Cell engineering: nanometric grafting of poly-N-isopropylacrylamide onto polystyrene film by different doses of gamma radiation

Abstract

Poly-N-isopropylacrylamide was successfully grafted onto a polystyrene cell culture dish and γ-preirradiated in air. In this study, the effect of a γ-pre-irradiation dose of radiation (radiation absorbed dosages of 10, 20, 30, 40 KGy) under appropriate temperature and grafting conditions was investigated. The Fourier transform infrared spectroscopy analysis showed the existence of the graft poly-N-isopropylacrylamide (PNIPAAm) on the substrate. The optimal value of the dose for grafting was 40 KGy at 50°C. The scanning electron microscopy and atomic force microscopy (AFM) images clearly showed that increasing the absorbed dose of radiation would increase the amount of grafting. Surface topography and graft thickness in AFM images of the radiated samples showed that the PNIPAAm at the absorbed dose of radiation was properly grafted. The thickness of these grafts was about 50–100 nm. The drop water contact angles of the best grafted sample at 37°C and 10°C were 55.3 ± 1.2° and 61.2 ± 0.9° respectively, which showed the hydrophilicity and hydrophobicity of the grafted surfaces. Differential scanning calorimetry analysis also revealed the low critical solution temperature of the grafted sample to be 32°C. Thermoresponsive polymers were grafted to dishes covalently which allowed fibroblast cells to attach and proliferate at 37°C; the cells also detached spontaneously without using enzymes when the temperature dropped below 32°C. This characteristic proves that this type of grafted material has potential as a biomaterial for cell sheet engineering.

Assessment of microplastic pollution: occurrence and characterisation in Vesijärvi lake and Pikku Vesijärvi pond, Finland

“…6. The spectra collected on the fibre show absorptions at 3024 (aromatic C–H stretching vibrations), 2908 and 2847 (CH 2 stretching), 1949 and 1878 (combination bands), 1600 and 1492 (aromatic ring stretching), and 1446 (CH 2 bending) and 1018 (aromatic CH bending) cm −1 which are characteristic of polystyrene (Verleye et al 2001; Noda et al 2007; Asensio et al 2009; Biazar et al 2010; Olmos et al 2014; Jung et al 2018).…”

Fabrication of Novel Ball-Like Polystyrene Films Containing Schiff Base Microspheres as Photostabilizers

“…Such a process led to a change in the electrical, optical, mechanical and chemical properties of the polymer [6]. In addition, it led to the production of free radicals, cross linking, C–C bonds permanent cleavage and the formation of small fragments containing various functional groups (e.g., OH, C=C and C=O) [36,37]. Figure 2 shows a possible pathway for the formation of carbonyl fragments from the photo-oxidation of PS [38].…”

Fourier transform infrared spectroscopy for irradiation coumarin doped polystyrene polymer films by alpha ray

“…By their large quantum yields and strong absorption, the coumarin dyes are super laser gain media in the near-UV to green wavelength region (Nedumpara et al, 2007). Polystyrene (PS) is contain the side group on the methylene chain is an aromatic ring; the infrared spectrum becomes a mixture of methylene and mono-substituted aromatic ring peaks (Biazar et al, 2010). Fourier transform infrared spectroscopy (FTIR) is an instrumental technique that measures the amount of IR radiation reflected from or transmitted through a sample.…”