Lipid Particles Research Articles

Effective mRNA Delivery by Condensation with Cationic Nanogels Incorporated into Liposomes.

The challenge in effective delivery of mRNA has been a major hurdle in their development as therapeutics. Herein, we present that the incorporation of cationic nanogels as the condensing material for mRNA into liposomes enables stable and enhanced mRNA delivery to cells in vitro. We prepared dextran-based nanogel particles, which were surface functionalized with oligoarginine peptide (DNPR9) and complexed with mRNA for incorporation into liposomes (LipoDNPR9). The use of DNPR9 with the liposomes resulted in enhanced internalization, as well as a 4-fold increase in transfection of luciferase mRNA when treated with A549 cells in vitro, compared to control liposomes. The enhancement in transfection efficiency was also observed in various cell lines while causing low cytotoxicity. The versatility of the strategy was also investigated by applying DNPR9 for mRNA condensation to ionizable lipid particles, which resulted in an ∼55% increase in transfection. The current development based on nanogel-incorporated liposomes introduces an effective platform for mRNA delivery, while the condensation strategy using DNPR9 can be widely applied for various lipid-based formulations to enhance their efficacy.

Abstract 148: Lipoprotein Lipase Deficiency Reprograms Bone Marrow Cellular Metabolic Activity And Inflammatory Responses

Objectives: Activated bone marrow (BM) hematopoiesis is associated with systemic inflammation that increases risk for atherosclerosis. We had reported that lipoprotein lipase (LpL), in addition to being a lipolytic enzyme, regulated peripheral and tissue leukocyte levels and affected BM monocyte progenitor differentiation. LpL is mainly expressed in the specialized BM niches. We now questioned the role of LpL in influencing BM microenvironment that affects the homing and differentiation of hematopoietic stem/progenitor cells toward distinct lineages. Methods and Results: We characterized the metabolic and transcriptional phenotypes of BM cells utilizing immunofluorescence, flow cytometry, quantitative RT-PCR, and Seahorse Bioenergetics analysis in transgenic LpL knockout (KO) mice rescued by muscle-specific LpL expression. Differential gene expression (DEG) of BM cells were examined by bulk RNA sequencing (RNAseq). Our data indicate that LpL deficiency reduced expression of key BM vascular niche markers by 2-3-fold (p<0.05), including CD31, Tie-2, endomucin, CXCL12, and CXCR4, as well their associated growth factors - HIF-1α and VEGF. BM vascular endothelial cadherin-labeled cells were decreased by >50% (p<0.05) in LpL KO when compared to that in WT. Cellular uptake of chylomicron-size lipid particles was reduced in LpL KO BM, which may link to metabolic adaptation from mitochondrial oxidative phosphorylation towards glycolysis observed in LpL KO BM (p<0.05). Although the leptin-receptor positive perivascular cells were remained intact, expression of key lipolytic genes, such as ATGL, MGL, and LAL, were markedly reduced by >50% in LpL KO (p < 0.05). KEGG enrichment analysis of DEG shows that LpL KO BM cells had altered hematopoietic lineage signaling pathway. NFκB-directed signaling cascade was also downregulated in LpL KO BM cells, resulting in the reduced expression of pro-inflammatory TNF-α, IL-1β and IL-6. Conclusions: Our results indicate that LpL regulates metabolic activity and inflammatory responses of BM cells. A further understanding of these mechanisms will open the possibilities to target reprogram of both hematopoietic and BM niche cells as a therapeutic strategy to improve atherosclerosis-associated inflammation.

Encapsulated Oxovanadium(IV) and Dioxovanadium(V) Complexes into Solid Lipid Nanoparticles Increase Cytotoxicity Against MDA-MB-231 Cell Line.

