Untreated Polystyrene Research Articles

Understanding the impact of bioactive coating materials for human mesenchymal stromal cells and implications for manufacturing

Bioactive materials interact with cells and modulate their characteristics which enable the generation of cell-based products with desired specifications. However, their evaluation and impact are often overlooked when establishing a cell therapy manufacturing process. In this study, we investigated the role of different surfaces for tissue culture including, untreated polystyrene surface, uncoated Cyclic Olefin Polymer (COP) and COP coated with collagen and recombinant fibronectin. It was observed that human mesenchymal stromal cells (hMSCs) expanded on COP-coated plates with different bioactive materials resulted in improved cell growth kinetics compared to traditional polystyrene plates and non-coated COP plates. The doubling time obtained was 2.78 and 3.02 days for hMSC seeded in COP plates coated with collagen type I and recombinant fibronectin respectively, and 4.64 days for cells plated in standard polystyrene treated plates. Metabolite analysis reinforced the findings of the growth kinetic studies, specifically that cells cultured on COP plates coated with collagen I and fibronectin exhibited improved growth as evidenced by a higher lactate production rate (9.38 × 105 and 9.67 × 105 pmol/cell/day, respectively) compared to cells from the polystyrene group (5.86 × 105 pmol/cell/day). This study demonstrated that COP is an effective alternative to polystyrene-treated plates when coated with bioactive materials such as collagen and fibronectin, however COP-treated plates without additional coatings were found not to be sufficient to support cell growth. These findings demonstrate the key role biomaterials play in the cell manufacturing process and the importance of optimising this selection.

Evaluation of the Deterioration of Untreated Commercial Polystyrene by Psychrotrophic Antarctic Bacterium.

Polystyrene (PS) and microplastic production pose persistent threats to the ecosystem. Even the pristine Antarctic, which is widely believed to be pollution-free, was also affected by the presence of microplastics. Therefore, it is important to comprehend the extent to which biological agents such as bacteria utilise PS microplastics as a carbon source. In this study, four soil bacteria from Greenwich Island, Antarctica, were isolated. A preliminary screening of the isolates for PS microplastics utilisation in the Bushnell Haas broth was conducted with the shake-flask method. The isolate AYDL1 identified as Brevundimonas sp. was found to be the most efficient in utilising PS microplastics. An assay on PS microplastics utilisation showed that the strain AYDL1 tolerated PS microplastics well under prolonged exposure with a weight loss percentage of 19.3% after the first interval (10 days of incubation). Infrared spectroscopy showed that the bacteria altered the chemical structure of PS while a deformation of the surface morphology of PS microplastics was observed via scanning electron microscopy after being incubated for 40 days. The obtained results may essentially indicate the utilisation of liable polymer additives or "leachates" and thus, validate the mechanistic approach for a typical initiation process of PS microplastics biodeterioration by the bacteria (AYDL1)-the biotic process.

Nanocomposites Transformed from Polystyrene Waste/Antimony, Barium and Nickel Oxides Nanoparticles with Improved Mechanical Properties

In this experiment, the oxide nanoparticles were synthesized via chemical precipitation and the nanocomposites were produced using in situ polymerization method with varying nanoparticles contents ranged from 0 to 5 g. The mechanical properties of the nanocomposites were investigated and compared with the values obtained for untreated polystyrene. It was observed that the mechanical properties were higher for the nanocomposites and increase with increasing nanoparticle concentrations in the samples. It can be observed that the untreated polystyrene gave a tensile strength of 945.25 N/mm2. At high nanoparticle content of 5 g, the nanocomposite containing NiO nanoparticles showed a tensile strength of 973.83 N/mm2 while nanocomposite containing BaO nanoparticles gave a tensile strength of 968.19 N/mm2 and nanocomposite containing Sb2O3 nanoparticle gave a tensile strength of 955.53 N/mm2. The results indicate that the tensile strength and percentage elongation of all the nanocomposites improved with the addition of metal oxides nanoparticles compared with the untreated polystyrene. Slight decrease in percentage reduction in area of the nanocomposites was recorded. Conclusively, with these results, the PS/NiO nano composite showed a better trend of behaviour due to better interfacial interaction between the nanofillers and the polymer matrix followed by PS/BaO and PS/Sb2O3 nanocomposites. It is recommended that during the production of polymer nanocomposite, PS/NiO, PS/BaO and PS/Sb2O3 nanocomposites could be used as reinforcements in the construction of buildings to add structural stability to the building.

