Provided 
nucleic acid- based expression construct for the target 
cell-specific production of a 
therapeutic protein, such as a pro-apoptotic 
protein, within a target 
cell, including a target 
cell thatis associated with aging, 
disease, or other condition, in particular a target cell that is a 
senescent cell or a 
cancer cell. Also provided are formulations and systems, including fusogenic lipid 
nanoparticle (LNP) formulations and systems, for the delivery of 
nucleic acid-based expression constructs as well as methods for making and using such 
nucleic acid-based expression constructs, formulations, and systems for reducing, preventing, and / or eliminating the growth and / or survival of a cell, such as a 
senescent cell and / or a 
cancer cell, which is associated with aging, 
disease, or other condition as well as methods for the treatment of aging, 
disease, or other conditions by the 
in vivo administration of a formulation, such as a fusogenic LPN formulation, comprising an expression constructfor the target cell-specific, production of a 
therapeutic protein, such as a pro-apoptotic 
protein, in a target cell that is associated with aging, disease, or other condition, in particular a targetcell that is a 
senescent cell or a 
cancer cell.