Targeted Delivery Platforms for the Treatment of Multiple Sclerosis

A Mechanistic Understanding of Reactive Oxygen Species (ROS)-Responsive Bio-Polymeric Nanoparticles: Current State, Challenges and Future Toward Precision Therapeutics

Inflammation is a hallmark of various pathological conditions, including cancer, cardiovascular diseases, neurodegenerative disorders, and autoimmune diseases. Reactive oxygen species (ROS) are crucial mediators in the inflammatory microenvironment, playing a pivotal role in both normal cellular processes and disease progression. Targeting ROS overproduction in inflamed tissues has emerged as a promising therapeutic strategy. Polymeric nanoparticles (NPs) responsive to ROS levels in pathological tissues have gained substantial attention as precision drug delivery systems, capable of ensuring controlled, site-specific drug release. This review provides a comprehensive mechanistic insight into ROS-responsive polymeric nanoparticles, examining their structural design, functionalization strategies, drug release mechanisms, and potential for targeted therapies in inflammatory conditions. Furthermore, we discuss recent advancements, challenges, and future directions in utilizing ROS-responsive polymeric nanoparticles for precision therapeutics, highlighting their transformative potential in clinical applications.

Immunoswitch Nanomodulators Enable Active Targeting and Selective Proliferation of Regulatory T Cells for Multiple Sclerosis Therapy

Interleukin-2 (IL-2) used in multiple sclerosis (MS) therapy modulates the balance between regulatory T (Treg) cells and effector T (Teff) cells. However, the off-target activation of Teff cells by IL-2 limits its clinical application. Therefore, a rapidly prepared immunoswitch nanomodulator termed aT-IL2C NPs was developed, which specifically recognized Treg cells with high TIGIT expression thanks to the presence of an anti-TIGIT and an IL-2/JES6-1 complex (IL2C) being delivered to Treg cells but not to Teff cells with low TIGIT expression. Then, IL2C released IL-2 due to the specific expression of the high-affinity IL-2 receptor on Treg cells, thus enabling the active targeting and selective proliferation of Treg cells. Moreover, the anti-TIGIT of aT-IL2C NPs selectively inhibited the proliferation of Teff cells while leaving the proliferation of Treg cells unaffected. In addition, since the IL-2 receptor on Teff cells had medium-affinity, the IL2C hardly released IL-2 to Teff cells, thus enabling the inhibition of Teff cell proliferation. The treatment of experimental autoimmune encephalomyelitis (EAE) mice with aT-IL2C NPs ameliorated the severity of the EAE and restored white matter integrity. Collectively, this work described a potential promising agent for effective MS therapy.

A better understanding of the role of the CTLA-CD80/86 axis in the treatment of autoimmune diseases

Autoimmune diseases are diseases in which the regulatory mechanisms of the immune response are disturbed. As a result, the body loses self-tolerance. Since one of the main regulatory mechanisms of the immune response is the CTLA4-CD80/86 axis, this hypothesis suggests that autoimmune diseases potentially share a similar molecular basis of pathogenesis. Hence, investigating the CTLA4-CD80/86 axis may be helpful in finding an appropriate treatment strategy. Therefore, this study aims to investigate the molecular basis of the CTLA4-CD80/86 axis in the regulation of the immune response, and then its role in developing some autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, and multiple sclerosis. As well, the main therapeutic strategies affecting the CTLA4-CD80/86 axis have been summarized to highlight the importance of this axis in management of autoimmune diseases.

Graphene Oxide Nanosheets Reduce Astrocyte Reactivity to Inflammation and Ameliorate Experimental Autoimmune Encephalomyelitis

In neuroinflammation, astrocytes play multifaceted roles that regulate the neuronal environment. Astrocytes sense and respond to pro-inflammatory cytokines (CKs) and, by a repertoire of intracellular Ca2+ signaling, contribute to disease progression. Therapeutic approaches wish to reduce the overactivation in Ca2+ signaling in inflammatory-reactive astrocytes to restore dysregulated cellular changes. Cell-targeting therapeutics might take advantage by the use of nanomaterial-multifunctional platforms such as graphene oxide (GO). GO biomedical applications in the nervous system involve therapeutic delivery and sensing, and GO flakes were shown to enable interfacing of neuronal and glial membrane dynamics. We exploit organotypic spinal cord cultures and optical imaging to explore Ca2+ changes in astrocytes, and we report, when spinal tissue is exposed to CKs, neuroinflammatory-associated modulation of resident glia. We show the efficacy of GO to revert these dynamic changes in astrocytic reactivity to CKs, and we translate this potential in an animal model of immune-mediated neuroinflammatory disease.

Peptide mediated targeted delivery of gold nanoparticles into the demyelination site ameliorates myelin impairment and gliosis

Drug development for multiple sclerosis (MS) clinical management focuses on both neuroprotection and repair strategies, and is challenging due to low permeability of the blood-brain barrier, off-target distribution, and the need for high doses of drugs. The changes in the extracellular matrix have been documented in MS patients. It has been shown that the expression of nidogen-1 increases in MS lesions. Laminin forms a stable complex with nidogen-1 through a heptapeptide which was selected to target the lesion area in this study. Here we showed that the peptide binding was specific to the injured area following lysophosphatidylcholine (LPC) induced demyelination. In vivo data showed enhanced delivery of the peptide-functionalized gold nanoparticles (Pep-GNPs) to the lesion area. In addition, Pep-GNPs administration significantly enhanced myelin content and reduced astrocyte/microglia activation. Results demonstrated the possibility of using this peptide to target and treat lesions in patients suffering from MS.