Urine congophilia associated with preeclampsia does not persist 6-months postpartum.

INTRODUCTION: Preeclampsia is a common hypertensive disorder of pregnancy. Several studies have demonstrated that protein aggregates, detected through urine congophilia, is associated with preeclampsia; however, it has yet to be investigated whether urine congophilia remains postpartum in these women. In this study, we aimed to augment prior studies and determine whether urine congophilia is present postpartum. METHODS: Women were recruited from Lyell McEwin Hospital, South Australia. Urine samples were collected during pregnancy and 6-months postpartum from women with non-preeclampsia pregnancies (n = 48) and women with pregnancies complicated by preeclampsia (n = 42). A Congo Red Dot blot test, total protein and creatinine levels from urine, as well as serum Soluble fms-like tyrosine kinase 1 to placental growth factor ratio (sFlt-1:PlGF), were assessed and correlated. RESULTS: Preeclamptic women exhibited increased urine congophilia (P < 0.01), sFlt-1:PlGF ratio (P < 0.0001) and total protein (P < 0.01) during pregnancy; with a positive correlation between urine congophilia and total protein across the entire cohort (P < 0.0001). Although urine congophilia was no longer detected 6-months postpartum in preeclamptic women, total protein remained elevated (P < 0.05). sFlt-1:PlGF ratio during pregnancy was positively correlated with congophilia across the cohort (P = 0.0007). Serum creatinine was also higher in preeclamptic women during pregnancy (P < 0.001). DISCUSSION: These results support that urine congophilia is significantly elevated in pregnancies complicated with preeclampsia and show that it does not continue postpartum, although larger cohort studies are needed to determine its feasibility as a diagnostic marker.

Investigating surface binding effects: antibacterial efficacy of bound 8-hydroxyquinoline against Staphylococcus aureus and Escherichia coli.

AIMS: To investigate the binding of the antimicrobial compound 8-hydroxyquinoline (8HQ) to a material interface and to determine whether immobilization affects the antibacterial efficacy. METHODS AND RESULTS: The 8HQ derivative 5-carboxy-8-hydroxyquinoline (5C8HQ) was attached to silica beads through amide bond coupling at the carboxyl moiety of 5C8HQ. Attachment of 5C8HQ was confirmed using a combination of mass spectrometry, thermogravimetric analysis, colorimetric testing and Soxhlet extraction. Computational modelling results indicated that this substitution did not compromise the active sites on the molecule, whereas other positions on the ring system could potentially inhibit antimicrobial activity. The antibacterial effect of 8HQ and the 5C8HQ-modified silica complex against Escherichia coli 15597 (ATCC® 25922) and Staphylococcus aureus (ATCC 25923) was evaluated. CONCLUSIONS: The test results show that the immobilized 8HQ continues to exhibit antibacterial activity, however, quantifying the efficacy compared to free 8HQ bears further investigation. The expected antibacterial mechanism requires that the metal chelation site of 8HQ be retained and available after attachment to a surface. The retention of antibacterial activity after surface bonding represents a novel mechanism of action not previously reported. SIGNIFICANCE AND IMPACT OF THE STUDY: Recent changes in regulations due to environmental concerns prompted many companies and organizations to explore antimicrobial treatments that are chemically bound to the product. Chemically bonding biocidal compounds to a surface limits environmental release; however, molecular mechanisms that drive antibacterial activity when compounds are immobilized are limited. The results reported here demonstrate that the 8HQ reactive site retains antibacterial efficacy even after covalent attachment to a surface. This approach supersedes other antimicrobial treatments where the active component is gradually released from the material surface in order to elicit antimicrobial effects. This specific antibacterial activity of bound 8HQ represents a novel mechanism of action not previously reported, and a potential conduit to a new class of bound antimicrobial materials.

Biological active matter aggregates: Inspiration for smart colloidal materials.

Aggregations of social organisms exhibit a remarkable range of properties and functionalities. Multiple examples, such as fire ants or slime mold, show how a population of individuals is able to overcome an existential threat by gathering into a solid-like aggregate with emergent functionality. Surprisingly, these aggregates are driven by simple rules, and their mechanisms show great parallelism among species. At the same time, great effort has been made by the scientific community to develop active colloidal materials, such as microbubbles or Janus particles, which exhibit similar behaviors. However, a direct connection between these two realms is still not evident, and it would greatly benefit future studies. In this review, we first discuss the current understanding of living aggregates, point out the mechanisms in their formation and explore the vast range of emergent properties. Second, we review the current knowledge in aggregated colloidal systems, the methods used to achieve the aggregations and their potential functionalities. Based on this knowledge, we finally identify a set of over-arching principles commonly found in biological aggregations, and further suggest potential future directions for the creation of bio-inspired colloid aggregations.