Nanocomposites transformed from polystyrene waste/antimony, barium and nickel oxides nanoparticles with improved thermal and electrical properties

In this experiment, the oxide nanoparticles were synthesized via chemical precipitation and the nanocomposites were produced using in situ polymerization method with varying nanoparticles contents ranged from 0.1 g to 1.0 g for electrical conductivity and from 0.05 g to 0.25 g for thermal conductivity. The electrical and thermal conductivities of nanocomposites were investigated and compared with the values obtained for untreated polystyrene. It was observed that the electrical and thermal properties were higher for the nanocomposites and increase with increasing nanoparticle concentrations in the samples. It can be observed that nanocomposite containing NiO nanoparticles gave a better electrical and thermal conductivity followed by nanocomposite containing BaO nanoparticles and nanocomposite containing Sb2O3 nanoparticles respectively. It can also be observed that nanocomposite containing NiO nanoparticle showed increase in rate of heat transfer from 1.60 W to 2.60 W, while nanocomposite containing BaO nanoparticles recorded increase in rate of heat transfer from 1.40 W to 2.45 W and nanoomposite containing Sb2O3 nanoparticle showed increase in rate of heat transfer from 1.07 W to 2.21 W, as concentration of nanoparticles increased from 0.05 g to 0.25 g respectively. Conclusively, with these results, the nanocomposite containing NiO nanoparticles gave a better thermal and electrical conductivity by having a better conducting filler network inside the matrix than nanocomposite containing BaO nanoparticles and nanocomposite containing Sb2O3 nanoparticles. It is recommended that during the production of polymer nanocomposite, PS/NiO, PS/BaO and PS/Sb2O3 nanocomposites could be used in electrically conductive devices as well as suitable materials for heat transfer applications.

Non-coating method for non-adherent cell culture using high molecular weight dextran sulfate and bovine serum albumin

Non-adherent cell culture surface has been widely used for producing cell spheroids and cell aggregates. The purpose of this study was to formulate a new method for non-adherent cell culture without coating or surface-modification that has been needed. We found that high-molecular-weight dextran sulfate (DS) and bovine serum albumin (BSA) synergistically prevented cell adhesion in media supplemented with no or low serum. This method worked on tissue culture-treated polystyrene surfaces as well as on commercially available low-attachment- and untreated polystyrene surfaces. Further investigation revealed that BSA may mediate the adsorption of DS to the surface. In addition, as the adsorption of fluorescently labeled fibronectin was inhibited by BSA alone, it appears that protein adsorption and cell adhesion do not always correlate. Finally, we demonstrated the successful formation of HepG2 spheroids and cardiomyocyte aggregates using this method. In conclusion, cell adhesion can be effectively suppressed by simply adding DS and BSA to the culture medium without coating or surface modification, and it may be useful for generating cell spheroids and aggregates.

Study on the Effect of Polystyrene-Polyvinylpyrrolidone Electrospun Fibre in Inhibiting the Adhesion of Porphyromonas gingivalis

