A sound approach for ova denudation.

Objective: To introduce an innovative non-contact method for denudation process of cumulus-oocyte complexes (COCs) for intracytoplasmic sperm injection (ICSI).

Design: We designed and fabricated novel acousto-hydrodynamic tweezers (AHT) to perform contactless denudation and tested them in mouse model. Cumulus removal efficiency, preimplantation development and live birth were assessed and compared to conventional manual pipetting denudation.

Faster sperm selected by rheotaxis leads to superior early embryonic development .

To understand the impact of sperm speed as they swim against the flow on fertilization rates, we created conditions similar to the female reproductive tract (FRT) on a microfluidic platform for sperm selection. Selected sperm were evaluated based on early development of fertilized embryos. Bovine and human spermatozoa were selected at various fluid flow rates within the device.

Screening the Degradation of Polymer Microparticles on a Chip.

Enzymatic degradation of polymers has advantages over standard degradation methods, such as soil burial and weathering, which are time-consuming and cannot provide time-resolved observations. We have developed a microfluidic device to study the degradation of single microparticles. The enzymatic degradation of poly (1,4-butylene adipate--terephthalate) (PBAT) microparticles was studied using Novozym 51032 cutinase.

Rheotaxis quality index: a new parameter that reveals male mammalian fertility and low sperm DNA fragmentation.

The female reproductive tract simultaneously guides and selects high-quality sperm using rheotaxis in mammalian species. Sperm quality, however, is traditionally evaluated only by their movement velocities and concentration using computer-assisted sperm analysis (CASA), which ignores sperm rheotaxis. Here, by mimicking the female reproductive tracts' dimensions and hydrodynamic features, a new method is introduced to quantify sperm rheotaxis ability for evaluating semen quality.

Non-contact ultrasound oocyte denudation.

Cumulus removal (CR) is a central prerequisite step for many protocols involved in the assisted reproductive technology (ART) such as intracytoplasmic sperm injection (ICSI) and preimplantation genetic testing (PGT). The most prevalent CR technique is based upon laborious manual pipetting, which suffers from inter-operator variability and therefore a lack of standardization. Automating CR procedures would alleviate many of these challenges, improving the odds of a successful ART or PGT outcome.

Rolling controls sperm navigation in response to the dynamic rheological properties of the environment.

Mammalian sperm rolling around their longitudinal axes is a long-observed component of motility, but its function in the fertilization process, and more specifically in sperm migration within the female reproductive tract, remains elusive. While investigating bovine sperm motion under simple shear flow and in a quiescent microfluidic reservoir and developing theoretical and computational models, we found that rolling regulates sperm navigation in response to the rheological properties of the sperm environment. In other words, rolling enables a sperm to swim progressively even if the flagellum beats asymmetrically.

Progressive bovine sperm separation using parallelized microchamber-based microfluidics.

Motility is one of the most important factors in sperm migration toward an egg. Therefore, sperm separation based on motility might enhance sperm selection for infertility treatments. Conventional centrifugation-based methods increase the risk of damage to sperm cells.

Biological small-molecule assays using gradient-based microfluidics.

Studying the potency of small-molecules on eukaryotic and prokaryotic cells using conventional biological settings requires time-consuming procedures and large volumes of expensive small-molecules. Microfluidics could significantly expedite these assays by enabling operation in high-throughput and (semi)automated modes. Here, we introduce a microfluidics platform based on multi-volume microchamber arrays that can produce a wide range of small-molecule concentrations with a desired gradient-based profile for rapid and precise biological testing within a single device with minimal hands-on time.

Theoretical study of the photothermal behaviour of self-assembled magnetic-plasmonic chain structures.

We study the field-directed self-assembly and photothermal behavior of one-dimensional (1D) chains of core-shell FeO@Au magnetic-plasmonic nanoparticles. Monte Carlo analysis is used to predict the self-assembly of the nanoparticles when they are subjected to a uniform magnetic field and confined to a fluidic nanochannel. A coupled photonic and thermodynamic analysis is performed to analyze the optical and photothermal properties of the 1D chain structures.