Inflammatory microenvironment-targeted nanotherapies

Exosomes in inflammation and cancer: from bench to bedside applications

Exosomes, lipid bilayer nanovesicles secreted by nearly all cell types, play pivotal roles in intercellular communication by transferring proteins, nucleic acids, and lipids. This review comprehensively summarizes their multiple functions in inflammation and cancer. In inflammation, exosomes exhibit context-dependent pro- or anti-inflammatory effects: they promote acute responses by delivering cytokines and miRNAs to activate immune cells, yet suppress chronic inflammation via immunoregulatory molecules. Two representative inflammatory diseases, namely sepsis and inflammatory bowel disease, were highlighted to elucidate their roles in the acute and chronic inflammatory diseases. In cancer, exosomes orchestrate tumor microenvironment (TME) remodeling by facilitating angiogenesis, metastasis, and immune evasion through interactions with cancer-associated fibroblasts, tumor-associated macrophages, and extracellular matrix components. Furthermore, exosomes can facilitate the transition from inflammation to cancer by impacting pertinent signaling pathways via their transported oncogenic and inflammatory molecules. Tumor-derived exosomes also serve as non-invasive biomarkers correlating with disease progression. Clinically, exosomes demonstrate promise as therapeutic agents and drug carriers, evidenced by ongoing trials targeting inflammatory diseases and cancers. However, challenges in isolation standardization, scalable production, and understanding functional heterogeneity hinder clinical translation. Future research should prioritize elucidating cargo-specific mechanisms, optimizing engineering strategies, and advancing personalized exosome-based therapies. By bridging molecular insights with clinical applications, exosomes hold great potential in precision medicine for inflammation and oncology.

Inflammatory targeted nanoplatform incorporated with antioxidative nano iron oxide to attenuate ulcerative colitis progression

Antioxidative nanomaterials with reactive oxygen species (ROS) scavenging capabilities hold promise for the treatment of ulcerative colitis (UC). However, their clinical application is limited by rapid diffusion, susceptibility to inactivation, and insufficient targeting of inflammatory sites. This study focuses on developing a nanoplatform by integrating iron oxide nanoparticles (IONPs) into zeolitic imidazolate frameworks-8 (ZIF-8), termed as ZIF-8@IONPs. ZIF-8@IONPs exhibited good biocompatibility and effective ROS scavenging capabilities in RAW 264.7 cells. To enhance inflammatory targeting, HA@ZIF-8@IONPs were generated through hyaluronic acid (HA) surface modification. HA@ZIF-8@IONPs effectively reduced damage to intestinal tissues in the UC mouse model. Mechanistic revealed that HA@ZIF-8@IONPs exhibited antioxidant and anti-inflammatory activities by eliminating endogenous ROS, activating the Nrf2 signaling pathway, and inhibiting the NF-κB signaling pathway. This study highlights the nanoplatform's potential as a promising candidate for UC treatment due to its great targeting of inflammatory microenvironments and efficient ROS scavenging.

Micro/nanomotors for active inflammatory disease therapy

Inflammation is a carefully orchestrated response of the immune system to repair injured tissues and clear various damage factors. However, dysregulated inflammation can eventually contribute to the development and progression of various inflammatory diseases. Although anti-inflammatory drugs have demonstrated certain therapeutic efficacy in clinical settings, significant limitations still persist, highlighting the necessity for the development of improved approaches to address complex inflammatory conditions. Micro/nanomotors (MNMs) have shown significant promise for applications in the biomedical field due to their micro/nano-scale sizes and autonomous movement. Unlike traditional nanoparticles, which exhibit passive diffusion in biological fluids, MNMs can convert external energy into a driving force for self-propulsion. This capability not only enhances the tissue penetration depth and retention rates but also facilitates interaction with inflammatory lesions. Recent efforts have suggested that MNMs for inflammatory disease therapy could provide an efficient therapeutic effect. Herein, we mainly introduce the recent advances in inflammatory disease therapy based on MNMs. We conclude by discussing both the obstacles and potential opportunities for MNMs innovations in addressing inflammation.