To explore the effect of polystyrene (PS) and PS-polyvinylpyrrolidone (PVP) electrospun materials on the adhesion ability of Porphyromonas gingivalis( P. gingivalis), a common periodontal pathogen. PS and PS-PVP electrospun materials were prepared with stainless steel needles in high-voltage electric field. The growth and adhesion of P. gingivalis on the surface of different materials were observed with scanning electron microscope (SEM). The changes in the amount of P. gingivalis biofilm formed on the surface of different materials were measured according to viable colony forming units (CFU). The effect of surface charge of the different materials on the adhesion ability of P. gingivalis was determined through changing the charge properties on the surface of the electrospun materials. SEM images showed that both PS and PS-PVP can be used to form electrospun fibers with a diameter of 0.2 μm. SEM images and CFU counts of the biofilm at 24 h and 48 h showed that there was a smaller amount of P. gingivalis biofilm on the surface of the two materials ( P<0.05). After treatment with tetrabutylammonium bromide (TBAB), the surface charge of the PS-PVP electrospun material changed from being negatively charged to being positively charged, and the amount of bacterial adhesion on the surface increased significantly in comparison to that of untreated PS and PS-PVP materials ( P<0.05). PS and PS-PVP electrospun materials can be used to reduce the adhesion ability of P. gingivalis on the surface of different materials, and this ability may be related to the surface charge properties of the materials.

Micropatterning of polymer substrates for cell culture

The cell microenvironment such as substrate topology plays an important role in biological processes. In this study, microgrooves were successfully produced on surfaces of both thermoplastic and thermoset polymers using cost-effective techniques for mass production. The micropatterning of thermoplastic polystyrene (PS) petri dish was accomplished efficiently using an in-house developed low-cost hot embossing system. The high replication fidelity of the microgroove with depth and width of 2μm and spacing of 2μm was achieved by using silicone rubber as a soft counter mold. This patterned petri dish subsequently served as the cast to replicate the micropattern onto thermoset polydimethylsiloxane (PDMS). It was found that the micropattern increased the hydrophobicity of both PS and PDMS surfaces. The effect of the substrate micropattern on cellular behaviors was preliminarily investigated with untreated and treated PS petri dish as well as PDMS. The results show that the micropattern significantly improved cell adhesion and proliferation for cells cultured on untreated PS petri dish and PDMS substrates. Moreover, the micropattern induced obvious cell alignment along the microgrooves for culturing on all substrates which were studied.

A study of plasma power effects on surface activation of polystyrene

In this study, polystyrene (PS) surface activation was performed with cyclonic atmospheric-pressure plasma to improve surface hydrophilicity, and the effects of plasma power on cyclonic plasma surface activation were investigated. Altered PS surface characteristics were observed through a wettability analysis. The PS surface hydrophilicity was highly enhanced during the cyclonic plasma treatment. The substantial growth of the PS surface hydrophilicity was attributed to the crosslinking by activated species of inert gases due to the presence of cyclonic plasma. Optical emission spectroscopy was used to determine various chemical plasma species and the association of the plasma surface treatment with the changes in the electron density and electron excitation temperature in cyclonic plasma with increasing plasma power. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy were used to determine the chemical and morphological variations on the cyclonic plasma-treated PS surface. The XPS analysis exhibited noticeably higher surface concentrations of oxygen functional groups on the cyclonic plasma-activated PS surface compared to the untreated PS. The results show that cyclonic plasma is an operative plasma device that can be used to improve PS surface hydrophilicity.

Evaluation of a Commercial Broth Microdilution Panel for Colistin Susceptibility Testing of Clinical Isolates of Escherichia coli and Klebsiella pneumoniae.