Solid lipid nanoparticles (SLN) have been considered lately as promising drug delivery system in treatment of many human diseases including cancers. We previously studied potential drug compounds that were effective inhibitors of PTP1B phosphatase - possible target for breast cancer treatment. Based on our studies, two complexes were selected for encapsulation into the SLNs, the compound 1 ([VO(dipic)(dmbipy)] · 2 H2O) and compound 2 ([VOO(dipic)](2-phepyH) · H2O). Here, we investigate the effect of encapsulation of those compounds on cell cytotoxicity against MDA-MB-231 breast cancer cell line. The study also included the stability evaluation of the obtained nanocarriers with incorporated active substances and characterization of their lipid matrix. Moreover, the cell cytotoxicity studies against the MDA-MB-231 breast cancer cell line in comparison and in combination with vincristine have been performed. Wound healing assay was carried out to observe cell migration rate. The properties of the SLNs such as particle size, zeta potential (ZP), and polydispersity index (PDI) were investigated. The morphology of SLNs was observed by scanning electron microscopy (SEM), while the crystallinity of the lipid particles was analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The cell cytotoxicity of complexes and their encapsulated forms was carried out against MDA-MB-231 breast cancer cell line using standard MTT protocols. The wound healing assay was performed using live imaging microscopy. SLNs with a mean size of 160 ± 25 nm, a ZP of -34.00 ± 0.5, and a polydispersity index of 30 ± 5% were obtained. Encapsulated forms of compounds showed significantly higher cytotoxicity also in co-incubation with vincristine. Moreover, our research shows that the best compound was complex 2 encapsulated into lipid nanoparticles. We observed that encapsulation of studied complexes into SLNs increases their cell cytotoxicity against MDA-MB-231 cell line and enhanced the effect of vincristine.

ATG9 vesicles comprise the seed membrane of mammalian autophagosomes.

As the autophagosome forms, its membrane surface area expands rapidly, while its volume is kept low. Protein-mediated transfer of lipids from another organelle to the autophagosome likely drives this expansion, but as these lipids are only introduced into the cytoplasmic-facing leaflet of the organelle, full membrane growth also requires lipid scramblase activity. ATG9 harbors scramblase activity and is essential to autophagosome formation; however, whether ATG9 is integrated into mammalian autophagosomes remains unclear. Here we show that in the absence of lipid transport, ATG9 vesicles are already competent to collect proteins found on mature autophagosomes, including LC3-II. Further, we use styrene-maleic acid lipid particles to reveal the nanoscale organization of protein on LC3-II membranes; ATG9 and LC3-II are each fully integrated into expanding autophagosomes. The ratios of these two proteins at different stages of maturation demonstrate that ATG9 proteins are not continuously integrated, but rather are present on the seed vesicles only and become diluted in the expanding autophagosome membrane.

Nanoemulsion carriers for drug delivery: Assessment of environmental hazards

Nanoemulsions (NEs) have been extensively studied as carriers for drug delivery, since these provide a good alternative to the existing non-nano systems, while promoting their target delivery and controlled release. NEs are considered safe drug carriers from a pre-clinical perspective, but there is currently no information on their ecotoxicological effects. In the present study we investigated the toxicity of a NE material (lecithin, sunflower oil, borate buffer) designed to be used as a liposomal excipient for eye drops, further referred to as (Lipid Particle:LP) LP_Eye and its dispersant (borate buffer) (LP_Eye disp.). Effects were assessed using two model species in soil ecotoxicology in LUFA 2.2 soil: Enchytraeus crypticus (Oligochaeta) and Folsomia candida (Collembola), based on the OECD standard guideline (28 days) and its extension, a longer-term exposure (56 days). The endpoints evaluated included survival, reproduction, and size. LP_Eye and LP_Eye disp. were toxic to E. crypticus and F. candida, affecting all measured endpoints. The toxicity of LP_Eye in E. crypticus seemed to be induced by the dispersant, whereas for F. candida, more sensitive, this was less explanatory. There were no indications that toxicity increased with longer exposure. Current results provide ecotoxicological data for a group of NMs that was absent, revealing toxicity to relevant environmental species. Indications were that the dispersant contributed to most of the observed effects, thus there is room to improve the formulation and achieve lower environmental impact.

