Synthesis, Formulation and Characterization of Immunotherapeutic Glycosylated Dendrimer/cGAMP Complexes for CD206 Targeted Delivery to M2 Macrophages in Cold Tumors

Dendrimer nanocarriers for targeted co-delivery of MiR-146b-3p and 5-ALA to synergistic photodynamic therapy in secondary hyperparathyroidism

The combination of photodynamic therapy (PDT) and gene therapy is a viable therapeutic approach for the management of secondary hyperparathyroidism (SHPT). Nevertheless, the effective delivery of photosensitizers or nucleotide drugs remains a crucial limitation in achieving therapeutic efficacy. MiR-146b-3p directly targeted BCL2, and its overexpression enhanced the antiproliferative, proautophagic, and proapoptotic effects during 5-aminolevulinic acid (5-ALA)-mediated PDT in this study. Herein, we investigated the potential of codelivering 5-ALA and miR-146b-3p to SHPT primary cells via polyamidoamine (PAMAM) and achieving enhanced therapeutic efficacy relative to that of monotreatment. The fabrication of the PAMAM-based 5-ALA and miR-146b-3p dual-delivery system (5-ALA@PAMAM/miR) involved the use of covalent condensation reactions and electrostatic self-assembly. The nanoparticles were characterized by various analytical techniques, including transmission electron microscopy (TEM), zeta potential measurements, and size measurements. Fluorescence and confocal laser scanning microscopy demonstrated a greater degree of cellular uptake of nanoparticles. Moreover, the synthesized nanoparticles considerably enhanced the effectiveness of PDT without systemic toxicity both in vitro and in vivo. Overall, the nanocarrier-gene-photosensitizer coloaded system is a promising platform for the efficient simultaneous delivery of miR-146b-3p and 5-ALA and achieves synergistic therapeutic effects.

Combining antimiR-25 and cGAMP Nanocomplexes Enhances Immune Responses via M2 Macrophage Reprogramming

Glioblastoma (GBM) is an aggressive brain cancer with a highly immunosuppressive tumor microenvironment (TME), invariably infiltrated by tumor-associated macrophages (TAMs). These TAMs resemble M2 macrophages, which promote tumor growth and suppress immune responses. GBM cells secrete extracellular vesicles (EVs) containing microRNA-25, which inhibits the cGAS-STING pathway and prevents TAMs from adopting a pro-inflammatory M1 phenotype. This study characterizes antimiR-25/cGAMP nanocomplexes (NCs) for potential therapeutic applications. A particle size analysis revealed a significant reduction upon complexation with antimiR-25, resulting in smaller, more stable nanoparticles. Stability tests across pH levels (4-6) and temperatures (25-37 °C) demonstrated their resilience in various biological environments. Biological assays showed that antimiR-25 NCs interacted strongly with transferrin (Tf), suggesting potential for blood-brain barrier passage. The use of cGAMP NCs activated the cGAS-STING pathway in macrophages, leading to increased type I IFN (IFN-β) production and promoting a shift from the M2 to M1 phenotype. The combined use of cGAMP and antimiR-25 NCs also increased the expression of markers involved in M1 polarization. These findings offer insights into optimizing antimiR-25/cGAMP NCs for enhancing immune responses in GBM.

Recent advances in multifunctional dendrimer-based complexes for cancer treatment