Targeting p38 MAPK signaling pathway and neutrophil extracellular traps: An important anti-inflammatory mechanism of Huangqin Qingre Chubi Capsule in rheumatoid arthritis

Rheumatoid arthritis (RA) is a common chronic autoimmune disease. Neutrophils release and their extracellular traps (NETs) tend to result in synovial inflammation and cartilage damage. Huangqin Qingre Chubi Capsule (HQC) is an important herbal formulation for RA treatment and has been used for many years. This study applied an interdisciplinary and integrated strategy combining clinical data, integrative bioinformatics, molecular modeling, and both in vitro and in vivo experiments to elucidate the efficacy and potential anti-inflammatory mechanisms of HQC for RA. Retrospective clinical data mining demonstrated that patients with RA treated with HQC exhibited recovery of immuno-inflammatory markers and self-perception. By applying network pharmacological analysis, molecular docking, molecular dynamics simulation, and cellular thermal shift assays, we determined that HQC can directly bind to MAPK14 and target p38 MAPK signaling pathway and NETs formation. Treatment of an adjuvant-induced arthritis rat model combining damp-heat patterns using HQC demonstrated it's effectiveness in reducing the severity of inflammatory arthritis in a dose-dependent manner and downregulated phosphorylation of p38 MAPK and NETs release. In vitro co-culture system mimicking inflammatory microenvironment of RA in vivo revealed that crosstalk between neutrophils (PMNs) and fibroblast-like synoviocytes (FLSs) was manifested by activation of p38 MAPK signaling pathway, release of NETs, and amplification of inflammation, which was blocked by HQC. Mechanistic validation using the p38 MAPK agonist diprovocim demonstrated that HQC inhibited NET formation by modulating the p38 MAPK pathway (mainly by inhibiting its phosphorylation) to exert anti-inflammatory effects. In conclusion, our interdisciplinary and integrated study demonstrated that HQC can target the p38 MAPK signaling pathway to inhibit NET formation and inflammatory response, thereby blocking the crosstalk between PMNs and FLSs to ameliorating RA.

Blended ƙ-carrageenan and xanthan gum hydrogel containing ketoprofen-loaded nanoemulsions: Design, characterization, and evaluation in an animal model of rheumatoid arthritis

This study reports the preparation of hydrogels (HG) made with xanthan gum (XG) and ƙ-carrageenan (KC) polysaccharides containing ketoprofen (KET)-loaded nanoemulsions (NK) and their evaluation in a rheumatoid arthritis (RA) model. The nano-based HGs exhibited nanometric-sized droplets (~ 100 nm), an acidic pH (5.10-6.83), drug content above 85%, a suitable spreadability factor, and pseudoplastic flow behavior. The most promising blend (HGCX 2:1) demonstrated sustained KET release, reaching 81.44 ± 6.11% after 5 h, and superior drug concentration in the skin layers (237.91 ± 41.0 µg/g). The formulation was selected due to its enhanced bioadhesiveness, with the HG-NK formulation showing the highest bioadhesion force and occlusion factor. RA was induced by complete Freund's adjuvant (CFA) intraplantar injection into the left hind paw of male and female Swiss mice. Treatments with HGs were applied to the animals' dorsal region for 7 days. Notably, HG-NK demonstrated remarkable efficacy, reversing mechanical sensitivity in male mice and significantly reducing thermal sensitivity in both genders. Moreover, HG-NK provided a significant reduction in paw edema (52-fold in males, 27-fold in females) and inflammatory markers, such as myeloperoxidase activity (32-fold in males, 14-fold in females) and lipid peroxidation (2.5-fold in males, twofold in females). The formulation also promoted greater permeation of KET across the skin. These findings underscore the significant reduction in inflammatory markers by the HG-NK formulation, highlighting its potent anti-inflammatory effects and potential as a promising therapeutic strategy for managing RA.

Simultaneously Controlling Inflammation and Infection by Smart Nanomedicine Responding to the Inflammatory Microenvironment

