Yb2o3

Er₂O₃ (99.9%), Yb₂O₃ (99.9%), Gd(NO₃)₃•6H₂O (99.9%), and anhydrous NH₄F (≥98%) were purchased from Sigma Aldrich. KCl (99%) and HNO₃ (65%) were acquired from Synth. Ethylenediaminetetraacetic acid (EDTA) was obtained from Alfa Aesar.

Polylactic-co-glycolic acids (PLGA) Purasorb PDLG7507 (PURAC Biochem, Netherlands) with an inherent viscosity midpoint of 0.7 dL/g and a lactic-to-glycolic-acid monomer ratio of 75:25 and type I collagen (COL, Nearmedic Plus LLC, Moscow, Russia) were used as polymeric materials for electrospinning. PLGA, hyaluronic acid glycidyl methacrylate (synthesized at the Federal Research Scientific Center “Crystallography and Photonics” RAS), polyethylene glycol diacrylate (PEGDA, Sigma-Aldrich, St. Louis, MO, USA), flavin mononucleotide (Pharmstandard, Moscow, Russia), and triethanolamine (Sigma-Aldrich, St. Louis, MO, USA) were used as initial materials for 3D printing. Highly volatile 1,1,1,3,3,3-hexafluoroisopropanol (HFIP, 99%, P&M-Invest, Moscow, Russia) and tetraglycol (Sigma Aldrich, St. Louis, MO, USA) were used to mix the polymeric solutions for scaffold fabrication. As a cross-linking agent, 1,4-butanediol diglycidyl ether (BDDGE, ≥95%, Sigma Aldrich, St. Louis, MO, USA) was used, and isopropanol (99%, Ekos-1, Moscow, Russia) was used for collagen chemical stabilization. Reagents for synthesis of UCNPs (Y₂O₃, Yb₂O₃, Er₂O₃, CF₃COOH:H₂O = 3:1, (CF3COO)Na, 1-octadecene, and oleic acid) were purchased from Sigma Aldrich, St. Louis, MO, USA.

The following chemicals for
the preparation of theranostic cubosomes were purchased from Sigma-Aldrich:
daunorubicin hydrochloride (DNR), Pluronic F108 (PF108), chitosan
(CHIT, low molecular weight), DNA sodium salt from herring testes
(DNA), Y₂O₃ (99.99%), Yb₂O₃ (99.99%), Er₂O₃ (99.99%), CF₃COOH
(reagent grade, 99%), oleic acid (technical grade, >93%), oleylamine
(technical grade, 70%), folic acid (reagent grade, ≥97%). Monoolein
(MO, 1-monooleoylglycerol, RYLO MG 19PHARMA, glycerol monooleate;
98.1 wt %) was a kind gift from Danisco A/S, DK-7200, Grinsted, Denmark.
Other reagents and solvents were of commercial grade and were used
as received. The water used for all experiments was doubly distilled
and purified by means of a Milli-Q purification system (Millipore,
Bedford, MA).

Er₂O₃ (99.9%), Yb₂O₃ (99.9%), Tm₂O₃ (99.9%), Nd₂O₃ (99.9%), tantalum ethoxide (99.98%), 2-ethoxyethanol (99%) and tetraethylorthosilicate (TEOS, 98%) were purchased from Sigma Aldrich. Anhydrous ethanol (≤0.005% H₂O) was obtained from Merck. HCL PA-ACS-ISO (37wt%) were acquired from Panreac.

Rare earth oxides, including Y₂O₃, Yb₂O₃, Tm₂O₃, and Ho₂O₃, were provided by the Sigma-Aldrich Corp while 1-octadecene (ODE), oleic acid (OA), and PS molecules were purchased from the Aladdin Reagent, Ltd. (Shanghai, China). The Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China) offered other chemical reagents of analytical grade. An OKP purification system (Shanghai Laikie Instrument Corp., China) was used to prepare the aqueous solution. Mice were bought from Hubei Biossci Biotechnology Co., Ltd. (Wuhan, China) and the animal experiment was guided by the Animal Care and Use Committee of Linyi University.

Y₂O₃, Yb₂O₃, Er₂O₃, trifluoroacetic acid, lithium trifluoroacetate (LiTFA), oleic acid, 1-octadecene, cysteine, HAuCl₄, sodium citrate and solvents were all purchased from Sigma Aldrich and were used without further purification.

The Tm³⁺, Yb³⁺:Zn₂TiO₄ inverse spinel materials have been synthesized by using solid state reaction method. The precursors ZnO, TiO₂, Tm₂O₃ and Yb₂O₃ were mixed in stoichiometric proportion in agate mortar for 2 hours. The host raw materials i.e. ZnO and TiO₂ have been taken from Merck (99.0% purity) and the dopants Tm₂O₃ and Yb₂O₃ from Sigma Aldrich (99.9% purity). The homogeneous mixture was kept in the alumina crucible and the samples were annealed in an electric furnace at 800 °C for 24 hours. The annealed samples were again grind in the agate mortar for 30 minutes and used for structural, luminescence and EPR studies. The balanced chemical reaction is presented as follows:
For the synthesis of codoped Zn₂TiO₄ crystals, Tm₂O₃ (x) optimized is fixed at 1 mol% and Yb₂O₃ (y) is varied as 1 mol%, 3 mol% and 5 mol%.