The regulatory mechanisms of cerium oxide nanoparticles in oxidative stress and emerging applications in refractory wound care

Cerium oxide nanoparticles (CeNPs) have emerged as a potent therapeutic agent in the realm of wound healing, attributing their efficacy predominantly to their exceptional antioxidant properties. Mimicking the activity of endogenous antioxidant enzymes, CeNPs alleviate oxidative stress and curtail the generation of inflammatory mediators, thus expediting the wound healing process. Their application spans various disease models, showcasing therapeutic potential in treating inflammatory responses and infections, particularly in oxidative stress-induced chronic wounds such as diabetic ulcers, radiation-induced skin injuries, and psoriasis. Despite the promising advancements in laboratory studies, the clinical translation of CeNPs is challenged by several factors, including biocompatibility, toxicity, effective drug delivery, and the development of multifunctional compounds. Addressing these challenges necessitates advancements in CeNP synthesis and functionalization, novel nano delivery systems, and comprehensive bio effectiveness and safety evaluations. This paper reviews the progress of CeNPs in wound healing, highlighting their mechanisms, applications, challenges, and future perspectives in clinical therapeutics.

An Ultrasmall Cu/Cu2O Nanoparticle-Based Diselenide-Bridged Nanoplatform Mediating Reactive Oxygen Species Scavenging and Neuronal Membrane Enhancement for Targeted Therapy of Ischemic Stroke

Ischemic stroke is one of the major causes of death and disability worldwide, and an effective and timely treatment of ischemic stroke has been a challenge because of the narrow therapeutic window and the poor affinity with thrombus of the thrombolytic agent. In this study, rPZDCu, a multifunctional nanoparticle (NP) with the effects of thrombolysis, reactive oxygen species (ROS) scavenging, and neuroprotection, was synthesized based on an ultrasmall Cu4.6O NP, the thrombolytic agent rt-PA, and docosahexaenoic acid (DHA), which is a major component of the neuronal membrane. rPZDCu showed strong thrombus-targeting ability, which was achieved by the platelet cell membrane coating on the NP surface, and a good thrombolytic effect in both the common carotid artery clot model and embolic middle cerebral artery occlusion (MCAO) model of rats. Furthermore, rPZDCu exhibited a good escape from the phagocytosis of macrophages, effective promotion of the polarization of microglia, and efficient recovery of neurobiological and behavioral functions in the embolic MCAO model of rats. This is a heuristic report of (1) the Cu0/Cu+ NP for the treatments of brain diseases, (2) the integration of DHA and ROS scavengers for central nervous system therapies, and (3) diselenide-based ROS-responsive NPs for ischemic stroke treatments. This study also offers an example of cell membrane-camouflaged stimuli-responsive nanomedicine for brain-targeting drug delivery.

Biogenic silver NPs alleviate LPS-induced neuroinflammation in a human fetal brain-derived cell line: Molecular switch to the M2 phenotype, modulation of TLR4/MyD88 and Nrf2/HO-1 signaling pathways, and molecular docking analysis

Silver nanoparticles (AgNPs) have inconsistent findings against inflammation. Although a wealth of literature on the beneficial effects of green-synthesized AgNPs has been published, a detailed mechanistic study of green AgNPs on the protective effects against lipopolysaccharide (LPS)-induced neuroinflammation using human microglial cells (HMC3) has not yet been reported. For the first time, we studied the inhibitory effect of biogenic AgNPs on inflammation and oxidative stress induced by LPS in HMC3 cells. X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and transmission electron microscopy were used to characterize AgNPs produced from honeyberry. Co-treatment with AgNPs significantly reduced mRNA expressions of inflammatory molecules such as interleukin (IL)-6 and tumor necrosis factor-α, while increasing the expressions of anti-inflammatory markers such as IL-10 and transforming growth factor (TGF)-β. HMC3 cells were also switched from M1 to M2, as shown by lower expression of M1 markers such as cluster of differentiation (CD)80, CD86, and CD68 and higher expression of M2 markers such as CD206, CD163, and triggering receptors expressed on myeloid cells (TREM2). Furthermore, AgNPs inhibited LPS-induced toll-like receptor (TLR)4 signaling, as evidenced by decreased expression of myeloid differentiation factor 88 (MyD88) and TLR4. In addition, AgNPs reduced the production of reactive oxygen species (ROS) and enhanced the expression of nuclear factor-E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), while decreasing the expression of inducible nitric oxide synthase. The docking score of the honeyberry phytoconstituents ranged from -14.93 to - 4.28 KJ/mol. In conclusion, biogenic AgNPs protect against neuroinflammation and oxidative stress by targeting TLR4/MyD88 and Nrf2/HO-1 signaling pathways in a LPS-induced in vitro model. Biogenic AgNPs could be utilized as potential nanomedicine against LPS-induced inflammatory disorders.

