Study of the surface morphology of a cholesteryl tethering system for lipidic bilayers

The immobilization of functional molecules embedded in lipidic membranes onto inorganic substrates is of great interest for numerous applications in the fields of biosensors and biomaterials. We report on the preparation and the morphological characterization of a tethering system for lipidic bilayers, which is based on cholesteryl derivatives deposited on hydrophilic surfaces by self-assembling and microcontact printing techniques. The investigation of the structural properties of the realized films by atomic, lateral, and surface potential microscopy allowed us to assess the high quality of the realized cholesteryl layers.     

A Bioartificial Renal Tubule Device Embedding Human Renal Stem/Progenitor Cells

We present a bio-inspired renal microdevice that resembles the in vivo structure of a kidney proximal tubule. For the first time, a population of tubular adult renal stem/progenitor cells (ARPCs) was embedded into a microsystem to create a bioengineered renal tubule. These cells have both multipotent differentiation abilities and an extraordinary capacity for injured renal cell regeneration. Therefore, ARPCs may be considered a promising tool for promoting regenerative processes in the kidney to treat acute and chronic renal injury. Here ARPCs were grown to confluence and exposed to a laminar fluid shear stress into the chip, in order to induce a functional cell polarization. Exposing ARPCs to fluid shear stress in the chip led the aquaporin-2 transporter to localize at their apical region and the Na⁺K⁺ATPase pump at their basolateral portion, in contrast to statically cultured ARPCs. A recovery of urea and creatinine of (20±5)% and (13±5)%, respectively, was obtained by the device. The microengineered biochip here-proposed might be an innovative “lab-on-a-chip” platform to investigate in vitro ARPCs behaviour or to test drugs for therapeutic and toxicological responses.     

Widespread allele-specific topological domains in the human genome are not confined to imprinted gene clusters

Neural networks such as variational autoencoders (VAE) perform dimensionality reduction for the visualization and analysis of genomic data, but are limited in their interpretability: it is unknown which data features are represented by each embedding dimension. We present siVAE, a VAE that is interpretable by design, thereby enhancing downstream analysis tasks. Through interpretation, siVAE also identifies gene modules and hubs without explicit gene network inference. We use siVAE to identify gene modules whose connectivity is associated with diverse phenotypes such as iPSC neuronal differentiation efficiency and dementia, showcasing the wide applicability of interpretable generative models for genomic data analysis.

     

Study of the surface morphology of a cholesteryl tethering system for lipidic bilayers

The immobilization of functional molecules embedded in lipidic membranes onto inorganic substrates is of great interest for numerous applications in the fields of biosensors and biomaterials. We report on the preparation and the morphological characterization of a tethering system for lipidic bilayers, which is based on cholesteryl derivatives deposited on hydrophilic surfaces by self-assembling and microcontact printing techniques. The investigation of the structural properties of the realized films by atomic, lateral, and surface potential microscopy allowed us to assess the high quality of the realized cholesteryl layers.     

Rapid nested-PCR for tyrosinase gene detection on chip

The availability of non-invasive, fast and sensitive technologies for detection of circulating cancer cells is still a critical need of clinical oncology, particularly for diagnosis of aggressive and highly metastatic tumors, like malignant melanoma. Here we present the first nested polymerase chain reaction process carried out by a microfabricated, hybrid plastic-glass microfluidic chip on the tyrosinase gene, a predictive marker for melanoma diagnosis. The device is a hybrid system consisting of a glass microchannel embedded in an elastomeric matrix, and operating in flow-oscillating modality on a droplet of biological sample. The convection heat transfer and the temperature distribution inside the carrier fluid in the device are investigated. The oil responds to temperature changes with a characteristic time around 53 s, and exhibits three different thermal gradients along the capillary, with temperature variations below 4°C in correspondence of heater electrodes. The sample heating/cooling rates in the chip are as high as 16°C/s, allowing rapid processes. The nested polymerase chain reaction process is performed in less than 50 min, namely more than four times faster than in a standard thermocycler. The rapidity of the analysis method, combined with the simple and low-cost fabrication, reduced sample evaporation, and flexibility of the overall microfluidic platform, make it promising for the detection of events of tumor spreading.