Dc-specific aptamer decorated gold nanoparticles: A new attractive insight into the nanocarriers for allergy epicutaneous immunotherapy

Mannose targeting of poly(lactic-co-glycolic acid): a promising approach for improving sublingual allergen-specific immunotherapy

OBJECTIVE

One of the most effective treatments for allergic respiratory diseases is allergen-specific sublingual immunotherapy (SLIT). While, mannose targeting has been applied in various immunostimulatory approaches, but it has not been investigated in sublingual allergen-specific immunosuppressive treatment. This study assesses mannose targeting for the ovalbumin (Ova) loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles(NPs).

METHODS

The emulsion-solvent evaporation method was employed for the synthesis of PLGA NPs containing Ova, and subsequently they attached to D-mannose. Ova-sensitized mice underwent treatment in different ways: subcutaneous administration of 10 µg Ova, sublingual administration of 5 and 10 µg Ova loaded in PLGA NPs, 5 and 10 µg Ova loaded in mannose-targeted PLGA NPs, 10 µg Ova, and 10 µg Ova loaded in dendritic cell-specific aptamer-attached PLGA NPs. Serum Ova-specific IgE and IgG2a levels, as well as IFN-γ, IL-4, IL-10, and IL-17a levels in the supernatant of Ova-stimulated splenocytes were measured. Splenocyte proliferation was assessed using an MTT assay, and also lung histological examinations, and nasal lavage fluid cell counting were performed.

RESULTS

Ova-specific IgE, IL-4, IL-17a levels, eosinophil cell count, and splenocyte proliferation were remarkably reduced in the mice treated with mannose or aptamer targeted NPs compared to other groups. Also, IL-10 and IFN-γ levels were remarkably increased in the targeted NPs groups.

CONCLUSION

Our findings indicated that mannose targeting of PLGA NPs could decrease allergen dose and improve immunomodulatory effects of SLIT. However, this approach suggests an effective formulation for SLIT in the mice model, further studies with common allergens are needed for application in humans.

Development of fast-dissolving sublingual nanofibers containing allergen and curcumin for immune response modulation in a mouse model of allergic rhinitis

Curcumin (CUR) has been considered a potential therapeutic agent for allergic reactions due to its antioxidant and anti-inflammatory activities. Nanofibers have attracted increasing attention in drug delivery. The aim of this study was to investigate the combined therapeutic effects of curcumin and allergen in nanofiber-based treatments in order to increase the effectiveness of sublingual immunotherapy (SLIT) efficacy in a mouse model of allergic rhinitis. Nanofibers containing CUR (1.25% and 2.5%) and ovalbumin 2% (OVA) as an allergen were prepared via electrospinning and characterized. BALB/c mice were sensitized with OVA to the induced allergic rhinitis model. SLIT with free and/or nanofibers was carried out. IL-4, INF-γ, and IgE serum levels were measured using ELISA. Splenocyte proliferation was evaluated by the MTT assay. Lung and nasal histological examinations and nasal lavage fluid (NALF) cell counting were carried out. Nanofibers containing 1.25% CUR and 2% OVA were chosen as the optimal formulations. SLIT treatment with the CUR and OVA nanofiber co-administration led to a significantly decreased serum IgE. Nanofiber containing 2.5 µg of CUR/mouse combined with OVA nanofiber showed a significant decrease in IL-4 and an increase in IFN-γ compared to other groups. NALF assessment showed a significant decrease in specific cell and eosinophil counts in the treated nanofiber groups. The histopathological results of NAL in the optimal formulations were near normal, with diminished cellular infiltration and inflammation. Our findings suggest that co-sublingual administration of allergen and CUR nanofibers can be considered as potential immunomodulatory agents.

An epicutaneous therapeutic pollen-allergen extract delivery system in an allergic rhinitis mouse model: based on allergen loading on DC-specific aptamers conjugated nanogolds

BACKGROUND

Gold nanoparticles (GNPs) have previously been suggested as appropriate carriers for allergen-specific immunotherapy (AIT). In this study, we assessed efficacy of GNPs and dendritic cells (DC)-specific aptamer-modified GNPs (Apts-GNP) for epicutaneous immunotherapy (EPIT) in the case of pollen allergen extracts containing a variety of allergenic and non-allergenic components.

