[Application of laser capture microdissection in screening phage-display peptide library from osteosarcoma tissues]

To establish a novel approach by using laser capture microdissection (LCM) for phage-display peptide library screening and direct recovery of the peptides specifically bound to the cells from fresh human tissue.

Fresh human osteosarcoma (OS) tissue specimens obtained from biopsy were incubated in phage peptide library solution, followed by shaking at 4 degrees celsius and subsequent preparation of frozen sections. Immunohistochemistry was employed to examine the infiltration of the phage in the tissues. After modification to improve the viability of the phage during the operation, LCM was used to isolate the targeted tumor cells that specifically bound the phage peptides. The phage was then recovered by transfecting the host bacteria, and the specificity of the selected phage was assessed by calculating the recovered phage transfection unit on different tissue sections.

Enough phages that specifically bound to tumor cells were recovered from the sections. After three rounds of screening, the eluted phage showed up to 16-fold selectivity for OS tissue.

Application of LCM makes it possible to screen phage display peptide library directly from fresh human tissue. Specific cell-binding peptides can be selected directly from fresh human tumor cells in their native tissue environment at the single cell level.