Formulation and Characterization of Solid Lipid Nanoparticles Loading RF22-c, a Potent and Selective 5-LO Inhibitor, in a Monocrotaline-Induced Model of Pulmonary Hypertension

Pulmonary arterial hypertension nanotherapeutics: New pharmacological targets and drug delivery strategies

Pulmonary arterial hypertension (PAH) is a rare, serious, and incurable disease characterized by high lung pressure. PAH-approved drugs based on conventional pathways are still not exhibiting favorable therapeutic outcomes. Drawbacks like short half-lives, toxicity, and teratogenicity hamper effectiveness, clinical conventionality, and long-term safety. Hence, approaches like repurposing drugs targeting various and new pharmacological cascades and/or loaded in non-toxic/efficient nanocarrier systems are being investigated lately. This review summarizes the status of conventional, repurposed, either in vitro, in vivo, and/or in clinical trials of PAH treatment. In-depth description, discussion, and classification of the new pharmacological targets and nanomedicine strategies with a description of all the nanocarriers that showed promising efficiency in delivering drugs are discussed. Ultimately, an illustration of the different nucleic acids tailored and nanoencapsulated within different types of nanocarriers to restore the pathways affected by this disease is presented.

Lipid Nanoparticles Loading Steroidal Alkaloids of Tomatoes Affect Neuroblastoma Cell Viability in an In Vitro Model

Tomato by-products represent a good source of phytochemical compounds with health properties, such as the steroidal glycoalkaloid α-tomatine (α-TM) and its aglycone tomatidine (TD). Both molecules have numerous beneficial properties, such as potential anticancer activity. Unfortunately, their therapeutic application is limited due to stability and bioavailability issues. Therefore, a valid strategy seems to be their encapsulation into Solid Lipid Nanoparticles (SLN). The nanoformulations containing α-TM (α-TM-SLN) and TD (TD-SLN) were prepared by solvent-diffusion technique and subsequently characterized in terms of technological parameters (particle size, polydispersity index, zeta potential, microscopy, and calorimetric studies). To assess the effect of α-TM and TD on the percentage of cellular viability in Olfactory Ensheathing Cells (OECs), a peculiar glial cell type of the olfactory system used as normal cells, and in SH-SY5Y, a neuroblastoma cancer cell line, an MTT test was performed. In addition, the effects of empty, α-TM-SLN, and TD-SLN were tested. Our results show that the treatment of OECs with blank-SLN, free α-TM (0.25 µg/mL), and TD (0.50 µg/mL) did not induce any significant change in the percentage of cell viability when compared with the control. In contrast, in SH-SY5Y-treated cells, a significant decrease in the percentage of cell viability when compared with the control was found. In particular, the effect appeared more evident when SH-SY5Y cells were exposed to α-TM-SLN and TD-SLN. No significant effect in blank-SLN-treated SH-SY5T cells was observed. Therefore, SLN is a promising approach for the delivery of α-TM and TD.

Synergetic EGCG and coenzyme Q10 DSPC liposome nanoparticles protect against myocardial infarction

At the site of myocardial infarction (MI), various phenomena such as oxidative stress and myocardial apoptosis can be observed. Both epigallocatechin gallate (EGCG) and coenzyme Q10 (CoQ10) exhibit antioxidant and anti-inflammatory effects. Macrophages have demonstrated a higher internalization rate of cationic liposomes, thereby increasing their bioavailability. This study utilized EGCG in synergy with CoQ10 as an antioxidant agent and distearyl phosphatidylcholine (DSPC) as the carrier, to create liposome nanoparticles known as CE-LNPs. The CE-LNPs exhibited favorable biocompatibility and were effectively engulfed by macrophages in vitro. In addition, the CE-LNPs effectively eradicated reactive oxygen species (ROS) in hypoxic cardiomyocytes, mitigated myocardial cell apoptosis, and sustained the functionality and proliferation of myocardial cells. The anti-apoptotic effect of the CE-LNPs was further validated through TUNEL and Annexin V FITC/PI experiments. The therapeutic efficacy of CE-LNPs was evaluated in a murine model of MI. CE-LNPs demonstrated a significant reduction in scar area in vivo, facilitating cardiac repair and improving cardiac function. These findings provide evidence that EGCG synergistically combined with CoQ10 in DSPC liposome nanoparticles offers protection against MI.