The application of nanotechnology in biological and medical fields have resulted in the creation of new devices, supramolecular systems, structures, complexes, and composites. Dendrimers are relatively new nanotechnological polymers with unique features; they are globular in shape, with a topological structure formed by monomeric subunit branches diverging to the sides from the central nucleus. This review analyzes the main features of dendrimers and their applications in biology and medicine regarding cancer treatment. Dendrimers have applications that include drug and gene carriers, antioxidant agents, imaging agents, and adjuvants, but importantly, dendrimers can create complex nanosized constructions that combine features such as drug/gene carriers and imaging agents. Dendrimer-based nanosystems include different metals that enhance oxidative stress, polyethylene glycol to provide biosafety, an imaging agent (a fluorescent, radioactive, magnetic resonance imaging probe), a drug or/and nucleic acid that provides a single or dual action on cells or tissues. One of major benefit of dendrimers is their easy release from the body (in contrast to metal nanoparticles, fullerenes, and carbon nanotubes), allowing the creation of biosafe constructions. Some dendrimers are already clinically approved and are being used as drugs, but many nanocomplexes are currently being studied for clinical practice. In summary, dendrimers are very useful tool in the creation of complex nanoconstructions for personalized nanomedicine. This article is categorized under: Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Hmox1 is Identified as a Ferroptosis Hub Gene and Associated with the M1 Type Microglia/Macrophage Polarization in Spinal Cord Injury: Bioinformatics and Experimental Validation

Ferroptosis and immune cell infiltration are important pathological events in spinal cord injury (SCI), but links between ferroptosis and immune microenvironment after SCI were rare reported. In our study, 77 FRDEGs were screened at 7 days after SCI. GO analysis of FRDEGs showed that aging (GO:0007568; P-value = 1.11E-05) was the most remarkable enriched for biological process, protein binding (GO:0005515; adjusted P-value = 4.44E-06) was the most significantly enriched for molecular function, cytosol (GO:0005829; adjusted P-value = 1.51E-04) was the most prominent enriched for cellular component. Meanwhile, Ferroptosis was significantly enriched both in KEGG (rno04216; adjusted P-value = 0.001) and GSEA (NES = 1.35; adjusted P-value = 0.004) analysis. Next, Hmox1 (Log2Fold change = 6.52; adjusted P-value = 0.004) was identified as one of hub genes in SCI-induced ferroptosis. In the results of immune cell infiltration analysis, proportion of microglia/macrophage was significantly increased after SCI, and Hmox1 was found to positively correlate to the M1 type microglia/macrophage abundance. Finally, effects of Hmox1 on ferroptosis and M1 type polarization were validated in vivo and in vitro. Summarily, we found that Hmox1 was the hub gene in SCI-induced ferroptosis and associated with the M1 type polarization.

The cross-talk between macrophages and tumor cells as a target for cancer treatment

Macrophages represent an important component of the innate immune system. Under physiological conditions, macrophages, which are essential phagocytes, maintain a proinflammatory response and repair damaged tissue. However, these processes are often impaired upon tumorigenesis, in which tumor-associated macrophages (TAMs) protect and support the growth, proliferation, and invasion of tumor cells and promote suppression of antitumor immunity. TAM abundance is closely associated with poor outcome of cancer, with impediment of chemotherapy effectiveness and ultimately a dismal therapy response and inferior overall survival. Thus, cross-talk between cancer cells and TAMs is an important target for immune checkpoint therapies and metabolic interventions, spurring interest in it as a therapeutic vulnerability for both hematological cancers and solid tumors. Furthermore, targeting of this cross-talk has emerged as a promising strategy for cancer treatment with the antibody against CD47 protein, a critical macrophage checkpoint recognized as the "don't eat me" signal, as well as other metabolism-focused strategies. Therapies targeting CD47 constitute an important milestone in the advancement of anticancer research and have had promising effects on not only phagocytosis activation but also innate and adaptive immune system activation, effectively counteracting tumor cells' evasion of therapy as shown in the context of myeloid cancers. Targeting of CD47 signaling is only one of several possibilities to reverse the immunosuppressive and tumor-protective tumor environment with the aim of enhancing the antitumor response. Several preclinical studies identified signaling pathways that regulate the recruitment, polarization, or metabolism of TAMs. In this review, we summarize the current understanding of the role of macrophages in cancer progression and the mechanisms by which they communicate with tumor cells. Additionally, we dissect various therapeutic strategies developed to target macrophage-tumor cell cross-talk, including modulation of macrophage polarization, blockade of signaling pathways, and disruption of physical interactions between leukemia cells and macrophages. Finally, we highlight the challenges associated with tumor hypoxia and acidosis as barriers to effective cancer therapy and discuss opportunities for future research in this field.