Patterning Poly(organophosphazenes) for Selective Cell Adhesion Applications

Abstract

Five polyphosphazenes with different hydrophilicites were synthesized and screened in vitro. The purpose was to identify unique types of polymeric substrates that distinctly favored or markedly prevented cellular adhesion. The SK-N-BE(2c) human neuroblastoma cell line, utilized for its electrogenic responses, was used to test this differential adhesion. In particular, the objective was to specifically culture this cell line in a highly selective pattern. Each candidate polymer was cast into films and plated with neuroblastoma cells for 3 days. The polyphosphazene materials which showed negative cellular adhesive properties (-CAPs) were poly[bis(trifluoroethoxy)phosphazene] (TFE) and poly[bis(methoxyethoxyethoxy)phosphazene] (MEEP). The polyphosphazenes which showed positive cellular adhesive properties (+CAPs) were poly[(methoxyethoxyethoxy)(1.0)(carboxylatophenoxy)(1.0)phosphazene] (PMCPP), poly[(methoxyethoxyethoxy)(1.0)(cinnamyloxy)(1.0)phosphazene] (PMCP), and poly[(methoxyethoxyethoxy)(1.0)(p-methylphenoxy)(1.0)phosphazene] (PMMP). To test cellular selectivity, films of -CAP and +CAP were copatterned onto glass substrates. The micropatterned films were plated with SK-N-BE(2c) neuroblastoma cells for one week. The results showed that neuroblastoma cells adhere selectively (over 60%) to the +CAP microfeatures. We also showed that multiple properties can be achieved with a single material and that we can use TFE as both a -CAP and an insulation layer and PMCP as a conductive +CAP layer.

Expanding Options in Polyphosphazene Biomedical Research

“…The number of cross-links, and therefore the degree of water swelling, is controlled by the length of radiation exposure time. A second method requires the introduction of a carboxylic acid substituent function (structure 22) or the two substituents shown in structure 23 [69][70][71][72][73][74][75][76][77][78][79]. The presence of the carboxylic acidic function in 22 or 23 means that hydrogels expand in basic media (e.g., dilute sodium hydroxide) but contract in acidic media, due to the charge repulsion between the protons in solution and the protonated carboxylic acid groups.…”

“…The resulting grafted interface is itself crosslinked so that all the attributes of MEEP hydrogels, such as LCST behavior, are incorporated into the system. This is extremely useful for the gel immobilization of enzymes and cells for biochemical reactors [91][92][93][94].…”

Recent Research Progress in the Synthesis of Polyphosphazene and Their Applications

“…Polyphosphazenes based on linear polymers with methoxy, ethoxy and related side-groups showed hydrogel-like behavior [64]. Proton-conducting polymer electrolyte membranes are chemically stable, excellent proton conductors and have good mechanical properties.…”

“Click Chemistry” as a Facile Approach to the Synthesis of Polyphosphazene Glycopolymers

“…Because of their prominent biodegradability and biocompatibility, polyphosphazenes open up broad prospects for biochemical, biological and biomedical applications. [2][3][4][5] Since the original synthesis of polyphosphazenes was reported by Allcock et al in the mid-1960 s, [6] a variety of polyphosphazenes with different side groups have been synthesized and their potential applications explored. [7][8][9][10][11][12][13][14][15] Polyphosphazene derivatives with carbohydrates as side groups are of particular interest for probes or effectors in biological processes involving carbohydrate/protein interactions.…”