Two-Photon 3D Printing of Functional Microstructures Inside Living Cells.

Area of Science:

• Biotechnology
• Materials Science
• Cell Biology

Background:

• 3D printing has revolutionized manufacturing and biomedicine but has not been achieved within living cells.
• Existing methods lack the ability to deliver micron-scale, free-standing solid microstructures into the cytosol of non-phagocytic cells.

Purpose of the Study:

• To demonstrate the feasibility of fabricating custom-shaped polymeric microstructures directly inside living cells.
• To overcome the limitations of current intracellular fabrication and delivery methods.

Main Methods:

• Utilized two-photon polymerization with a femtosecond laser to selectively polymerize a biocompatible photoresist injected into cells.
• Achieved intracellular structures with submicron resolution, enabling the printing of various shapes and functional components.

Main Results:

• Successfully printed diverse structures within live cells, including a 10 µm elephant, cell-tracking barcodes, diffraction gratings, and microlasers.
• Demonstrated that the printed intracellular structures can influence cell biology.

Conclusions:

• Developed a top-down intracellular biofabrication approach for creating functional microstructures within living cells.
• This technique opens new avenues for intracellular sensing, biomechanical manipulation, bioelectronics, and targeted drug delivery, potentially enabling engineering of cellular properties beyond natural limits.