Identifying lipid particle sub-types in live Caenorhabditis elegans with two-photon fluorescence lifetime imaging.

Fat metabolism is an important modifier of aging and longevity in Caenorhabditis elegans. Given the anatomy and hermaphroditic nature of C. elegans, a major challenge is to distinguish fats that serve the energetic needs of the parent from those that are allocated to the progeny. Broadband coherent anti-Stokes Raman scattering (BCARS) microscopy has revealed that the composition and dynamics of lipid particles are heterogeneous both within and between different tissues of this organism. Using BCARS, we have previously succeeded in distinguishing lipid-rich particles that serve as energetic reservoirs of the parent from those that are destined for the progeny. While BCARS microscopy produces high-resolution images with very high information content, it is not yet a widely available platform. Here we report a new approach combining the lipophilic vital dye Nile Red and two-photon fluorescence lifetime imaging microscopy (2p-FLIM) for the in vivo discrimination of lipid particle sub-types. While it is widely accepted that Nile Red staining yields unreliable results for detecting lipid structures in live C. elegans due to strong interference of autofluorescence and non-specific staining signals, our results show that simple FLIM phasor analysis can effectively separate those signals and is capable of differentiating the non-polar lipid-dominant (lipid-storage), polar lipid-dominant (yolk lipoprotein) particles, and the intermediates that have been observed using BCARS microscopy. An advantage of this approach is that images can be acquired using common, commercially available 2p-FLIM systems within about 10% of the time required to generate a BCARS image. Our work provides a novel, broadly accessible approach for analyzing lipid-containing structures in a complex, live whole organism context.

Triglyceride mixtures: Cold-bursting and double emulsion formation

It was shown recently that a solid-to-solid phase transitions (α-to-β, gel-to-crystal), typical for many lipid substances, can lead to formation of nanoporous network inside lipid micro-particles dispersed in aqueous surfactant solutions (Cholakova et al. ACS Nano2020, 14, 8594). These nanopores are spontaneously infused by the aqueous phase when appropriate combination of water-soluble and oil-soluble surfactants is applied. As a result, the initial lipid micro-particles can spontaneously burst into much smaller nanoparticles, just by cooling and heating of the initial dispersion. Under certain conditions, the infused aqueous phase is entrapped in the moment of lipid particle melting and double emulsion of type water-in-oil-in-water (W/O/W) is formed. The current study aims to clarify how the composition of the lipid micro-drops and surfactants affect the observed phenomena. Selected mixtures of monoacid triglycerides are studied systematically. The results show that the bursting efficiency usually decreases when the complexity of the lipid mixture increases, due to the expanded temperature interval for lipid melting. Nevertheless, complete particle bursting and lipid nanoparticles with diameters down to 20 nm are formed even for the most complex lipid compositions under appropriate conditions. The key mechanisms leading to efficient fragmentation and double emulsion formation are clarified, and the main governing factors are explored. On this basis, we reveal that the system behavior can be switched between complete particle bursting and W/O/W emulsion formation by: (1) Change in the cooling and heating rates without any changes in the chemical composition, (2) Change in the concentration of oil-soluble surfactant, and/or (3) Change in the phase in which the oil-soluble surfactant is introduced initially. Thus, we have formulated guiding rules to control the formation of lipid nanoparticles and W/O/W emulsions with triglyceride mixtures promising multiple potential applications.