METHODS

BALB/c mice were sensitized to the total protein extract of Platanus orientalis pollen and epicutaneously treated in different groups either with free P. orientalis total pollen extract, naked GNPs, total extract loaded GNPs, and total extract loaded Apts-GNPs with and without skin-penetrating peptides (SPPs). Then, the specific IgE level (sIgE), total IgE concentration (tIgE) in the serum sample, IL-4, IL-17a, IFN-γ, and IL-10 cytokine concentrations in re-stimulated splenocytes with the total extract and mixture of recombinant allergens, nasopharyngeal lavage fluid (NALF) analysis, and histopathological analysis of lung tissue were evaluated.

RESULTS

This study indicated the total extract-loaded GNPs, especially Pla. ext (50 μg)-GNPs, significantly decreased sIgE, tIgE, IL-17a, and IL-4 concentrations, immune cells and eosinophils infiltration in NALF, and increased IL-10 and IFN-γ concentrations compared with the PBS-treated group. In addition, the histopathological analysis of lung tissue showed a significant decrease in allergic inflammation and histopathological damage. The DC-targeted group revealed the most significant improvement in allergic-related immune factors with no histopathological damage compared with the same dose without aptamer.

CONCLUSION

Loading total protein extract on the GNPs and the Apt-modified GNPs could be an effective approach to improve EPIT efficacy in a pollen-induced allergic mouse model.

Advancing immunotherapy using biomaterials to control tissue, cellular, and molecular level immune signaling in skin

Immunotherapies have been transformative in many areas, including cancer treatments, allergies, and autoimmune diseases. However, significant challenges persist in extending the reach of these technologies to new indications and patients. Some of the major hurdles include narrow applicability to patient groups, transient efficacy, high cost burdens, poor immunogenicity, and side effects or off-target toxicity that results from lack of disease-specificity and inefficient delivery. Thus, there is a significant need for strategies that control immune responses generated by immunotherapies while targeting infection, cancer, allergy, and autoimmunity. Being the outermost barrier of the body and the first line of host defense, the skin presents a unique immunological interface to achieve these goals. The skin contains a high concentration of specialized immune cells, such as antigen-presenting cells and tissue-resident memory T cells. These cells feature diverse and potent combinations of immune receptors, providing access to cellular and molecular level control to modulate immune responses. Thus, skin provides accessible tissue, cellular, and molecular level controls that can be harnessed to improve immunotherapies. Biomaterial platforms - microneedles, nano- and micro-particles, scaffolds, and other technologies - are uniquely capable of modulating the specialized immunological niche in skin by targeting these distinct biological levels of control. This review highlights recent pre-clinical and clinical advances in biomaterial-based approaches to target and modulate immune signaling in the skin at the tissue, cellular, and molecular levels for immunotherapeutic applications. We begin by discussing skin cytoarchitecture and resident immune cells to establish the biological rationale for skin-targeting immunotherapies. This is followed by a critical presentation of biomaterial-based pre-clinical and clinical studies aimed at controlling the immune response in the skin for immunotherapy and therapeutic vaccine applications in cancer, allergy, and autoimmunity.

The Hydrogel Based Allergen-Coated Gold Nanoparticles for Topical Administration: A Possible Epicutaneous Immunotherapy in Pollen-Sensitized Mice?

BACKGROUND

The rapid uptake of antigens by antigen-presenting cells (APCs) and their migration to draining lymph nodes in the initial hours after antigen administration in epicutaneous allergen specific immunotherapy (EPIT) prompted us to investigate whether the topical administration of allergens without patch application could alleviate allergy in pollen-sensitized mice. We evaluated the immunotherapeutic effect of topically administering hydrogel-based Gold nanoparticles (AuNPs) loaded with a total extract of Platanus orientalis pollen (Pla. ext (50 μg)-AuNPs) on intact skin.

METHODS

Mice sensitized to P. orientalis pollen were divided into three groups and treated with Pla. ext (50 μg)-AuNPs: 1) patch with Pla. ext (50 μg)-AuNPs, 2) patch with Pla. ext (50 μg)-AuNPs in combination with hydrogel, and 3) topical application of Pla. ext (50 μg)-AuNPs in combination with hydrogel. The immunotherapeutic effects were evaluated by measuring serum specific and total IgE antibodies, total cell and eosinophil count in nasopharyngeal lavage fluid, cytokines in the supernatants of re-stimulated splenocytes by the total extract, and histological examination of lung and nasal mucosa.

RESULTS

Topical administration of Pla. ext (50 μg)-AuNPs, like patch-based administration, significantly downregulated specific and total IgE and IL-4 production, promoted secretion of IFN-γ and IL-10, markedly reduced the number of inflammatory cells, particularly eosinophils, in nasopharyngeal lavage fluid (p < .05), and inhibited inflammation and pathological damage in lung and nasal mucosa.

