Enzyme mimicry is a topic of considerable interest in the development of multifunctional biomimetic materials. Mimicking enzyme activity is a major challenge in biomaterials research, and artificial analogs that simultaneously recapitulate the catalytic and metabolic activity of native enzymes are considered to be the ultimate goal of this field. This consensus may be challenged by self‐assembling multifunctional nanostructures to develop close‐to‐fidelity enzyme mimics. Here, the ability of fullerene nanostructures decorated with active units to form enzyme‐like materials that can mimic phosphatases in a metal‐free manner is presented. These nanostructures self‐assemble into nanoclusters forming multiple random active sites that can cleave both phosphomonoesters and phosphodiesters while being more specific for the phosphomonoesters. Moreover, they are reusable and show an increase in catalytic activity over multiple cycles similar to their natural counterparts. In addition to having enzyme‐like catalytic properties, these nanocatalysts imitate the biological functions of their natural analogs by inducing biomineralization and osteoinduction in preosteoblast and mesenchymal stem cells in vitro studies.
Self-assembling enzyme mimics offer
an easy way to imitate
activities
of natural enzymes but have not been thus far used to understand the
effect of different amino acids on the catalytic activity and why
they are evolutionarily preserved for specific catalytic roles. Here,
we demonstrated that fullerene nanostructures functionalized with
catalytically active amino acids, which form multiple active sites
via the self-assembly process in the aqueous environment, serve as
an effective system to distinguish the catalytic activity differences
resulting from single amino acid changes. A nano-level tuning of intermolecular
and intramolecular interactions enabled formation of efficient enzyme
mimics. Furthermore, using the carboxyl–imidazole couple found
in quite different enzymes as the main catalytic unit, we could mimic
different enzyme classes, like hydrolases and lyases, with significant
catalytic activities. These designed nanocatalysts were also reusable
and catalytically active under physiological conditions like natural
enzymes.
The major drawbacks of metal‐based implants are weak osseointegration and post‐operational infections. These limitations restrict the long‐term use of implants that may cause severe tissue damage and replacement of the implant. Recent strategies to enhance the osseointegration process require an elaborate fabrication process and suffer from post‐operative complications. To address the current challenges taking inspiration from the extracellular matrix (ECM), the current study is designed to establish enhanced osseointegration with lowered risk of infection. Natural biopolymer pectin, peptide amphiphiles, and enzyme‐mimicking fullerene moieties are governed to present an ECM‐like environment around the implant surfaces. This multifunctional approach promotes osseointegration via inducing biomineralization and osteoblast differentiation. Application of the biopolymer‐based composite to the metal surfaces significantly enhances cellular attachment, supports the mineral deposition, and upregulates osteoblast‐specific gene expression. In addition to the osteoinductive properties of the constructed layers, the inherent antimicrobial properties of multilayer coating are also used to prevent infection possibility. The reported biopolymer‐artificial enzyme composite demonstrates antimicrobial activity against Escherichia coli and Bacillus subtilis as a multifunctional surface coating.
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