Are nanotechnological approaches the future of treating inflammatory diseases?

Advanced Immunomodulatory Biomaterials for Therapeutic Applications

The multifaceted biological defense system modulating complex immune responses against pathogens and foreign materials plays a critical role in tissue homeostasis and disease progression. Recently developed biomaterials that can specifically regulate immune responses, nanoparticles, graphene, and functional hydrogels have contributed to the advancement of tissue engineering as well as disease treatment. The interaction between innate and adaptive immunity, collectively determining immune responses, can be regulated by mechanobiological recognition and adaptation of immune cells to the extracellular microenvironment. Therefore, applying immunomodulation to tissue regeneration and cancer therapy involves manipulating the properties of biomaterials by tailoring their composition in the context of the immune system. This review provides a comprehensive overview of how the physicochemical attributes of biomaterials determine immune responses, focusing on the physical properties that influence innate and adaptive immunity. This review also underscores the critical aspect of biomaterial-based immune engineering for the development of novel therapeutics and emphasizes the importance of understanding the biomaterials-mediated immunological mechanisms and their role in modulating the immune system.

Liposome-based nanoparticles impact on regulatory and effector phenotypes of macrophages and T cells in multiple Sclerosis patients

Current available treatments of Multiple Sclerosis (MS) reduce neuroinflammation acting on different targets on the immune system, but potentially lead to severe side effects and have a limited efficacy in slowing the progression of the disease. Here, we evaluated in vitro the immunomodulatory potential of a new class of nanoparticles - liposomes, constituted by a double-layer of phosphatidylserine (PSCho/PS), and double-faced, with an outer layer of phosphatidylserine and an inner layer of phosphatidic acid (PSCho/PA), either alone or in the presence of the myelin basic protein (MBP) peptide (residues 85-99) (PSCho/PS-MBP and PSCho/PA-MBP). Results showed that PSCho/PS are equally and efficiently internalized by pro- and anti-inflammatory macrophages (M1 and M2 respectively), while PSCho/PA were internalized better by M2 than M1. PSCho/PS liposomes were able to inhibit the secretion of innate pro-inflammatory cytokine IL-1β. PSCho/PS liposomes expanded Tregs, reducing Th1 and Th17 cells, while PSCho/PA liposomes were unable to dampen pro-inflammatory T cells and to promote immune-regulatory phenotype (Treg). The ability of PSCho/PS liposomes to up-regulate Treg cells was more pronounced in MS patients with high basal expression of M2 markers. PSCho/PS liposomes were more effective in decreasing Th1 (but not Th17) cells in MS patients with a disease duration >3 months. On the other hand, down-modulation of Th17 cells was evident in MS patients with active, Gadolinium enhancing lesions at MRI and in MS patients with a high basal expression of M1-associated markers in the monocytes. The same findings were observed for the modulation of MBP-driven Th1/Th17/Treg responses. These observations suggest that early MS associate to a hard-wired pro-Th1 phenotype of M1 that is lost later during disease course. On the other hand, acute inflammatory events reflect a temporary decrease of M2 phenotype that however is amenable to restauration upon treatment with PSCho/PS liposomes. Thus, together these data indicate that monocytes/macrophages may play an important regulatory function during MS course and suggest a role for PSCho/PS and PSCho/PS-MBP as new therapeutic tools to dampen the pro-inflammatory immune responses and to promote its regulatory branch.

A Tissue-Tended Mycophenolate-Modified Nanoparticle Alleviates Systemic Lupus Erythematosus in MRL/Lpr Mouse Model Mainly by Promoting Local M2-Like Macrophagocytes Polarization

Background

Mycophenolate mofetil (MMF), for which the bioactive metabolite is mycophenolic acid (MPA), is a frequently used immunosuppressant for systemic lupus erythematosus (SLE). However, its short half-life and poor biodistribution into cells and tissues hinder its clinical efficacy. Our dextran mycophenolate-based nanoparticles (MPA@Dex-MPA NPs) have greatly improved the pharmacokinetics of MMF/MPA. We here tested the therapeutic efficacy of MPA@Dex-MPA NPs against SLE and investigated the underlying mechanism.

Methods

The tissue and immune cell biodistributions of MPA@Dex-MPA NPs were traced using live fluorescence imaging system and flow cytometry, respectively. Serological proinflammatory mediators and kidney damage were detected to assess the efficacy of MPA@Dex-MPA NPs treatments of MRL/lpr lupus-prone mice. Immune cell changes in the kidney and spleen were further analyzed post-treatment via flow cytometry. Bone marrow-derived macrophages were used to investigate the potential mechanism.

