Internalization and cytotoxicity of graphene oxide and carboxyl graphene nanoplatelets in the human hepatocellular carcinoma cell line Hep G2

Table 1 Hydrodynamic size distribution in GO suspensions as function of concentration and incubation time

GO in MEM+		Average hydrodynamic diameter						Relative intensity
Time	Conc.	Peak 1		Peak 2	Peak 3	Peak 4	Peak 5	Peak 1	Peak 2	Peak 3	Peak 4	Peak 5	PdI
[hrs]	[μg/ml]	d. ± SD [nm]		d. ± SD [nm]	d. ± SD [nm]	d. ± SD [nm]	d. ± SD [nm]	[%]	[%]	[%]	[%]	[%]
0	16	4.39	n =1	9.8 ± 2.0	42.0 ± 11.3	382.9 ± 22.0	4672.5 ± 414.9	0.3	9.6	7.4	81.7	1.0	0.7
0	8	1.25	n =1	9.2 ± 2.5	34.4 ± 12.7	314.4 ± 44.0	5140.8 ± 47.3	0.6	13.7	12.2	72.5	1.1	0.9
0	4	-	-	10.0 ± 1.4	35.9 ± 10.3	336.0 ± 38.3	5069.5 ± 163.7	0.0	19.1	17.2	62.7	1.0	1.0
0	2	-	-	9.9 ± 1.2	41.9 ± 7.8	333.8 ± 34.3	4899.4 ± 189.3	0.0	29.6	24.8	44.2	1.7	0.8
48	16	-	-	8.1 ± 1.0	32.5 ± 11.7	367.9 ± 18.6	5081.3 ± 201.5	0.0	7.17	8.1	84.0	0.7	0.7
48	8	-	-	9.5 ± 1.0	36.2 ± 7.1	682.4 ± 96.6	4182.0 ± 514.9	0.0	10.1	7.5	78.8	2.8	1.0
48	4	-	-	9.0 ± 0.4	38.6 ± 5.0	389.0 ± 16.1	-	0.0	19.1	17.1	63.9	0.0	1.0
48	2	-	-	9.6 ± 0.9	37.1 ± 7.6	363.5 ± 50.8	5043.0 n =1	0.0	27.3	21.8	50.6	0.3	0.9
120	16	-	-	9.8 ± 0.6	56.4 ± 19.2	683.7 ± 99.7	4596.3 ± 381.1	0.0	6.2	6.2	85.0	2.7	0.7
120	8	-	-	9.0 ± 1.1	39.1 ± 14.4	346.9 ± 21.2	4796.5 ± 95.5	0.0	8.8	9.1	81.4	0.7	0.7
120	4	-	-	9.8 ± 1.0	33.5 ± 5.5	357.7 ± 33.1	5103.3 ± 145.7	0.0	19.2	14.1	66.2	0.7	1.0
120	2	-	-	10.7 ± 1.2	42.4 ± 9.0	334.2 ± 46.0	4914.7 ± 109.4	0.0	31.3	16.1	51.5	1.2	0.9
blank	-		-	9.6 ± 0.4	62.4 ± 2.5	-	4268.5 ± 129.9	0.0	49.6	46.9	0.0	3.5	0.5

DLS analysis was performed on serial dilutions of a GO suspension (16 μg/ml) prepared in culture medium supplemented with 10% FBS (MEM+). The samples were analyzed directly after preparation as well as after incubation at 37°C for 48 and 120 h, respectively. The average hydrodynamic size is represented as mean diameter (d.) ± standard deviation (SD) in nm. Data are from six consecutively performed measurements. The relative intensities of the size peaks are indicated in [%], respectively. The polydispersity index (PdI) of the analyzed samples is shown in the last column. “n = 1” indicates that no SD could be calculated since the peak was detected in only one of the six performed measurements. The minus (“-“) indicates that no peak could be identified at the respective dilution stage.

ISSN: 1743-8977