Colistin is among the last resort antibiotics for the treatment of infections caused by multidrug-resistant Gram-negative pathogens. Antimicrobial susceptibility testing of colistin is challenging due to its physicochemical properties. Broth microdilution (BMD) is the recommended method for colistin susceptibility testing. However BMD is not practical for clinical microbiology laboratories as manual preparation of BMD plates is time-consuming and labor intensive. Recently, some more user-friendly BMD products with commercial panels have become available. Our objective was to evaluate the performance of a commercial broth microdilution (BMD) product [Sensititre (Thermo Fisher Scientific)] for colistin MIC determination by comparison with reference BMD method using a collection of E. coli and K. pneumoniae isolates. A total of 323 unique patient isolates (102 E. coli, 221 K. pneumoniae) were included in the study. Isolates were stored at -70°C and subcultured twice on sheep blood agar before testing. Colistin MICs of the isolates were determined using Sensititre (a premade BMD product with dried antibiotics) and an 'in-house prepared BMD panel prepared in accordance with CLSI guidelines' (reference method). MIC determination with Sensititre was performed according to manufacturer's instructions. The reference method was performed using untreated 96-well sterile polystyrene plates. Colistin MIC results were interpreted according to EUCAST breakpoints (susceptible, ≤ 2 mg/L; resistant, > 2 mg/L). Overall susceptibility rate of isolates to colistin by reference BMD was 75.9%. Overall categorical agreement (CA), essential agreement (EA), very major error (VME), and major error (ME) rates for Sensititre were 98.5%, 72.5%, 3.8%, and 0.8%, respectively. The CA and EA between Sensititre and reference BMD for the isolates with reference colistin MICs close to the susceptibility breakpoint (2 - 8 mg/L) was 94.2% and 48.1%, respectively. Sensititre yielded a VME rate of 15% and ME rate of 0%, respectively, for this subset of isolates. In conclusion, Sensititre showed high CA but low EA with reference BMD for entire collection of isolates. The VME rate was just slightly above 3% and ME rate was acceptable. The rates of CA and EA were decreased and the rate of VME was increased when a subset consisting of more challenging isolates was used.

Low-temperature plasma polymerized fluorocarbon coating promotes surface charge dissipation in polystyrene

Polystyrene (PS) is a common insulating material in pulsed power devices, which has excellent and reliable insulation properties. However, the charge accumulation on the insulator surface seriously threatens its surface insulation property. Surface modification has been verified as an effective way for inhibiting surface charge accumulation. In this paper, plasma polymerized fluorocarbon (PPFC) coating was prepared by low-temperature plasma polymerization in the mixture of methyl-methacrylate and dodecafluoroheptyl-methacrylate (DFHMA). Compared with the untreated PS, the surface charge dissipation rate of PPFC coating is increased by more than 6 times. The introduction of DFHMA makes the coating have no obvious ageing effect after the storage, and has good reusability after the surface flashover. This work provides a new method for modification of polymer dielectrics and a novel way for the preparation of high-charge-dissipation polymers in other related fields.

Protein film formation on cell culture surfaces investigated by quartz crystal microbalance with dissipation monitoring and atomic force microscopy

Conventional cell culture surfaces typically consist of polystyrene, with or without surface modifications created through plasma treatment or protein/peptide coating strategies. Other polymers such as fluorinated ethylene propylene are increasingly being implemented in the design of closed cell culture vessels, for example to facilitate the production of cells for cancer immunotherapy. Cultured cells are sensitive to culture vessel material changes through different mechanisms including cell-surface interactions, which are in turn dependent on the amount, type, and conformation of proteins adsorbed on the surface. Here, we investigate the protein deposition from cell culture medium onto untreated polystyrene and fluoropolymer surfaces using quartz crystal microbalance with dissipation monitoring and atomic force microscopy. Both of these non-polar surfaces showed comparable protein deposition kinetics and resulted in similar mechanical and topographical film properties. At protein concentrations found in typical serum-free media used to culture dendritic cells, two deposition phases can be observed. The protein layers form within the first few minutes of contact with the cell culture medium and likely consist almost exclusively of albumin. It is indicated that initial protein film formation will be completed prior to cell settling and initial cell contact will be established with the secondary protein layer. The structural properties of the protein film surface will strongly depend on the albumin concentration in the medium and presumably be less affected by the chemical composition of the cell culture surface.

