Isolation and Characterization of Extracellular Vesicles Through Orthogonal Approaches for the Development of Intraocular EV Therapy.

Purpose: Isolating extracellular vesicles (EVs) with high yield, replicable purity, and characterization remains a bottleneck in the development of EV therapeutics. To address these challenges, the current study aims to establish the necessary framework for preclinical and clinical studies in the development of stem cell-derived intraocular EV therapeutics. Methods: Small EVs (sEVs) were separated from the conditioned cell culture medium (CCM) of the human embryogenic stem cell-derived fully polarized retinal pigment epithelium (hESC-RPE-sEV) by a commercially available microfluidic tangential flow filtration (TFF) device ExoDisc (ED) or differential ultracentrifugation (dUC). The scaling and concentration capabilities and purity of recovered sEVs were assessed. Size, number, and surface markers of sEVs were determined by orthogonal approaches using multiple devices. Results: ED yielded higher numbers of sEVs, ranging from three to eight times higher depending on the measurement device, compared to dUC using the same 5 mL of CCM input. Within the same setting, the purity of ED-recovered hESC-RPE-sEVs was higher than that for dUC-recovered sEVs. ED yielded a higher concentration of particles, which is strongly correlated with the input volume, up to 10 mL (r = 0.98, P = 0.016). Meanwhile, comprehensive characterization profiles of EV surface markers between ED- and dUC-recovered hESC-RPE-sEVs were compatible. Conclusions: Our study supports TFF as a valuable strategy for separating sEVs for the development of intraocular EV therapeutics. However, there is a growing need for diverse devices to optimize TFF for use in EV preparation. Using orthogonal approaches in EV characterization remains ideal for reliably characterizing heterogeneous EV.

Antenatal care is associated with adherence to iron supplementation among pregnant women in selected low-middle-income-countries of Asia, Africa, and Latin America & the Caribbean regions: Insights from Demographic and Health Surveys.

Anaemia is a global public health problem affecting 800 million women and children globally. Anaemia is associated with perinatal mortality, child morbidity and mortality, mental development, immune competence, susceptibility to lead poisoning and performance at work. The objective of this article is to identify whether antenatal care-seeking was associated with the uptake of iron supplementation among pregnant women, adjusting for a range of covariates. This article used data from the cross-sectional recent Demographic and Health Surveys (DHS) of 12 countries in Asia, Africa and Latin America & the Caribbean regions. The individual-level data from 273,144 women of reproductive age (15-49 years) were analysed from multi-country DHS. Multiple Logistic regression analyses were conducted using Predictive Analytics Software for Windows (PASW), Release 18.0. Receiving at least four antenatal care visits was significantly associated with the consumption of 90 or more iron-containing supplements in 12 low and middle income countries across three regions after adjusting for different household and respondent characteristics, while mass media exposure was found to be a significant predictor in India and Indonesia. Antenatal care seems to be the most important predictor of adherence to iron intake in the selected countries across Africa, Asia, Latin America and Caribbean regions.