CONCLUSION

Our results suggest that topical administration of AuNPs loaded with P. orientalis total pollen extract on intact skin could be a potential application for EPIT in the P. orientalis pollen -sensitized mice.

Therapeutic potential of mesenchymal stem cell-derived exosomes for allergic airway inflammation

Due to their immunomodulatory capacities, mesenchymal stem cells (MSCs) have been extensively used as therapeutic approaches in cell-based therapy for various inflammatory diseases. Several lines of studies have shown that the most beneficial effects of MSCs are associated with MSC-derived exosomes. Exosomes are nanoscale extracellular vesicles that contain important biomolecules such as RNA, microRNAs (miRNAs), DNA, growth factors, enzymes, chemokines, and cytokines that regulate immune cell functions and parenchymal cell survival. Recently, exosomes, especially MSC-derived exosomes, have been shown to have protective effects in allergic airway inflammation. This review focused on the immune-regulatory potential of MSC-derived exosomes as nanoscale delivery systems in the treatment of allergic airway inflammation.

Self-Assembled Skin-Penetrating Peptides with Controlled Supramolecular Properties for Enhanced Transdermal Delivery

The use of nanocarriers decorated with penetration-enhancing agents (PEAs) is considered to be a promising approach for efficient transdermal delivery. In this study, we developed short amphiphilic skin-penetrating peptides (17 amino acids) that functioned not only as PEAs but also as building blocks of nanocarriers without the incorporation of additional macromolecules for self-assembly and guest molecule encapsulation. Interestingly, varying only two amino acids in the hydrophobic moiety of the peptides resulted in significantly different self-assembly behavior, thermal stability, protease resistance, and skin-penetration efficiency in a human skin model. The analysis of the peptide secondary structure revealed that such characteristic changes arose due to the sequence variation-mediated conformational change in the hydrophobic block. These findings hold significant promise for the development of simple and effective delivery systems exhibiting controllable supramolecular properties.

Peptide-containing nanoformulations: Skin barrier penetration and activity contribution

Transdermal drug delivery presents a less invasive pathway, circumventing the need to pass through the gastrointestinal tract and liver, thereby reducing drug breakdown, initial metabolism, and gastrointestinal discomfort. Nevertheless, the unique composition and dense structure of the stratum corneum present a significant barrier to transdermal delivery. This article presents an overview of the current developments in peptides and nanotechnology to address this challenge. Initially, we sum up peptide-containing nanoformulations for transdermal drug delivery, examining them through the lenses of both inorganic and organic materials. Particular emphasis is placed on the diverse roles that peptides play within these nanoformulations, including conferring functionality upon nanocarriers and enhancing the biological efficacy of drugs. Subsequently, we summarize innovative strategies for enhancing skin penetration, categorizing them into passive and active approaches. Lastly, we discuss the therapeutic potential of peptide-containing nanoformulations in addressing a range of diseases, drawing insights from the biological activities and functions of peptides. Furthermore, the challenges hindering clinical translation are also discussed, providing valuable insights for future advancements in transdermal drug delivery.

Current practices and future trends in cockroach allergen immunotherapy

PURPOSE OF REVIEW

This review evaluates the current modes of allergen-specific immunotherapy for cockroach allergens, in terms of clinical outcomes and explores future trends in the research and development needed for a more targeted cockroach immunotherapy approach with the best efficacy and minimum adverse effects.

SUMMARY

Cockroach allergy is an important risk factor for allergic rhinitis in the tropics, that disproportionately affects children and young adults and those living in poor socio-economic environments. Immunotherapy would provide long-lasting improvement in quality of life, with reduced medication intake. However, the present treatment regime is long and has a risk of adverse effects. In addition, cockroach does not seem to have an immuno-dominant allergen, that has been traditionally used to treat allergies from other sources. Future trends of cockroach immunotherapy involve precision diagnosis, to correctly identify the offending allergen. Next, precision immunotherapy with standardized allergens, which have been processed in a way that maintains an immunological response without allergic reactions. This approach can be coupled with modern adjuvants and delivery systems that promote a Th1/Treg environment, thereby modulating the immune response away from the allergenic response.