The overactivated immune cells in the infectious lesion may lead to irreversible organ damages under severe infections. However, clinically used immunosuppressive anti-inflammatory drugs will usually disturb immune homeostasis and conversely increase the risk of infections. Regulating the balance between anti-inflammation and anti-infection is thus critical in treating certain infectious diseases. Herein, considering that hydrogen peroxide (H2O2), myeloperoxidase (MPO), and neutrophils are upregulated in the inflammatory microenvironment and closely related to the severity of appendectomy patients, an inflammatory-microenvironment-responsive nanomedicine is designed by using poly(lactic-co-glycolic) acid (PLGA) nanoparticles to load chlorine E6 (Ce6), a photosensitizer, and luminal (Lum), a chemiluminescent agent. The obtained Lum/Ce6@PLGA nanoparticles, being non-toxic within normal physiological environment, can generate cytotoxic single oxygen via bioluminescence resonance energy transfer (BRET) in the inflammatory microenvironment with upregulated H2O2 and MPO, simultaneously killing pathogens and excessive inflammatory immune cells in the lesion, without disturbing immune homeostasis. As evidenced in various clinically relevant bacterial infection models and virus-induced pneumonia, Lum/Ce6@PLGA nanoparticles appeared to be rather effective in controlling both infection and inflammation, resulting in significantly improved animal survival. Therefore, the BRET-based nanoparticles by simultaneously controlling infections and inflammation may be promising nano-therapeutics for treatment of severe infectious diseases.

Integrating clinical data mining, network analysis and experimental validation reveal the anti-inflammatory mechanism of Huangqin Qingre Chubi Capsule in rheumatoid arthritis treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Huangqin Qingre Chubi Capsule (HQC) is a Chinese medicinal compound used for the treatment of damp-heat pattern rheumatism, guided by the traditional Chinese medicine syndrome differentiation practice. HQC has been used in the clinical treatment of rheumatic diseases for more than 20 years with remarkable efficacy. HQC has been experimentally shown to exert anti-arthritic effects via the Wnt signaling pathway.

AIM OF THE STUDY

This study used clinical data mining, network analysis, and in vitro and in vivo tests to investigate the anti-arthritic and possible anti-inflammatory mechanism of HQC. Specifically, emphasis was placed on the function of the hsa_circ_0091,685/EIF4A3/IL-17 axis in the anti-inflammatory process.

MATERIALS AND METHODS

A random walk model was used to evaluate the effects of HQC on clinical immune inflammatory marker function in patients with RA. Network analysis was used to predict the potential target genes and pathways of HQC. Hematoxylin & eosin, safranin O-fast green and toluidine blue staining, immunohistochemistry, and transmission electron microscopy were performed to evaluate the anti-arthritic effects of HQC in rat models. Cell Counting Kit-8 assay, quantitative real-time polymerase chain reaction, western blotting, enzyme-linked immunosorbent assay, and RNA pull-down were used to study the anti-proliferation and anti-inflammatory mechanisms of HQC.

RESULTS

Patients with RA who underwent HQC treatment showed a significant reduction in inflammatory response levels, according to retrospective clinical study. Network analysis revealed that HQC potentially targeted genes and pathways related to inflammation, especially IL-6, IL-17, TNF-α, IL-23, and IL-17 signaling pathway. Animal experiments showed that HQC inhibits inflammation through the IL-17 signaling pathway in rat models. Cellular experiments showed that HQC-containing serum inhibited the inflammatory response in patients with RA-FLS or RA by blocking hsa_circ_0091,685 and EIF4A3 expression.

CONCLUSION

In RA patients, HQC reduces the inflammatory response. The antiproliferative and anti-inflammatory qualities of HQC are responsible for its therapeutic impact. The suppression of the hsa_circ_0091,685/EIF4A3/IL-17 axis was linked to these favorable outcomes.

Hybrid Nanogel Drug Delivery Systems: Transforming the Tumor Microenvironment through Tumor Tissue Editing

The future of drug delivery offers immense potential for the creation of nanoplatforms based on nanogels. Nanogels present a significant possibility for pharmaceutical advancements because of their excellent stability and effective drug-loading capability for both hydrophobic and hydrophilic agents. As multifunctional systems, composite nanogels demonstrate the capacity to carry genes, drugs, and diagnostic agents while offering a perfect platform for theranostic multimodal applications. Nanogels can achieve diverse responsiveness and enable the stimuli-responsive release of chemo-/immunotherapy drugs and thus reprogramming cells within the TME in order to inhibit tumor proliferation, progression, and metastasis. In order to achieve active targeting and boost drug accumulation at target sites, particular ligands can be added to nanogels to improve the therapeutic outcomes and enhance the precision of cancer therapy. Modern "immune-specific" nanogels also have extra sophisticated tumor tissue-editing properties. Consequently, the introduction of a multifunctional nanogel-based drug delivery system improves the targeted distribution of immunotherapy drugs and combinational therapeutic treatments, thereby increasing the effectiveness of tumor therapy.

