Abstract: Compounds having the following structure: wherein Y= wherein: [R2bR2a] represents a reaction product between R2b and R2a of Formulas (2) and (1), respectively, R3 functions as a cell penetration moiety, and R1 functions as a binding moiety to bind to the payload (P) to form a conjugate with P, wherein R1, R3, A, D, L1, L2, L3, L4, L5, L6, L7, r, m, s, n, p, and q are as defined in further detail elsewhere in this disclosure. Also described herein are methods of producing compounds of Formulas (1), (2), and (3), conjugates thereof with a payload (P), pharmaceutical compositions thereof, methods of delivering the conjugates to subjects or cells, and methods of treating a disease or condition by administering such conjugates.