Solid lipid nanoparticles release DNA upon endosomal acidification in human embryonic kidney cells

Abstract

Nanotechnology can produce materials with unique features compared to their bulk counterparts, which can be useful for medical applications (i.e. nanomedicine). Among the therapeutic agents used in nanomedicine, small molecules or biomacromolecules, such as proteins or genetic materials, can be designed for disease diagnostics and treatment. To transport these biomacromolecules to the target cells, nanomedicine requires nanocarriers. Solid lipid nanoparticles (SLNs) are among the promising nanocarriers available, because they can be made from biocompatible materials and present high stability (over one year). In addition, upon the binding genetic material, SLNs form SLNplexes. However, little is yet known about how cells process these SLNplexes-in particular, how internalization and endosome acidification affects the transfection mediated by SLNplexes. Therefore, we aim to investigate how these processes affect SLNplex transfection in HEK293T cells. We find that the SLNplex is mainly internalized by clathrin-mediated endocytosis, which is a fast and reliable pathway to transfection, leading to approximately 60% transfection efficiency. Interestingly, upon acidification (below pH 5.0), the SLN seems to release its DNA content, which can be an essential step for SLNplex transfection. The underlying mechanisms described in this work may help improve SLNplex formulations and transfection efficiency. Moreover, these advances can improve the field of nanomedical research and bring new ways to cure diseases.

Nutlin-Loaded Magnetic Solid Lipid Nanoparticles for Targeted Glioblastoma Treatment

“…Nanoparticles are in fact able to bypass drug efflux pumps expressed on human cancer cells, thus increasing intracellular drug concentration [69]. Our particles showed to be highly internalized by cancer cells in correspondence of acidic subcellular compartment, and as widely described in the literature the exposure of lipid nanoparticles to an acidic environment could lead to a disruption of the lipid matrix with a consequent release of compounds encapsulated within [70].…”

The oralome and its dysbiosis: New insights into oral microbiome-host interactions

“…Nanoparticles are colloidal particles made out of a variety of materials, such as lipids, metals, and polymers, that have sizes between 1 and 1000 nm [321] , [322] . At this size range, these nanoparticles possess unique features compared with their bulkier counterparts – they can offer a high surface area, increased reactivity, reduction in thermal resistivity, intracellular delivery of therapeutics depending on the particle shape, size, surface area and charge, and release of high levels of ions at low incorporated amounts, distinguishing them from their bulkier size and micro-sized materials [16] , [321] , [322] .…”

“…Nanoparticles are colloidal particles made out of a variety of materials, such as lipids, metals, and polymers, that have sizes between 1 and 1000 nm [321] , [322] . At this size range, these nanoparticles possess unique features compared with their bulkier counterparts – they can offer a high surface area, increased reactivity, reduction in thermal resistivity, intracellular delivery of therapeutics depending on the particle shape, size, surface area and charge, and release of high levels of ions at low incorporated amounts, distinguishing them from their bulkier size and micro-sized materials [16] , [321] , [322] . Indeed, an inverse relationship has been demonstrated between the size of the metallic nanoparticles and their antimicrobial activity; particles in the size range of 1–10 nm have the greatest biocidal activity against bacteria [323] , [324] , with silver nanoparticles, ranging from 5 − 40 nm being able to inactivate most microorganisms, including HIV-1 [325] .…”

<p>Endocytosis and Organelle Targeting of Nanomedicines in Cancer Therapy</p>

“…95 Charge of nanoparticles may also affect endocytosis pathway. NMs with positive surface charge were reported to prefer CME for cellular uptake, 31 such as DOTAP based liposome for gene delivery, 37 cationic silica-based nanomaterials (SNTs) 38 and cationic chitosan NMs, 39 while negatively charged NMs were more likely to utilize caveolae-mediated endocytosis, with one typical example as Doxil. 25 For the effect of cell types, PLGA based nanoparticle employed different endocytosis pathways to enter three different kinds of hepatoma cells.…”

“…NMs with positive surface charge are reported to enter cells with relatively higher efficiency due to negative charges on the cell surface and prefer CME for cellular uptake. 31,36 Cationic liposomes based on 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) for gene delivery, 37 cationic silica-based nanomaterials (SNTs), 38 cationic chitosan NMs 39 are shown to utilize CME for cellular entry. What's more, surface modification with cationic polymer is explored to design positively charged NMs that employ CME.…”