Table 1.

Biologically relevant metabolites which changed significantly in THP-1 and A549 cells after treatment with free MTX and MTX loaded NPs, IDC: metabolite identification level according to metabolomics standards initiative L1 – Level 1, L2 – Level 2. Colours represent changes in metabolite levels with blue indicating a decrease and red denoting an increase.

	THP-1 cells
Mass	RT	FORMULA	Putative metabolite	IDC	MTX NPS	Free MTX
	Redox homeostasis
307.0838	9.80	C10H17N3O6S	Glutathione	L1	1.01	0.65
612.1523	11.00	C20H32N6O12S2	Glutathione disulfide	L1	0.80	0.97
132.0898	16.19	C5H12N2O2	Ornithine	L1	1.46	1.91
	Energy metabolism
146.0215	10.32	C5H6O5	2-Oxoglutarate	L2	0.71	0.59
192.0270	11.72	C6H8O7	Citrate	L2	0.70	0.43
174.0164	11.29	C6H6O6	cis-Aconitate	L2	0.71	0.39
167.9823	11.42	C3H5O6P	Phosphoenolpyruvate	L1	1.02	0.43
	Nucleotide Metabolism
286.0567	10.72	C7H15N2O8P	GAR	L2	17.12	8.20
308.0411	9.41	C9H13N2O8P	dUMP	L1	1017	705
228.0747	7.84	C9H12N2O5	Deoxyuridine	L2	7.88	9.20
	A549 Cells
Mass	RT	FORMULA	Putative metabolite		MTX NPS	Free MTX
	Redox homeostasis and apoptotic markers
307.0837	9.77	C10H17N3O6S	Glutathione	L1	0.72	0.74
306.0759	10.83	C20H32N6O12S2	Glutathione disulfide	L1	0.93	0.84
183.0661	10.15	C5H14NO4P	Choline phosphate	L1	0.64	0.84
103.0997	10.43	C5H13NO	Choline	L2	0.47	0.59
	Energy metabolism
260.0297	10.46	C6H13O9P	Fructose 6-phosphate	L1	0.66	0.64
359.2670	5.51	C19H37NO5	2-Hydroxylauroylcarnitine	L2	2.29	2.03
259.1784	5.72	C13H25NO4	Hexanoylcarnitine	L2	2.09	2.17
397.3190	5.19	C23H43NO4	Hexadecenoylcarnitine	L2	1.96	2.32
425.3503	5.08	C25H47NO4	Elaidiccarnitine	L2	1.69	1.82
387.2983	5.49	C21H41NO5	2-Hydroxymyristoylcarnitine	L2	1.66	1.87
371.3034	5.28	C21H41NO4	Tetradecanoylcarnitine	L2	1.60	1.79
	Nucleotide Metabolism
136.0384	8.89	C5H4N4O	Hypoxanthine	L1	0.81	1.42
267.0967	8.22	C10H13N5O4	Adenosine	L1	0.74	1.74
135.0545	8.64	C5H5N5	Adenine	L1	0.79	1.10
347.0630	9.46	C10H14N5O7P	AMP	L1	0.64	0.65
286.0565	10.56	C7H15N2O8P	GAR	L2	11.46	9.78