Innovative delivery systems for epicutaneous immunotherapy

Allergen-specific immunotherapy (AIT) describes the establishment of peripheral tolerance through repeated allergen exposure, which qualifies as the only curative treatment for allergic diseases. Although conventional subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) have been approved to treat respiratory allergies clinically, the progress made is far from satisfactory. Epicutaneous immunotherapy (EPIT) exploits the skin's immune properties to modulate immunological response, which is emerging as a promising alternative and has shown effectiveness in many preclinical and clinical studies for both respiratory and food allergies. It is worth noting that the stratum corneum (SC) barrier impedes the effective delivery of allergens, while disrupting the SC layer excessively often triggers unexpected Th2 immune responses. This work aims to comprehend the immunological mechanisms of EPIT, and summarize the innovative system for sufficient delivery of allergens as well as tolerogenic adjuvants. Finally, the safety, acceptability, and cost-effectiveness of these innovative delivery systems are discussed, which directs the development of future immunotherapies with all desirable characteristics.

Sublingual prophylactic administration of OVA-loaded MSC-derived exosomes to prevent allergic sensitization

AIM

This study evaluated the immunomodulatory and delivery potential of adipose tissue-isolated MSC-derived exosomes as a prophylactic regimen through a sublingual route in the ovalbumin (OVA)-induced allergic asthma murine model.

MATERIAL AND METHODS

Balb/c mice received 10 μg/dose of OVA-enriched MSC-derived exosomes as a prophylactic regimen in six doses during three weeks, and then OVA sensitization was conducted through intraperitoneal and aerosol administration of allergen. The total cells and eosinophils counted in nasal lavage fluid (NALF) and lung tissues were assessed for histopathological analysis. In addition, the secretion of IFN-γ, IL-4, and TGF-β by spleen cells and serum OVA-specific IgE levels were measured via ELISA.

RESULTS

Significant reduction in the IgE levels and IL-4 production, along with elevated TGF-β levels, were observed. Also, limited cellular infiltrations and perivascular and peribronchiolar inflammation in the lung tissues and normal total numbers of cells and eosinophils in the NALF were reported.

CONCLUSION

Prophylactic regimen using OVA-enriched MSC-derived exosomes modulated immune responses and inhibited allergic OVA sensitization.

Immune response modulation by allergen loaded into mesenchymal stem cell-derived exosomes as an effective carrier through sublingual immunotherapy

BACKGROUND

Allergen-specific sublingual immunotherapy (SLIT) was considered an interesting needle-free alternative for subcutaneous immunotherapy (SCIT). Mesenchymal stem cell (MSC)-derived exosomes were introduced as potent nanoscale delivery systems with immunomodulatory potentials. The current study investigated the therapeutic efficacy of SLIT using ovalbumin (OVA)-enriched MSC-derived exosomes formulation in a murine model of allergic asthma.

MATERIAL AND METHODS

MSCs were harvested from mice adipose tissues. Then, exosomes were isolated, and OVA-loaded exosomes were prepared. Following sensitization, Balb/c mice received therapeutic formulation (10 μg/dose OVA-containing MSC-derived exosomes) twice a week for two months. Serum OVA-specific IgE levels as well as IFN-γ, IL-4, and TGF-β secretions by cultured splenocytes were measured by ELISA. Also, lung tissue underwent histopathologic analysis, and the numbers of inflammatory cells and eosinophils in nasopharyngeal lavage fluid (NALF) were examined.

RESULTS

SLIT using OVA-enriched exosomes significantly reduced IgE levels and IL-4 production, while the secretion of IFN-γ and TGF-β were significantly elevated. Also, a decrease was observed in the numbers of total cells and eosinophils in the NALF, and lower levels of perivascular and peribronchiolar inflammation and cellular infiltrations were observed in the lung tissue.

CONCLUSION

SLIT using OVA-loaded exosomes improved immunomodulatory responses and efficiently alleviated allergic inflammation.

Gold nanoparticles for skin drug delivery

Nanoparticle-based drug carriers are being pursued intensely to overcome the skin barrier and improve even hydrophilic or macromolecular drug delivery into or across the skin efficiently. Over the past few years, the application of gold nanoparticles as a novel kind of drug carrier for skin drug delivery has attracted increasing attention because of their unique properties and versatility. In this review, we summarized the possible factors contributing to the penetration behaviors of gold nanoparticles, including size, surface chemistry, and shape. Drug loading, release, and penetration patterns were captured towards implicating the design of gold nanoparticles for dermal or transdermal drug delivery. Physical methods applicable for future enhancing the delivery efficacy of GNPs were also presented, which mainly included microneedles and iontophoresis. As a promising "drug", the inherent activities of GNPs were finally discussed, especially regarding their application in the treatment of skin disease. Thus, this paper provided a comprehensive review of the use of gold nanoparticles for skin drug delivery, which would help the design of multifunctional systems for skin drug delivery based on gold nanoparticles.