Results

MPA@Dex-MPA NPs exhibited superior therapeutic efficacy and safety in the MRL/lpr mice using significantly lower administration dosage (one-fifth) and frequency (once/3 days) compared to MMF/MPA used in ordinary practice. The overall prognosis of the mice was improved as they showed lower levels of serological proinflammatory mediators. Moreover, kidney injury was alleviated with reduced pathological signs and decreased urine protein-creatinine ratio. Further investigations of the underlying mechanism revealed a preferential penetration and persistent retention of MPA@Dex-MPA NPs in the spleen and kidney, where they were mostly phagocytosed by macrophages. The macrophages were found to be polarized towards a CD206⁺ M2-like phenotype, with a downregulation of surface CD80 and CD40, and reduced TNF-α production in the spleen and kidney and in vitro. The expansion of T cells was also significantly inhibited in these two organs.

Conclusion

Our research improved the efficacy of MPA for MRL/lpr mice through synthesizing MPA@Dex-MPA NPs to enhance its tissue biodistribution and explored the possible mechanism, providing a promising strategy for SLE therapy.

Tailoring the physicochemical properties of nanomaterials for immunomodulation

Immunomodulation is poised to revolutionize the treatment of cancer, autoimmune diseases, and many other inflammation-related disorders. The immune system in these conditions can be either activated or suppressed by nanocarriers loaded with bioactive molecules. Although immunomodulation via these therapeutics has long been recognized, and a broad range of nanocarriers have been designed to accommodate varied usages, less studies have focused on the effects of nanomaterial physicochemical properties on immune responses, especially the immunity altered by nanocarrier materials alone. Conclusions are sometimes seemly inconsistent due to the complexities of nanomaterials and the immune system. An in-depth understanding of the nanocarrier-induced immune responses is essential for clinical applications. In this review, we summarize recent studies of the immune responses influenced by nanomaterial physicochemical properties with an emphasis on the intrinsic features of nanomaterials that modulate the innate and adaptive immunities. We then provide our perspectives on the design of nanomaterials for immunomodulation.

The impact of nanocarriers in the induction of antigen-specific immunotolerance in autoimmune diseases

Immunotolerance induction in an antigen-specific manner is the long-term goal of immunotherapy to treat autoimmune diseases. Nanocarriers (NCs) can be designed as a new generation of delivery systems to modulate the immune responses through targeted delivery of antigens and immunomodulators to antigen presenting cells (APCs). In this manuscript, several formulation factors in the preparation of NCs which affect their uptake using APCs and generation of tolerance have been reviewed. The physicochemical properties and composition of NCs have been shown to play essential roles in achieving the desired immunological outcome. Also, targeting of dendritic cells and macrophages as APCs and direct targeting of the autoreactive lymphocytes have been presented as two main ways for induction of antigen-specific tolerance by these tolerogenic nanocarriers (tNCs). These particles herald a promising approach to treat or even prevent unwanted immune reactions in humans specifically.

Nanomaterials for the Diagnosis and Treatment of Inflammatory Arthritis

Nanomaterials have received increasing attention due to their unique chemical and physical properties for the treatment of rheumatoid arthritis (RA), the most common complex multifactorial joint-associated autoimmune inflammatory disorder. RA is characterized by an inflammation of the synovium with increased production of proinflammatory cytokines (IL-1, IL-6, IL-8, and IL-10) and by the destruction of the articular cartilage and bone, and it is associated with the development of cardiovascular disorders such as heart attack and stroke. While a number of imaging tools allow for the monitoring and diagnosis of inflammatory arthritis, and despite ongoing work to enhance their sensitivity and precision, the proper assessment of RA remains difficult particularly in the early stages of the disease. Our goal here is to describe the benefits of applying various nanomaterials as next-generation RA imaging and detection tools using contrast agents and nanosensors and as improved drug delivery systems for the effective treatment of the disease.

JAK-STAT Targeting Offers Novel Therapeutic Opportunities in Sepsis

Sepsis is a life-threatening condition caused by exaggerated host responses to infections taking place in two phases: (i) a systemic (hyper)inflammatory response syndrome (SIRS), participating in multiple organ failure (MOF), a major complication of septic shock, followed by (ii) a compensatory anti-inflammatory response syndrome (CARS), leading to sepsis-induced immunosuppression and resulting in late infections and long-term mortality. The Janus kinase-signal transducer and activator of transcription (JAK-STAT)-dependent signaling pathway is involved in both manifestations, hence playing a key role during sepsis. It is also involved in emergency myelopoiesis, which participates in host defense. The aim of this review is to highlight and refine the recent implications of this signaling pathway in sepsis and illustrate why its central position makes it a potential biomarker and therapeutic target.

Thirty Years of Cancer Nanomedicine: Success, Frustration, and Hope

Starting with the enhanced permeability and retention (EPR) effect discovery, nanomedicine has gained a crucial role in cancer treatment. The advances in the field have led to the approval of nanodrugs with improved safety profile and still inspire the ongoing investigations. However, several restrictions, such as high manufacturing costs, technical challenges, and effectiveness below expectations, raised skeptical opinions within the scientific community about the clinical relevance of nanomedicine. In this review, we aim to give an overall vision of the current hurdles encountered by nanotherapeutics along with their design, development, and translation, and we offer a prospective view on possible strategies to overcome such limitations.