Table 2.
X-ray photoelectron spectroscopy of maleimide-PEG-PCL:MPEG-PCL mixture (1:10), PO-coupled with or without CBSA
| Samples | XPS elemental ratio (%) | XPS C1s envelope ratios (%) | XPS O1s envelope ratios (%) | ||||||
|---|---|---|---|---|---|---|---|---|---|
|
|
|
|
|||||||
| C | O | N | C–C/C–H | C–O–C | C–O–C=O | O–C=O | O=C | O–C | |
|
|
|||||||||
| Binding energy (eV) | |||||||||
|
|
|||||||||
| 285.0 | 286.6 | 287.3 | 289.4 | 533.5 | 534.4 | ||||
| Copolymers | 75.1 | 24.9 | * | 7.5 | 18.7 | 56.6 | 17.2 | 34.7 | 65.3 |
| PO | 74.2 | 25.8 | * | 27.4 | 30.8 | 27.3 | 14.5 | 44 | 56 |
| CBSA-PO | 74.1 | 25.5 | 0.4 | 13.5 | 33.6 | 33.1 | 19.8 | 37.7 | 62.3 |
Notes:
*
Below the detection limit. Copolymers are maleimide-PEG-PCL:MPEG-PCL mixture (1:10).
Abbreviations: XPS, x-ray photoelectron spectroscopy; PO, polymersomes; PEG, poly(ethylene glycol); PCL, poly(ɛ-caprolactone); CBSA, cationic bovine serum albumin; MPEG, methoxy poly(ethylene glycol).