Synthetic Peptide Antibodies as TNF‐α Inhibitors: Molecularly Imprinted Polymer Nanogels Neutralize the Inflammatory Activity of TNF‐α in THP‐1 Derived Macrophages

Tumor Necrosis Factor‐α (TNF‐α) is a cytokine that is normally produced by immune cells when fighting an infection. But, when too much TNF‐α is produced as in autoimmune diseases, this leads to unwanted and persistent inflammation. Anti‐TNF‐α monoclonal antibodies have revolutionized the therapy of these disorders by blocking TNF‐α and preventing its binding to TNF‐α receptors, thus suppressing the inflammation. Herein, we propose an alternative in the form of molecularly imprinted polymer nanogels (MIP‐NGs). MIP‐NGs are synthetic antibodies obtained by nanomoulding the 3‐dimensional shape and chemical functionalities of a desired target in a synthetic polymer. Using an in‐house developed in silico rational approach, epitope peptides of TNF‐α were generated and ‘synthetic peptide antibodies’ were prepared. The resultant MIP‐NGs bind the template peptide and recombinant TNF‐α with high affinity and selectivity, and can block the binding of TNF‐α to its receptor. Consequently they were applied to neutralize pro‐inflammatory TNF‐α in the supernatant of human THP‐1 macrophages, leading to a downregulation of the secretion of pro‐inflammatory cytokines. Our results suggest that MIP‐NGs, which are thermally and biochemically more stable and easier to manufacture than antibodies, and cost‐effective, are very promising as next generation TNF‐α inhibitors for the treatment of inflammatory diseases. TNF‐α inhibitors, drugs based on monoclonal antibodies, are currently used to treat inflammatory diseases. Synthetic peptide antibodies based on molecularly imprinted polymer nanogels (MIP‐NGs) can be promising alternatives. MIP‐NGs neutralize biologically active TNF‐α secreted in the supernatant of lipopolysaccharide (LPS)‐induced human THP‐1 derived macrophages. Consequently, TNF‐α cannot bind to its receptor, suppressing inflammatory responses.