Review: Endometrial function in pregnancy establishment in cattle.

The endometrium is fundamentally required for successful pregnancy in ruminants and species where the posthatching conceptus undergoes a protracted elongation and peri-implantation phase of pregnancy. Moreover, there are substantial waves of pregnancy loss during this pre- and peri-implantation period of pregnancy the precise source of which has not been clearly defined i.e., the maternal uterine contribution to this loss. Understanding the molecular interactions required for successful pregnancy in cattle will allow us to intervene to support pregnancy success during this vulnerable window. The endometrium contributes to most key developmental milestones of pregnancy establishment, including (1) contributing to the regulation of the oestrus cycle, (2) nourishing the preimplantation conceptus, (3) responding to the conceptus to create a more receptive microenvironment, (4) providing essential biophysical support, and (5) signalling and producing factors which affect the mother systemically. This review will summarise what we currently know about conceptus-maternal interactions as well as identify the gaps in our knowledge that could be filled with newer in vitro model approaches. These include the use of microfluidics, organ-on-a-chip devices, and bioinformatic approaches. This will help maximise food production efficiency (both meat and dairy) and decrease the environmental burden, while enhancing our understanding of the fundamental processes required for successful implantation in cattle.

Recreating cellular barriers in human microphysiological systems in-vitro.

Within cellular barriers, cells are separated by basement membranes (BMs), nanometer-thick extracellular matrix layers. In existing in-vitro cellular-barrier models, cell-to-cell signaling can be preserved by culturing different cells in individual chambers separated by a semipermeable membrane. Their structure does not always replicate the BM thickness nor diffusion through it. Here, a porous polymeric nanofilm made of poly(D-L-lactic acid) (PDLLA) is proposed to recreate the BM in a microfluidic blood-brain-barrier model. Nanofilms showed an average thickness of [Formula: see text] and a maximum pore diameter of 1.6 µm. Human umbilical vein endothelial cells (HUVECs) were cultured on PDLLA. After 7 days, viability was >95% and cell morphology did not show relevant differences with HUVECs grown on control substrates. A protocol for suspending the nanofilm between 2 microfluidic chambers was identified and showed no leakage and good sealing. Clinical Relevance- Preclinical models of cellular barriers are a key step towards a deeper understanding of their roles in pathogenesis of various diseases: a physiologically relevant microfluidic model of the blood brain barrier (BBB) allows high-throughput investigations of BBB contribution in neurodegenerative diseases and cruelty-free screenings of drugs targeting the brain.

Mouse embryo assay to evaluate polydimethylsiloxane (PDMS) embryo-toxicity.

In vitro embryo culture to support In Vitro Fertilization (IVF) procedures is a well-established but still critical technique. In the last decade first attempts to use microfluidic devices in IVF have shown positive results, enabling to control the culture conditions and to preserve the quality of the embryos during their development. In this study we completed an industry standard mouse embryo assay (MEA) to exclude potential toxic effects of PDMS.

Optimization of electrospun fibrous membranes for in vitro modeling of blood-brain barrier.

The blood-brain barrier (BBB) plays a critical role in brain homeostasis at the cellular and global level. Mimicking the selective permeability and transport properties of the BBB to specific molecules and cells remains a significant challenge towards the development of a physiologically relevant in vitro BBB model. In this study, we developed electrospun poly (ε-caprolactone) (PCL) and polyethylene glycol (PEG) copolymer membranes that supported different cellular components of the neurovascular unit including human-derived endothelial cells, pericytes and astrocytes. Comparative analyses of thickness, morphology, biocompatibility and permeability of membranes were also conducted. We found that collagen coated 4%PEG-96%PCL membranes supported the growth of a confluent and tight endothelium confirmed by transendothelial electrical resistance measurements (TEER). Based on fabrication process and reported results, we finally discuss the adoption of these electrospun fiber membranes for in vitro and on-a-chip human BBB models.

Mucoadhesive film for anchoring assistive surgical instruments in endoscopic surgery: in vivo assessment of deployment and attachment.

BACKGROUND: Flexible endoscopic procedures in the gastric cavity are usually performed by operative instruments introduced through the working channels of a gastroscope. To enable additional functions and to widen the spectrum of possible surgical procedures, assistive internal surgical instruments (AISI) may be deployed through the esophagus and fixed onto the gastric wall for the entire duration of the procedure. This paper presents a solution for deploying, positioning, and anchoring AISI inside the stomach by exploiting a chemical approach. METHODS: A mucoadhesive polymer was synthesized and tested inside the stomach. In vivo trials were performed on a porcine model by introducing the AISI provided with mucoadhesive by means of an overtube through the mouth. Targeted deployment was achieved by a purposely developed delivery device, passed through the operative channel of a gastroscope. The total time for deployment, positioning, and anchoring of the AISI was evaluated by testing the procedure with passive modules (10, 12, 15, 20 mm in diameter) and active devices: e.g., a miniaturized wired camera and a wireless illumination module. The time and force required for the detachment of the modules were measured. RESULTS: The whole procedure of in vivo deployment, positioning, and attachment of an AISI was performed in approximately 6 min. A preload force of 5 N for 3 min was required for anchoring the modules. The stable adhesion was maintained for a maximum of 110 min. Thanks to the positioning of the camera in the fundus, a wide view of the gastric cavity was obtained. The force required to detach the modules reached 2.8 N. CONCLUSIONS: Mucoadhesive anchoring represents a completely biocompatible and safe solution for stable positioning of AISI onto mucosal tissue. This novel polymeric mechanism can be useful for designing intraluminal accessories and tools that enhance surgeons' performances in endoluminal procedures.