Cubosome Lipid Nanocarriers As a Drug Delivery Vehicle for Intracellular Mycobacterium tuberculosis Infections

Mycobacterium tuberculosis (MTB) causes the infectious disease tuberculosis (TB), responsible for more deaths than any other single infectious disease in history. Intracellular MTB are slow growing and difficult to target with traditional antitubercular drugs, leading to the emergence of multidrug resistance in TB infection, which is a major global public health issue. Recent advances in innovative lipid nanotechnologies for drug delivery have demonstrated promising outcomes for chronic infectious diseases but have not yet been tested as potential delivery systems for intracellular infections such as TB. The current study evaluates the potential of monoolein (MO)-based cationic cubosomes for the encapsulation and delivery of the first line antitubercular drug rifampicin (RIF) against an MTB-H37Ra in vitro culture model. In particular, we show that the use of cationic cubosomes as delivery vehicles reduced the minimum inhibitory concentration (MIC) of RIF by 2-fold against actively replicating MTB-H37Ra (compared to that of the free drug) and also shortened the lifecycle duration of axenic MTB-H37Ra from 5 to 3 days. The cubosome-mediated delivery was also found to be effective against intracellular MTB-H37Ra within THP-1 human macrophages, with a 2.8 log reduction in viability of the bacilli after 6 days incubation at the MIC. The killing time was also reduced from 8 to 6 days without distressing the host macrophages. Mechanistic studies on the uptake of RIF-loaded cationic cubosomes using total internal reflection fluorescence microscopy (TIRFM) demonstrated the capacity of these lipid particles to effectively target intracellular bacteria. Overall, these results demonstrate that cationic cubosomes are a potent delivery system for the antitubercular drug RIF for therapeutic management of TB.

Extracellular Vesicles as Potential Bladder Cancer Biomarkers: Take It or Leave It?

Bladder cancer (BC) is the 10th most frequently diagnosed cancer worldwide. Although urine cytology and cystoscopy are current standards for BC diagnosis, both have limited sensitivity to detect low-grade and small tumors. Moreover, effective prognostic biomarkers are lacking. Extracellular vesicles (EVs) are lipidic particles that contain nucleic acids, proteins, and metabolites, which are released by cells into the extracellular space, being crucial effectors in intercellular communication. These particles have emerged as potential tools carrying biomarkers for either diagnosis or prognosis in liquid biopsies namely urine, plasma, and serum. Herein, we review the potential of liquid biopsies EVs' cargo as BC diagnosis and prognosis biomarkers. Additionally, we address the emerging advantages and downsides of using EVs within this framework.

Abstract 743: Association between physical activity and lipid profile among breast cancer survivors

Abstract Backgrounds/Aims: Unfavorable lipid profiles may be associated with prognosis among breast cancer survivors. We aimed to examine the association between physical activity levels and subclasses of lipoprotein among breast cancer survivors. Methods: We included a total of 378 women diagnosed with primary breast cancer and survived for ≥6 months since the surgery. Physical activity levels were presented as the metabolic equivalent of task (MET) hours/week from a structured questionnaire. High-throughput proton nuclear magnetic resonance (NMR) metabolomics platform was used to quantify plasma levels of specific lipid biomarkers and particle sizes. The multivariable adjusted least-square means (LS-means) and 95% confidence intervals (CIs) of lipid profile markers across physical activity (quartile) were estimated by using generalized linear models. Results: We observed inverse associations of physical activity levels with circulating levels of total triglycerides (TG), TG in very low-density lipoprotein (VLDL), and TG in high-density lipoprotein (HDL) among breast cancer survivors. LS-means (95% CIs) for 1st and 4th quartiles of physical activity were 1.07 (0.99-1.17) and 0.96 (0.88-1.04; p for trend=0.048) for total TG (nmol/L), 0.68 (0.62-0.74) and 0.60 (0.54-0.66; p for trend=0.045) for TG in VLDL (nmol/L), and 0.14 (0.13-0.15) and 0.12 (0.11-0.13; p for trend=0.045) for TG in HDL (nmol/L). These associations were limited to breast cancer survivors with stage II or III. We also found a smaller VLDL size with high physical activity among those with stage II or III. Among participants with a BMI of ≥25 kg/m2, we found that high physical activity was associated with decreased levels of TG in VLDL and small VLDL size; according to subsequent quartiles of physical activity, LS-means (95% CIs) were 0.73 (0.62-0.87), 0.88 (0.72-1.08), 0.74 (0.61-0.89), and 0.56 (0.44-0.71) for TG in VLDL (nmol/L), respectively (p for trend=0.047); and 38.67 (38.34-39.00), 38.75 (38.36-39.15), 38.65 (38.28-39.01), and 37.98 (37.52-38.45) for VLDL size (nm), respectively (p for trend=0.024). Conclusions: We found that high physical activity was associated with lower circulating levels of subclasses of TG and smaller VLDL size among breast cancer survivors with stage II or III or those with a BMI of ≥25 kg/m2. Further prospective or randomized controlled studies are warranted to confirm the significance of physical activity associated with favorable lipid profiles among breast cancer survivors. Funding Information: This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Science and ICT, MSIT) (No. 2014R1A2A2A01007794, 2019R1F1A1061017, and 2021R1F1A1062476) and K-BIO KIURI Center program (NRF2020M3H1A107330413). Citation Format: Hyun Jeong Cho, Minji Kang, Zisun Kim, Hyun Jo Youn, Jihyoung Cho, Jun Won Min, Yoo Seok Kim, Jung Eun Lee. Association between physical activity and lipid profile among breast cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 743.

