Polyelectrolytes with Tunable Charge Based on Polydehydroalanine: Synthesis and Solution Properties

Abstract

Poly(tert‐butoxycarbonylaminomethylacrylate) (PtBAMA), a derivative of polydehydroalanine (PDha), is synthesized using free radical polymerization (FRP) and nitroxide mediated polymerization (NMP). Due to the presence of orthogonal protective groups, the resulting polymers can be selectively deprotected to yield either a polyanion (poly(tert‐butoxycarbonylaminoacrylic acid), PtBAA) or a polycation (poly(aminomethylacrylate), PAMA). Deprotection of both the amino‐ and the carboxyl‐functionality in a sequential manner leads to the potential polyzwitterion polydehydroalanine (PDha). The pH‐dependent solution behavior of PtBAA, PAMA, and PDha are examined in aqueous solution by potentiometric and turbidimetric titrations as well as ζ‐potential measurements.

SPION@polydehydroalanine hybrid particles

“…The 1 H-NMR-spectrum of PtBAMA was measured in CDCl 3 and shows signals at d ¼ 5.4 ppm (b, 1H) for the amino function, d ¼ 3.7 ppm (3H) for the methyl ester and d ¼ 1.4 ppm (11H) for the boc protective group and the polymer backbone according to literature. 30 SEC measurements in DMAc (Fig. S2 †) revealed the molar masses shown in Table 1.…”

“…Poly(tert-butoxycarbonylamino methacrylate) (PtBAMA) was synthesized via free radical polymerization (FRP) using Lucirin-TPO® as UV-photoinitiator. Compared to our earlier study, 30 we also used solution polymerization in 1,4-dioxane (50 wt%) as, in this case, it was possible to obtain materials with molar masses below 50 000 g mol À1 in a straightforward manner. The reason for using PtBAMA with molar masses below 50 000 g mol À1 is that we anticipated the encapsulation of single MNPs to be achieved more easily compared to longer polymer chains.…”

“…This leads to either polycationic poly(aminomethyl acrylate) (PAMA), polyanionic poly(tert-butoxycarbonylamino acrylic acid) (PtBAA), or in the case of complete deprotection, to polyzwitterionic poly(dehydroalanine) (PDha, Scheme 1). 30 Magnetite MNP with 8 nm in diameter have been successfully coated with both PtBAA and PDha in different amounts. The obtained hybrid particles have been characterized by dynamic light scattering (DLS), zeta-potential measurements, vibrating sample magnetometry (VSM), and transmission electron microscopy (TEM).…”

Preparation of Core-Shell Hybrid Materials by Producing a Protein Corona Around Magnetic Nanoparticles

“…For this, we used particles coated with poly(tert-butoxycarbonyl acrylic acid) (PtBAA), a negatively charged polyelectrolyte [16]. PtBAA-coated MNP show a negative surface charge, similar to earlier observations after coating MNP with CMD.…”

“…Due to limited stability against agglomeration of dextran-based coatings, MNP with a coating of poly(tert-butoxycarbonyl acrylic acid) (PtBAA) were used for some investigations [16]. This particle system shows high stability against agglomeration and thus allows the minimization of the influence of agglomeration on corona formation.…”