Drug delivery with microsecond laser pulses into gelatin

Area of Science:

• Biomedical Engineering
• Acoustic Sciences
• Drug Delivery Systems

Background:

• Photoacoustic drug delivery offers localized therapeutic potential.
• Cavitation bubbles generated by laser pulses are key to this technique.
• Understanding bubble dynamics is crucial for optimizing drug delivery.

Purpose of the Study:

• To investigate photoacoustic drug delivery mechanisms.
• To evaluate drug penetration in gelatin-based thrombus models.
• To determine the role of cavitation in localized delivery.

Main Methods:

• Utilized microsecond laser pulses on gelatin thrombus models.
• Employed a hydrophobic dye in mineral oil to visualize delivery.
• Observed cavitation bubble dynamics and drug penetration using flash photography.

Main Results:

• Cavitation bubble dynamics were identified as the primary driver of photoacoustic drug delivery.
• The deepest penetration of delivered dye occurred post-bubble collapse.
• Dye penetration reached millimeters axially and radially, but was limited to <500 µm in intact gelatin structures.

Conclusions:

• Cavitation is the governing mechanism in photoacoustic drug delivery.
• Laser-induced cavitation enables localized drug transport within thrombus models.
• Further research can optimize this technique for targeted therapeutic applications.