Biopharmaceuticals, also known as biotechnological drugs, have revolutionized the treatment of many diseases by providing access to new mechanisms of action that can target the underlying biological processes behind the diseases. Technological advancement in biological sciences opens new paths to uncover new biopharmaceutical modalities in nature as well as to augment the existing modalities new functions. The implementation of engineering principles i.e., synthetic biology approaches have been transforming biopharmaceutical research wherein “smart” therapeutics are developed and deployed for treatment of previously intractable diseases. However, there are still unmet clinical needs that require novel and advanced biopharmaceuticals. In this thesis, I explored different biopharmaceuticals to characterize and/or advance their capabilities for diverse indications. Firstly, we have developed a prophylactic agent from the lectin protein, griffithsin, as for ancestral and the emerged strains of SARS-CoV-2. Secondly, we have advanced genetic technologies to engineer the probiotic Escherichia coli (E. coli) strain, Nissle 1917 (EcN), for therapeutical purposes. We developed a stable recombinant DNA transfer system based on cryptic plasmids of EcN. Furthermore, a synthetic protein secretion system was envisioned and functionally validated in EcN to shuttle therapeutical proteins to diseases site. Finally, peptide tags for extracellular protein secretion as well as a cell surface protein display system were developed for Lachnospiraceae species which are parts of the healthy human gut microbiome. The technologies and methodologies described herein will pay the way for inventing and/or discovering novel biopharmaceuticals to treat current and future diseases.