Remodeling of the Intra-Conduit Inflammatory Microenvironment to Improve Peripheral Nerve Regeneration with a Neuromechanical Matching Protein-Based Conduit

Peripheral nerve injury (PNI) remains a challenging area in regenerative medicine. Nerve guide conduit (NGC) transplantation is a common treatment for PNI, but the prognosis of NGC treatment is unsatisfactory due to 1) neuromechanical unmatching and 2) the intra-conduit inflammatory microenvironment (IME) resulting from Schwann cell pyroptosis and inflammatory-polarized macrophages. A neuromechanically matched NGC composed of regenerated silk fibroin (RSF) loaded with poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (P:P) and dimethyl fumarate (DMF) are designed, which exhibits a matched elastic modulus (25.1 ± 3.5 MPa) for the peripheral nerve and the highest 80% elongation at break, better than most protein-based conduits. Moreover, the NGC can gradually regulate the intra-conduit IME by releasing DMF and monitoring sciatic nerve movements via piezoresistive sensing. The combination of NGC and electrical stimulation modulates the IME to support PNI regeneration by synergistically inhibiting Schwann cell pyroptosis and reducing inflammatory factor release, shifting macrophage polarization from the inflammatory M1 phenotype to the tissue regenerative M2 phenotype and resulting in functional recovery of neurons. In a rat sciatic nerve crush model, NGC promoted remyelination and functional and structural regeneration. Generally, the DMF/RSF/P:P conduit provides a new potential therapeutic approach to promote nerve repair in future clinical treatments.

Emerging polymeric materials for treatment of oral diseases: design strategy towards a unique oral environment

Oral diseases are prevalent but challenging diseases owing to the highly movable and wet, microbial and inflammatory environment. Polymeric materials are regarded as one of the most promising biomaterials due to their good compatibility, facile preparation, and flexible design to obtain multifunctionality. Therefore, a variety of strategies have been employed to develop materials with improved therapeutic efficacy by overcoming physicobiological barriers in oral diseases. In this review, we summarize the design strategies of polymeric biomaterials for the treatment of oral diseases. First, we present the unique oral environment including highly movable and wet, microbial and inflammatory environment, which hinders the effective treatment of oral diseases. Second, a series of strategies for designing polymeric materials towards such a unique oral environment are highlighted. For example, multifunctional polymeric materials are armed with wet-adhesive, antimicrobial, and anti-inflammatory functions through advanced chemistry and nanotechnology to effectively treat oral diseases. These are achieved by designing wet-adhesive polymers modified with hydroxy, amine, quinone, and aldehyde groups to provide strong wet-adhesion through hydrogen and covalent bonding, and electrostatic and hydrophobic interactions, by developing antimicrobial polymers including cationic polymers, antimicrobial peptides, and antibiotic-conjugated polymers, and by synthesizing anti-inflammatory polymers with phenolic hydroxy and cysteine groups that function as immunomodulators and electron donors to reactive oxygen species to reduce inflammation. Third, various delivery systems with strong wet-adhesion and enhanced mucosa and biofilm penetration capabilities, such as nanoparticles, hydrogels, patches, and microneedles, are constructed for delivery of antibiotics, immunomodulators, and antioxidants to achieve therapeutic efficacy. Finally, we provide insights into challenges and future development of polymeric materials for oral diseases with promise for clinical translation.

Carrageenan-xanthan nanocomposite film with improved bioadhesion and permeation profile in human skin: A cutaneous-friendly platform for ketoprofen local delivery

Ketoprofen (KET), commonly used for inflammation in clinical settings, leads to systemic adverse effects with prolonged use, mitigated by topical administration. Nanotechnology-based cutaneous forms, like films, may enhance KET efficacy. Therefore, this study aimed to prepare and characterize films containing KET nanoemulsions (F-NK) regarding mechanical properties, chemical composition and interactions, occlusive potential, bioadhesion, drug permeation in human skin, and safety. The films were prepared using a κ-carrageenan and xanthan gum blend (2 % w/w, ratio 3: 1) plasticized with glycerol through the solvent casting method. Non-nanoemulsioned KET films (F-K) were prepared for comparative purposes. F-NK was flexible and hydrophilic, exhibited higher drug content and better uniformity (94.40 ± 3.61 %), maintained the NK droplet size (157 ± 12 nm), and was thinner and lighter than the F-K. This film also showed increased tensile strength and Young's modulus values, enhanced bioadhesion and occlusive potential, and resulted in more of the drug in the human skin layers. Data also suggested that nano-based formulations are homogeneous and more stable than F-KET. Hemolysis and chorioallantoic membrane tests suggested the formulations' safety. Thus, the nano-based film is suitable for cutaneous KET delivery, which may improve the drug's efficacy in managing inflammatory conditions.

