microRNA-27a is a promising candidate for miRNA mimic therapy to combat obesity, but its clinical application is hindered by enzymatic degradation and low membrane permeability. To address these challenges, we developed cationic nanostructured lipid carriers (cNLCs) via high-pressure homogenization as non-viral carriers for miRNA-27a. However, the formation of a protein corona in biologically-relevant media altered the particle size and surface charge, significantly reducing cellular uptake. To mitigate this issue, we hypothesized that coating miRNA/cNLC complexes with human serum albumin (HSA) will prevent protein corona formation and enhance cellular uptake. The HSA-coated miRNA/cNLC complexes, termed albuplexes, were characterized for particle size, zeta potential, morphology, and stability in various media. The integrity of the HSA coat was assessed using circular dichroism and UV/Vis spectroscopy. We also evaluated the biocompatibility and cellular uptake of albuplexes in 3T3-L1 cells. The biological effects of miRNA-27a on adipocyte development were analyzed through light microscopy and absorbance measurements of Oil-red-O dye in lipid droplets. Results indicated that albuplexes possess favourable physicochemical properties and enhanced stability in serum. Notably, albuplexes were rapidly taken up by 3T3-L cells via endocytosis, although 20 % HSA in the culture medium completely inhibited uptake. Furthermore, albuplexes exhibited an anti-adipogenic effect by reducing the lipid droplet accumulation, suggesting their potential as a therapeutic strategy for miRNA replacement in obesity treatment.

Cationic nanostructured lipid carriers (cNLCs) represent promising non-viral carriers for nucleic acids, such as miRNAs, forming stable self-assembled miRNA complexes due to electrostatic interactions. Prepared by high-pressure homogenization, cNLC formulations, both with and without Nile Red dye demonstrated stable particle sizes in the range of 100-120 nm and positive surface charges (> 30 mV), which are necessary for effective cellular uptake. The miRNA complexes formed at mass ratios of 1:2.5 and 1:5 showed similar stability and size, with positive zeta potentials, as well as high cell viability (> 80%) in 3T3-L1 and MCF-7 cell lines. The cellular uptake studies of miRNA:cNLC complexes in both cell lines revealed that uptake was time- and concentration-dependent, with rapid initial uptake in 30 minutes and a zig-zag pattern over 24 hours. To elucidate the endocytosis mechanism of miRNA:cNLC complexes, 3T3-L1 and MCF-7 cells were incubated with different inhibitors (chlorpromazine, 5-[N-ethyl-N-isopropyl] amiloride, dynasore, nystatin, or sodium azide with 2-deoxy-D-glucose). Results showed significant inhibition of uptake at low temperatures and with ATP depletion, suggesting endocytosis, particularly macropinocytosis, as the main uptake mechanism in 3T3-L1 cells. In MCF-7 cells, the uptake was less inhibited by the substances, indicating the need for more specific methods to fully decipher the endocytic mechanisms involved. Confocal laser scanning microscopy images revealed that the complexes are internalized in vesicles, and are primarily localized in the juxtanuclear region, suggesting trafficking through the endolysosomal system. Colocalization study with LysoTracker™ Green DND-26 showed significant colocalization of miRNA:cNLC complexes with lysosomes in 3T3-L1 cells, indicating trafficking through the endolysosomal system. In MCF-7 cells, colocalization was lower, suggesting macropinocytosis as the primary uptake mechanism. Additional studies showed partial colocalization between labeled NLCs and miRNA, indicating that about 50% of miRNA is released from NLCs within 30 minutes post-transfection.

Paediatric and geriatric populations, as well as other special patient populations with swallowing problems, require patient-tai-lored dosage forms. One promising dosage form for these specific populations is orodispersible films. When preparing orodispersible films using sodium carboxymethyl cellulose as the film-forming polymer and glycerine as the plasticizer, it is essential to determine the optimal mixing time and mixing speed of the casting solution to achieve the desired transparency/opacity of the orodispersible films. In this paper, the primary focus is on mixing time and mixing speed, and determining how these two parameters can influence optical characteristics. All tested parameters are supported by FTIR anal - ysis. The obtained results show that either a mixing speed of 7000 rpm on a high-shear mixer for 15 min or a mixing speed of 9000 rpm for 5 min can produce films with optimal optical characteristics.

