Exploring Inorganic–Organic Hybrids: Poly(meth)acrylate-Polydimethylsiloxane Copolymers Synthesis in Mild Conditions

Highly economical and environmentally friendly synthesis of a wide range of hydrophobic and hydrophilic poly(meth)acrylates with a low dispersity of D̵ < 1.3 and an initiation efficiency close to 100% by means of atom transfer radical polymerization (ATRP) is reported. This was possible thanks to the use of 2-propanol, which creates a versatile reaction medium that allows polymerization of monomers showing different hydrophilicities. The developed procedures of polymerization, utilizing metallic copper, ascorbic acid, or tertiary amine groups of monomers in the role of reducing agents, were furthermore applied in synthesis of triblock copolymers (TBC) grafted from the polydimethylsiloxane (PDMS) bifunctional, linear macroinitiator. This way, a series of amphiphilic macromolecules with various PDMS contents, including functional, pH-sensitive, and thermosensitive copolymers, were synthesized and characterized using proton and carbon-13 nuclear magnetic resonance (1H NMR, 13C NMR) and attenuated total reflectance infrared (ATR-IR) spectroscopies. The presence of the flexible PDMS core and hydroxyl groups in the outer blocks further enabled the preparation of copolymers with a complex structure of bottlebrushes with spherical topology, which were visualized using atom force microscopy (AFM). Biocompatibility of the obtained PDMS-based materials was evaluated with lactate dehydrogenase (LDH) cytotoxicity assay toward human dermal fibroblasts (HDF) and retinal pigment epithelium cells (RPE), which demonstrated over 85% cell viability after 7 days of incubation.