Analysis on the Methods and Techniques of Sunscreen Enhancement

In recent years, sunscreen products have been the research focus in the field of daily chemicals. Sunscreen products with high sun protection factor (SPF), fresh skin feeling and high safety are the market hotspots of sunscreen products. This article systematically sorts out the key points of sunscreen synergistic technology from the aspects of sunscreen compound synergism, the influence of plant-derived active ingredients on sunscreen, the carrier modification of sunscreen microcapsules, the solid lipid particles and sunscreen product formulation system. This article explained the future development direction of sunscreen enhancement, hoping to provide scientific basis for the research and development of sunscreen product formula.

Food Peptides for the Nutricosmetic Industry.

In recent years, numerous reports have described bioactive peptides (biopeptides)/hydrolysates produced from various food sources. Biopeptides are considered interesting for industrial application since they show numerous functional properties (e.g., anti-aging, antioxidant, anti-inflammatory, and antimicrobial properties) and technological properties (e.g., solubility, emulsifying, and foaming). Moreover, they have fewer side effects than synthetic drugs. Nevertheless, some challenges must be overcome before their administration via the oral route. The gastric, pancreatic, and small intestinal enzymes and acidic stomach conditions can affect their bioavailability and the levels that can reach the site of action. Some delivery systems have been studied to avoid these problems (e.g., microemulsions, liposomes, solid lipid particles). This paper summarizes the results of studies conducted on biopeptides isolated from plants, marine organisms, animals, and biowaste by-products, discusses their potential application in the nutricosmetic industry, and considers potential delivery systems that could maintain their bioactivity. Our results show that food peptides are environmentally sustainable products that can be used as antioxidant, antimicrobial, anti-aging, and anti-inflammatory agents in nutricosmetic formulations. Biopeptide production from biowaste requires expertise in analytical procedures and good manufacturing practice. It is hoped that new analytical procedures can be developed to simplify large-scale production and that the authorities adopt and regulate use of appropriate testing standards to guarantee the population's safety.

SMALPs Are Not Simply Nanodiscs: The Polymer-to-Lipid Ratios of Fractionated SMALPs Underline Their Heterogeneous Nature.

