PB1 is a potent intracellular disulfide reducing agent with several advantages including good cell permeability, the ability to form a high intracellular concentration gradient, and stability. PB1 is a borane-protected TCEP (tris(2-carboxyethyl)phosphine) analogue. PB1 increases retinal ganglion cells survival after axotomy in vitro at nanomolar and picomolar concentrations. PB1 can be used for the research of neuroprotective.