Synthetic Biology: Marking the Dawn of a New Era in Medicine

What does synthetic biology mean for medicine? 

Synthetic biology introduces the concept of modularity. By leveraging a broader range of "inputs" and "outputs," using DNA as the fundamental coding element, and guided by existing biological knowledge, synthetic biology enables the coupling of multiple genes or biomolecules. These are then assembled into functional biological modules, which are ultimately integrated into systems to achieve biological functions that are not found in nature but are essential for human needs.

This paradigm shift drives transformative changes and applications in medical systems thinking across three distinct phases: accelerating the production of medical drugs, iterating rapid disease detection, and revolutionizing precision disease treatment.

1. Synthetic Biology Accelerates the Production of Drug Molecules

The biomanufacturing process for drug molecules involves three critical steps: the manipulation and generation of chassis cells, the construction and integration of molecular synthesis pathways, and the artificial regulation and enhancement of enzymes within metabolic networks. For the production of specific drug molecules in cellular factories, "engineerable chassis" are typically chosen, with prominent examples including E. coli, Saccharomyces cerevisiae (brewer's yeast), and Chinese Hamster Ovary (CHO) cells.

Advancements in synthetic biology have significantly accelerated this process, for instance, by constructing artificial cells with minimized genomes as more controllable chassis, incorporating non-standard amino acids into metabolic reconstruction, and enabling the creation of novel enzymes. Numerous impressive application results have already been achieved, including laboratory-scale production of cannabinoids, monoterpene indole alkaloids (MIAs), and non-natural amino acid drugs, as well as factory-scale production of amorphadiene and ginsenosides.

2. Synthetic Biology Enhances Disease Diagnosis

Traditional diagnostic methods, such as imaging and biochemical assays, may not accurately diagnose all types of diseases, especially in their early stages or when symptoms are atypical. However, the rapid development of DNA and RNA sequencing technologies allows for the direct extraction of genetic material from patient samples, enabling precise disease identification and risk assessment based on genotype.

Sequencing technology also demonstrates high sensitivity and specificity in pathogen diagnosis, facilitating rapid detection and comprehensive identification of viruses, bacteria, fungi, and parasites. Even for diseases with prior knowledge, the etiology of up to 60% of infectious diseases remains unknown. For emerging, rare, or challenging infectious diseases, sequencing technology offers significant advantages not available through traditional diagnostics.

3. Synthetic Biology Revolutionizes Disease Treatment

Disease treatment presents a quintessential challenge in medicine, requiring two fundamental steps to address the body's inherent response to illness: precise localization of affected sites and the implementation of effective therapies. The advent of synthetic biology has fundamentally transformed disease treatment approaches. It embodies a paradigm of programmable design, a concept manifested across various stages and responsive to diverse intracellular and exogenous signals.

Looking ahead, this overview focuses on several groundbreaking strategies, including gene editing, therapeutic nucleic acid drugs, cell therapy, virus-based disease treatment, bacterial therapies, and various organoid applications.

Gene editing stands as one of the most powerful and versatile tools in synthetic biology, holding immense potential for next-generation gene therapies. This overview primarily reviews advancements in using gene editing tools for treating genetic diseases, with a focus on CRISPR-Cas, base editing, and prime editing, as well as their applications in monogenic diseases and complex diseases involving polygenic mutations.

Therapeutic nucleic acids represent a new generation of drug technology, emerging as promising candidates in the biomedical field. These are modified RNA or DNA molecules with diverse functions, designed to treat diseases at the genetic level and achieve sustained therapeutic effects. Several therapeutically relevant nucleic acid modalities have been developed, including DNA vaccines, RNA vaccines, and programmable molecules such as microRNA (miRNA), small interfering RNA (siRNA), and antisense oligonucleotides (ASOs). These tools are either approved or undergoing clinical trials.