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Summary: Mixtures of diethyl glycol dimethyl ether vapors and argon were used to feed RF (13.56 MHz) glow discharges and coat polystyrene substrates with poly(ethylene oxide) (PEO)‐like thin films. Different power input values have been used to obtain coatings with different cell‐adhesive properties. Cell‐culture experiments showed a tight correlation between the adhesion/morphology of cultured cell‐lines and the chemical composition of the coatings; the ability of PEO‐like coatings to discourage or promote cell adhesion could thus easily be related to the power delivered to the plasma. Combined deposition processes of different PEO‐like coatings have been performed, with the method of physical masking, to produce surfaces micro‐patterned with cell‐adhesive tracks alternating with cell‐repulsive domains. The micro‐arrangement of different cell‐adhesive domains enabled the patterning of cell cultures and induced the alignment of cells along predefined directions.

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Summary: Micro‐ and nanofabrication methods are essential today in microelectronics, optoelectronics, catalysis, and analytics. Recent advances in biomaterials show that micro‐ and nanofeatures, either at the surface or embedded in materials, can drive specific responses both in in vivo and in vitro biological systems. With such an approach, scientists can understand better, and possibly exploit, biological responses stimulated by properly designed biomedical surfaces. Because of their versatility, plasma treatment, deposition, and etching processes are often part of procedures optimized to create micro‐ and nanofeatures of different shape, size, and position, onto and inside materials. Presented here are recent examples of such processes developed in our group for biomedical applications.

Over the past decade, cold atmospheric plasmas have shown promising application in cancer therapy. The therapeutic use of plasma-activated media is a topic addressed in an emerging field known as plasma pharmacy. In oncology, plasma-activated media are  used to harness the therapeutic effects of oxidant species when they come in contact with cancer cells. Among several factors that contribute to the anticancer effect of plasma-activated liquid media (PALM), H2O2 and NO derivatives likely play a key role in the apoptotic pathway. Despite the significant amount of literature produced in recent years, a full understanding of the mechanisms by which PALM exert their activity against cancer cells is limited. In this paper, a sealed dielectric-barrier discharge was used to disentangle the effect of reactive nitrogen species (RNS) from that of reactive oxygen species (ROS) on cancer cells. Two cancers characterized by poor prognosis have been investigated: metastatic melanoma and pancreatic cancer. Both tumour models exposed to PALM rich in H2O2 showed a reduction in proliferation and an increase in calreticulin exposure and ATP release, suggesting the potential use of activated media as an inducer of immunogenic cell death via activation of the innate immune system.

A Functional Bio-Interlayer Organic Field-Effect Transistor (FBI-OFET) sensor, embedding a streptavidin protein capturing layer, capable of performing label-free selective electronic detection of biotin at 3 part per trillion (mass fraction) or 15 pM, is proposed here. The response shows a logarithmic dependence spanning over 5 orders of magnitude of analyte concentration. The optimization of the FBI analytical performances is achieved by depositing the capturing layer through a controllable Layer-by-Layer (LbL) assembly, while an easy processable spin-coating deposition is proposed for potential low-cost production of equally highly performing sensors. Furthermore, a Langmuirian adsorption based model allows rationalizing the analyte binding process to the capturing layer. The FBI-OFET device is shown to operate also with an antibody interlayer as well as with an ad hoc designed microfluidic system. These occurrences, along with the proven extremely high sensitivity and selectivity, open to FBI-OFETs consideration as disposable electronic strip-tests for assays in biological fluids requiring very low detection limits.

In this paper, we describe the deposition of PEO‐like coatings using dielectric barrier discharges (DBDs) fed with aerosols of the TEGDME organic precursor in helium. By properly tuning plasma parameters such as aerosol/carrier flow ratio, frequency of the electric field applied and input power, the deposition process could be modulated to obtain coatings with variable PEO character, from 50% (cell adhesive) to 70% (nonfouling), which are interesting for surface modification of biomaterials and biomedical devices.

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