Tinware-Inspired Aerobic Surface-Initiated Controlled Radical Polymerization (SI-Sn⁰CRP) for Biocompatible Surface Engineering

Abstract

Surface anchored polymer brushes prepared by surface-initiated controlled radical polymerization (SI-CRP) have raised considerable interest in biomaterials and bioengineering. However, undesired residues of noxious transition metal catalysts critically restrain their widespread biomedical applications. Herein, we present a robust and biocompatible surface-initiated controlled radical polymerization catalyzed by a Sn(0) sheet (SI-Sn 0 CRP) under ambient conditions. Through this approach, microliter volumes of vinyl monomers with diverse functions (heterocyclic, ionic, hydrophilic, and hydrophobic) could be efficiently converted to homogeneous polymer brushes. The excellent controllability of SI-Sn 0 CRP strategy is further demonstrated by the exquisite fabrication of predetermined block and patterned polymer brushes through chain extension and photolithography, respectively. Additionally, in virtue of intrinsic biocompatibility of Sn, the resultant polymer brushes present transcendent affinity toward blood and cell, in marked contrast to those of copper-based approaches. This strategy could provide an avenue for the controllable fabrication of biocompatible polymer brushes toward biological applications.

Surface-Initiated Zerovalent Metal-Mediated Controlled Radical Polymerization (SI-Mt0CRP) for Brush Engineering

“…On the other hand, it has been demonstrated that the presence of an additional Cu II -based deactivator with respect to that generated through the ATRP equilibrium suppresses irreversible termination reactions. 56,57 In this scenario, SI-Mt 0 CRP could be described by the SARA ATRP mechanism, 56 as the same case of other zerovalent metals, including Fe(0) 43,44 and Sn(0) 4 (Figure 7a and 7b).…”

“…Ed.20211331373313737 WuD.YinX.ZhaoY.WangY.LiD.YangF.WangL.ChenY.WangJ.YangH.LuG.LiuX.LiuF.ZhangT. Wu, D. Yin, X. Zhao, Y. Wang, Y. Li, D. Yang, F. Wang, L. Chen, Y. Wang, J. Yang, H. Lu, G. Liu, X. Liu, F. Zhang, T. 10.1021/acsmacrolett.2c005562023127176 …”

“…Although the SI-CRP in the presence of zerovalent copper has been extensively studied, the undesired accumulation of the noxious Cu species on the polymer matrix critically restrains the widespread application in biomaterials and bioengineering. , To tackle this problem, Benetti’s group substituted the copper plate with an iron plate and reported the SI-Fe 0 ATRP, which could generate in situ polymer brushes in the presence of live articular chondrocytes under ambient conditions without affecting cell viability . Recently, inspired by the biosafety of tinware, we showed that a Sn 0 sheet could be directly used as the only catalyst for SI-CRP (SI-Sn 0 CRP) to fabricate biocompatible polymer brushes under ambient condition (Figure a) . The resultant polymer brushes by SI-Sn 0 CRP showed superior affinity toward blood and cells (lower hemolysis rate (<5%, Figure b) and above 90% cell viability (Figure c) even after 72 h of incubation, overwhelming those of copper-based approaches.…”

“…However, SI-CRP strategies have long been suffering from poor polymerization efficiency, rigorous inert atmosphere, and vast consumption of transition-metal halide catalysts and monomer solution . To overcome these obstacles, a series of innovative and powerful techniques have been explored, triggered by various external stimuli such as electrochemistry, − the addition of a reducing agent, , photochemistry, − enzymes, microbial metabolism, and the use of zerovalent metals. ,− Among these, using zerovalent metals in SI-CRP is not brand new as it has been widely used in traditional supplemental activator and reducing agent atom-transfer radical polymerization (SARA ATRP) . In 2015, our group first reported the surface-initiated Cu(0)-mediated CRP (SI-Cu 0 CRP), , which succinctly used a copper plate as the catalyst but no additional Cu I/II species, coupled with ligand and monomer mixtures.…”

“…Notably, this concept has been expanded to the other metal plate systems, and various zerovalent transition metals (such as Fe, , Zn, − and Sn) have been explored to catalyze the SI-CRP (Figure ). Because of its diverse characteristics and advantages, SI-Mt 0 CRP has become a prevalent technique for preparing functional polymer brushes with great application potential in the fields of surface lubrication, − sensing platforms, , biomedical engineering, , and blue energy harvesting. , …”