MicroRNAs (miRNAs) are important regulators of gene expression in cells. However, their application in gene therapy is limited by obstacles such as poor cellular uptake and instability (Mendonça et al., 2023). To overcome these limitations, cationic nanostructured lipid carriers (cNLCs) as delivery systems for miRNAs are developed. cNLCs protect and stabilize miRNAs, and also enhance cellular uptake, which results in effective nucleic acid-based therapy. Another approach, found in literature, to enhance cellular uptake is coating particles with human serum albumin (HSA) (Liu et al., 2012). Therefore, the effect of functionalization of miRNA-cNLC complexes with HSA was investigated. The physicochemical properties of uncoated and HSA-coated complexes were compared in terms of particle size, size distribution, surface charge, topography, and cellular uptake in 3T3-L1 mouse embryonic fibroblasts and MCF-7 human breast cancer cells.

Nowadays, nucleic acids are gaining much attention as leading therapeutics. MicroRNAs (miRNAs) are one part of this family of promising tools that can be used in the treatment of numerous diseases. However, the application of miRNAs is limited due to their poor stability and limited cellular uptake. Here, we developed cationic nanostructured lipid carriers (cNLCs) as delivery agents for miRNA. Furthermore, we used human serum album (HSA) as a coat for the cNLCs, to see how it will influence the uptake. These nanoparticles showed favorable physicochemical properties to be used as drug delivery systems, as they successfully complexed miRNA. Therefore, our next goal is to study and understand their cellular uptake. For this purpose, we traced the uptake of the miRNA/cNLCs in two different cell lines (3T3-L1 and MCF-7 cells) under varying experimental conditions.

Although solid oral dosage forms present majority of commonly prescribed drugs, some patients struggle with ingesting them (Awad et al., 2021). Amongst those, a very significant group is the pediatric population. On the other side, questions concerning dosage consistency arise when it comes to liquid oral preparations, particularly for suspensions (Gupta et al., 2021). To avoid the limitations of conventional oral dosage forms, orodispersible films (ODFs) were developed as a promising, patient-tailored therapeutic alternative. After the administration, ODFs are swallowed naturally with saliva, and there is no need for additional water (Yadav et al., 2021). Furthermore, in terms of the pediatric population, the product not only has to be easy to swallow, but it also has to be visually appealing. Therefore, a lot of attention is dedicated to the visual appearance of ODFs, including their color and transparency or opacity (Zamanian et al., 2021). One of the methods used to produce ODFs is the solvent casting of polymer solution/dispersion. The aim of our study was to determine whether high shear mixer heads have an influence on the optical characteristics and disintegration time of the obtained ODFs.

Although miRNA-27a has been identified as a promising candidate for miRNA mimic therapy of obesity, its application is limited due to enzymatic degradation and low membrane permeation. To overcome these problems, we developed cationic nanostructured lipid carriers (cNLCs) using high-pressure homogenization and used them as non-viral carriers for the anti-adipogenic miRNA-27a. Cargo-free octadecylamine-containing NLCs and miRNA/cNLC complexes were characterized regarding particle size, size distributions, zeta potential, pH values, particle topography and morphology, and entrapment efficacy. Furthermore, the cytotoxicity and cellular uptake of the miRNA/cNLC complex in the 3T3-L1 cell line were investigated. The investigation of the biological effect of miRNA-27a on adipocyte development and an estimation of the accumulated Oil-Red-O (ORO) dye in lipid droplets in mature adipocytes were assessed with light microscopy and absorbance measurements. The obtained data show that cNLCs represent a suitable DDS for miRNAs, as miRNA/cNLC particles are rapidly formed through non-covalent complexation due to electrostatic interactions between both components. The miRNA-27a/cNLC complex induced an anti-adipogenic effect on miRNA-27a by reducing lipid droplet accumulation in mature adipocytes, indicating that this approach might be used as a new therapeutic strategy for miRNA mimic replacement therapies in the prevention or treatment of obesity and obesity-related disorders.