Ultra-Thin Plasma-Polymerized Functional Coatings for Biosensing: Polyacrylic Acid, Polystyrene and Their Co-Polymer

Recently, many efforts have been done to chemically functionalize sensors surface to achieve selectivity towards diagnostics targets, such as DNA, RNA fragments and protein tumoural biomarkers, through the surface immobilization of the related specific receptor. Especially, some kind of sensors such as microcantilevers (gravimetric sensors) and one-dimensional photonics crystals (optical sensors) able to couple Bloch surface waves are very sensitive. Thus, any kind of surface modifications devoted to functionalize them has to be finely controlled in terms of mass and optical characteristics, such as refractive index, to minimize the perturbation, on the transduced signal, that can affect the response sensitivity towards the detected target species

Electrostimulation of a 3D in vitro skin model to activate wound healing

The aim of the work is to propose a methodology for the stimulation of a 3D in vitro skin model to activate wound healing. The presented work is in the frame of the national research project, CronXCov, “Checking the CHRONIC to prevent COVID-19”, devoted to understand how physiologic and inflamed skin on chip 3D models evolve upon a range of physical (e.g., electrical, mechanical, optical) stimulations, over time. Thanks to the 3D modelling, using Next Generation Sequencing and the network medicine frame of analysis to process the data, we will systematically characterize the effects of the applied stimuli, offering new insight for the exploitation of wound healing

Morphological Characterization and Lumped Element Model of Graphene and Biochar Thick Films

Carbon based materials exhibit interesting mechanical, thermal and electrical properties which make them excellent contenders for use as fillers in composites as film. Graphene has been vastly used among the carbon-based materials. More recently eco-friendly carbon-based materials like biochar have emerged. The deployment of carbon-based materials in films needs to be studied since films are more versatile and permit the exploitation of electrical properties of such materials over circuits and systems. Typical circuits and systems exploiting electrical properties of novel materials perform a number of applications including sensing, detection, tunable devices and energy harvesting. In this paper, films composed of 9:1 graphene or biochar are deployed on a microstrip line. The morphological properties of graphene and biochar and their respective films are studied with Raman spectra and Field Emission Scanning Electron Microscope (FESEM). The electrical properties (four-point probe measurements and scattering parameter measurements) of the films. Low frequency measurements are used as starting point for circuit models estimating the lumped impedance of the films. From the morphological characterization it is shown that biochar films appear as granulates carbonaceous materials whereas graphene films contains several flakes forming a network. From the low frequency measurements and microwave characterization it is seen that graphene films are more conductive as compared to biochar films. In many applications, it is useful to know the surface impedance of the film since it varies on interaction with any external stimulus (variation of pressure, humidity, gas, etc.)

Printability study by selective laser sintering of bio-based samples obtained by using PBS as polymeric matrix

The emerging request to reduce the environmental impact of plastics encourages scientists to use novel sustainable polymeric materials for many applications fields. The present paper aims to use for the first-time poly (butylene succinate) (PBS), a biodegradable and compostable polymer, for Selective Laser Sintering (SLS) applications. PBS is a flexible semicrystalline aliphatic polyester, which can represent a very good alternative to the traditional thermoplastic polymers obtained by fossil sources. The present work started from a lab-scale production of PBS powders by means of an emulsion solvent evaporation/precipitation method, with the purpose to increase the number of polymeric powders available for SLS. The obtained PBS powders were first characterized by morphological and thermal point of view, and then employed as innovative polymeric material in SLS to realized 3D printed parts with increasing geometrical complexity. To confirm PBS cytocompatibility, cell proliferation and cell viability assays (MTT and Live&Dead) were measured using a lung adenocarcinoma epithelial cell line (H1299). The in vitro cytotoxicity of the 3D printed material was also investigated, showing no harm on cells

Development of in vitro 3D culture system to mimic lung cancer tissue

A 3D culture system based on a photocurable matrix has been developed. The aim is to create a 3D printable platform mimicking lung cancer tissue, to study tumor microenvironment evolution, in terms of structural (architecture) and molecular (signalling) components

Design of a Portable Microfluidic Platform for EGOT-Based in Liquid Biosensing

In biosensing applications, the exploitation of organic transistors gated via a liquid electrolyte has increased in the last years thanks to their enormous advantages in terms of sensitivity, low cost and power consumption. However, a practical aspect limiting the use of these devices in real applications is the contamination of the organic material, which represents an obstacle for the realization of a portable sensing platform based on electrolyte-gated organic transistors (EGOTs). In this work, a novel contamination-free microfluidic platform allowing differential measurements is presented and validated through finite element modeling simulations. The proposed design allows the exposure of the sensing electrode without contaminating the EGOT device during the whole sensing tests protocol. Furthermore, the platform is exploited to perform the detection of bovine serum albumin (BSA) as a validation test for the introduced differential protocol, demonstrating the capability to detect BSA at 1 pM concentration. The lack of contamination and the differential measurements provided in this work can be the first steps towards the realization of a reliable EGOT-based portable sensing instrument

3D printable acrylate polydimethylsiloxane resins for cell culture and drug testing

Nowadays, most of the microfluidic devices for biological applications are fabricated with only few wellestablished materials. Among these, polydimethylsiloxane (PDMS) is the most used and known. However, it has many limitations, like the operator dependent and time-consuming manufacturing technique and the high molecule retention. TEGORad or Acrylate PDMS is an acrylate polydimethylsiloxane copolymer that can be 3D printed through Digital Light Processing (DLP), a technology that can boast reduction of waste products and the possibility of low cost and rapid manufacturing of complex components. Here, we developed 3D printed Acrylate PDMS-based devices for cell culture and drug testing. Our in vitro study shows that Acrylate PDMS can sustain cell growth of lung and skin epithelium, both of great interest for in vitro drug testing, without causing any genotoxic effect. Moreover, flow experiments with a druglike solution (Rhodamine 6G) show that Acrylate PDMS drug retention is negligible unlike the high signal shown by PDMS. In conclusion, the study demonstrates that this acrylate resin can be an excellent alternative to PDMS to design stretchable platforms for cell culture and drug testing

Bloch surface waves-controlled fluorescence emission: coupling into nanometer-sized polymeric waveguides

The lateral confinement of Bloch surface waves on a patterned multilayer is investigated by means of leakage radiation microscopy (LRM). Arrays of nanometric polymeric waveguides are fabricated on a proper silicon-nitride/silicon-oxide multilayer grown on a standard glass coverslip. By exploiting the functional properties of the polymer, fluorescent proteins are grafted onto the waveguides. A fluorescence LRM analysis of both the direct and the Fourier image plane reveals that a substantial amount of emitted radiation couples into a guided mode and then propagates into the nanometric waveguide. The observations of the mode are supported by numerical simulations