Tetraethyl orthosilicate

Gadolinium chloride hexahydrate ([GdCl₃, 6H₂O], 99.999%), sodium hydroxide (NaOH, 99.99%), tetraethyl orthosilicate (Si(OC₂H₅)₄, TEOS, 98%), aminopropyl-triethoxysilane (H₂N(CH₂)₃-Si(OC₂H₅)₃, APTES, 99%), triethylamine (TEA, 99.5%), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES, 99.5%), sodium hydroxide (NaOH, 99.99%), sodium chloride (NaCl, 99.8%), calcium chloride (CaCl₂, 99%), the bovine serum albumin and dimethyl sulfoxide (DMSO, 99.5%) were purchased from Aldrich Chemicals (France). Diethylene glycol (DEG, 99%) was purchased from SDS Carlo Erba (France). Acetone (reagent grade) was purchased from Sodipro (France) and was used in the same conditions as received. 1,4,7,10-tetraazacyclododecane-1-glutaric anhydride-4,7,10-triacetic acid (DOTAGA) was furnished by CheMatech (Dijon, France). Gadolinium oxide cores were furnished by Nano-H S.A.S (Saint-Quentin Fallavier, France). Only milli-Q water was used for the preparation of aqueous solutions of nanoparticles.

The reagents employed in the synthesis of the MCFs were hydrochloric acid (HCl) (VWR, 37%), triblock copolymer, Pluronic P123, (PEO₂₀PPO₇₀PEO₂₀) with an average molecular weight of 5,800 g mol⁻¹ (Aldrich^®), as directing agent structure; tetraethylorthosilicate (TEOS) (Aldrich®, 98%), as silicon source; 1,3,5-trimethylbenzene (TMB) (Aldrich^®, 98%), as pore expander and ammonium fluoride (NH₄F) (Aldrich^®) to limit the growth of the silica mesochannels.
The functionalization of the MCFs with amine groups was carried out using 3-aminopropyltriethoxysilane (APTES) (Aldrich^®, 98%) and toluene (Aldrich^®, 99.5%) in the case of the grafting. The impregnation protocol was performed using branched polyethylenimine (PEI) (average Mn ≈ 600, Aldrich^®) and tetraethylenepentamine (TEPA) (AcrosOrganics^®, 98%) dissolved in methanol (Aldrich^®, 99.9%).
The gases used in the textural characterization and adsorption experiments were He (AirLiquide^®, 99.999%,), N₂ (AirLiquide^®, 99.9999%), and CO₂ (AirLiquide^®, 99.998%).

Tetraethyl orthosilicate (TEOS, 99%), cetyltrimethylammonium bromide (CTAB, 99%), N-isopropyl acrylamide (NIPAm, 97%), acrylamide (AAm, 98%), 3-glycidoxypropyl trimethoxysilane (GPTMS, 98%) azobisisobutyronitrile (AIBN, 98%), and doxorubicin hydrochloride (Dox), tetrahydrofuron (THF, 99%), toluene (98%), hydrochloric acid (HCl, 36%), sodium hydroxide (NaOH, 98%), ammonium nitrate (NH₄NO₃, 98%) were purchased from Aldrich Chemical Co., Saint Louis, MO, USA. All the chemicals were used as received. Human breast cancer cells, MDA-MB-231 (Korea cell line bank, Seoul, Republic of Korea), were purchased and used for this study.

Tetraethylorthosilicate (TEOS, 98%) and 3-aminopropyltriethoxysilane (APS, 99%) were purchased from Aldrich (Louis, MO, USA). Sodium chloride (99.5%), ammonium chloride (99.5%) and urea (99%) from UNIVAR (Seattle, WA, USA). Chromoionophore ETH 5294, magnesium chloride (99.5%), KH₂PO₄ (99.5%) and K₂HPO₄ were obtained from Fluka (Buchs, Switzerland). NH₃ solution (25%, A.R.) was purchased from Baker Analyzed (Corporate Parkway, Center Valley, USA), ethanol (EtOH, 95%) from Systerm Company (Zellwood, FL, USA), glutaric acid (GA, 99%) from Merck (Boston, MA, USA), glutaraldehyde (GD, 25% w/w) from Unilap (Doncaster, UK), cetyltrimethylammonium bromide (C₁₆TAB, 99%) from BDH-GPR (Lutterworth, UK), potassium chloride (99.5%) from Merck, urease enzyme type III-Jack Bens EC 3.5.1.5 (40,100 units/g) from Sigma-Aldrich and p-dimethylaminobenzaldehyde (DMAB, 99%) from Riedel de Haen (Seelze, Germany). Pure water with a resistivity of 18.2 MΩ · cm was used in all solution preparations. All chemicals were used without further purification.

A general synthesis procedure was as follows. First, tetraethylorthosilicate (Aldrich) was added to the OSDA in its hydroxide form. For aluminosilicates, aluminum isopropoxide (Aldrich) was then added and for titanosilicates titanium(iv) butoxide (Aldrich) was added. The container was closed, and stirred for at least 12 h to allow for complete hydrolysis. The lid was then removed, and the alcohol and appropriate amount of water were allowed to evaporate under a stream of air. Composition was monitored gravimetrically. Additional water was added as necessary, and then aqueous HF (48 wt%, Aldrich) was added and the mixture was stirred by hand until a homogenous gel was obtained. (Caution: use appropriate personal protective equipment, ventilation and other safety measures when working with HF.) If necessary, a second evaporation step was used after the addition of HF to reach the necessary water level. The final molar ratios are given in Table S1.† The autoclave was sealed and placed in a rotating oven at 175 °C. Aliquots of the material were taken periodically by first quenching the reactor in water and then removing enough material for X-ray powder diffraction (XPD).