Short Wave — “Synthetic Cells: The Next Bioengineering Frontier”

NPR, October 13, 2025 | Host: Regina Barber | Guests: Kate Ademala (University of Minnesota), Drew Endy (Stanford University)

Episode Overview

This episode explores the rapidly advancing field of synthetic biology—specifically, the quest to build a living cell from non-living components. Host Regina Barber is joined by synthetic cell pioneers Kate Ademala and Drew Endy. Together, they demystify why building synthetic cells is so challenging, what it might enable for bioengineering and medicine, and how approaching life from scratch opens up new ways to understand biology at the most fundamental level. The conversation is colorful, accessible, and full of creative analogies, making the fascinating frontier of synthetic cells understandable—and exciting.

Key Discussion Points & Insights

1. What Makes Living Cells So Complex?

• Vast Numbers, Small Scales
  • Humans contain around 30 trillion cells—far outnumbering the stars in the Milky Way (00:25).
  • Despite centuries of study, we still lack a full “ingredient list” for even the simplest living cell.
• The “Black Box” of Biology
  • “There is no natural living cell that we can have a full chemical ingredient list for… it's kind of like a black box.”
    — Kate Ademala (00:50)
  • Complexity means a trial-and-error approach (“tinker and test”) dominates current bioengineering efforts (01:15).

2. The Synthetic Cell Dream: Goals and Possibilities

• Why Build Synthetic Cells?
  • Synthetic cells could be programmed to:
    • Enable new cancer therapies
    • Manufacture medicines more efficiently
    • Support green energy projects (artificial photosynthesis/fuels)
      (02:03)
  • The field promises fundamental scientific insights and practical applications.
• Still Mystery at the Core
  • “As the engineers learn how to construct cells, there will still be profound mysteries… that will lurk underneath.”
    — Drew Endy (02:30)
• Turning Science into Engineering
  • Building cells is transitioning from a speculative project to a systematic, engineering-driven enterprise.
  • “Building cells from scratch is no longer a research project. It's now an engine...”
    — Drew Endy (02:47)

3. Visualizing the Cell: A Walkthrough

• “Building as a Cell” Analogy (Discussion: 04:25–07:31)
  • To understand a cell’s complexity, imagine scaling it up to the size of a large building (100 meters):
    • Proteins become the size of basketballs.
    • Ribosomes (the protein-makers) are person-sized.
    • DNA would be kilometers long, packed and coiled through the “building.”
    • Cells are packed almost like a hoarder’s bookstore, with 20–40% filled with “stuff” (molecules).
  • “Imagine a bookstore that's 50% full of books and you could just barely move through it…”
    — Drew Endy (06:26)
  • Everything inside is in constant rapid motion—the “basketball”-sized protein zips through the full “building” in a second.
  • This level of chaotic, dynamic activity is what makes cellular replication so mysterious and hard to model.

4. Building a Cell from Scratch: The Synthetic Approach

• Engineering a Predictable Bookstore
  • “The synthetic cell would be like a bookstore that you're filling one shelf at a time... Because we built it from the parts that we know about and we know what they're supposed to be doing, then we can actually understand and most importantly, predict where they go.”
    — Kate Ademala (07:43)
  • Control, predictability, and understanding are core motivations.
• Bottom-Up vs. Top-Down Approaches (08:40–12:36)
  • Three Lineages in Synthetic Biology:
    1. Origins of Life Researchers: Recreating early cells to study life's beginnings.
    2. Minimal Genomes: Stripping existing cells down to basics for insight into essential functions.
    3. Engineers: Building new systems from molecular parts—now capable of assembling complex gene circuits (09:08–09:59).
  • Past “synthetic cells” often relied on “top-down” genetic swaps—using a living host cell. True synthetic cells involve assembling from nonliving components—a “bottom up” process that offers full creative control.
  • “When Kate's talking about building a cell from scratch, we are not subject to [lineage] constraint because she gets to choose every block of DNA that goes into that system.”
    — Drew Endy (11:01)
  • Analogy to LEGO or Minecraft: leaving an existing world (“lineage land”) to create entirely new biology from scratch (12:00–12:36).

5. How Close Are We? What Counts as Synthetic Life?

• Defining Life Itself is Tricky
  • “There is no good definition of life… if it quacks like a cell, moves like a cell, then it's starting to be a cell-like entity, and that's where the field is.”
    — Kate Ademala (13:04)
  • Current synthetic systems perform many cell-like functions, but aren’t as complex as natural cells (13:04–13:29).
  • Progress is rapid and ongoing; this isn’t just science fiction or a dream for future decades.

6. Why It Matters

• Delivering the Promise of Bioengineering
  • “Building a cell from scratch is absolutely essential to realize the promise of bioengineering… we cannot keep running our economy on petrochemicals, on oil. We have to build more equitable economy. We have to really understand biology on this very fundamental molecular level. And all those things will not happen unless we truly understand this very basic building block, which is a cell.”
    — Kate Ademala (13:46)
  • Only by building and understanding cells at the fundamental level can science and engineering deliver on promises of greener, more sustainable, and equitable products and industries.

Notable Quotes & Memorable Moments

• “Biology, from the chemical point of view, is actually really boring... it uses only 22 amino acids out of hundreds possible... We want to do things that biology never bothered doing.”
  — Kate Ademala (01:41)
• On the “cell as hoarder" analogy:
  “It's like a hoarder of molecules.” — Drew Endy (06:26)
  “It's like those terrible bookstores… get organized!” — Regina Barber (06:28)
• “I would love for somebody to build a building that's a cell…” — Drew Endy (05:22)
• On possibility and creativity:
  “Every time you build something, you're limiting the possibilities because you have to make choices. And biology has been making those choices for over 3 billion years… we're now revisiting all those alternatives. That's the fascinating part...”
  — Kate Ademala (12:36)

Timestamps for Key Segments

• [00:25] – Introduction: The sheer number and complexity of cells
• [01:01] – Introducing Kate Ademala; the black box of cellular biology
• [01:41] – Amino acids, biological limitations, and synthetic possibilities
• [02:03] – Potential societal applications of synthetic cells
• [04:25] – Visualizing a cell as a giant building; scaling up biology
• [07:43] – The engineered “inventory” of a synthetic cell
• [08:40] – Historical groups and approaches in synthetic biology
• [10:21] – The distinction between synthetic genomes and synthetic cells
• [11:01] – Escaping lineage: bottom-up synthetic cellular engineering
• [12:36] – Revisiting alternative biological solutions
• [13:04] – How close are we? What qualifies as life?
• [13:46] – Why this work matters for the future of science, engineering, and society

Tone and Language

The episode blends scientific rigor with playful analogies and an encouraging, open-minded tone. Both guests and the host frequently use metaphors and pop culture references (e.g., bookstores, LEGOs, Minecraft) to clarify concepts, making the topic approachable for all listeners.

This summary captures the major themes, technical insights, and quotable moments from an engaging, thought-provoking episode that welcomes everyone into the vanguard of what might soon be a new era in biology—and engineering.