Central nervous system injury meets nanoceria: opportunities and challenges

Central nervous system (CNS) injury, induced by ischemic/hemorrhagic or traumatic damage, is one of the most common causes of death and long-term disability worldwide. Reactive oxygen and nitrogen species (RONS) resulting in oxidative/nitrosative stress play a critical role in the pathological cascade of molecular events after CNS injury. Therefore, by targeting RONS, antioxidant therapies have been intensively explored in previous studies. However, traditional antioxidants have achieved limited success thus far, and the development of new antioxidants to achieve highly effective RONS modulation in CNS injury still remains a great challenge. With the rapid development of nanotechnology, novel nanomaterials provided promising opportunities to address this challenge. Within these, nanoceria has gained much attention due to its regenerative and excellent RONS elimination capability. To promote its practical application, it is important to know what has been done and what has yet to be done. This review aims to present the opportunities and challenges of nanoceria in treating CNS injury. The physicochemical properties of nanoceria and its interaction with RONS are described. The applications of nanoceria for stroke and neurotrauma treatment are summarized. The possible directions for future application of nanoceria in CNS injury treatment are proposed.

Stem cell-derived exosomes and copper sulfide nanoparticles attenuate the progression of neurodegenerative disorders induced by cadmium in rats

The goal of the current study was to investigate the therapeutic effects of exosomes derived from mesenchymal stem cells (MSCs-Exo) and copper sulfide nanoparticles (CuSNPs) as biomaterials in order to understand the mechanisms that contribute to overcoming cadmium (Cad) induced neurological disorders in rats. Animals were divided into five groups (n = 10): group 1 was served as a negative control and receive vehicle saline (Con), group 2 Positive control groups were received Cad as cadmium chloride at a dose of 20 mg/kg/day for six weeks (Cad group), group 3 was received Cad plus MSCs-Exo as a single dose of 100 μLi. v. (Cad + MSCs-Exo), group 4 was received Cad plus CuSNPs at a dose of 6.5 mg/kg orally (Cad + CuSNPs), group 5 was received Cad + MSCs-Exo + CuSNPs for six weeks. However, the activities of each acetylcholine (Ach), acetylcholinesterase (AchE), total antioxidant status (TAC) were measured. Also, the levels of ROS, nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), Brain brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were evaluated. Beneficial effects on the behavior of animals were observed after treatment with MSCs-Exo and CuSNPs. Furthermore, the administration of MSCs-Exo and CuSNPs have been improve the TAC, BDNF and NGF via ameliorating the oxidative stress and inflammatory markers. Moreover, Histopathological studies had shown that great development in the brain of Cad rats treated with MSCs-Exo and CuSNPs. In conclusion, this study offers an overview of innovative stem cell therapy techniques and how to integrate them with nanotechnology to boost therapeutic performance.

Immunomodulatory nanosystems for treating inflammatory diseases

Inflammatory disease (ID) is an umbrella term encompassing all illnesses involving chronic inflammation as the central manifestation of pathogenesis. These include, inflammatory bowel diseases, hepatitis, pulmonary disorders, atherosclerosis, myocardial infarction, pancreatitis, arthritis, periodontitis, psoriasis. The IDs create a severe burden on healthcare and significantly impact the global socio-economic balance. Unfortunately, the standard therapies that rely on a combination of anti-inflammatory and immunosuppressive agents are palliative and provide only short-term relief. In contrast, the emerging concept of immunomodulatory nanosystems (IMNs) has the potential to address the underlying causes and prevent reoccurrence, thereby, creating new opportunities for treating IDs. The IMNs offer exquisite ability to precisely modulate the immune system for a therapeutic advantage. The nano-sized dimension of IMNs allows them to efficiently infiltrate lymphatic drainage, interact with immune cells, and subsequently to undergo rapid endocytosis by hyperactive immune cells (HICs) at inflamed sites. Thus, IMNs serve to restore dysfunctional or HICs and alleviate the inflammation. We identified that different IMNs exert their immunomodulatory action via either of the seven mechanisms to modulate; cytokine production, cytokine neutralization, cellular infiltration, macrophage polarization, HICs growth inhibition, stimulating T-reg mediated tolerance and modulating oxidative-stress. In this article, we discussed representative examples of IMNs by highlighting their rationalization, design principle, and mechanism of action in context of treating various IDs. Lastly, we highlighted technical challenges in the application of IMNs and explored the future direction of research, which could potentially help to overcome those challenges.