Amphipathic styrene-maleic acid (SMA) copolymers directly solubilize biomembranes into SMA-lipid particles, or SMALPs, that are often regarded as nanodiscs and hailed as a native membrane platform. The promising outlook of SMALPs inspires the discovery of many SMA-like copolymers that also solubilize biomembranes into putative nanodiscs, but a fundamental question remains on how much the SMALPs or SMALP analogues truly resemble the bilayer structure of nanodiscs. This unfortunate ambiguity undermines the utility of SMA or SMA-like copolymers in membrane biology because the structure and function of many membrane proteins depend critically on their surrounding matrices. Here, we report the structural heterogeneity of SMALPs revealed through fractionating SMALPs comprised of lipids and well-defined SMAs via size-exclusion chromatography followed by quantitative determination of the polymer-to-lipid (P/L) stoichiometric ratios in individual fractions. Through the lens of P/L stoichiometric ratios, different self-assembled polymer-lipid nanostructures are inferred, such as polymer-remodeled liposomes, polymer-encased nanodiscs, polymer-lipid mixed micelles, and lipid-doped polymer micellar aggregates. We attribute the structural heterogeneity of SMALPs to the microstructure variations amongst individual polymer chains that give rise to their polydisperse detergency. As an example, we demonstrate that SMAs with a similar S/MA ratio but different chain sizes participate preferentially in different polymer-lipid nanostructures. We further demonstrate that proteorhodopsin, a light-driven proton pump solubilized within the same SMALPs is distributed amongst different self-assembled nanostructures to display different photocycle kinetics. Our discovery challenges the native nanodisc notion of SMALPs or SMALP analogues and highlights the necessity to separate and identify the structurally dissimilar polymer-lipid particles in membrane biology studies.

Formulation and Characterization of Bioactive Agent Containing Nanodisks.

The term nanodisk refers to a discrete type of nanoparticle comprised of a bilayer forming lipid, a scaffold protein, and an integrated bioactive agent. Nanodisks are organized as a disk-shaped lipid bilayer whose perimeter is circumscribed by the scaffold protein, usually a member of the exchangeable apolipoprotein family. Numerous hydrophobic bioactive agents have been efficiently solubilized in nanodisks by their integration into the hydrophobic milieu of the particle's lipid bilayer, yielding a largely homogenous population of particles in the range of 10-20 nm in diameter. The formulation of nanodisks requires a precise ratio of individual components, an appropriate sequential addition of each component, followed by bath sonication of the formulation mixture. The amphipathic scaffold protein spontaneously contacts and reorganizes the dispersed bilayer forming lipid/bioactive agent mixture to form a discrete, homogeneous population of nanodiskparticles. During this process, the reaction mixture transitions from an opaque, turbid appearance to a clarified sample that, when fully optimized, yields no precipitate upon centrifugation. Characterization studies involve the determination of bioactive agent solubilization efficiency, electron microscopy, gel filtration chromatography, ultraviolet visible (UV/Vis) absorbance spectroscopy, and/or fluorescence spectroscopy. This is normally followed by an investigation of biological activity using cultured cells or mice. In the case of nanodisks harboring an antibiotic (i.e., the macrolide polyene antibiotic amphotericin B), their ability to inhibit the growth of yeast or fungi as a function of concentration or time can be measured. The relative ease of formulation, versatility with respect to component parts, nanoscale particle size, inherent stability, and aqueous solubility permits myriad in vitro and in vivo applications of nanodisk technology. In the present article, we describe a general methodology to formulate and characterize nanodisks containing amphotericinB as the hydrophobic bioactive agent.

Evaluation of bone marrow aspirates using the automated hematology analyzer Sysmex XN-3000.

This study evaluated the feasibility of the Sysmex XN-3000 automated hematology analyzer for the assessment of total nucleated cells (TNC) and bone marrow (BM) cell density in routine bone marrow aspiration (BMA) samples. A total of 54 BMA samples from 39 hematological patients were evaluated. The number of megakaryocytes was calculated by a specific gating algorithm using the body fluid mode of the WBC differential (WDF) channel. Lipid contents were calculated through a newly developed algorithm utilizing the WDF channel. The ratio of lipid particles over TNCs by the WNR channel was compared with the BM cellularity assessed by the BM biopsy. The myeloid/erythroid (M/E) ratio was calculated by measuring the number of myeloid cells in the WDF channel and the number of nucleated red blood cells (NRBCs) in the WNR channel. XN-3000 counts and microscopic results showed a linear correlation in TNC (R2 =.98, p < .001), megakaryocytes (R2 =.59, p=.002), NRBC (R2 =.84, p < .001), and M/E ratio (R2 =.59, p < .001). There were significant differences in the lipid/TNC ratios of hypercellular, normocellular, and hypocellular BMs measured by XN-3000 (p < .001). Receiver-operating characteristic analysis detected cut-off values of the lipid/TNC ratio of >0.4054 for hypoplasia and <0.157 for hyperplasia. The sensitivity and specificity for hypoplasia were 100% and 88%, and for hyperplasia were 89% and 86%, respectively. XN-3000 provides a quantitative assessment of BM cellularity, supporting the qualitative assessment by myelogram and BM biopsy.

