• Existing methods of intracellular delivery have limitations in terms of transfection efficiency, precision, and cell viability.
• Lack of a reliable and efficient method for intracellular delivery of biomolecules while maintaining cell viability.
• Need for a technique that offers precise targeting, enhanced delivery efficiency, and non-invasive delivery.
• Current methods often result in low delivery efficiency or damage to cells.
• Demand for a solution that overcomes limitations and enables successful intracellular delivery for various applications in medicine, biotechnology, and genetic research.

The invention provides a method for delivery of biomolecules via nanosecond pulse laser mediated photoporation. The invention also includes a process for the preparation of the metal ring microstructure and process for intracellular delivery using the microstructure.

• The principal of the invention is to provide the step-by-step process of fabricating the metal ring microstructure.The photoresist-coated substrate is exposed to UV light to form a patterned photoresist substrate.
• A metal layer (such as Titanium or Gold) is deposited onto the patterned photoresist substrate using e-beam evaporation technique, resulting in a metal patterned photoresist substrate.
• The photoresist is stripped off from the metal patterned substrate using acetone, leaving behind the metal ring microstructure. (Fig.1)
• The metal ring microstructure device is placed on cultured cells in a petri dish. Then the nanosecond pulsed laser is used to assist the delivery of biomolecules into the cells through photoporation.
• Laser pulses create temporary pores in the cell membrane, enabling the entry of biomolecules. Delivery of biomolecules is detected by scanning the cells using a confocal microscope with specific excitation/emission filters. The cells remain viable even after biomolecule delivery.(Fig. 2)