A Virus-Mimicking Nucleic Acid Nanogel Reprograms Microglia and Macrophages for Glioblastoma Therapy

Immunotherapy is recognized as one of the most promising approaches to treat cancers. However, its effect in glioblastoma (GBM) treatment is insufficient, which can in part be attributed to the immunosuppressive tumor microenvironment (TME). Microglia and macrophages are the main immune infiltrating cells in the TME of GBM. Unfortunately, instead of initiating the anti-tumor response, GBM-infiltrating microglia and macrophages switch to a tumor-promoting phenotype (M2), and support tumor growth, angiogenesis, and immunosuppression by the release of cytokines. In this work, a virus-mimicking membrane-coated nucleic acid nanogel Vir-Gel embedded with therapeutic miRNA is developed, which can reprogram microglia and macrophages from a pro-invasive M2 phenotype to an anti-tumor M1 phenotype. By mimicking the virus infection process, Vir-Gel significantly enhances the targetability and cell uptake efficiency of the miR155-bearing nucleic acid nanogel. In vivo evaluations demonstrate that Vir-Gel apparently prolongs the circulation lifetime of miR155 and endows it with an active tumor-targeting capability and excellent tumor inhibition efficacy. Owing to its noninvasive feature and effective delivery capability, the virus-mimicking nucleic acid nanogel provides a general and convenient platform that can successfully treat a wide range of diseases.

Understanding the Nano-Bio Interactions and the Corresponding Biological Responses

Due to the increasing amount of work being put into the development of nanotechnology, the field of nanomaterials holds great promise for revolutionizing biomedicine. However, insufficient understanding of nanomaterial-biological microenvironment (nano-bio) interactions hinders the clinical translation of nanomedicine. Therefore, a systematic understanding of nano-bio interaction is needed for the intelligent design of safe and effective nanomaterials for biomedical applications. In this review, we summarize the latest experimental and theoretical developments in the fields of nano-bio interfaces and corresponding biological outcomes from the perspective of corona and redox reactions. We also show that nano-bio interaction can offer a variety of multifunctional platforms with a broad range of applications in the field of biomedicine. The potential challenges and opportunities in the study of nano-bio interfaces are also provided.

Mitochondria-targeted TPP-MoS2 with dual enzyme activity provides efficient neuroprotection through M1/M2 microglial polarization in an Alzheimer's disease model

Alzheimer's disease (AD) is one of the most common age-associated brain diseases and is induced by the accumulation of amyloid beta (Aβ) and oxidative stress. Many studies have focused on eliminating Aβ by nanoparticle affinity; however, nanoparticles are taken up mainly by microglia rather than neurons, leading poor control of AD. Herein, mitochondria-targeted nanozymes known as (3-carboxypropyl)triphenyl-phosphonium bromide-conjugated 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000]-functionalized molybdenum disulfide quantum dots (TPP-MoS₂ QDs) were designed. TPP-MoS₂ QDs mitigate Aβ aggregate-mediated neurotoxicity and eliminate Aβ aggregates in AD mice by switching microglia from the proinflammatory M1 phenotype to the anti-inflammatory M2 phenotype. TPP-MoS₂ QDs cross the blood-brain barrier, escape from lysosomes, target mitochondria and exhibit the comprehensive activity of a bifunctional nanozyme, thus preventing spontaneous neuroinflammation by regulating the proinflammatory substances interleukin-1β, interleukin-6 and tumor necrosis factors as well as the anti-inflammatory substance transforming growth factor-β. In contrast to the low efficacy of eliminating Aβ by nanoparticle affinity, the present study provides a new pathway to mitigate AD pathology through mitochondria-targeted nanozymes and M1/M2 microglial polarization.