Tannic acid-poloxamer self-assembled nanoparticles for advanced atherosclerosis therapy by regulation of macrophage polarization.

Atherosclerosis (AS) is a significant contributor to cardiovascular events. Advanced AS is particularly concerning, as it leads to the formation of high-risk vulnerable plaques. Current treatments for AS focus on antithrombotic and lipid-lowering interventions, which are effective in treating early-stage AS. Recent studies have shown that macrophage polarization plays a crucial role in the development of AS. This study presents a new biomedical application of natural tannic acid as an anti-inflammatory nanoplatform for advanced AS. Tannic acid-poloxamer nanoparticles (TPNP) are fabricated through self-assembly of tannic acid (TA) and poloxamer. TPNP has the potential to provide effective treatment for advanced AS. According to in vitro studies, TPNP has been found to suppress the inflammatory response in lipopolysaccharide-stimulated macrophages by scavenging reactive oxygen species (ROS), downregulating the expression levels of inflammatory cytokines (such as interleukin-10 and tumor necrosis factor-α) and regulating polarization of macrophages. In vivo studies further reveal that TPNP can retard the development of advanced atherosclerotic plaques by reducing ROS production and promoting M2 macrophage polarization in the aorta of ApoE-/- mice. Overall, these findings suggest that TPNP could be used to develop natural multifunctional nanoplatforms for molecular therapy of AS and other inflammation-related diseases.

MOF-derived bimetallic nanozyme to catalyze ROS scavenging for protection of myocardial injury.

Rationale: Myocardial injury triggers intense oxidative stress, inflammatory response, and cytokine release, which are essential for myocardial repair and remodeling. Excess reactive oxygen species (ROS) scavenging and inflammation elimination have long been considered to reverse myocardial injuries. However, the efficacy of traditional treatments (antioxidant, anti-inflammatory drugs and natural enzymes) is still poor due to their intrinsic defects such as unfavorable pharmacokinetics and bioavailability, low biological stability, and potential side effects. Nanozyme represents a candidate to effectively modulate redox homeostasis for the treatment of ROS related inflammation diseases. Methods: We develop an integrated bimetallic nanozyme derived from metal-organic framework (MOF) to eliminate ROS and alleviate inflammation. The bimetallic nanozyme (Cu-TCPP-Mn) is synthesized by embedding manganese and copper into the porphyrin followed by sonication, which could mimic the cascade activities of superoxide dismutase (SOD) and catalase (CAT) to transform oxygen radicals to hydrogen peroxide, followed by the catalysis of hydrogen peroxide into oxygen and water. Enzyme kinetic analysis and oxygen-production velocities analysis were performed to evaluate the enzymatic activities of Cu-TCPP-Mn. We also established myocardial infarction (MI) and myocardial ischemia-reperfusion (I/R) injury animal models to verify the ROS scavenging and anti-inflammation effect of Cu-TCPP-Mn. Results: As demonstrated by kinetic analysis and oxygen-production velocities analysis, Cu-TCPP-Mn nanozyme possesses good performance in both SOD- and CAT-like activities to achieve synergistic ROS scavenging effect and provide protection for myocardial injury. In both MI and I/R injury animal models, this bimetallic nanozyme represents a promising and reliable technology to protect the heart tissue from oxidative stress and inflammation-induced injury, and enables the myocardial function to recover from otherwise severe damage. Conclusions: This research provides a facile and applicable method to develop a bimetallic MOF nanozyme, which represents a promising alternative to the treatment of myocardial injuries.

Engineered Toll-like Receptor Nanoagonist Binding to Extracellular Matrix Elicits Safe and Robust Antitumor Immunity.

Cancer immunotherapy, such as the Toll-like receptor (TLR) agonist including CpG oligodeoxynucleotide, has shown potency in clinical settings. However, it is still confronted with multiple challenges, which include the limited efficacy and severe adverse events caused by the rapid clearance and systemic diffusion of CpG. Here we report an improved CpG-based immunotherapy approach composed of a synthetic extracellular matrix (ECM)-anchored DNA/peptide hybrid nanoagonist (EaCpG) via (1) a tailor designed DNA template that encodes tetramer CpG and additional short DNA moieties, (2) generation of elongated multimeric CpG through rolling circle amplification (RCA), (3) self-assembly of densely packaged CpG particles composed of tandem CpG building blocks and magnesium pyrophosphate, and (4) incorporation of multiple copies of ECM binding peptide through hybridization to short DNA moieties. The structurally well-defined EaCpG shows dramatically increased intratumoral retention and marginal systemic dissemination through peritumoral administration, leading to potent antitumor immune response and subsequent tumor elimination, with minimal treatment-related toxicity. Combined with conventional standard-of-care therapies, peritumor administration of EaCpG generates systemic immune responses that lead to a curative abscopal effect on distant untreated tumors in multiple cancer models, which is superior to the unmodified CpG. Taken together, EaCpG provides a facile and generalizable strategy to simultaneously potentiate the potency and safety of CpG for combinational cancer immunotherapies.