Nanocarrier-based localized and effective treatment of renal disorders: currently employed targeting strategies

Renal disorders pose a global health threat, with targeted drug-delivery systems emerging as a promising strategy to enhance therapy safety and efficacy. Recent efforts have harnessed targeted nanomaterials for kidney disease treatment. While some systems remain in the early stages, they show immense potential in delivering cargo to specific sites. Through animal model experimentations, it has been demonstrated to reduce systemic side effects and enhance treatment effectiveness. This review presents current strategies for kidney disorder treatment, emphasizing site-specific targeting critical to renal disease pathophysiology. Recent advancements in nano-drug delivery systems for kidney targeting are explored. Finally, toxicological aspects and prospects of the most promising kidney-targeting delivery systems are discussed in this review article.

Microglia-derived exosomes modulate myelin regeneration via miR-615-5p/MYRF axis

Demyelination and failure of remyelination in the central nervous system (CNS) characterize a number of neurological disorders. Spontaneous remyelination in demyelinating diseases is limited, as oligodendrocyte precursor cells (OPCs), which are often present in demyelinated lesions in abundance, mostly fail to differentiate into oligodendrocytes, the myelinating cells in the CNS. In addition to OPCs, the lesions are assembled numbers of activated resident microglia/infiltrated macrophages; however, the mechanisms and potential role of interactions between the microglia/macrophages and OPCs are poorly understood. Here, we generated a transcriptional profile of exosomes from activated microglia, and found that miR-615-5p was elevated. miR-615-5p bound to 3'UTR of myelin regulator factor (MYRF), a crucial myelination transcription factor expressed in oligodendrocyte lineage cells. Mechanistically, exosomes from activated microglia transferred miR-615-5p to OPCs, which directly bound to MYRF and inhibited OPC maturation. Furthermore, an effect of AAV expressing miR-615-5p sponge in microglia was tested in experimental autoimmune encephalomyelitis (EAE) and cuprizone (CPZ)-induced demyelination model, the classical mouse models of multiple sclerosis. miR-615-5p sponge effectively alleviated disease progression and promoted remyelination. This study identifies miR-615-5p/MYRF as a new target for the therapy of demyelinating diseases.

Stimulus-Responsive Hydrogels as Drug Delivery Systems for Inflammation Targeted Therapy

Deregulated inflammations induced by various factors are one of the most common diseases in people's daily life, while severe inflammation can even lead to death. Thus, the efficient treatment of inflammation has always been the hot topic in the research of medicine. In the past decades, as a potential biomaterial, stimuli-responsive hydrogels have been a focus of attention for the inflammation treatment due to their excellent biocompatibility and design flexibility. Recently, thanks to the rapid development of nanotechnology and material science, more and more efforts have been made to develop safer, more personal and more effective hydrogels for the therapy of some frequent but tough inflammations such as sepsis, rheumatoid arthritis, osteoarthritis, periodontitis, and ulcerative colitis. Herein, from recent studies and articles, the conventional and emerging hydrogels in the delivery of anti-inflammatory drugs and the therapy for various inflammations are summarized. And their prospects of clinical translation and future development are also discussed in further detail.

Microenvironment of pancreatic inflammation: calling for nanotechnology for diagnosis and treatment

Acute pancreatitis (AP) is a common and life-threatening digestive disorder. However, its diagnosis and treatment are still impeded by our limited understanding of its etiology, pathogenesis, and clinical manifestations, as well as by the available detection methods. Fortunately, the progress of microenvironment-targeted nanoplatforms has shown their remarkable potential to change the status quo. The pancreatic inflammatory microenvironment is typically characterized by low pH, abundant reactive oxygen species (ROS) and enzymes, overproduction of inflammatory cells, and hypoxia, which exacerbate the pathological development of AP but also provide potential targeting sites for nanoagents to achieve early diagnosis and treatment. This review elaborates the various potential targets of the inflammatory microenvironment of AP and summarizes in detail the prospects for the development and application of functional nanomaterials for specific targets. Additionally, it presents the challenges and future trends to develop multifunctional targeted nanomaterials for the early diagnosis and effective treatment of AP, providing a valuable reference for future research.

