The silyl ether bond is becoming increasingly attractive as linker and crosslinker to produce acid-sensitive nanocarriers (Figure ). It has gained in interest as a protective group because its deprotection rate can be easily tuned by the nature of the substituents (e.g., methyl, ethyl or isopropyl) carried by the silicon atom. The precise control with time of the linker cleavage could prove useful in achieving sustained drug release. In addition, it is tolerant to radical polymerization conditions, and degradation products after cleavage are non-toxic, allowing the design of acid-sensitive biomaterials with no expected detrimental side effect. This has been illustrated by the coupling of Gem to HEA via a silyl ether bond, obtained by reacting dichlorodiethylsilane in the presence of 4-(dimethylamino)pyridine (DMAP). 153 HEAsilyl-Gem and OEGMA were then copolymerized by RAFT polymerization either simultaneously to yield P(HEA-silyl-Gem-co-OEGMA) statistical copolymers, or sequentially to produce PHEA-silyl-Gem-b-POEGMA diblock copolymers. The use of a cyclooctyne-based RAFT agent enabled grafting of the copolymers via copper-free click chemistry onto the surface of nanodiamonds (NDs) bearing azide groups (Figure ). The resulting coated NDs had an average diameter of between 160 and 270 nm, and gave faster and quantitative Gem release at pH 5 in less than 20 h, compared to pH 7.4 for which the maximum release remained below 80 % after almost 100 h. In vitro evaluation on AsPC-1 cells showed the greatest cytotoxicity using the smallest nanoparticles with the highest OEGMA content and the longest polymer chains. This increase in cytotoxicity may be due to the shielding effect of the OEGMA coating, as well as better stabilization against aggregation, which improved cellular uptake.