The Possible Role of Sex As an Important Factor in Development and Administration of Lipid Nanomedicine-Based COVID-19 Vaccine.

Nanomedicine has demonstrated a substantial role in vaccine development against severe acute respiratory syndrome coronavirus (SARS-CoV-2 and COVID-19). Although nanomedicine-based vaccines have now been validated in millions of individuals worldwide in phase 4 and tracking of sex-disaggregated data on COVID-19 is ongoing, immune responses that underlie COVID-19 disease outcomes have not been clarified yet. A full understanding of sex-role effects on the response to nanomedicine products is essential to building an effective and unbiased response to the pandemic. Here, we exposed model lipid nanoparticles (LNPs) to whole blood of 18 healthy donors (10 females and 8 males) and used flow cytometry to measure cellular uptake by circulating leukocytes. Our results demonstrated significant differences in the uptake of LNP between male and female natural killer (NK) cells. The results of this proof-of-concept study show the importance of recipient sex as a critical factor which enables researchers to better consider sex in the development and administration of vaccines for safer and more-efficient sex-specific outcomes.

Optimizing Transfection Efficiency in CAR-T Cell Manufacturing through Multiple Administrations of Lipid-Based Nanoparticles.

The existing manufacturing protocols for CAR-T cell therapies pose notable challenges, particularly in attaining a transient transfection that endures for a significant duration. To address this gap, this study aims to formulate a transfection protocol utilizing multiple lipid-based nanoparticles (LNPs) administrations to enhance transfection efficiency (TE) to clinically relevant levels. By systematically fine-tuning and optimizing our transfection protocol through a series of iterative refinements, we have accomplished a remarkable one-order-of-magnitude augmentation in TE within the immortalized T-lymphocyte Jurkat cell line. This enhancement has been consistently observed over 2 weeks, and importantly, it has been achieved without any detrimental impact on cell viability. In the subsequent phase of our study, we aimed to optimize the gene delivery system by evaluating three lipid-based formulations tailored for DNA encapsulation using our refined protocol. These formulations encompassed two LNPs constructed from ionizable lipids and featuring systematic variations in lipid composition (iLNPs) and a cationic lipoplex (cLNP). Our findings showcased a notable standout among the three formulations, with cLNP emerging as a frontrunner for further refinement and integration into the production pipeline of CAR-T therapies. Consequently, cLNP was scrutinized for its potential to deliver CAR-encoding plasmid DNA to the HEK-293 cell line. Confocal microscopy experiments demonstrated its efficiency, revealing substantial internalization compared to iLNPs. By employing a recently developed confocal image analysis method, we substantiated that cellular entry of cLNP predominantly occurs through macropinocytosis. This mechanism leads to heightened intracellular endosomal escape and mitigates lysosomal accumulation. The successful expression of anti-CD19-CD28-CD3z, a CAR engineered to target CD19, a protein often expressed on the surface of B cells, was confirmed using a fluorescence-based assay. Overall, our results indicated the effectiveness of cLNP in gene delivery and suggested the potential of multiple administration transfection as a practical approach for refining T-cell engineering protocols in CAR therapies. Future investigations may focus on refining outcomes by adjusting transfection parameters like nucleic acid concentration, lipid-to-DNA ratio, and incubation time to achieve improved TE and increased gene expression levels.

The protein corona reduces the anticancer effect of graphene oxide in HER-2-positive cancer cells.