Distance-controlled surface-enhanced Raman spectroscopy of nanoparticles.

Biological particles, e.g., viruses, lipid particles, and extracellular vesicles, are attracting significant research interest due to their role in biological processes and potential in practical applications, such as vaccines, diagnostics, and therapies. Their surface and interior contain many different molecules including lipids, nucleic acids, proteins, and carbohydrates. In this Letter, we show how distance-controlled surface-enhanced Raman spectroscopy (SERS) is a promising method to extract essential information from the spatial origin of the signal. This is a highly important parameter in the analysis of these biological particles. The principle of the method is demonstrated by using polystyrene (PS) beads as a biological particle model conjugated with gold nanospheres (AuNSs) functioning as distance-controlled SERS probes via biotin-streptavidin binding. By tuning the size of AuNSs, the Raman signal from the PS beads can be weakened while the signal from the biotin-streptavidin complex is enhanced.

ENHANCEMENT OF DISSOLUTION OF CANDESARTAN CILEXETIL

Objective: The main aim of our investigation was to enhance the dissolution of Candesartan Cilexetil (CC), a prodrug of Candesartan, used in the treatment of hypertension. CC bioavailability is dissolution rate limited. The drug was formulated using various excipients such as surfactants, and liquid lipids to improve solubility, dissolution, and hence bioavailability. Methods: The solubility of CC was determined at 25°C by shake flask method and those showing maximum solubility were selected for the formulation of CC. In vitro dissolution studies were done in different media in pH 6.8 phosphate buffer with 1% SLS, tween 20, and 0.1 N HCl with 1% SLS. The surface morphology of LBDDS was studied with scanning electron microscope (SEM) and the crystallinity of the drug and the formulation were studied using X-ray diffraction (XRD). Results: CC showed maximum solubility in transcutol and labrasol, which, hence, were selected as excipients for the formulation of CC capsules. Drug release was high in 0.1 N HCl with 1% SLS and, hence, was selected as the dissolution medium. The dissolution profile for formulation F5 containing the drug with transcutol and labrasol showed the highest drug release among all formulations, that is, 94.09%. The SEM of the F5 formulation showed that the drug was completely embedded into the lipid matrix and particles were spherical and porous with a size of around 25 μ. XRD of formulation F5 indicated the absence of crystallinity in CC capsules containing transcutol and labrasol. Conclusion: It was concluded that CC containing transcutol and labrasol significantly increases the solubility and dissolution of the drug.

Effect of Cholesterol on the Structure and Composition of Glyco-DIBMA Lipid Particles.

