FIG. 1.

Illustration of charge shielding by multivalent CPCs, defined as a reduction in the physiological chemical stress of the tissue. (A) Cartilage immersed in a hypertonic bath will deswell to a zero-strain reference thickness, representing zero osmotic pressure within the tissue. (B) Moving the tissue to physiological salinity will result in tissue swelling, and the force required to compress the tissue back to the hypertonic reference thickness is the tissue's free osmotic swelling pressure. (C) The same tissue pre-equilibrated in CPC will require less force to compress back to reference thickness, representing a reduced capacity for physiological swelling due to charge shielding by the cationic carrier. Red dashed line is the hypertonic reference thickness; black downward arrows represent compressive force; green circles are CPCs. CPCs, cationic peptide carriers.