A niosomal bilayer of sorbitan monostearate in complex with flavones: a molecular dynamics simulation study

Insight into molecular structures and dynamical properties of niosome bilayers containing melatonin molecules: a molecular dynamics simulation approach

Niosomes represent vesicular carriers capable of encapsulating both hydrophobic and hydrophilic drugs within their inner core or bilayer shell. They are typically composed of non-ionic synthetic surfactants such as sorbitan monostearate (Span60) with the addition of cholesterol (Chol). The physical properties and stability of niosomal vesicles strongly depend on the composition of their bilayers, which plays a significant role in determining the efficiency of drug encapsulation and release in drug delivery systems. In this study, we have explored the interactions between melatonin (Mel) molecules and the niosome bilayer, as well as their resulting physical properties. Molecular dynamics simulations were employed to investigate melatonin-inserted niosome bilayers, both with and without the inclusion of cholesterol. The simulation results revealed that cholesterol notably influences the location of melatonin molecules within the niosome bilayers. In the absence of cholesterol, melatonin tends to occupy the region around the Span60 tail groups. However, in the presence of cholesterol, melatonin is found in the vicinity of the Span60 head groups. Melatonin molecules in niosome bilayers without cholesterol exhibit a more ordered orientation when compared to those in bilayers containing 50 mol% cholesterol. The bilayer structure of the Span60/Mel and Span60/Chol/Mel systems exhibited a liquid-disordered phase (Ld). In contrast, the Span60/Chol bilayer system displays a liquid-ordered phase (Lo) with less fluidity. This study reveals that melatonin induces a disorderly bilayer structure and greater lateral expansion, whereas cholesterol induces an orderly bilayer structure and a more condensed effect. Cholesterol plays a crucial role in condensing the bilayer structure with stronger interactions between Span60 and cholesterol. The addition of 50 mol% cholesterol in the Span60 bilayers not only enhances the stability and rigidity of niosomes but also facilitates the easier release of melatonin from the bilayer membranes. This finding is particularly valuable in the context of preparing niosomes for drug delivery systems.

Niosomes: a novel targeted drug delivery system for cancer

Recently, nanotechnology is involved in various fields of science, of which medicine is one of the most obvious. The use of nanoparticles in the process of treating and diagnosing diseases has created a novel way of therapeutic strategies with effective mechanisms of action. Also, due to the remarkable progress of personalized medicine, the effort is to reduce the side effects of treatment paths as much as possible and to provide targeted treatments. Therefore, the targeted delivery of drugs is important in different diseases, especially in patients who receive combined drugs, because the delivery of different drug structures requires different systems so that there is no change in the drug and its effectiveness. Niosomes are polymeric nanoparticles that show favorable characteristics in drug delivery. In addition to biocompatibility and high absorption, these nanoparticles also provide the possibility of reducing the drug dosage and targeting the release of drugs, as well as the delivery of both hydrophilic and lipophilic drugs by Niosome vesicles. Since various factors such as components, preparation, and optimization methods are effective in the size and formation of niosomal structures, in this review, the characteristics related to niosome vesicles were first examined and then the in silico tools for designing, prediction, and optimization were explained. Finally, anticancer drugs delivered by niosomes were compared and discussed to be a suitable model for designing therapeutic strategies. In this research, it has been tried to examine all the aspects required for drug delivery engineering using niosomes and finally, by presenting clinical examples of the use of these nanocarriers in cancer, its clinical characteristics were also expressed.

Mechanistic Understanding From Molecular Dynamics Simulation in Pharmaceutical Research 1: Drug Delivery

In this review, we outline the growing role that molecular dynamics simulation is able to play as a design tool in drug delivery. We cover both the pharmaceutical and computational backgrounds, in a pedagogical fashion, as this review is designed to be equally accessible to pharmaceutical researchers interested in what this new computational tool is capable of and experts in molecular modeling who wish to pursue pharmaceutical applications as a context for their research. The field has become too broad for us to concisely describe all work that has been carried out; many comprehensive reviews on subtopics of this area are cited. We discuss the insight molecular dynamics modeling has provided in dissolution and solubility, however, the majority of the discussion is focused on nanomedicine: the development of nanoscale drug delivery vehicles. Here we focus on three areas where molecular dynamics modeling has had a particularly strong impact: (1) behavior in the bloodstream and protective polymer corona, (2) Drug loading and controlled release, and (3) Nanoparticle interaction with both model and biological membranes. We conclude with some thoughts on the role that molecular dynamics simulation can grow to play in the development of new drug delivery systems.

Flavonol clustering in model lipid membranes: DSC, AFM, force spectroscopy and MD simulations study

We here report on flavonols (myricetin (MCE) and its glycoside myricitrin (MCI)) - 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membrane interactions focusing on the effects of flavonol clustering on the membrane thermotropic and nanomechanical properties. Atomic force microscopy (AFM), force spectroscopy (FS) and differential scanning calorimetry (DSC) together with molecular dynamics (MD) simulations provided a consistent picture of flavonol - DMPC membrane interactions. DMPC membrane as a supported lipid bilayer preserved its integrity even at higher flavonol molar fraction x. When present at x = 0.1 - 0.3, MCE and MCI both slightly improve DMPC bilayer fluidity which is evidenced by the decrease in the main phase transition temperature T_m. MCE is found within the interior of the bilayer, while MCI incorporates in the head group-water interface region. AFM and FS confirmed clusters as protrusions with an average height of 0.012 μm and average diameters of 0.60 and 0.24 μm for MCE and MCI clusters, respectively. The average membrane thickness in DMPC fluid phase decreases for 7% at x_MCE = 0.30, while only 4% at x_MCI = 0.27. The induced membrane changes are dependent on the chemical and physical properties of inserted flavonols. The hypothesis regarding the tendency of flavonol to clustering in membranes by increasing flavonol molar fraction has been confirmed.

Salts Influence Cathechins and Flavonoids Encapsulation in Liposomes: A Molecular Dynamics Investigation

Cathechins and flavonoids are responsible of numerous health benefits. Two of the most representatives' compounds for their antioxidant and therapeutic effects are Epigallocatechin 3-Gallate (EGCG), from green tea extracts, and morelloflavone (MF), from Garcinia dulcis. Here we explore, by atomistic Molecular Dynamics simulations, how EGCG and MF interact with lipid bilayers and we show the salts' influence on their encapsulation degree in neutral liposomes. As a result, we found out that EGCGs naturally bind to the hydrophilic regions of phospholipids, positioning themselves mostly at the interface between water and lipid phases. The presence of a salt clearly influences the EGCG molecules' absorption and the total effect depends strongly on the salt nature and concentration. Beside, for MF, we observed a high stability of the intermolecular MFs aggregates in water that strongly penalizes the flavonoid's interaction with the lipid polar heads. However, salts can influence MF's liposomal penetration, even if they are not able to promote completely its absorption inside the bilayer. For both compounds, the increase of penetration is more marked in presence of magnesium chloride, whilst calcium chloride showed the opposite effect.