Nanomedicine-mediated therapeutic approaches for pulmonary arterial hypertension

Nanomedicine has emerged as a field in which there are opportunities to improve the diagnosis, treatment and prevention of incurable diseases. Pulmonary arterial hypertension (PAH) is known as a severe and fatal disease affecting children and adults. Conventional treatments have not produced optimal effectiveness in treating this condition. Several reasons for this include drug instability, poor solubility of the drug and a shortened duration of pharmacological action. The present review focuses on new approaches for delivering anti-PAH drugs using nanotechnology with the aim of overcoming these shortcomings and increasing their efficacy. Solid-lipid nanoparticles, liposomes, metal-organic frameworks and polymeric nanoparticles have demonstrated advantages for the potential treatment of PAH, including increased drug bioavailability, drug solubility and accumulation in the lungs.

Association between Sex-Related ALOX5 Gene Polymorphisms and Lung Atopy Risk

Atopy is an exaggerated IgE-mediated immune response to foreign antigens in which metabolic abnormalities of the leukotrienes (LTs) pathway play a crucial role. Recent studies have described sex as a key variable in LT biosynthesis, partly explaining why treatment with anti-LT drugs in atopic subjects leads to better control of symptoms in women. In addition, variability in LT production is often associated with single nucleotide polymorphisms (SNPs) in the arachidonate 5-lipoxygenase (ALOX5) gene, which encodes the leukotriene-synthesizing enzyme machinery, 5-lipoxygenase (5-LO). This study aimed to investigate whether two SNPs of ALOX5 are implicated in sex differences in allergic diseases in a prospective cohort of 150 age- and sex-matched atopic and healthy subjects. Rs2029253 and rs2115819 were genotyped using allele-specific RT-PCR, and serum levels of 5-LO and LTB4 were measured by ELISA. Both polymorphisms are significantly more common in women than in men, and their influences on LT production vary as a function of sex, leading to a decrease in men's and an increase in women's serum levels of 5-LO and LTB4. These data represent a new resource for understanding sex-related differences in lung inflammatory diseases, partly explaining why women are more likely to develop allergic disorders than men.

Nanostructured Lipid Carriers Aimed to the Ocular Delivery of Mangiferin: In Vitro Evidence

Although mangiferin (MGN) is a natural antioxidant that could be a good candidate for the treatment of ocular diseases, its use in ophthalmology is strongly compromised due to its high lipophilicity. Its encapsulation in nanostructured lipid carriers (NLC) seems to be an interesting strategy for improving its ocular bioavailability. As reported in our previous work, MGN–NLC showed high ocular compatibility and fulfilled the nanotechnological requirements needed for ocular delivery. The aim of the present work was to investigate, in vitro and ex vivo, the capability of MGN–NLC to act as a potential drug delivery system for MGN ocular administration. The data obtained in vitro on arising retinal pigment epithelium cells (ARPE-19) did not show cytotoxic effects for blank NLC and MGN–NLC; likewise, MGN–NLC showed the maintenance of the antioxidant role of MGN by mitigating ROS (Reactive Oxygen Species) formation and GSH (glutathione) depletion induced by H2O2. In addition, the capacity of MGN-released to permeate through and accumulate into the ocular tissues was confirmed ex vivo using bovine corneas. Finally, the NLC suspension has been formulated as a freeze-dried powder using mannitol at a concentration of 3% (w/v) in order to optimize its storage for long periods of time. All this evidence suggests a potential application of MGN–NLC in the treatment of oxidative stress-related ocular diseases.

