Biological laser printing (BioLP) for high resolution cell deposition

Biological laser printing, or BioLP, is a modified laser induced forward transfer (LIFT) technique that has the demonstrated ability to print cells from living cultures and paraffin-embedded fixed tissue sections. Detailed studies have been published that demonstrate the energy conversion layer used by BioLP to absorb incident laser energy and promote forward transfer of biological materials prevents damage to the printed cells. Additionally, this layer helps maintain reproducible transfer conditions so that large arrays and patterns of cells can be precisely generated down to the single cell level. BioLP's nozzle-free print head allows both liquids and solids to be printed with micron-scale resolution and is unique to modified LIFT technologies. This chapter will describe recent experiments that applied BioLP to two distinct applications of cell printing: regenerative medicine and tissue microdissection. Specifically, three dimensional patterns of olfactory ensheathing cells (OECs) were created and the application of these scaffolds to spinal cord repair will be discussed. High resolution stem and branch patterns of human umbilical vein endothelial cells (HUVECs) have also been created by BioLP. These patterns show controlled differentiation and lumen formation along the printed pattern. Co-culture printing experiments were also performed where the natural vascular structure of endothelial and smooth muscle cell contacts are explored as well as interactions between OECs and rat cortical neurons. We will also discuss the use of BioLP as a tissue microdissection tool. We show examples of prostate tissue dissection where single malignant cells are removed from a prepared tissue section.