Molly Stevens: A new way to grow bone

Summary

The speaker, head of a biomaterials lab, discusses the historical and modern use of materials in the body, from the Mayans' use of blue nacre shell to modern regenerative medicine. They highlight the shift from bioinert to bioactive materials and showcase their lab's innovative approach to bone repair using the 'in vivo bioreactor' method, which stimulates bone growth on demand. The talk also touches on the challenges and potential of applying these techniques to cardiovascular disease.

Takeaways

• 🌐 Humans have a natural desire to improve health and minimize suffering, leading to creative uses of materials in the body.
• 🐚 The Mayans used blue nacre shells as artificial tooth replacements, demonstrating early biomaterial integration.
• 👨‍⚕️ Sir Harold Ridley's observation of plastic shards in pilots' eyes during WWII led to the development of PMMA for intraocular lenses, highlighting the importance of bioinert materials.
• 🔬 Regenerative medicine has shifted from using bioinert materials to bioactive ones that interact with the body and dissolve over time.
• 🧪 The speaker's lab focuses on simplifying tissue engineering by eliminating the need for patient-derived cells, complex chemistries, and lab culturing of scaffolds.
• 🦴 Bone repair is a significant area of focus, with the lab developing methods to regenerate bone on demand, such as the in vivo bioreactor approach.
• 💉 The in vivo bioreactor technique involves injecting a liquid under the periosteum that solidifies into a gel, lifting the periosteum and stimulating bone growth.
• 🦴 The new bone grown in the bioreactor can be harvested and used elsewhere in the body, offering a less painful alternative to traditional bone grafts.
• 🔬 The lab also explores materials that mimic the structure and properties of natural tissues, such as hybrid organic-inorganic matrices in bone.
• 💓 Efforts are being made to apply biomaterial science to cardiovascular disease, focusing on materials that can support cell survival and regeneration in the heart.

Q & A

What is the speaker's profession and area of interest?

The speaker is the head of a biomaterials lab and is fascinated by the creative ways humans have historically used materials within the body.

Why were the Mayans using blue nacre shells as artificial tooth replacements?

The exact reasons are not clear, but the blue nacre shells were hard, durable, and had the ability to integrate into the jawbone due to their specific design and chemistry.

How did Sir Harold Ridley's observation during World War II lead to a medical innovation?

Sir Harold Ridley noticed that pilots had plastic shards from Spitfire canopies in their eyes without inflammation. This led him to propose PMMA as a material for intraocular lenses, which is now widely used to prevent cataracts.

What is the difference between the historical use of bioinert materials and the current approach in regenerative medicine?

Historically, bioinert materials were used to perform mechanical functions without causing adverse responses. In contrast, regenerative medicine seeks bioactive materials that interact with the body and dissolve over time.

What is the typical approach in tissue engineering?

The typical tissue-engineering approach involves using cells from the patient, often placed onto a material scaffold, which can be grown in the lab or implanted directly into the patient.

Why is it important to consider the environment for stem cells when regenerating tissues?

Stem cells can differentiate into many types of tissues, so the environment must provide enough information to guide them into becoming the correct type of specialized tissue.

What is the concept of an 'in vivo bioreactor' mentioned by the speaker?

The 'in vivo bioreactor' is an approach where a liquid is injected under the periosteum layer of stem cells, forming a rigid gel that lifts the periosteum away from the bone, creating an artificial cavity that stimulates stem cell proliferation and new tissue formation.

How does the 'in vivo bioreactor' technique differ from traditional bone repair methods?

The 'in vivo bioreactor' technique eliminates the need for cell harvesting, complex chemistries, and lab culture of scaffolds. It uses the body's own stem cells and materials to generate new bone on demand, with less pain and complications compared to traditional methods like iliac crest harvest.

What was the unusual request the speaker received after presenting their work on bone regeneration?

The speaker received a request from a team of American football players who wanted to have double-thickness skulls made, presumably for added protection.

How does the speaker's team approach the design of biomaterials for regenerative medicine?

The team, which includes chemists, cell biologists, surgeons, and physicists, focuses on understanding the structure of body tissues and designing materials with the right balance of information to guide cell behavior without being overly complex for clinical application.

What is the potential application of the developed materials in cardiovascular disease?

The materials could potentially be used to prevent dead heart tissue from dying further or to help it regenerate, addressing the clinical problem of heart attacks and tissue death.