Here, we conducted a series of translocation studies using either a lysine-rich carrier(pep-1)or a guanidinium-rich carrier (D9)and compared the results.we found that,unlike pep-1,guanidinium-based carriers trafficked molecular cargo without the need for an applied voltage or asymmetric membrane.moreover,the D9 carrier was able to "extract" protein cargo from the opposite side of a membrane,thereby highlighting a unique capability of the carrier.