Identification of G-quadruplex anti-Interleukin-2 aptamer with high specificity through SELEX stringency

Aptamers are short single-stranded oligonucleotides capable of binding to various targets with high specificity and affinity. This study aimed to identify an aptamer against mouse interleukin-2 (mIL-2) as one of the most important cytokines in autoimmune diseases for diagnostic and therapeutic purposes. For this purpose, 14 SELEX rounds were performed on recombinant mIL-2 with high stringency. The dot blot and flow cytometry techniques were conducted to determine affinity, dissociation constant (K_d), specificity, and SELEX rounds screening. The stringency of rounds was considered based on aptamer/target incubation time, washing steps, and target proteins. Finally, the aptamer's structure was mapped and predicted by M-fold and QGRS Mapper web-based software. After 14 rounds, the flow cytometry analysis revealed that the 11^th round was a proper round. The high-affinity aptamers M20 and M15 were chosen for their ability to bind mIL-2. According to DNA folding software, M20 and M15 aptamers had G-quadruplex and stem-loop structures, respectively. The M20 aptamer affinity was greater than M15, and its predicted K_d was 91 nM. A simple SELEX protocol with round stringency was explained to identify DNA aptamers against protein targets. The reported G-quadruplex aptamer might have potential diagnostic or therapeutic application in IL-2–related disorders.

PLGA-Based Curcumin Delivery System: An Interesting Therapeutic Approach in the Treatment of Alzheimer's Disease

Progressive degeneration and dysfunction of the nervous system because of oxidative stress, aggregations of misfolded proteins, and neuroinflammation are the key pathological features of neurodegenerative diseases. Alzheimer's disease is a chronic neurodegenerative disorder driven by uncontrolled extracellular deposition of β-amyloid (Aβ) in the amyloid plaques and intracellular accumulation of hyperphosphorylated tau protein. Curcumin is a hydrophobic polyphenol with noticeable neuroprotective and anti-inflammatory effects that can cross the blood-brain barrier. Therefore, it is widely studied for the alleviation of inflammatory and neurological disorders. However, the clinical application of curcumin is limited due to its low aqueous solubility and bioavailability. Recently, nano-based curcumin delivery systems are developed to overcome these limitations effectively. This review article discusses the effects and potential mechanisms of curcumin-loaded PLGA nanoparticles in Alzheimer's disease.

Plaque-type psoriasis inhibitors

Psoriasis is a common inflammatory skin disorder, which is mediated by the immune system and affects 1-4% of the world's population. Psoriasis is caused by a complex interaction between the immune system, autoantigens, psoriasis-associated genetic factors, and various environmental factors. As a chronic disease requiring long-term treatment, psoriasis is associated with follow-up costs and an economic burden on the patients, their families, and healthcare systems. The current treatments for moderate-to-severe plaque psoriasis include topical therapy, phototherapy, and systemic drugs consisting of biological/non-biological drugs. Within the past two decades, recent biological therapies for psoriasis have rapidly advanced. Moreover, new bispecific agents have the potential for better disease control, while small molecule drugs offer a future alternative to biological drugs and the more cost-effective, long-term treatment of the disease. The present study aimed to review updated data regarding the inhibitors used to improve plaque psoriasis that contain biologics, bispecific agents, small molecules, and aptamers (either approved or in the research phase).

Gold Nanoparticles: Multifaceted Roles in the Management of Autoimmune Disorders

Gold nanoparticles (GNPs) have been recently applied for various diagnostic and therapeutic purposes. The unique properties of these nanoparticles (NPs), such as relative ease of synthesis in various sizes, shapes and charges, stability, high drug-loading capacity and relative availability for modification accompanied by non-cytotoxicity and biocompatibility, make them an ideal field of research in bio-nanotechnology. Moreover, their potential to alleviate various inflammatory factors, nitrite species, and reactive oxygen production and the capacity to deliver therapeutic agents has attracted attention for further studies in inflammatory and autoimmune disorders. Furthermore, the characteristics of GNPs and surface modification can modulate their toxicity, biodistribution, biocompatibility, and effects. This review discusses in vitro and in vivo effects of GNPs and their functionalized forms in managing various autoimmune disorders (Ads) such as rheumatoid arthritis, type 1 diabetes, and multiple sclerosis.