In the last decade, graphene oxide (GO)-based nanomaterials have attracted much attention for their potential anti-cancer properties against various cancer cell types. However, while in vitro studies are promising, following in vivo investigations fail to show any relevant efficacy. Recent research has clarified that the wide gap between benchtop discoveries and clinical practice is due to our limited knowledge about the physical-chemical transformation of nanomaterials in vivo. In physiological environments, nanomaterials are quickly coated by a complex dress of biological molecules referred to as the protein corona. Mediating the interaction between the pristine material and the biological system the protein corona controls the mechanisms of action of nanomaterials up to the sub-cellular level. Here we investigate the anticancer ability of GO in SK-BR-3 human breast cancer cells over-expressing the human epidermal growth factor receptor 2 (HER-2), which is functionally implicated in the cell growth and proliferation through the activation of downstream pathways, including the PI3K/AKT/mTOR and MAPK/ERK signaling cascades. Western blot analysis demonstrated that GO treatment resulted in a marked decrease in total HER-2, associated with a down-regulation of the expression and activation of protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) thus indicating that GO may act as a potent HER-2 inhibitor. On the other side, the protein corona reverted the effects of GO on HER-2 expression and molecular downstream events to the control level. Our findings may suggest a mechanistic explanation of the reduced anticancer properties of GO-based nanomaterials in vivo. These results may also represent a good prediction strategy for the anticancer activity of nanomaterials designed for biomedical purposes, reaffirming the necessity of exploring their effectiveness under physiologically relevant conditions before moving on to the next in vivo studies.

In vitro and ex vivo nano-enabled immunomodulation by the protein corona.

New technologies with the capacity to tune immune system activity are highly desired in clinical practice and disease management. Here we demonstrate that nanoparticles with a protein corona enriched with gelsolin (GSN), an abundant plasma protein that acts as a modulator of immune responses, are avidly captured by human monocytic THP-1 cells in vitro and by leukocyte subpopulations derived from healthy donors ex vivo. In human monocytes, GSN modulates the production of tumor necrosis factor alpha (TNF-α) in an inverse dose-dependent manner. Overall, our results suggest that artificial coronas can be exploited to finely tune the immune response, opening new approaches for the prevention and treatment of diseases.

Opsonin-Deficient Nucleoproteic Corona Endows UnPEGylated Liposomes with Stealth Properties In Vivo.

For several decades, surface grafted polyethylene glycol (PEG) has been a go-to strategy for preserving the synthetic identity of liposomes in physiological milieu and preventing clearance by immune cells. However, the limited clinical translation of PEGylated liposomes is mainly due to the protein corona formation and the subsequent modification of liposomes' synthetic identity, which affects their interactions with immune cells and blood residency. Here we exploit the electric charge of DNA to generate unPEGylated liposome/DNA complexes that, upon exposure to human plasma, gets covered with an opsonin-deficient protein corona. The final product of the synthetic process is a biomimetic nanoparticle type covered by a proteonucleotidic corona, or "proteoDNAsome", which maintains its synthetic identity in vivo and is able to slip past the immune system more efficiently than PEGylated liposomes. Accumulation of proteoDNAsomes in the spleen and the liver was lower than that of PEGylated systems. Our work highlights the importance of generating stable biomolecular coronas in the development of stealth unPEGylated particles, thus providing a connection between the biological behavior of particles in vivo and their synthetic identity.

Efficient pancreatic cancer detection through personalized protein corona of gold nanoparticles.

Characterization of the personalized protein corona (PC) that forms around nanomaterials upon exposure to human plasma is emerging as powerful technology for early cancer detection. However, low material stability and interbatch variability have limited its clinical application so far. Here, we present a nanoparticle-enabled blood (NEB) test that uses 120 nm gold nanoparticles (NPs) as the accumulator of blood plasma proteins. In the test, the personalized PC of gold NPs is characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. As a paradigmatic case study, pancreatic ductal adenocarcinoma (PDAC) was chosen due to the lack of effective detection strategies that lead to poor survival rate after diagnosis (<1 year) and extremely low 5-years survival rate (15-20%). Densitometric analysis of 75 protein patterns (28 from healthy subjects and 47 from PDAC patients) allowed us to distinguish nononcological and PDAC patients with good sensitivity (78.6%) and specificity (85.3%). The gold NEB test is completely aligned to affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free, and deliverable to end users criteria stated by the World Health Organization for cancer screening and detection. Thus, it could be very useful in clinical practice at the first level of investigation to decide whether to carry out more invasive analyses or not.

Inhibiting the Growth of 3D Brain Cancer Models with Bio-Coronated Liposomal Temozolomide.