'Waste-to-Energy’ Fuel Cell Systems

In this paper, a review of the different possible gas and solid fuels for solid oxide fuel cells (SOFCs) is presented. Much research has been performed with gaseous fuels in SOFCs. On the contrary, much work remains on the direct use of solid fuels in SOFCs to overcome all the technical challenges that these systems present. The challenges are even greater when the use of complex solid waste is considered. However, the development of efficient and sustainable energy systems that can operate with waste is of general interest to the energy sector and the environment, as waste management is of major concern. In particular, the re-utilisation or disposal of plastics is of great importance due to their worldwide usage and their slow degradation. The use of an untreated wood and polystyrene mixture in an electrolyte-supported fuel cell with a NiO-YSZ anode and LSM-based cathode was also investigated in this work.

A versatile method for the UVA-induced cross-linking of acetophenone- or benzophenone-functionalized DNA

Bioconjugation, biosensing, bioimaging, bionanomaterials, etc., are only a few examples of application of functionalized DNA. Since base-modified nucleic acids contribute not only to a broad range of biotechnological fields but also to the understanding of various cellular processes, it is crucial to design novel modifications with unique properties. Here, we demonstrate the utilization of N4-cytidine modified oligonucleotides, which contain reactive acetophenone (AP) or benzophenone (BP) groups, for the UV-induced cross-linking. We find that terminal deoxynucleotidyl transferase-mediated 3′-tailing using AP/BP-containing modified nucleotides generates photoactive DNA, suitable for a straightforward covalent cross-linking with both interacting proteins and a variety of well-known solid polymeric supports. Moreover, we show that AP/BP-functionalization of nucleic acid molecules induces an efficient cross-linking upon exposure to UVA light. Our findings reveal that 3′-tailed single-stranded DNA bearing AP/BP-moieties is easily photoimmobilized onto untreated polystyrene, polypropylene, polylactate, polydimethylsiloxane, sol-gel and borosilicate glass substrates. Furthermore, we demonstrate that such immobilized DNA probes can be further used for successful hybridization of complementary DNA targets. Our results establish novel N4-cytosine nucleobase modifications as photoreactive labels and suggest an effortless approach for photoimmobilization of nucleic acids.

Adsorption behavior of phenanthrene on CTAB-modified polystyrene microspheres

Adsorption behavior of phenanthrene on cetyltrimethyl ammonium bromide (CTAB)-modified polystyrene (PS) microspheres was investigated thoroughly to develop a novel adsorbent material. CTAB-modified PS microspheres were characterized through atomic force microscopy (AFM) and Brunauer–Emmet–Teller analysis. AFM images showed that conical admicelles made of CTAB replaced polyvinylpyrrolidone (PVP) macromolecules on the surface of the PS microspheres. After CTAB modification, the surface area of the PS microspheres increased noticeably from 0.56 to 2.08 m2 g−1, which confirmed that the formation of discrete CTAB admicelles replaced PVP macromolecules coated on the surface of the PS microspheres. Through conductivity measurements, two critical micelle concentrations (CMCs) were obtained. The first was the CMC of CTAB admicelles on the PS microspheres, and the second was the CMC of CTAB micelles in the solution, which further confirmed the formation of the admicelles on PS microspheres. Cation–π electron interaction between CTAB and phenanthrene helped adsolubilize phenanthrene in the admicelles on the CTAB-modified PS microspheres. The equilibrium adsorption capacity of the CTAB-modified PS microspheres for phenanthrene was 11.67 mg g−1, nearly three times that of the untreated PS microspheres. The adsorption kinetic curves of phenanthrene on CTAB-modified PS microspheres followed a pseudo-second-order model. The adsorption process closely fit the Freundlich model, which indicated a multilayer adsorption process, rather than monolayer behavior.