Development of Solid Lipid Nanoparticles as Dry Powder: Characterization and Formulation Considerations

Solid lipid nanoparticles (SLNs) are lipid-based colloidal systems used for the delivery of active compounds. Although SLNs have many benefits, they show important issues due to physical and chemical instability phenomena during storage. For these reasons, it is highly desirable to have a dried SLN formulation available. Therefore, the aim of the project was to identify suitable methods to obtain a dry powder formulation from an SLN suspension. The nanoparticle suspension was dried using both freeze- and spray-drying techniques. The suitability of these methods in obtaining SLN dry powders was evaluated from the analyses of nanotechnological parameters, system morphology and thermal behavior using differential scanning calorimetry. Results pointed out that both drying techniques, although at different yields, were able to produce an SLN dry powder suitable for pharmaceutical applications. Noteworthily, the freeze-drying of SLNs under optimized conditions led to a dry powder endowed with good reconstitution properties and technological parameters similar to the starting conditions. Moreover, freeze-thaw cycles were carried out as a pretest to study the protective effect of different cryoprotectants (e.g., glucose and mannitol with a concentration ranging from 1% to 10% w/v). Glucose proved to be the most effective in preventing particle growth during freezing, thawing, and freeze-drying processes; in particular, the optimum concentration of glucose was 1% w/v.

Design and synthesis of functionalized 4-aryl-Catechol derivatives as new antiinflammtory agents with in vivo efficacy

Oxidative stress and inflammation are two conditions that coexist in many multifactorial diseases and the discovery of antioxidants is an attractive approach that can simultaneously tackle two or more therapeutic targets of the arachidonic acid cascade. We report that the simple structural variations on the 4-aryl-benzene-1,2-diol side-arm of the scaffold significantly influence the selectivity against 5-LOX vs 12- and 15-LOX. Derivatives 4 a-l were evaluated for their antioxidant activity, using the DPPH, and ferric ion reducing antioxidant power (FRAP) methods. Docking simulations proposed concrete binding of the catechol series to 5-LO. Selected active compound 4-(3,4-dihydroxyphenyl)dibenzofuran (4l) was also tested in different in vivo mouse models of inflammation. 4l (0.1 mg/kg; i.p.) impaired (I) bronchoconstriction in ovalbumin-sensitized mice challenged with acetylcholine, (II) exudate formation in carrageenan-induced paw edema, and (III) zymosan-induced leukocyte infiltration in air pouches. These results pave the way for investigating the therapeutic potential of 4-aryl-benzene-1,2-diol, as novel multitarget therapeutic drugs, able to regulate the complex inflammatory cascade mechanisms.

Overview of Antiviral Drug Therapy for COVID-19: Where Do We Stand?

The vaccine weapon has resulted in being essential in fighting the COVID-19 outbreak, but it is not fully preventing infection due to an alarming spreading of several identified variants of concern. In fact, the recent emergence of variants has pointed out how the SARS-CoV-2 pandemic still represents a global health threat. Moreover, oral antivirals also develop resistance, supporting the need to find new targets as therapeutic tools. However, cocktail therapy is useful to reduce drug resistance and maximize vaccination efficacy. Natural products and metal-drug-based treatments have also shown interesting antiviral activity, representing a valid contribution to counter COVID-19 outbreak. This report summarizes the available evidence which supports the use of approved drugs and further focuses on significant clinical trials that have investigated the safety and efficacy of repurposing drugs and new molecules in different COVID-19 phenotypes. To date, there are many individuals vulnerable to COVID-19 exhibiting severe symptoms, thus characterizing valid therapeutic strategies for better management of the disease is still a challenge.

Role of solid lipid nanoparticle for the delivery of Lipophilic Drugs and Herbal Medicines in the treatment of pulmonary hypertension

Pulmonary arterial hypertension (PAH) is an uncommon condition marked by elevated pulmonary artery pressure that leads to right ventricular failure. The majority of drugs are now been approved by FDA for PAH, however, several biopharmaceutical hindrances lead to failure of the therapy. Various novel drug delivery systems are available in the literature from which lipid-based nanoparticles i.e. solid lipid nanoparticle is widely investigated for improving the solubility and bioavailability of drugs. In this paper, the prototype phytoconstituents used in pulmonary arterial hypertension have limited solubility and bioavailability. We highlighted the novel concepts of SLN for lipophilic phytoconstituents with their potential applications. This paper also reviews the present state of the art regarding production techniques for SLN like High-Pressure Homogenization, Micro-emulsion Technique, and Phase Inversion Temperature Method, etc. Furthermore, toxicity aspects and in vivo fate of SLN are also highlighted in this review. In a nutshell, safer delivery of phytoconstituents by SLN added a novel feather to the cap of successful drug delivery technologies.