Table 1.

Fractional factorial design parameters and response variable data. The parameters tested include pH, ionic strength, PBAE concentration, and siRNA concentration. Ranges were determined based on parameters previously published by our lab. Response variables of PBAE loading, siRNA loading, w/w ratio, and knockdown are reported as the mean and the standard deviation (SD). Cells are colored to depict differences in magnitude. JMP was used to determine Runs 1-8 for the fractional factorial design. Runs 9 – 12 were added as midpoints for pH and polymer concentration to test for non-linearity.

Run	pH	Ionic Strength (mM)	PBAE Conc. (mg/mL)	siRNA Conc. (μg/mL)	PBAE Loading (μg/cm)		siRNA Loading (μg/cm)		w/w ratio		Knockdown (%)
					Mean	SD	Mean	SD	Mean	SD	Mean	SD
1	4.5	150	2.0	20	1.18	0.14	0.66	0.08	1.80	0.20	17.88	6.49
2	4.5	150	2.0	30	0.90	0.03	1.30	0.21	0.71	0.11	8.16	3.44
3	4.5	250	0.5	20	0.57	0.05	1.08	0.06	0.53	0.05	10.82	10.19	Response Variables		High
4	4.5	250	0.5	30	0.80	0.02	1.95	0.07	0.41	0.02	9.23	2.39
5	6.0	150	0.5	20	1.55	0.09	1.42	0.23	1.13	0.27	7.54	3.81
6	6.0	150	0.5	30	1.30	0.10	2.17	0.08	0.60	0.05	36.96	17.98
7	6.0	250	2.0	20	0.67	0.10	0.09	0.02	8.62	3.24	0.00	0.00			Low
8	6.0	250	2.0	30	0.89	0.11	0.29	0.01	3.07	0.31	1.04	1.13
9	5.2	150	1.0	20	1.07	0.01	0.89	0.09	1.22	0.13	2.26	1.60
10	5.2	150	1.0	30	1.18	0.11	1.41	0.15	0.85	0.09	2.10	1.49
11	5.2	250	1.0	20	1.41	0.08	0.72	0.11	2.02	0.45	0.34	0.48
12	5.2	250	1.0	30	1.16	0.07	1.34	0.08	0.87	0.05	3.61	2.47