Nanoparticles (NPs) have emerged as an effective means to deliver anticancer drugs into the brain. Among various forms of NPs, liposomal temozolomide (TMZ) is the drug-of-choice for the treatment and management of brain tumours, but its therapeutic benefit is suboptimal. Although many possible reasons may account for the compromised therapeutic efficacy, the inefficient tumour penetration of liposomal TMZ can be a vital obstacle. Recently, the protein corona, i.e., the layer of plasma proteins that surround NPs after exposure to human plasma, has emerged as an endogenous trigger that mostly controls their anticancer efficacy. Exposition of particular biomolecules from the corona referred to as protein corona fingerprints (PCFs) may facilitate interactions with specific receptors of target cells, thus, promoting efficient internalization. In this work, we have synthesized a set of four TMZ-encapsulating nanomedicines made of four cationic liposome (CL) formulations with systematic changes in lipid composition and physical-chemical properties. We have demonstrated that precoating liposomal TMZ with a protein corona made of human plasma proteins can increase drug penetration in a 3D brain cancer model derived from U87 human glioblastoma multiforme cell line leading to marked inhibition of tumour growth. On the other side, by fine-tuning corona composition we have also provided experimental evidence of a non-unique effect of the corona on the tumour growth for all the complexes investigated, thus, clarifying that certain PCFs (i.e., APO-B and APO-E) enable favoured interactions with specific receptors of brain cancer cells. Reported results open new perspectives into the development of corona-coated liposomal drugs with enhanced tumour penetration and antitumour efficacy.

Optimal centrifugal isolating of liposome-protein complexes from human plasma.

In the past few years, characterization of the protein corona (PC) that forms around liposomal systems has gained increasing interest for the development of novel therapeutic and diagnostic technologies. At the crossroads of fast-moving research fields, the interdisciplinarity of protein corona investigations poses challenges for experimental design and reporting. Isolation of liposome-protein complexes from biological fluids has been identified as a fundamental step of the entire workflow of PC characterization but exact specifications for conditions to optimize pelleting remain elusive. In the present work, key factors affecting precipitation of liposome-protein complexes by centrifugation, including time of centrifugation, total sample volume, lipid : protein ratio and contamination from biological NPs were comprehensively evaluated. Here we show that the total amount of isolated liposome-protein complexes and the extent of contamination from biological NPs may vary with influence factors. Our results provide protein corona researchers with precise indications to separate liposome-protein complexes from protein-rich fluids and include proper controls, thus they are anticipated to catalyze improved consistency of data mining and computational modelling of protein corona composition.

Microfluidic Formulation of DNA-Loaded Multicomponent Lipid Nanoparticles for Gene Delivery.

In recent years, lipid nanoparticles (LNPs) have gained considerable attention in numerous research fields ranging from gene therapy to cancer immunotherapy and DNA vaccination. While some RNA-encapsulating LNP formulations passed clinical trials, DNA-loaded LNPs have been only marginally explored so far. To fulfil this gap, herein we investigated the effect of several factors influencing the microfluidic formulation and transfection behavior of DNA-loaded LNPs such as PEGylation, total flow rate (TFR), concentration and particle density at the cell surface. We show that PEGylation and post-synthesis sample concentration facilitated formulation of homogeneous and small size LNPs with high transfection efficiency and minor, if any, cytotoxicity on human Embryonic Kidney293 (HEK-293), spontaneously immortalized human keratinocytes (HaCaT), immortalized keratinocytes (N/TERT) generated from the transduction of human primary keratinocytes, and epidermoid cervical cancer (CaSki) cell lines. On the other side, increasing TFR had a detrimental effect both on the physicochemical properties and transfection properties of LNPs. Lastly, the effect of particle concentration at the cell surface on the transfection efficiency (TE) and cell viability was largely dependent on the cell line, suggesting that its case-by-case optimization would be necessary. Overall, we demonstrate that fine tuning formulation and microfluidic parameters is a vital step for the generation of highly efficient DNA-loaded LNPs.

