Table 1.
Characterization of PAMAM coupling via EDX and Raman spectroscopy as well as surface analyses via contact angle measurements and entropy-based surface roughness analysis (mean ± SD, n ≥ 3)
| Sample | EDX | Raman | Contact angle | Surface roughness | |||
|---|---|---|---|---|---|---|---|
| Nitrogen content (Wt%) | Peak area (amide I band) (a.u.) | Native (°) | With FCS (°) | Entropy | |||
| Native (unitless) | With FCS (unitless) | ||||||
| ALG | 1.82 ± 0.55 | 1.49 ± 0.15 | 45.77 ± 2.28 | 35.26 ± 4.59 | 2.95 ± 0.10 | 2.92 ± 0.12 | |
| AMG | n.a. | n.a. | 39.90 ± 5.72 | 33.21 ± 3.11 | 1.43 ± 0.19*** | 1.48 ± 0.30*** | |
| PC | n.a. | n.a. | 39.80 ± 0.95** | 34.35 ± 0.50 | 1.84 ± 0.18*** | 1.98 ± 0.19*** | |
| PAMAM (nmol/cm2) | 1.6 | 2.19 ± 0.78** | 1.59 ± 0.66 | 34.19 ± 2.06*** | 35.80 ± 1.59 | 3.51 ± 0.09*** | 3.42 ± 0.16*** |
| 3.2 | 2.32 ± 0.93** | 2.65 ± 0.64 | 33.20 ± 3.02*** | 35.08 ± 1.55 | 2.91 ± 0.15 | 3.43 ± 0.10*** | |
| 32 | 3.42 ± 1.34 | 3.01 ± 0.84 | 34.46 ± 3.78*** | 36.92 ± 2.02 | 2.65 ± 0.09*** | 2.44 ± 0.11*** | |
| 324 | 7.57 ± 1.24*** | 6.22 ± 0.82*** | 36.25 ± 3.53** | 36.62 ± 1.78 | 2.54 ± 0.32*** | 2.31 ± 0.12*** | |
| 3245 | 7.63 ± 1.16*** | 6.31 ± 2.01*** | 38.15 ± 7.51 | 35.92 ± 2.91 | 1.55 ± 0.22*** | 1.86 ± 0.17*** | |
Differences of groups compared to ALG were considered significant by *p < 0.05, **p < 0.01 and ***p < 0.001 (n ≥ 3)
PAMAM poly(amidoamine), EDX energy dispersive X-ray, SD standard deviation, NHS N-hydroxysuccinimide, a.u. arbitrary unit, FCS fetal calf serum, ALG alginate, AMG matrigel-coated alginate hydrogel, PC polystyrene-based coverslips, n.a. not available