic nanomedicine for pancreatic cancer chemoimmunotherapy

The therapeutic effect of chemotherapeutics such as gemcitabine against pancreatic cancer is considerably attenuated by immune-suppressive tumor microenvironment. Improvement of chemotherapeutic efficacy by targeting tumor-associated macrophage and reprograming tumor microenvironment to enhance their efficacy may become a promising strategy. To this end, we developed a biomimetic dual-targeting nanomedicine (PG@KMCM) where gemcitabine-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles are coated with a layer of bioengineered cancer cell membrane that stably expresses peptides targeting M2-like macrophages (M2pep) while reserving tumor-associated antigens (TAAs). The PG@KMCM nanomedicine enables the simultaneous targeted delivery of gemcitabine to pancreatic tumor sites and TAMs to potentiate its therapeutic effects. Furthermore, the combination of an immune checkpoint inhibitor (PD-L1 antibody) with PG@KMCM synergistically enhanced the anti-tumoral effect by reprogramming the immune-suppressive tumor microenvironment, including the elimination of PD-L1-positive macrophages and the downregulation of PD-L1 expression. Our study proved dual-targeting PG@KMCM nanomedicine in combination with PD-L1 immune checkpoint inhibitor therapy is able to effectively reprogram the tumor microenvironment and kill pancreatic cancer cells to enhance overall therapeutic potential.

GBE1 Is an Independent Prognostic Marker and Associated With CD163+ Tumor-Associated Macrophage Infiltration in Lung Adenocarcinoma

Glycogen branching enzyme (GBE1) is a critical gene that participates in regulating glycogen metabolism. However, the correlations between GBE1 expression and the prognosis and tumor-associated macrophages in lung adenocarcinoma (LUAD) also remain unclear. Herein, we firstly analyzed the expression level of GBE1 in LUAD tissues and adjacent lung tissues via The Cancer Genome Atlas (TCGA) database. The effect of GBE1 on prognosis was estimated by utilizing TCGA database and the PrognoScan database. The relationships between the clinical characteristics and GBE1 expression were evaluated via TCGA database. We then investigated the relationships between GBE1 and infiltration of immune cells in LUAD by utilizing the CIBERSORT algorithm and Tumor Immune Estimation Resource (TIMER) database. In addition, we used a tissue microarray (TMA) containing 92 LUAD tissues and 88 adjacent lung tissues with immunohistochemistry staining to verify the association between GBE1 expression and clinical characteristics, as well as the immune cell infiltrations. We found the expression level of GBE1 was significantly higher in LUAD tissues. High expression of GBE1 was associated with poorer overall survival (OS) in LUAD. In addition, high expression of GBE1 was correlated with advanced T classification, N classification, M classification, TNM stage, and lower grade. Moreover, GBE1 was positively correlated with infiltrating levels of CD163⁺ tumor-associated macrophages in LUAD. In conclusion, the expression of GBE1 is associated with the prognosis and CD163⁺ tumor-associated macrophage infiltration in LUAD, suggesting that it has potential to be prognostic and immunological biomarkers in LUAD.

Epigenetic Platinum Complexes Breaking the "Eat Me/Don't Eat Me" Balance for Enhanced Cancer Chemoimmunotherapy

Platinum complexes, despite being the most successful organometallic anticancer chemotherapy drugs, still suffer from serious side effects and therapy resistance. Inspired by the immunomodulation effect of platinum drugs, an epigenetic platinum(IV) complex was synthesized for enhanced cancer chemoimmunotherapy by conjugating oxidized oxaliplatin (OXA) with 2-bromo-1-(3,3-dinitro-1-azetidinyl)ethenone (RRx-001), the latter of which as a nitric oxide (NO) donor is also an epigenetic agent. The obtained complex (named OXA-NO) could significantly increase the level of "eat me" signal CRT expression and decrease the level of "don't eat me" signal CD47 expression on cancer cell membranes to promote their phagocytosis by macrophages. In addition, OXA-NO could release nitric oxide to trigger the transformation of pro-tumorigenic M2-type macrophages into antitumor M1-type macrophages within the tumor to reverse the immunosuppressive tumor microenvironment. Compared to commercial OXA, OXA-NO exhibited much stronger tumor growth inhibition ability and was much better tolerated, with obviously weakened side effects observed in spleen, lung, and kidneys. Therefore, this epigenetic platinum(IV) complex that exhibits excellent therapeutic efficacy and safety has great potential in the clinic.

