Table 1. Influence of the amount of stannous chloride on the labeling efficiency of NPs.

SnCl2·2H2O (μg)	20	30	50	100
K237/FA-PEG-PLGA (LA/GA = 60/40)
% Labeled (mean ± SD)	97.95 ± 1.13	95.88 ± 2.73	94.3 ± 1.90	86.92 ± 2.85
% colloids (mean ± SD)	0.37 ± 0.35	1.16 ± 0.87	1.77 ± 0.55	2.71 ± 1.83
% free (mean ± SD)	1.68 ± 0.44	2.96 ± 1.07	3.93 ± 1.61	10.37 ± 3.32
K237/FA-PEG-PLGA (LA/GA = 70/30)
% Labeled (mean ± SD)	96.56 ± 3.66	94.12 ± 3.12	93.58 ± 3.16	84.12 ± 3.24
% colloids (mean ± SD)	1.08 ± 0.36	2.03 ± 0.82	2.37 ± 1.00	4.06 ± 2.75
% free (mean ± SD)	2.36 ± 1.42	3.75 ± 1.28	4.05 ± 0.78	11.82 ± 2.47
K237/FA-PEG-PLGA (LA/GA = 80/20)
% Labeled (mean ± SD)	95.40 ± 2.29	94.39 ± 1.93	93.26 ± 3.19	82.98 ± 2.70
% colloids (mean ± SD)	1.73 ± 0.72	2.099 ± 0.54	2.56 ± 0.82	4.75 ± 2.50
% free (mean ± SD)	2.87 ± 0.72	3.52 ± 1.86	4.18 ± 2.04	12.27 ± 3.43