Biomimetic Systems Involving Macrophages and Their Potential for Targeted Drug Delivery

The concept of targeted drug delivery can be described in terms of the drug systems' ability to mimic the biological objects' property to localize to target cells or tissues. For example, drug delivery systems based on red blood cells or mimicking some of their useful features, such as long circulation in stealth mode, have been known for decades. On the contrary, therapeutic strategies based on macrophages have gained very limited attention until recently. Here, we review two biomimetic strategies associated with macrophages that can be used to develop new therapeutic modalities: first, the mimicry of certain types of macrophages (i.e., the use of macrophages, including tumor-associated or macrophage-derived particles as a carrier for the targeted delivery of therapeutic agents); second, the mimicry of ligands, naturally absorbed by macrophages (i.e., the use of therapeutic agents specifically targeted at macrophages). We discuss the potential applications of biomimetic systems involving macrophages for new advancements in the treatment of infections, inflammatory diseases, and cancer.

A Biomimetic Nanoplatform with Improved Inflammatory Targeting Behavior for ROS Scavenging-Based Treatment of Ulcerative Colitis

Ulcerative colitis (UC), a refractory disease, has become a global problem. Herein, a biomimetic nanoplatform (AU-LIP-CM) comprising Au cluster enzymes (AU)-loaded liposomes (AU-LIP) camouflaged with the fusion membrane (CM) consisting of neutrophil (NC) and red blood cell (RBC) membrane is designed for the treatment of UC. Briefly, revealed by second near-infrared (NIR-II) imaging through collection of fluorescence emitting >1200 nm from AU, the improved inflammatory targeting behavior contributed by CM cloaking, which inherits abilities of inflammatory targeting and immune escape from NC and RBC, respectively, promotes specific accumulation of AU within inflammatory intestines with up to ≈11.5 times higher than that of bare AU. Afterward, AU possessing superoxide dismutase- and catalase-like activities realizes high-efficiency scavenging of reactive oxygen species (ROS), leading to repair of intestinal barriers, regulation of the immune system, and modulation of gut microbiota, which surpass first-line UC drug. In addition, study of underlying therapeutic mechanism demonstrated that the treatment with AU-LIP-CM can alter the gene signature associated with response to ROS for UC mice to a profile similar to that of healthy mice, deciphering related signal pathways. The strategy developed here provides insights of learning from properties of natural bio-substances to empower biomimetic nanoplatform to confront diseases.

Thermal/ultrasound-triggered release of liposomes loaded with Ganoderma applanatum polysaccharide from microbubbles for enhanced tumour ablation

The effectiveness of thermal ablation for the treatment of liver tumours is limited by the risk of incomplete ablation, which can result in residual tumours. Herein, an enhancement strategy is proposed based on the controlled release of Ganoderma applanatum polysaccharide (GAP) liposome-microbubble complexes (GLMCs) via ultrasound (US)-targeted microbubble destruction (UTMD) and sublethal hyperthermic (SH) field. GLMCs were prepared by conjugating GAP liposomes onto the surface of microbubbles via biotin-avidin linkage. In vitro, UTMD promotes the cellular uptake of liposomes and leads to apoptosis of M2-like macrophages. Secretion of arginase-1 (Arg-1) and transforming growth factor-beta (TGF-β) by M2-like macrophages decreased. In vivo, restriction of tumour volume was observed in rabbit VX2 liver tumours after treatment with GLMCs via UTMD in GLMCs + SH + US group. The expression levels of CD68 and CD163, as markers of tumour-associated macrophages (TAMs) in the GLMCs + SH + US group were reduced in liver tumour tissue. Decreased Arg-1, TGF-β, Ki67, and CD31 factors related to tumour cell proliferation and angiogenesis was evident on histological analysis. In conclusion, thermal/US-triggered drug release from GLMCs suppressed rabbit VX2 liver tumour growth in the SH field by inhibiting TAMs, which represents a potential approach to improve the effectiveness of thermal ablation.

