Scientists Successfully Transplant Chloroplasts into Animal Cells, Opening New Frontiers in Tissue Engineering

A team of Japanese scientists has achieved a groundbreaking feat by successfully transplanting chloroplasts—organelles responsible for photosynthesis in plants and algae—into animal cells, retaining their functionality. This innovative research was led by Professor Yukihiro Matsunaga from the University of Tokyo and represents a significant step toward integrating plant-like capabilities into animal cells.  

Chloroplasts are believed to have evolved over a billion years ago when photosynthetic cyanobacteria began living symbiotically within primitive cellular organisms. Recreating this process in modern animal cells was previously thought impossible, as animal cells typically digest chloroplasts as foreign invaders.  

Using chloroplasts from the algae Cyanidioschyzon, the researchers transplanted them into Chinese hamster ovary (CHO) cells, a cultured animal cell line. By promoting phagocytosis, the process by which cells engulf foreign substances, they successfully integrated photosynthetically active chloroplasts into the cytoplasm of the animal cells.  

Advanced imaging techniques, such as fluorescence laser microscopy and super-resolution microscopy, revealed that some chloroplasts remained near the cell nucleus and maintained their photosynthetic activity for up to two days. However, by the fourth day, the thylakoid membrane structure—essential for photosynthesis—began to deteriorate, leading to reduced activity.  

This discovery could revolutionize tissue engineering, particularly in environments with low oxygen levels. Artificial organs, meat, or multilayered skin sheets could benefit from chloroplast-enhanced cells that generate oxygen under light exposure, promoting growth and functionality.  

To advance this technology, the researchers aim to extend the lifespan of photosynthetic activity in transplanted chloroplasts and quantify their oxygen and carbon dioxide exchange using isotope labeling techniques.  

The ultimate goal of the research is to create "planimal" cells—animal cells with plant-like capabilities. Such cells could have transformative applications across industries, including medicine, food production, and energy generation.  

This pioneering study not only bridges the gap between plant and animal biology but also opens new horizons for sustainable innovations in various fields.