Titanium 4 oxide

Low molecular weight chitosan (50 kDa, DDA 90), methotrexate and titanium (IV) oxide (99.5%, <100 nm) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Sodium tripolyphosphate (TPP) was purchased from AZ Chem for Chemicals (Dongguan, Guangdong, China). All other chemicals used in this work are of analytical grade.

2-Aminoethyl dihydrogen phosphate (AEP) (98%) was purchased from Tokyo Chemical Industry (TCI, Tokyo, Japan); DAEMA (98%), copper (I) bromide, 2,2-bipyridyl (99%), carboxymethyl-dextran sodium salt (10-20 kDa), titanium(IV) oxide (anatase, <25 nm particle size, 99.7%), α-bromoisobutyryl bromide (98%), mPBA, methylthiazolyldiphenyl-tetrazolium bromide (MTT), DPBF, thiol tracker violet, and 2,7-dichlorofluorescin diacetate (DCF-DA) were purchased from Sigma-Aldrich (St. Louis, MO, USA). All other chemicals were of analytical grade and used without further purification. SCC7 and L929 cells were purchased from the American Type Culture Collection (Manassas, MD, USA). For cell culture, RPMI 1640 and fetal bovine serum (FBS) were purchased from Capricorn Scientific (Ebsdorfergrund, Germany). The antibiotic-antimycotic solution, trypsin-EDTA, and Dulbecco's phosphate-buffered saline (DPBS) were obtained from Welgene (Daegu, Korea). All experiments involving live animals were carried out in accordance with the relevant laws and institutional guidelines of Sungkyunkwan University (SKKUIACUC2019-08-22-1).

Ciprofloxacin (CIP) (≥99%), titanium (IV) oxide (≥99.5%), polyvinylpyrrolidone (average mol wt 10,000) (PVP), tert-butanol, tetrahydrofuran (THF) and triethanolamine were obtained from Sigma-Aldrich (Schnelldorf, Germany). Formic acid (98%) for mass spectrometry was from Fluka Analytical. HPLC-grade acetonitrile was purchased from Scharlab (Barcelona, Spain). Ethyleneglycol and melamine (99%) were from Alfa Aesar (Kandel, Germany). Nylon syringe filters (13 mm, 0.22 µm) were from Scharlab (Barcelona, Spain).
The precursor [Au₂Ag₂(C₆F₅)₄(OEt₂)₂]_n was prepared according to the literature [15 (link)].

The following reagents were used: Titanium (IV) oxide from Sigma-Aldrich (718467-100G, St. Louis, MO, USA); nanopowder Aeroxide^® P25 of Ebonik Degussa, known as Degussa P25, with an average size of 21 nm, purity $\ge$ 99.5%, and Lot. # MKBC4174; sodium borohydride NaBH₄ from Aldrich (452874-25G, St. Louis, MO, USA), and Lot. # MKBZ2657V; isopropyl alcohol from J. T. Baker (9084-02, Phillipsburg, NJ, USA); Baker analyzed ACS; absolute ethanol, J. T. Baker; reactive Baker ACS (Cat. # 9000-03, USA), and Lot. # V32C55. For the photocatalytic test, deionized water with a resistivity of 18.2 MΩ cm and methylene blue dye from Sigma (M9140-25G, St. Louis, MO, USA) were used.

Leupeptin (L2884), AgNO₃, sodium borohydride, Nα‐benzoyl‐dl‐arginine‐4‐nitroanilide hydrochloride (BAPA), trypsin from porcine pancreas type IX‐S, titanium(IV) oxide, zinc oxide, 1,1ʹ‐CDI, triethylamine, APTES, DMSO, acetonitrile (ACN), formic acid, acetic acid, O‐(1H‐6‐chlorobenzotriazole‐1‐yl)‐1,1,3,3‐tetramethyluronium‐hexafluorophosphate, N,N‐diisopropylethylamine, dichloromethane, piperidine, acetic anhydride, trifluoroacetic acid (TFA), triisopropylsilane, Fmoc–Leu–OH, Fmoc–Phe–OH and Boc–Ahx–OH were all purchased from Sigma‐Aldrich. WorkBeads™ 40/1000 ACT was a kind gift from Bio‐Works Sweden AB, Uppsala.

ATL (>98%), whose structure is shown in Figure 1, magnetite (97%, nanopowder 50–100 nm), titanium (IV) oxide (>99.5% P25 degussa, nanopowder), silver chloride (99%), toluene (≥99.5%), sulfuric acid (72%), acetic acid (99%), hydrogen peroxide (30% in H₂O), acetone (≥99.5%), and ammonia (25%) were obtained from Merck / Sigma-Aldrich (Germany). Ethanol (99.8%) and sodium hydroxide were purchased from Panreac, and mEthanol (99.9%, HPLC) was supplied by Scharlau (Barcelona, España). [P_6,6,6,14]Cl, was obtained from CYTEC industries (Woodland Park, New Jersey, United States) under the trade name CYPHOS IL 101 (97.7%); Figure 2. The IL was dried at 70 °C under high vacuum (absolute pressure < 1 Pa) for 24 h and then stored under inert atmosphere. The water content (<2000 ppm) was measured by titration using a Metrohm 737 Karl Fischer coulometer. IL final purity was checked by ¹H and ¹³C NMR analyses (Figure S1).