Different amphiphilic co-polymers have been introduced to produce polymer-lipid particles with nanodisc structure composed of an inner lipid bilayer and polymer chains self-assembled as an outer belt. These particles can be used to stabilize membrane proteins in solution and enable their characterization by means of biophysical methods, including small-angle X-ray scattering (SAXS). Some of these co-polymers have also been used to directly extract membrane proteins together with their associated lipids from native membranes. Styrene/maleic acid and diisobutylene/maleic acid are among the most commonly used co-polymers for producing polymer-lipid particles, named SMALPs and DIBMALPs, respectively. Recently, a new co-polymer, named Glyco-DIBMA, was produced by partial amidation of DIBMA with the amino sugar N-methyl-d-glucosamine. Polymer-lipid particles produced with Glyco-DIBMA, named Glyco-DIBMALPs, exhibit improved structural properties and stability compared to those of SMALPs and DIBMALPs while retaining the capability of directly extracting membrane proteins from native membranes. Here, we characterize the structure and lipid composition of Glyco-DIBMALPs produced with either 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). Glyco-DIBMALPs were also prepared with mixtures of either POPC or DMPC and cholesterol at different mole fractions. We estimated the lipid content in the Glyco-DIBMALPs and determined the particle structure and morphology by SAXS. We show that the Glyco-DIBMALPs are nanodisc-like particles whose size and shape depend on the polymer/lipid ratio. This is relevant for designing nanodisc particles with a tunable diameter according to the size of the membrane protein to be incorporated. We also report that the addition of >20 mol % cholesterol strongly perturbed the formation of Glyco-DIBMALPs. Altogether, we describe a detailed characterization of the Glyco-DIBMALPs, which provides relevant inputs for future application of these particles in the biophysical investigation of membrane proteins.

The development of highly dense highly protected surfactant ionizable lipid RNA loaded nanoparticles.

The long quest for efficient drug administration has been looking for a universal carrier that can precisely transport traditional drugs, new genomic and proteic therapeutic agents. Today, researchers have found conditions to overcome the two main drug delivery dilemmas. On the one side, the versatility of the vehicle to efficiently load, protect and transport the drug and then release it at the target place. On the other hand, the questions related to the degree of PEGylation which are needed to avoid nanoparticle (NP) aggregation and opsonization while preventing cellular uptake. The development of different kinds of lipidic drug delivery vehicles and particles has resulted in the development of ionizable lipid nanoparticles (iLNPs), which can overcome most of the typical drug delivery problems. Proof of their success is the late approval and massive administration as the prophylactic vaccine for SARS-CoV-2. These ILNPs are built by electrostatic aggregation of surfactants, the therapeutic agent, and lipids that self-segregate from an aqueous solution, forming nanoparticles stabilized with lipid polymers, such as PEG. These vehicles overcome previous limitations such as low loading and high toxicity, likely thanks to low charge at the working pH and reduced size, and their entry into the cells via endocytosis rather than membrane perforation or fusion, always associated with higher toxicity. We herein revise their primary features, synthetic methods to prepare and characterize them, pharmacokinetic (administration, distribution, metabolization and excretion) aspects, and biodistribution and fate. Owing to their advantages, iLNPs are potential drug delivery systems to improve the management of various diseases and widely available for clinical use.

One-pot synthesis of compact DNA silica particles for gene delivery and extraordinary DNA preservation

Repairing genetic defects using exogenous DNA is a major challenge the science is currently facing. This requires the design of vectors that can effectively encapsulate, protect and target nucleic acids to specific cells safely and precisely. Here we have designed silica-based physiologically responsive particles to encapsulate, store, and transfer DNA. Unlike existing vectors (e.g., viral or lipidic particles), these DNA@SiO2 systems are very stable at room temperature. We also demonstrate how they protect the encapsulated DNA from exposure to different biological and physicochemical stresses, including DNase, denaturation temperatures (>100 °C), or reactive oxygen species (ROS). Remarkably, upon cellular uptake, these vectors dissolve safely unpacking the DNA and transfecting the cells.The versatility of the design is such that it can encapsulate genes without gene/size restrictions, in single or multiple layers of silica, so different genes can be expressed sequentially. This allows the time-controlled transcription of several genes, mimicking viral gene expression cascades, or even “fine-tuning” gene expression in transfected cells on demand. In addition, the method is easily scalable, reproducible, and inexpensive, enabling large-scale production and batch-quality testing, all of which are important for the personalized therapeutics industry. The high stability of these DNA vectors allows for easy and low-cost transport from the point of production to virtually any destination, making them unique as gene delivery tools.