Cell creeping and controlled migration by magnetic carbon nanotubes.

Carbon nanotubes (CNTs) are tubular nanostructures that exhibit magnetic properties due to the metal catalyst impurities entrapped at their extremities during fabrication. When mammalian cells are cultured in a CNT-containing medium, the nanotubes interact with the cells, as a result of which, on exposure to a magnetic field, they are able to move cells towards the magnetic source. In the present paper, we report on a model that describes the dynamics of this mammalian cell movement in a magnetic field consequent on CNT attachment. The model is based on Bell's theory of unbinding dynamics of receptor-ligand bonds modified and validated by experimental data of the movement dynamics of mammalian cells cultured with nanotubes and exposed to a magnetic field, generated by a permanent magnet, in the vicinity of the cell culture wells. We demonstrate that when the applied magnetic force is below a critical value (about Fc ≈ 10-11 N), the cell 'creeps' very slowly on the culture dish at a very low velocity (10-20 nm/s) but becomes detached from the substrate when this critical magnetic force is exceeded and then move towards the magnetic source.

Neuroblastoma cells displacement by magnetic carbon nanotubes.

In this paper, as-produced multiwall carbon nanotubes (MWNTs) have been analyzed by scanning electron microscopy and energy dispersive X-ray spectrometry, revealing the presence of Fe, Al, and Zn residuals and impurities. MWNTs have then been dispersed in Pluronic F127 aqueous solution and used to seed neuroblastoma cell lines (HN9.10e and SH-SY5Y) for three days. We found that MWNTs interact with cells and induce, under a permanent constant magnetic field, the cell displacement toward the magnetic source.

FIB-nanostructured surfaces and investigation of Bio/nonbio interactions at the nanoscale.

A better understanding of the interactions between biological entities and nanostructures is of central importance for developing functionalized materials and systems such as active surfaces with adapted biocompatibility. There is clear evidence in literature that cells and proteins generally interact with nanoscale-featured surfaces. Despite this quantity of information, little is known about the functional relationship between surface properties (i.e., roughness and nanostructuration) and biomolecules interaction. The main obstacle in the achievement of this goal is a technological one. Precise and straightforward control on surface modification at the nanometer level is required for understanding how nanostructuration influences interactions at bio/nonbio interface. In this paper, the authors describe the advantages of the focused ion beam (FIB) for surface nanostructuration of any material. The use of light transmitting substrates (especially glass) is often useful when studying the influence of surface morphology-in terms of shape and feature size-on bio/nonbio interactions by using traditional methods of biology and biotechnology. A simple methodology enabling a very efficient patterning of glass surfaces is thus described and validated: the enhancement of proteins interaction on FIB-nanostructured glass surfaces is demonstrated via fluorescence assays and a relationship between the adsorbed protein concentration and the density of surface patterning is derived.

Investigation of CNTs interaction with fibroblast cells.

The need for toxicological studies on carbon nanotubes (CNTs) has arisen from the rapidly emerging applications of CNTs well beyond material science and engineering. In order to provide a method to collect data about toxicology, we characterized by Scanning Electron Microscopy (SEM), by Energy Dispersive X-ray Spectrometry (EDS) analysis and by Focused Ion Beam (FIB) microscopy different kinds of treated CNTs. The bio-interaction was investigated seeding Crandell feline kidney fibroblasts with CNT-modified medium; a dedicated sample preparation by FIB has been defined to fix cells. In the present study, the cytotoxic effects of CNTs with 91% and 97% of purity were compared and changes in the growth behaviour of cells after 3 days in culture with modified medium have been recorded, considering also the distribution of CNTs within cells. While lower purified CNTs induced a slight cytotoxic effect, homogeneously suspended CNTs with high purity were less cytotoxic, and the rate of cell growth remained constant. CNTs aggregated in bundles, showed high adhesion on cell membrane. Interestingly, CNTs bundles were observed inside cells, underneath the cell membrane, and despite of that, cells were extended, in good vitality conditions and no cell-degeneration was observed.

Intracerebral hematoma following evacuation of chronic subdural hematomas. Report of two cases.

Two cases of intracerebral hemorrhage occurring after evacuation of bilateral chronic subdural hematomas are reported. Possible pathogenic mechanisms included hemorrhage into previously undetected areas of contusion, damage to cerebral vasculature secondary to rapid perioperative parenchymal shift, and sudden increase in cerebral blood flow combined with focal disruption of autoregulation; of these, the latter mechanism seemed most likely to be responsible for the hematoma formation. The need for clinical awareness of this nearly uniformly devastating complication, as well as prompt use of computerized tomography scanning in assessing the postoperative course, are stressed.