PEG Grafted-Nanodiamonds for the Delivery of Gemcitabine

Carboxyl end‐functionalized poly[poly(ethylene glycol) methyl ether methacrylate] [P(PEGMEMA)] and its block copolymer with gemcitabine substituted poly(N‐hydroxysuccinimide methacrylate) [PGem‐block‐P(PEGMEMA)] are synthesized via reversible addition‐fragmentation transfer (RAFT) polymerization. Then, two polymers are grafted onto the surface of amine‐functionalized nanodiamonds to obtain [P(PEGMEMA)]‐grafted nanodiamonds (ND‐PEG) and [PGem‐block‐P(PEGMEMA)]‐grafted nanodiamonds (ND‐PF). Gemcitabine is physically absorbed to ND‐PEG to produce ND‐PEG (Gem). Two polymer‐grafted nanodiamonds (i.e., with physically absorbed gemcitabine ND‐PEG (Gem) and with chemically conjugated gemcitabine ND‐PF) are characterized using attenuated total reflectance infrared spectroscopy, dynamic light scattering, and thermogravimetric analysis. The drug release, cytotoxicity (to seed human pancreatic carcinoma AsPC‐1 cells), and cellular uptake of ND‐PEG (Gem) and ND‐PF are also investigated. Nanodiamonds grafted with block copolymer of poly[poly(ethylene glycol) methyl ether methacrylate and gemcitabine substituted poly(N‐hydroxysuccinimide methacrylate) can be used as suitable theragnostic nanoparticles for gemcitabine.