Evaluation of adhesion, proliferation, and differentiation of human adipose-derived stem cells on keratin

Controlled adhesion and continuous growth of human adipose stem cells (hASCs) on delivery carriers are critical to cell therapy and tissue engineering. Keratin, derived from human hair, can be manipulated as a desired configuration and serve as an extracellular matrix. However, the effects of keratin on stem cells have not been fully understood. In this study, keratin-coting substrates were prepared to demonstrate the modulations of keratin matrix to the adhesion, proliferation, and differentiation of hASCs. The present results showed that keratin-coating substrates promoted hASCs adhesion, proliferation, and viability relative to those of untreated polystyrene plates. Evaluations of lineage-specific genetic markers and proteins revealed that the adipogenic, osteogenic and chondrogenic differentiations of hASCs can be successfully induced, which suggested that the stemness of hASCs was maintained when cultured on keratin-coating substrates. Relative to untreated polystyrene plates, keratin-coating increased the mRNA levels of lipoprotein lipase (LPL), peroxisome proliferator-activated receptor gamma (PPAR- γ), and CCAAT-enhancer binding protein alpha (CEBP-α) to hASCs, which reveals an improvement in adipogenic differentiation. Likewise, keratin also upregulated osteogenic markers such as type I collagen, alpha 1 (COL1A1), runt-related transcription factor 2 (RUNX2), and vitamin D receptor (VDR) to hASCs. Similarly, the chondrogenic marker SRY-box 9 (SOX9) was improved to hASCs on keratin-coating. The combination of hASCs with keratin shall be promising in the application of tissue repair to regenerative medicine.

Silicon based solvent immersion imprint lithography for rapid polystyrene microfluidic chip prototyping

Polystyrene (PS) is preferred over polydimethylsiloxane (PDMS) in microfluidics for applications in cell biology. However, PS has not found widespread use in microfluidics due mainly to the lack of rapid prototyping techniques. Here we address this issue by developing a silicon based solvent immersion imprint lithography (Si-SIIL) technique. Silicon is rigid, mechanically robust, and highly compatible with standard microfabrication processes, and therefore, is a promising candidate for molds. Various PS microfluidic channels as small as 20μm in width with the aspect ratio as high as 5 were demonstrated using Si-SIIL. Bubbles and bending generated in the fabrication process were analyzed and eliminated. The surface roughness was about 27nm (rms). Compared to the untreated PS, the molded PS retained almost the same surface properties, as characterized by contact angle measurement and X-ray photoelectron spectroscopy. Cell culture was tested to demonstrate the utility of Si-SIIL in cell biology applications. The results show that PS, with the aid of Si-SIIL, can be an alternative material to PDMS in building microfluidic chips.

Understanding the Interactions of Peptides and Proteins that are Commonly used in Biological Media on Polystyrene Surfaces

Polystyrene(PS) is a commonly used material for designing cell culture surfaces like assay plates, petridishes, T flasks to name a few. These surfaces when used for the culture of adherent cells will modulate cell growth and function depending of the quality of adhesion provided. To enable biological activity on polystyrene, surfaces can be modified by different treatments which result in an increase in the amount of certain surface chemical species like oxygen. To understand the differences between treated and untreated polystyrene surfaces, we examine in this study the interaction between two commonly occurring biological entities in these applications i) Albumin which is a common component of cell culture media and is used to sustain the growth and activity of biological cells and ii) commonly occurring peptide motifs that are a typical part of the ECM proteins which allow the cells to interact with the surface through these binding motifs.

How do wettability, zeta potential and hydroxylation degree affect the biological response of biomaterials?

