Drug retention after intradiscal administration.

Intradiscal drug delivery is a promising strategy for treating intervertebral disk degeneration (IVDD). Local degenerative processes and intrinsically low fluid exchange are likely to influence drug retention. Understanding their connection will enable the optimization of IVDD therapeutics.

Transmembrane helix assembly and the role of salt bridges.

Transmembrane helix-helix interactions mediate the folding and assembly of membrane proteins. Recognition motifs range from GxxxG and leucine zippers to polar side chains and salt bridges. Some canonical membrane proteins contain local charge clusters that are important for folding and function, and which have to be compatible with a stable insertion into the bilayer via the translocon.