Buildup of Exponentially Growing Multilayer Polypeptide Films with Internal Secondary Structure

Abstract

The buildup and secondary structure of poly(L-glutamic acid)/poly(allylamine) (PGA/PAH) multilayer films were investigated by means of optical waveguide lightmode spectroscopy, quartz crystal microbalance, and Fourier transform infrared spectroscopy in attenuated total reflection mode. The thickness and the mass of these films grow exponentially with the number of deposited bilayers. Moreover, PGA undergoes a random/R-helix transition when interacting with PAH during the film buildup process. This structural transition leads to (PGA/PAH)i films with an R-helix content (contribution of the R-helices to the amide I band) that switches regularly between 30% and 40% during the film buildup, when the multilayer is alternatively brought into contact with the PAH and PGA solutions. The secondary structure of the film is thus entirely driven by the last deposited layer. The independence of the R-helix content with the number of deposited bilayers also strongly suggests that the film is structurally homogeneous over its whole thickness.

Biocompatible polypeptide microcapsules via templating mesoporous silica spheres

“…the material adsorbed on the electrode increases more than linearly with the number of deposited layers. This nonlinear or exponential growth of the film was also observed previously in the formation of PLL/PGA films on other substrates [13,18,19] and in films comprising PLL or PGA, for example, PLL/hyaluronic acid [20] and PGA/poly(allylamine hydrochloride) [21] multilayer films. Previous studies on polyelectrolyte LbL multilayer films have demonstrated that the growth of the multilayer film is entropy driven and an endothermic complexation process of PLL/PGA corresponds to the exponential growth of the film [22].…”

Doxorubicin-loaded poly (lactic-co-glycolic acid) nanoparticles coated with chitosan/alginate by layer by layer technology for antitumor applications

“…42,43 Moreover, the intersection of the curves with 1 and 2 mg/mL was probably due to the viscosity and film-forming properties of the polyelectrolyte. 44,45 Initially, the growth rate of the multilayer with 2 mg/mL was very slow, which was limited by the high viscosity of the polyelectrolyte solution. After several adsorption cycles, the growth of the multilayer was more stable and regular with little effect of viscosity on polyelectrolyte adsorption.…”

Polyelectrolyte Multilayer Films as Substrates for Photoreceptor Cells

“…Cell number that the nature of the terminating layer affected cells greatly in terms of viability and attachment, which is in good agreement with the literature. 39,40,64 From the physicochemical characterization it was concluded that glass slides were not totally covered by (PLL/CSA) 10 multilayers (Figures 4a and 5a). The build-up of 20 bilayers of (PLL/CSA) 20 resulted in a homogenous film covering the entire surface (Figures 4b, 5b).…”