A mechanistic explanation of the inhibitory role of the protein corona on liposomal gene expression.

The past three decades have witnessed fast advances in the use of cationic liposome-DNA complexes (lipoplexes) for gene delivery applications. However, no lipoplex formulation has reached into the clinical practice so far. The primary drawback limiting clinical use of lipoplexes is the lack of mechanistic understanding of their low transfection efficiency (TE) in vivo. In physiological environments, lipoplexes are coated by a protein corona (PC) that mediates the interactions with the cell machinery. Here we show that the formation of PC can change the interactions of multicomponent (MC) lipoplexes with our cell model (i.e., HeLa). At the highest lipoplex concentration, the formation of PC can reduce the TE of MC lipoplexes from 60% to <5%. Combining dynamic light scattering and synchrotron small-angle X-ray scattering (SAXS), we clarify that the formation of PC modifies physical-chemical properties of MC lipoplexes so as to affect their TE. Moreover, we examined single transfection barriers by a combination of fluorescence-activated cell sorting, single-cell real-time fluorescence confocal microscopy, and synchrotron SAXS. We demonstrate that PC formation has the ability to modify the relative contribution of caveolae-mediated endocytosis and macropinocytosis in lipoplexes uptake, in favor of the latter, increasing accumulation of PC-decorated lipoplexes into degradative lysosomal compartments. Finally, we report evidences that PC reduces the structural stability of lipoplexes against solubilization by cellular lipids, likely favoring premature DNA release and cytosolic digestion by DNAase. These combined effects revealed here offer a comprehensive mechanistic explanation on the reason behind reduction in gene expression of MC lipoplexes.

Author Correction: Interplay of protein corona and immune cells controls blood residency of liposomes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Effect of molecular crowding on the biological identity of liposomes: an overlooked factor at the bio-nano interface.

Once embedded in a physiological environment, the surface of nanoparticles (NPs) gets covered with a biomolecular corona (BC) that alters their synthetic characteristics and subsequently gives them a peculiar biological identity. Despite recent studies having clarified the role of NP composition, surface chemistry and biological source (e.g., human/animal serum or plasma) in the formation of the BC, little is known about the possible impact of molecular crowding. To fill this gap, we used a cationic liposomal formulation as a model system and studied its biological identity upon incubation with human plasma, at a fixed liposome-to-plasma volume ratio and different concentrations. We carried out dynamic light scattering measurements to quantify the size and zeta potential of the investigated systems and gel electrophoresis to evaluate the composition of the corresponding coronas. Our findings suggest that NP stability may be compromised by molecular crowding, but the corona composition is stable over a wide range of concentrations, which extend over more than two orders of magnitude. As the biological identity of NPs eventually determines their final fate in vivo, we predict that this study could contribute to the development of a safe and effective nanosystem for the targeted delivery of therapeutic agents.

The biomolecular corona of gold nanoparticles in a controlled microfluidic environment.

Nanoparticles (NPs) exposed to biological media are coated by proteins and other biomolecules forming a biomolecular corona (BC) on the particle surface. Recent studies have shown that shear stress as that created by laminar fluid flow generates more complex coronas with systematic changes in composition with respect to counterparts formed under static incubation. However, in most studies reported so far, dynamic environments have been produced by peristaltic pumps and comparing experimental results appears challenging. On the other side, generating shear stress by microfluidic devices could help to remove user variability and ensure better reproducibility of experimental data. This study was therefore aimed at exploring formation of NP-BC in a microfluidic environment. To this end, 100 nm gold nanoparticles and human plasma (HP) were used as models for nano-formulation and biological medium. We injected gold nanoparticles and HP in each of the islets of a remote-controlled microfluidic cartridge. Static incubation was used as a reference. BC-decorated NPs were thoroughly characterized by dynamic light scattering (DLS), micro-electrophoresis (ME), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) and nano-liquid chromatography tandem mass spectrometry (nano-LC MS/MS). By varying the incubation time from 30 s to 2.5 min we demonstrate that BC is already determined by the earliest exposure time point and does not appreciably evolve in time. DLS and ME results demonstrate that the BC formed in a microfluidic chip is thicker and more negatively charged than its counterpart formed under static incubation. SDS-PAGE and nano-LC MS/MS revealed that the incubation procedure had a major effect on BC composition. As an example, immunoglobulins are the most abundant plasma proteins of the BC generated in a microfluidic environment (relative protein abundance ∼30%), while tissue leakage proteins (relative protein abundance ∼26%) are the most enriched proteins when the BC is formed upon static incubation. Potential implications in emerging biomedical research arenas are discussed.

