For the first time, scientists have successfully engineered animal cells to capture energy from light, a feat usually reserved for plants and algae. Researchers at the University of Tokyo inserted chloroplasts – the tiny biological engines that drive photosynthesis – into cultured hamster cells. Surprisingly, these foreign structures were not immediately destroyed; instead, they continued to function for at least two days, producing energy and helping the animal cells grow faster.
This breakthrough challenges the long-held biological rule that animal cells simply digest and destroy foreign plant material. By creating these hybrid “planimal” cells, the team has opened a new door for tissue engineering. The ability to generate oxygen and energy from light could solve one of the biggest hurdles in growing artificial organs and lab-grown meat: keeping the inner layers of thick tissue alive.
Scientists put algae engines into hamster cells
In nature, animals eat plants to get energy, while plants make their own energy from sunlight using specialized structures called chloroplasts. Animal cells lack these structures and typically treat them as invaders or food if they encounter them. For decades, biologists believed that transplanting functional chloroplasts into animal cells was impossible because the animal cells would quickly break them down.
A team led by Professor Sachihiro Matsunaga at the University of Tokyo found a way around this problem. They chose chloroplasts from a specific type of primitive red algae called Cyanidioschyzon merolae. Unlike most plant chloroplasts, which prefer cooler temperatures, these algal chloroplasts are robust and can function at the higher temperatures typical of mammalian bodies.
The researchers introduced these algal chloroplasts into cultured cells taken from hamsters (specifically, Chinese hamster ovary cells). Instead of digesting the new arrivals, the hamster cells accepted them. The chloroplasts settled near the cell nucleus and mitochondria, the cell’s own power plants. This kind of cross-species integration reminds us of other recent biotech advances, such as engineered bacterial networks that mimic neural systems.
The hybrid cells worked for two days
Once the chloroplasts were inside, the key question was whether they would actually work. The team used specialized light pulses and microscopy to check for signs of photosynthesis.
They confirmed that the chloroplasts continued to perform photosynthetic electron transport – the first step in turning light into chemical energy – for at least two days inside the animal environment. This is the first time such activity has been detected in mammalian cells.
The effect on the hamster cells was measurable. When exposed to light, the cells containing chloroplasts grew faster than normal cells. This suggests that the chloroplasts were acting like an internal fuel source, providing carbon and energy that the animal cells could use to build new tissue.
Why this matters for medicine and lab-grown meat
This discovery is not just a biological curiosity; it addresses a practical bottleneck in biotechnology. When scientists try to grow artificial tissues – whether for medical transplants, skin grafts, or lab-grown meat – they face a “limit of thickness.”
Cells on the outside of a tissue clump can easily get oxygen and nutrients from the liquid around them. However, cells deep inside often starve or suffocate because oxygen cannot reach them fast enough. This condition, called hypoxia, prevents tissues from growing large or complex.
Professor Matsunaga suggests that “planimal” cells could solve this. By mixing these photosynthetic cells into a tissue structure, researchers could shine a light on the growing tissue to generate oxygen right where it is needed most. This internal supply could allow lab-grown organs and meats to grow thicker and healthier than is currently possible. This mirrors progress in other regenerative fields, such as the recent stem cell transplant that restores insulin production in diabetes patients.
Sources & related information
Proceedings of the Japan Academy – Incorporation of photosynthetically active algal chloroplasts – 2024
Researchers incorporated chloroplasts from red algae into cultured hamster cells, where they maintained photosynthetic electron transport for two days and boosted cell growth.
University of Tokyo – Solar-powered animal cells – 2024
The university explains how Professor Sachihiro Matsunaga’s team achieved this hybrid state and discusses the potential applications for “planimal” cells in green transformation and tissue engineering.
Techno-Science – Researchers modify animal cells and enable them to perform photosynthesis – 2024
A summary of the method used to introduce chloroplasts into mammalian cells and the implications for overcoming hypoxia in artificial tissues.
0 Comments