Arthritic Microenvironment-Dictated Fate Decisions for Stem Cells in Cartilage Repair

The microenvironment and stem cell fate guidance of post-traumatic articular cartilage regeneration is primarily the focus of cartilage tissue engineering. In articular cartilage, stem cells are characterized by overlapping lineages and uneven effectiveness. Within the first 12 weeks after trauma, the articular inflammatory microenvironment (AIME) plays a decisive role in determining the fate of stem cells and cartilage. The development of fibrocartilage and osteophyte hyperplasia is an adverse outcome of chronic inflammation, which results from an imbalance in the AIME during the cartilage tissue repair process. In this review, the sources for the different types of stem cells and their fate are summarized. The main pathophysiological events that occur within the AIME as well as their protagonists are also discussed. Additionally, regulatory strategies that may guide the fate of stem cells within the AIME are proposed. Finally, strategies that provide insight into AIME pathophysiology are discussed and the design of new materials that match the post-traumatic progress of AIME pathophysiology in a spatial and temporal manner is guided. Thus, by regulating an appropriately modified inflammatory microenvironment, efficient stem cell-mediated tissue repair may be achieved.

Anti-inflammatory efficacy and relevant SAR investigations of novel chiral pyrazolo isoquinoline derivatives: Design, synthesis, in-vitro, in-vivo, and computational studies targeting iNOS

Isoquinoline alkaloids are a rich source of multimodal agents with distinctive structural specificity and various pharmacological activities. In the present report, we propose a combination of design, synthesis, computational study, primary in-vitro screening using the lipopolysaccharide (LPS)-induced RAW 264.7 cell line, and in-vivo evaluation in mice models as a novel approach to speed up anti-inflammatory drugs discovery. The nitric oxide (NO) inhibitory effect of new compounds revealed that all of them displayed the potent NO inhibitory ability in a dose-dependent manner with no obvious cytotoxicity. A series of the model compounds 7a, 7b, 7d, 7f, and 7g have been identified as the most promising, with IC₅₀ values of 47.76 μM, 33.8 μM, 20.76 μM, 26.74 μM, and 47.8 μM respectively in LPS-induced RAW 264.7 cell line. Structure-activity relationship (SAR) studies on a range of derivatives aided in identifying key pharmacophores in the lead compound. Western blotting data of 7d identified that our synthesized compounds can down-regulate and suppress the expression of the key inflammatory enzyme, inducible nitric oxide synthase (iNOS). These results suggested that synthesized compounds may be potent anti-inflammatory agents, inhibiting the NO-release, in turn, iNOS inflammatory pathways. Furthermore, in-vivo anti-inflammatory detection via xylene-induced ear edema in mice revealed that these compounds could also inhibit swelling in mice, with model compound 7h showing an inhibition activity (64.4%) at a concentration of 10 mg/kg comparable to the reference drug celecoxib. Molecular docking results showed that shortlisted compounds (7b, 7c, 7d, 7e, and 7h) had a potential binding affinity for iNOS with low energies, with S-Score to be -7.57, -8.22, -7.35, -8.95, -9.94 kcal/mol, respectively. All results demonstrated that the newly synthesized chiral pyrazolo isoquinoline derivatives are highly potential anti-inflammatory agents.

Inflammation-Controlled Anti-Inflammatory Hydrogels

While autoregulative adaptation is a common feature of living tissues, only a few feedback-controlled adaptive biomaterials are available so far. This paper herein reports a new polymer hydrogel platform designed to release anti-inflammatory molecules in response to the inflammatory activation of human blood. In this system, anti-inflammatory peptide drugs, targeting either the complement cascade, a complement receptor, or cyclophilin A, are conjugated to the hydrogel by a peptide sequence that is cleaved by elastase released from activated granulocytes. As a proof of concept, the adaptive drug delivery from the gel triggered by activated granulocytes and the effect of the released drug on the respective inflammatory pathways are demonstrated. Adjusting the gel functionalization degree is shown to allow for tuning the drug release profiles to effective doses within a micromolar range. Feedback-controlled delivery of covalently conjugated drugs from a hydrogel matrix is concluded to provide valuable safety features suitable to equip medical devices with highly active anti-inflammatory agents without suppressing the general immunosurveillance.