Remodeling Macrophages by an Iron Nanotrap for Tumor Growth Suppression

Tumor-associated macrophages (TAMs) that infiltrate in most tumor tissues are closely correlated with proliferation and metastasis of tumor cells. Immunomodulation of TAMs from pro-tumorigenic M2 phenotype to anti-tumorigenic M1 phenotype is crucial for oncotherapy. Herein, an iron nanotrap was utilized to remodel TAMs for tumor growth inhibition. In the formulation, the ultrasmall nanotrap could capture and targetedly transport endogenous iron into TAMs even inside the tumor. Upon exposing to the lysosomal acidic conditions and intracellular H₂O₂, iron was released from the nanotrap and produced the generation of oxidative stress, which could reprogram TAMs. The activated M1 macrophages could induce immune responses and suppress tumor growth ultimately. Meanwhile, this metal-free nanotrap with degradability by H₂O₂ possessed favorable biocompatibility. Our work would present potential opportunities of utilizing endogenous substances for secure treatment of various diseases.

Emerging Nanoparticle Strategies for Modulating Tumor-Associated Macrophage Polarization

Immunotherapy has made great progress in recent years, yet the efficacy of solid tumors remains far less than expected. One of the main hurdles is to overcome the immune-suppressive tumor microenvironment (TME). Among all cells in TME, tumor-associated macrophages (TAMs) play pivotal roles because of their abundance, multifaceted interactions to adaptive and host immune systems, as well as their context-dependent plasticity. Underlying the highly plastic characteristic, lots of research interests are focused on repolarizing TAMs from M2-like pro-tumor phenotype towards M1-like antitumoral ones. Nanotechnology offers great opportunities for targeting and modulating TAM polarization to mount the therapeutic efficacy in cancer immunotherapy. Here, this mini-review highlights those emerging nano-approaches for TAM repolarization in the last three years.

Biointerfacing Antagonizing T-Cell Inhibitory Nanoparticles Potentiate Hepatocellular Carcinoma Checkpoint Blockade Therapy

Hepatocellular carcinoma (HCC) is one of the most fatal malignancies with few effective treatment options all around the world. The efficacy of the arisen immune checkpoint therapy is still uncertain due to local immunosuppression. In order to further overcome T cell suppression in the tumor immune microenvironment while promoting the immune response of antigen-presenting cells, a biointerfacing antagonizing T-cell inhibitory nanoparticles (BAT NPs) has been developed by cloaking platelet membrane on the PLGA microsphere surface to load T-cell immunoglobulin domain and mucin domain-3 antibodies (anti-TIM-3) as well as PD-L1. Notably, in addition to activating the proliferation and migration of T cells, the contained anti-TIM-3 can cooperate with PD-L1 checkpoint blockade to exert therapeutic effects. Furthermore, the components of BAT NPs like anti-TIM-3 and platelet can act together for collagen deposition in tumor starvation treatment. Thus, a novel targeting therapeutic strategy that can effectively reverse the immune-inhibiting microenvironment is effectively applied to PD-L1 checkpoint combination therapy. Such therapeutic effect can subsequently activate the effector T lymphocytes and antigen presentation of dendritic cells as well as the polarization of M1-type macrophages. Last, the study presented the synergistic effect of immune therapeutic adjuvants and BAT NPs components in achieving tumor inhibition and prolonging tumor-burden survival.

Nanomaterials targeting tumor associated macrophages for cancer immunotherapy

Tumor-associated macrophages (TAMs) play an important role in regulating tumor growth, invasion and metastasis, and constitute approximately 50% of tumor mass. TAMs can exist in two different subtypes, M1-polarized phenotype (pro-inflammatory and immunostimulatory) and M2-polarized phenotype (immunosuppressive myeloid cells). M2 macrophages can suppress CD8⁺ T cells to support tumor survival. A number of biological strategies aimed at engineering macrophages to modulate the tumor immune microenvironment remain at the forefront of cancer research. Here, we review the different therapeutic strategies that have been developed based on nanotechnology to modulate macrophage functions, such as inhibition of macrophage recruitment to tumor, depletion of M2-polarized macrophages, reprograming of M2-polarized macrophages to M1-polarized macrophages, and blocking of the CD47-signal-regulatory protein alpha (CD47-SIRPα) pathway. Furthermore, we also discuss how to image TAMs with nanoparticles to unravel novel treatment options and observe their responses to the various therapies. Overall, macrophage-mediated immune modulation based on nanotechnology can be further investigated to be effectively developed as an immunoadjuvant therapy against different cancers.

