Controlling Drug Partitioning in Individual Protein Condensates through Laser-Induced Microscale Phase Transitions

Area of Science:

• Biomaterials Science
• Protein Engineering
• Biophysics

Background:

• Protein condensates are crucial in biological processes, from biomaterial assembly to disease-related aggregation.
• Controlling the soluble-to-gel (sol-gel) transition in these condensates is vital for biomedical applications.
• Current methods for inducing sol-gel transitions rely on bulk changes (temperature, buffer) and occur over minutes to hours.

Purpose of the Study:

• To investigate spontaneous and externally triggered sol-gel transitions in engineered mini-spidroin condensates.
• To explore the potential for precise control over condensate gelation for functional applications.
• To demonstrate the trapping of target proteins within spidroin microgels.

Main Methods:

• Utilized microscopy and mass spectrometry to analyze condensate behavior.
• Engineered a mini-spidroin (NT2repCT^YF) for condensate formation.
• Applied laser pulses to induce gelation and observed effects on encapsulated molecules.

Main Results:

• Engineered spidroin condensates exhibited spontaneous sol-gel transitions, trapping proteins.
• Laser pulses triggered near-instantaneous gelation of individual condensates.
• Gelation wavelength could be controlled by loading condensates with specific dyes or drugs.
• Laser-induced gelation enhanced the partitioning of fluorescent molecules into condensates.

Conclusions:

• Demonstrated direct, localized control over phase transitions in protein condensates via laser stimulation.
• This precise control offers new possibilities for functional and structural characterization of biomolecular condensates.
• Opens avenues for advanced biomaterial design and targeted drug delivery systems.