It is well known that composition, electric charge, wettability and roughness of implant surfaces have great influence on their interaction with the biological fluids and tissues, but systematic studies of different materials in the same experimental conditions are still lacking in the scientific literature. The aim of this research is to investigate the correlations between some surface characteristics (wettability, zeta potential and hydroxylation degree) and the biological response (protein adsorption, blood wettability, cell and bacterial adhesion) to some model biomaterials. The resulting knowledge can be applied for the development of future innovative surfaces for implantable biomaterials. Roughness was not considered as a variable because it is a widely explored feature: smooth surfaces prepared by a controlled protocol were compared in order to have no roughness effects. Three oxides (ZrO2, Al2O3, SiO2), three metals (316LSS steel, Ti, Nb) and two polymers (corona treated polystyrene for cell culture and untreated polystyrene for bacteria culture), widely used for biomedical applications, were considered. The surfaces were characterized by contact profilometry, SEM-EDS, XPS, FTIR, zeta potential and wettability with different fluids. Protein adsorption, blood wettability, bacterial and cell adhesion were evaluated in order to investigate the correlations between the surface physiochemical properties and biological responses.From a methodological standpoint, XPS and electrokinetic measurements emerged as the more suitable techniques respectively for the evaluation of hydroxylation degree and surface charge/isoelectric point. Moreover, determination of wettability by blood appeared a specific and crucial test, the results of which are not easily predictable by using other type of tests.Hydroxylation degree resulted correlated to the wettability by water, but not directly to surface charge. Wetting tests with different media showed the possibility to highlight some differences among look-alike materials. A dependence of protein absorption on hydroxylation degree, charge and wettability was evidenced and its maximum was registered for surfaces with low wettability in both water based and protein containing media and a moderate surface charge. As far as bacterial adhesion is concerned, no effect of surface charge or protein adsorption was evidenced, while the presence of a high acid component of the surface energy appeared significant. Finally, the combination of hydroxylation degree, wettability, surface charge and energy (polar component) emerged as a key parameter for cell adhesion and viability.

The impact of surface chemistry modification on macrophage polarisation

Macrophages are innate immune cells that have a central role in combating infection and maintaining tissue homeostasis. They exhibit remarkable plasticity in response to environmental cues. At either end of a broad activation spectrum are pro-inflammatory (M1) and anti-inflammatory (M2) macrophages with distinct functional and phenotypical characteristics. Macrophages also play a crucial role in orchestrating immune responses to biomaterials used in the fabrication of implantable devices and drug delivery systems. To assess the impact of different surface chemistries on macrophage polarisation, human monocytes were cultured for 6 days on untreated hydrophobic polystyrene (PS) and hydrophilic O2 plasma-etched polystyrene (O2-PS40) surfaces. Our data clearly show that monocytes cultured on the hydrophilic O2-PS40 surface are polarised towards an M1-like phenotype, as evidenced by significantly higher expression of the pro-inflammatory transcription factors STAT1 and IRF5. By comparison, monocytes cultured on the hydrophobic PS surface exhibited an M2-like phenotype with high expression of mannose receptor (MR) and production of the anti-inflammatory cytokines IL-10 and CCL18. While the molecular basis of such different patterns of cell differentiation is yet to be fully elucidated, we hypothesise that it is due to the adsorption of different biomolecules on these surface chemistries. Indeed our surface characterisation data show quantitative and qualitative differences between the protein layers on the O2-PS40 surface compared to PS surface which could be responsible for the observed differential macrophage polarisation on each surface.

Comparison of two types of non-adherent plate for neuronal differentiation of mouse embryonic stem cells.

In vitro differentiation systems of mouse embryonic stem cells (ESCs) are widely used as tools for studies of cell differentiation, organogenesis, and regenerative medicine. We have studied the regulation of neuron-specific imprinting genes, Ube3a and its antisense transcripts (Ube3a ATS), using in vitro neuronal differentiation of F1 hybrid ESCs. Each different non-adherent plate used for embryoid body (EB) formation during differentiation is associated with different costs; notably, plates coated with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer are more expensive than untreated polystyrene plates. Here, we assessed whether the polymer-coated plates gave better results than the untreated plates. The first stage of differentation was performed in the MPC polymer-coated or untreated plates. The formed EBs were then passaged onto laminin-coated plates for further differentiation into neurons. Neither the neuron-specific imprinting status of Ube3a nor the expression levels of the neuron-specific markers Ube3a ATS and Mtap2 differed between neurons prepared on untreated plates and those prepared on MPC polymer-coated plates. These results suggest that the two non-adherent plates displayed almost the same characteristics for inducing neuronal differentiation of mouse ESCs and EB formation. Our study proved that untreated polystyrene plates are a cost-effective choice for EB formation in in vitro differentiation systems of mouse ESCs.