Effect of Cationic Charge Density on Transcytosis of Polyethylenimine

The adsorption-mediated transcytosis (AMT) induced by the electrostatic interaction between the positively charged surface of carriers and negatively charged cell membrane is a new paradigm enabling nanomedicine's tumor extravasation and infiltration. However, little is known about the correlation between the carrier's charge density and its AMT-induced tumor infiltration efficiency. Herein, we investigate the effect of the cationic polymer's charge on the AMT-induced tumor penetration ability using in vitro multilayer tumor spheroids (MTSs). A cationic polymer, polyethylenimine (PEI), is amidized with acetic anhydride to obtain acetylated PEIs (AcPEIs) with different cationic charge densities. As the amidization ratio increases, the AcPEIs' cytotoxicity, zeta potential, and cell-binding affinity significantly decrease. Notably, not only does the weak cell binding (AcPEIs with high acetylation degrees) lead to slow endocytosis and inefficient transcytosis, so does the strong cell-binding PEI. The PEI with 24% acetylation (AcPEI_24%) is found to have the highest transcytosis efficiency because its balanced cell-binding affinity triggers fast adsorption-mediated endocytosis. The subsequent Golgi apparatus/endoplasmic reticulum-mediated exocytosis via extracellular vesicles leads to highly effective transcellular delivery and tumor penetration in MTSs. Therefore, the drug carrier's surface cationic charge density critically influences its AMT-induced tumor penetration efficiency. This study provides mechanistic insights into the design of drug-delivery systems with active transcytosis for improved tumor penetration and enhanced therapeutic efficiency.

Influence of the Modulation of the Protein Corona on Gene Expression Using Polyethylenimine (PEI) Polyplexes as Delivery Vehicle

The protein corona can significantly modulate the physicochemical properties and gene delivery of polyethylenimine (PEI)/DNA complexes (polyplexes). The effects of the protein corona on the transfection have been well studied in terms of averaged gene expression in a whole cell population. Such evaluation methods give excellent and reliable statistics, but they in general provide the final transfection efficiency without reflecting the dynamic process of gene expression. In this regard the influence of bovine serum albumin (BSA) on the gene expression of PEI polyplexes also on a single cell level via live imaging is analyzed. The results reveal that although the BSA corona causes difference in the overall gene expression and mRNA transcription, the gene expression behavior on the level of individual cell is similar, including the mitosis-dependent expression, distributions of onset time, expression pattern in two daughter cells, and expression kinetics in successfully transfected cells. Comparison of single cell and ensemble data on whole cell cultures indicate that the protein corona does not alter the transfection process after nuclear entry, including cell division, polyplex dissociation, and protein expression. Its influence on other steps of in vitro gene delivery before nuclear entry shall render the difference in the overall transfection.

Mesenchymal Stem Cells Engineered by Nonviral Vectors: A Powerful Tool in Cancer Gene Therapy

Due to their "tumor homing" and "immune privilege" characteristics, the use of mesenchymal stem cells (MSCs) has been proposed as a novel tool against cancer. MSCs are genetically engineered in vitro and then utilized to deliver tumoricidal agents, including prodrugs and bioactive molecules, to tumors. The genetic modification of MSCs can be achieved by various vectors, and in most cases viral vectors are used; however, viruses may be associated with carcinogenesis and immunogenicity, restricting their clinical translational potential. As such, nonviral vectors have emerged as a potential solution to address these limitations and have gradually attracted increasing attention. In this review, we briefly revisit the current knowledge about MSC-based cancer gene therapy. Then, we summarize the advantages and challenges of nonviral vectors for MSC transfection. Finally, we discuss recent advances in the development of new nonviral vectors, which have provided promising strategies to overcome obstacles in the gene modulation of MSCs.

Dose-Independent Transfection of Hydrophobized Polyplexes

Cationic polymers dynamically complex DNA into complexes (polyplexes). So, upon dilution, polyplexes easily dissociate and lose transfection ability, limiting their in vivo systemic gene delivery. Herein, it is found that polyplex's stability and endocytosis pathway determine its transfection dose-dependence. The polyplexes of hydrophilic polycations have dose-dependent integrity and lysosome-trafficking endocytosis; at low doses, most of these polyplexes dissociate, and the remaining few are internalized and trapped in lysosomes, abolishing their transfection ability. In contrast, the polyplexes of the polycations with optimal hydrophobicity remain integrated even at low concentrations and enter cells via macropinocytosis directly into the cytosol evading lysosomes, so each polyplex can accomplish its infection process, leading to dose-independent DNA transfection like viral vectors. Furthermore, the tuned hydrophobicity balancing the affinity of anionic poly(γ-glutamic acid) (γ-PGA) to the polyplex surface enables γ-PGA to stick on the polyplex surface as a shielding layer but peel off on the cell membrane to release the naked polyplexes for dose-independent transfection. These findings may provide guidelines for developing polyplexes that mimick a viral vector's dose-independent transfection for effective in vivo gene delivery.