Antibody-Hapten Recognition at the Surface of Functionalized Liposomes Studied by SPR: Steric Hindrance of Pegylated Phospholipids in Stealth Liposomes Prepared for Targeted Radionuclide Delivery

Table 2

Analysis of MAb 734 binding with DSPC/Chol/DSPE-DTPA-indium/DSPE-PEG2000 liposomes via 𝑘_on (1/Ms), 𝑘_off (1/s), and 𝐾_𝐷 (M). The amount of DSPE-PEG contained in PEGylated liposomes varied from 0% to 5%. Liposomes were immobilized on L1 chip. The length of PEG chain was fixed unchanged at 2000. The DTPA amount was fixed. The score of χ ² (Chi2) is <5; it means that the model used adequately describes our data. All experiments were duplicated. 𝑘_on, 𝑘_off, and 𝐾_𝐷 values are the average ± standard deviations.

Formulations (%DSPE-PEG2000)	𝑘on (1/Ms)	𝑘off (1/s)	𝐾𝐷(M)
0%	5.08±0.0410^5	8.03±0.0310^−4	1.59±0.0110^−9
0.5%	3.31±0.3810^5	8.03±0.0710^−4	2.45±0.2610^−9
1.5%	1.52±0.2310^5	1.21±0.1310^−3	8.04±0.3910^−9
2.5%	6.01±0.0710^4	2.06±0.0510^−3	3.28±0.1210^−8
3.5%	1.02±0.2510^4	2.68±0.0210^−3	2.78±0.6310^−7
5%	/	/	/