Converting the personalized biomolecular corona of graphene oxide nanoflakes into a high-throughput diagnostic test for early cancer detection.

Advances in nanotechnology are introducing the exciting possibility of cancer identification at early stages via analysis of the personalized biomolecular corona (BC), i.e. the dynamic "halo" of proteins that adsorbs onto NPs following exposure to patients' plasma. In this study, we develop a blood test for early cancer detection based on the characterization of the BC that forms around Graphene Oxide (GO) nanoflakes. Among its elective properties, GO binds low amounts of albumin, the most abundant protein in the blood and one of the most enriched proteins in the BC of many nanomaterials. This unique property of GO allows strong adsorption of poorly concentrated plasma proteins without abundant protein depletion. In our study, GO nanometric flakes have been used to analyze BCs from 50 subjects, half of them diagnosed with pancreatic cancer and half of them being healthy volunteers. Pancreatic cancer was chosen as the model of a high mortality disease with poor survival rates due to its delayed diagnosis. The receiver operating characteristic (ROC) curve analysis was applied to measure the diagnostic accuracy of the BC-based test. We obtained an area under the curve (AUC) of 0.96 and the test discriminated cancer patients from healthy subjects with a sensitivity of 92%. Finally, a double-blind validation was made using a second test dataset (10 healthy subjects + 10 pancreatic cancer patients) and it confirmed the results obtained on the first training dataset. Being highly accurate, fast, inexpensive and easy to perform, we believe that the BC-enabled blood test has the potential to become a turning point in early detection of cancer and other diseases.

Interplay of protein corona and immune cells controls blood residency of liposomes.

In vivo liposomes, like other types of nanoparticles, acquire a totally new 'biological identity' due to the formation of a biomolecular coating known as the protein corona that depends on and modifies the liposomes' synthetic identity. The liposome-protein corona is a dynamic interface that regulates the interaction of liposomes with the physiological environment. Here we show that the biological identity of liposomes is clearly linked to their sequestration from peripheral blood mononuclear cells (PBMCs) of healthy donors that ultimately leads to removal from the bloodstream. Pre-coating liposomes with an artificial corona made of human plasma proteins drastically reduces capture by circulating leukocytes in whole blood and may be an effective strategy to enable prolonged circulation in vivo. We conclude with a critical assessment of the key concepts of liposome technology that need to be reviewed for its definitive clinical translation.

Identification of a novel chalcone derivative that inhibits Notch signaling in T-cell acute lymphoblastic leukemia.

Notch signaling is considered a rational target in the therapy of several cancers, particularly those harbouring Notch gain of function mutations, including T-cell acute lymphoblastic leukemia (T-ALL). Although currently available Notch-blocking agents are showing anti-tumor activity in preclinical studies, they are not effective in all the patients and often cause severe side-effects, limiting their widespread therapeutic use. Here, by functional and biological analysis of the most representative molecules of an in house library of natural products, we have designed and synthetized the chalcone-derivative 8 possessing Notch inhibitory activity at low micro molar concentration in T-ALL cell lines. Structure-activity relationships were afforded for the chalcone scaffold. Short term treatments with compound 8 resulted in a dose-dependent decrease of Notch signaling activity, halted cell cycle progression and induced apoptosis, thus affecting leukemia cell growth. Taken together, our data indicate that 8 is a novel Notch inhibitor, candidate for further investigation and development as an additional therapeutic option against Notch-dependent cancers.