Metal-Based Nanozymes with Multienzyme-Like Activities as Therapeutic Candidates: Applications, Mechanisms, and Optimization Strategy

Most nanozymes in development for medical applications only exhibit single-enzyme-like activity, and are thus limited by insufficient catalytic activity and dysfunctionality in complex pathological microenvironments. To overcome the impediments of limited substrate availabilities and concentrations, some metal-based nanozymes may mimic two or more activities of natural enzymes to catalyze cascade reactions or to catalyze multiple substrates simultaneously, thereby amplifying catalysis. Metal-based nanozymes with multienzyme-like activities (MNMs) may adapt to dissimilar catalytic conditions to exert different enzyme-like effects. These multienzyme-like activities can synergize to realize "self-provision of the substrate," in which upstream catalysts produce substrates for downstream catalytic reactions to overcome the limitation of insufficient substrates in the microenvironment. Consequently, MNMs exert more potent antitumor, antibacterial, and anti-inflammatory effects in preclinical models. This review summarizes the cellular effects and underlying mechanisms of MNMs. Their potential medical utility and optimization strategy from the perspective of clinical requirements are also discussed, with the aim to provide a theoretical reference for the design, development, and therapeutic application of their catalytic effects.

Ferroptosis interaction with inflammatory microenvironments: Mechanism, biology, and treatment

Ferroptosis is a newly discovered form of regulated cell death. Ferroptosis is an iron-dependent lipid peroxidation reaction of cell membrane lipids, and it is closely related to the occurrence and development of many inflammatory diseases, such as ischemia-reperfusion injury, nonalcoholic steatohepatitis, and tumors. Although the precise role of ferroptosis in these inflammatory diseases is still unclear, recent evidence indicates that the association between ferroptosis and inflammatory diseases is related to the interaction of ferroptosis and inflammatory microenvironments. In inflammatory microenvironments, ferroptosis can be regulated by metabolic changes or the secretion of related substances between microorganisms and host cells or between host cells. At the same time, ferroptotic cells can also recruit immune cells by releasing injury-related molecular patterns, which in turn induces the generation of inflammatory microenvironments. Molecular crosstalk between ferroptosis and other cell death types also exists in inflammatory microenvironments. In addition, the interaction of ferroptosis and the tumor microenvironment is also correlated with tumor growth. This article reviews the main metabolic processes of ferroptosis, describes the interaction mechanism between ferroptosis and inflammatory microenvironments, and summarizes the role of ferroptosis in the treatment of diseases.

Mesenchymal stem cells and their microenvironment

Mesenchymal stem cells (MSCs), coming from a wide range of sources, have multi-directional differentiation ability. MSCs play vital roles in immunomodulation, hematopoiesis and tissue repair. The microenvironment of cells often refers to the intercellular matrix, other cells, cytokines and humoral components. It is also the place for cells’ interaction. The stability of the microenvironment is pivotal for maintaining cell proliferation, differentiation, metabolism and functional activities. Abnormal changes in microenvironment components can interfere cell functions. In some diseases, MSCs can interact with the microenvironment and accelerate disease progression. This review will discuss the characteristics of MSCs and their microenvironment, as well as the interaction between MSCs and microenvironment in disease.

A drug-free nanozyme for mitigating oxidative stress and inflammatory bowel disease

Inflammatory bowel disease (IBD) is an incurable disease of the gastrointestinal tract with a lack of effective therapeutic strategies. The proinflammatory microenvironment plays a significant role in both amplifying and sustaining inflammation during IBD progression. Herein, biocompatible drug-free ceria nanoparticles (CeNP-PEG) with regenerable scavenging activities against multiple reactive oxygen species (ROS) were developed. CeNP-PEG exerted therapeutic effect in dextran sulfate sodium (DSS)-induced colitis murine model, evidenced by corrected the disease activity index, restrained colon length shortening, improved intestinal permeability and restored the colonic epithelium disruption. CeNP-PEG ameliorated the proinflammatory microenvironment by persistently scavenging ROS, down-regulating the levels of multiple proinflammatory cytokines, restraining the proinflammatory profile of macrophages and Th1/Th17 response. The underlying mechanism may involve restraining the co-activation of NF-κB and JAK2/STAT3 pathways. In summary, this work demonstrates an effective strategy for IBD treatment by ameliorating the self-perpetuating proinflammatory microenvironment, which offers a new avenue in the treatment of inflammation-related diseases.