Endothelial cells represent the first biological barrier for compounds, including nanoparticles, administered via the intravascular route. In the case of ischemic stroke and other vascular diseases, the endothelium overexpresses specific markers, which can be used as molecular targets to facilitate drug delivery and imaging. However, targeting these markers can be quite challenging due to the presence of blood flow and the associated hydrodynamic forces, reducing the likelihood of adhesion to the vessel wall. To overcome these challenges, various parameters including size, shape, charge or ligand coating have been explored to increase the targeting efficiency. Geometric shape can modulate nanoparticle binding to the cell, especially by counteracting part of the hydrodynamic forces of the bloodstream encountered by the classical spherical shape. In this study, the binding affinity of polystyrene nanoparticles with two different shapes, spherical and rod-shaped, were compared. First, vascular adhesion molecule-1 (VCAM-1) was evaluated as a vascular target of inflammation, induced by lipopolysaccharide (LPS) stimulation. To evaluate the effect of nanoparticle shape on particle adhesion, nanoparticles were coated with anti-VCAM-1 and tested under static conditions in cell culture dishes coated with cerebral microvasculature cells (bEnd.3) and under dynamic flow conditions in microfluidic channels lined with hCMEC/D3 cells. Effect of particle shape on accumulation was also assessed in two in vivo models including systemic inflammation and local brain inflammation. The elongated rod-shaped particles demonstrated greater binding ability in vitro, reaching a 2.5-fold increase in the accumulation for static cultures and 1.5-fold for flow conditions. Anti-VCAM-1 coated rods exhibited a 3.5-fold increase in the brain accumulation compared to control rods. These results suggest shape offers a useful parameter in future design of drug delivery nanosystems or contrast agents for neurovascular pathologies.

Purpose: To elucidate dysregulated proteins in keratoconus (KC) to provide a better understanding of the molecular mechanisms that lead to the development of the disease using sequential window acquisition of all theoretical mass spectra (SWATH-MS) as a protein quantification tool of the tear proteomic profile. Methods: Prospective cross-sectional study that includes 25 keratoconic eyes and 25 healthy eyes. All participants underwent a clinical, tomographic, and aberrometric exam. Tear sample was collected using Schirmer strips and analyzed by liquid chromatography with tandem mass spectrometry. SWATH-MS was used as a quantification tool of the tear proteomic profile. The expression of the quantified proteins was compared between groups, and the biological and molecular functions of the dysregulated proteins as well as their functional relationships were studied by in silico analysis. Results: A total of 203 proteins were quantified in tear samples of patients with KC and control participants, of which 18 showed differential expression between groups (P < 0.05). An increase in the expression of 7 proteins and a decrease in the expression of 11 proteins were observed. Protein–protein interactions and gene ontology analysis showed the involvement of these dysregulated proteins in structural, inflammatory-immune, iron homeostasis, oxidative stress, and extracellular matrix proteolysis processes. Conclusions: Tear protein quantification has revealed the dysregulation of proteins involved in biological processes previously associated with KC. Among them, iron homeostasis should be highlighted as a relevant pathway in the KC pathophysiology, and it should be taken into account in the development of therapeutic targets to cope with tissue damage derived from iron accumulation and toxicity.

Background: Recent preclinical studies have shown that regulatory T cells (Treg) play a key role in the immune response after ischemic stroke (IS). However, the role of Treg in human acute IS has been poorly investigated. Our aim was to study the relationship between circulating Treg and outcome in human IS patients.Methods: A total of 204 IS patients and 22 control subjects were recruited. The main study variable was good functional outcome at 3 months (modified Rankin scale ≤2) considering infarct volume, Early Neurological Deterioration (END) and risk of infections as secondary variables. The percentage of circulating Treg was measured at admission, 48, 72 h and at day 7 after stroke onset.Results: Circulating Treg levels were higher in IS patients compared to control subjects. Treg at 48 h were independently associated with good functional outcome (OR, 3.5; CI: 1.9–7.8) after adjusting by confounding factors. Patients with lower Treg at 48 h showed higher frequency of END and risk of infections. In addition, a negative correlation was found between circulating Treg at 48 h (r = − 0.414) and 72 h (r = − 0.418) and infarct volume.Conclusions: These findings suggest that Treg may participate in the recovery of IS patients. Therefore, Treg may be considered a potential therapeutic target in acute ischemic stroke.