SLIPS-LAB—A bioinspired bioanalysis system for metabolic evaluation of urinary stone disease

Abstract

Urinary stone disease is among the most common medical conditions. Standard evaluation of urinary stone disease involves a metabolic workup of stone formers based on measurement of minerals and solutes excreted in 24-hour urine samples. Nevertheless, 24-hour urine testing is slow, expensive, and inconvenient for patients, which has hindered widespread adoption in clinical practice. Here, we demonstrate SLIPS-LAB (Slippery Liquid-Infused Porous Surface Laboratory), a droplet-based bioanalysis system, for rapid measurement of urinary stone–associated analytes. The ultra-repellent and antifouling properties of SLIPS, which is a biologically inspired surface technology, allow autonomous liquid handling and manipulation of physiological samples without complicated sample preparation procedures and supporting equipment. We pilot a study that examines key urinary analytes in clinical samples from patients with urinary stone. The simplicity and speed of SLIPS-LAB hold the potential to provide actionable diagnostic information for patients with urinary stone disease and rapid feedback for responses to dietary and pharmacologic treatments.

Microfluidic particle dam for direct visualization of SARS-CoV-2 antibody levels in COVID-19 vaccinees

“…Second, the inner surface of the PDMS loading chamber was coated with hydroxy-terminated PDMS as a lubricant. This coating, called the SLIP-LAB (Slippery Liquid-Infused Porous Surface Laboratory) concept, prepares the microchannel with excellent repellence to particle stiction ( 52 ). With this modification, the microfluidic device consists of PDMS as the bottom layer and NOA 63 as the top layer (fig.…”

“…S4), peeled off, cut, and immersed in a hydroxy-terminated PDMS bath (viscosity: 25 cSt; Sigma-Aldrich, 481939) at 55°C overnight before drying it using an air gun (step 3 in fig. S4) ( 52 ). The NOA 63 bottom layer fabrication was based on traditional soft lithography, as previously mentioned ( 44 ).…”

Recent advances in slippery liquid-infused surfaces with unique properties inspired by nature

“…2c). More recently, inspired by the Nepenthes pitcher plant, a hydrophobic surface with an ultralow sliding angle was prepared [23,43] which can be used in medical equipment [17], microfluid delivery, and corrosion prevention in the marine industry [44,45] (see Fig. 2d).…”

“…Because of their excellent toughness properties and easy adjustment to different shapes and sizes, porous polymers are very popular for preparing slippery liquid-infused porous surfaces. Currently reported are polyvinyl chloride, polycarbonate, polytetrafluoroethylene (PTFE) [79], poly(methyl methacrylate), PDMS [17,80], and polystyrene (PS), among others. The first liquid-infused porous surface designed by Aizenberg et al tried to use periodically ordered and random arrays of nanoposts functionalized with a low-surface energy polyfluoroalkyl silane and a random network of Teflon nanofibers as the substrate.…”

“…In recent decades, a large number of studies have been conducted on superhydrophobic surfaces. Bionic surfaces with special wettability have gradually penetrated into all aspects of our lives, including antifouling for hygiene and sanitation [4][5][6][7][8][9][10], antiice and anticorrosion in the transportation industry [11][12][13][14][15][16], anti-thrombosis and bacterial adhesion in the medical field [17][18][19][20][21][22]. In the process of continuous exploration, more and more deficiencies have gradually been exposed.…”