title: Mechanism study on pH-responsive cyclodextrin capped mesoporous silica: effect of different stalk densities and the type of cyclodextrin.
abstract: Cyclodextrin (CD)-capped mesoporous silica nanoparticles (MSN) with pH-responsive properties were synthesized, but little research has been carried out to evaluate the impact of critical factors such as the stalk density and the type of CD on the pH-responsive release behavior. Here, the effect of different stalk densities on the pH-responsive release behavior was investigated. Either too low or too high density of the grafted p-anisidine stalk could result in poor cargo release, and the optimum stalk density for MSN was measured by thermal analysis, and found to be approximately 8.7 stalks nm(-2). To achieve effective release control, the CD capes, α-CD and β-CD, were also investigated. Isothermal titration calorimetry (ITC) analysis was employed to determine the formation constants (Kf) of the two CD with p-anisidine at different pH values. The results obtained showed that the complex of β-CD with p-anisidine had excellent pH-responsive behavior as it exhibited the largest changed formation constant (ΔKf) in different pH media. Furthermore, the pH-responsive mechanism between CD and p-anisidine molecules was investigated through ITC and a molecular modeling study. The release of antitumor drug DOX presents a significant prospect toward the development of pH-responsive nanoparticles as a drug delivery vehicle.
authors.affiliation: Liaoning Provincial Key Laboratory of Studying the Modern Drug preparations, Shenyang Pharmaceutical University, No.103 Wenhua Road, Shenyang 110016, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Bai
authors.forename: Qinfu
authors.initials: Q
authors.lastname: Zhao
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Yikun
authors.initials: Y
authors.lastname: Gao
authors.forename: Zhou
authors.initials: Z
authors.lastname: Sha
authors.forename: Donghua
authors.initials: D
authors.lastname: Di
authors.forename: Ning
authors.initials: N
authors.lastname: Han
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Jinghai
authors.initials: J
authors.lastname: Zhang
authors.forename: Siling
authors.initials: S
authors.lastname: Wang
mesh_terms: D003505:Cyclodextrins / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D003505:Cyclodextrins; D004337:Drug Carriers; D012822:Silicon Dioxide