Improvement of metal and tissue adhesion on surface‐modified parylene C

Abstract

A general method for chemical surface functionalization of parylene C [PC, (para-CH2-C6H3Cl-CH2-)n] films is reported. Friedel-Crafts acylation is used to activate the surface of the PC film, and the resulting carbonyl groups are then used to form a range of different organic functional groups to the surface of the parylene film, including alcohol, imine, thiol, phthalimide, amine, and maleimide. The presence of these functional groups on the parylene surface was confirmed by Fourier transform infrared spectroscopy. Static water drop contact angle measurements were also used to demonstrate the changes in hydrophilicity of the PC film surface, consistent with each of the surface modifications. Enhanced metal (gold) adhesion was achieved by anchoring a thiol group onto the acylated surface of PC film. Acylation of parylene with 2-chloropropionyl chloride gave a surface bound chloropropionyl group. Grafting of poly-N-isopropylacrylamide (pNIPAM) onto the chloropropionyl substituted PC film via atom transfer radical polymerization (ATRP) was carried out. The grafted pNIPAM on the parylene surface leads to temperature-dependent cellular tissue adhesion on the PC film.

Modification of Parylene film-coated glass with TiO2 nanoparticles and its photocatalytic properties

“…The solution was sonochemically irradiated with an immersed Ti-horn (20 kHz, 750 W at 70% efficiency). The Ti(i-OPr) 4 in concentrations of 10-20 g/L was added drop-wise to the working solution under sonication, and the process continued for 1 h. After the reaction, the coated glass was washed with water and ethanol and allowed to dry in air at room temperature. For the stabilization of TiO 2 in the dispersed state, PVP (MW = 89,000-98,000) was added to the reaction slurry before sonication at a concentration range of 3-12 g/L.…”

“…Ti(i-OPr) 4 was used as a precursor for the synthesis of TiO 2 . The TiO 2 nanoparticles (NPs) were deposited on the Parylene-glass slides by the ultrasound-assisted hydrolysis of Ti(i-OPr) 4 . The procedure was as follows.…”

“…In the everyday application of Parylene, advantage was taken of their excellent mechanical properties, chemical inertness, low dielectric constant, and excellent barrier properties. The stability of Parylene films toward organic solvents and biological fluids makes them ideal coatings for microelectronic devices, medical instruments, implants, and prostheses [2][3][4]. Significant progress was achieved recently in the fabrication of medical implants and organic electronics protected with Parylene layers [5,6].…”

Histopathological Effects of Parylene C (poly-chloro-p-xylylene) in the Inner Ear

“…The most common parylene materials are parylene N, parylene D, and parylene C [poly(chloro-p-xylylene)] (PC). PC is hydrophobic and is conformably deposited and chemically inert toward most common organic and biological fluids and water till up to 150°C (10). It has a high resistance and elasticity, low dielectric constant, and the highest biocompatibility certification with United States Pharmacopeial Class VI (11,12).…”

Surface chemical immobilization of parylene C with thermosensitive block copolymer brushes based onN‐isopropylacrylamide andN‐tert‐butylacrylamide: Synthesis, characterization, and cell adhesion/detachment

“…These modification methods have been suggested to have their roles in medical applications, such as anti-biofouling, temperature responsive biosensors, controlled drug release, thermal responsive chromatography, and reversible cell adhesion/detachment. [26][27][28][29][30][31][32][33][34][35] Among this applications, homo pNIPAM grafted substrates has been intensely applied for mammalian cell adhesion/detachment study. 34,36,37 Below LCST, it has been found that the cells do not adhere to the pNIPAM-coated substrate.…”