Angiogenic & Immunomodulatory Cargo
PLGA microspheres encapsulating VEGF-165, PDGF-BB, TGF-β3 and IL-10 with engineered burst + sustained release over 21 days.
Growth factors and immunomodulatory cytokines are loaded into double-emulsion PLGA (50:50) microspheres (Ø 12 ± 2 µm, span <0.7) with bovine serum albumin as a stabilizing co-encapsulant. Loading efficiencies are 78–85 % for VEGF-165, 81 % for PDGF-BB, 72 % for TGF-β3, and 84 % for IL-10.
Release follows a designed burst-then-sustained profile: 22 % cumulative release at 24 h (initial burst), reaching 85 % at day 21. Daily release rates are calibrated to maintain local VEGF in the 50–100 ng/mL range during the angiogenic window (day 3–10).
IL-10 and TGF-β3 establish a tolerogenic local milieu that biases tissue-resident macrophages toward an M2 (CD163⁺ / CD206⁺) phenotype during the first 10 days, suppressing foreign-body fibrotic encapsulation around the scaffold.
Designed burst (≈22 % @ 24 h) followed by sustained release through day 28.
| Parameter | Value | Unit | Tolerance / Note |
|---|---|---|---|
| Microsphere polymer | PLGA 50:50 | ||
| Microsphere diameter | 12 ± 2 | µm | |
| VEGF-165 loading eff. | 78–85 | % | |
| PDGF-BB loading eff. | 81 | % | |
| TGF-β3 loading eff. | 72 | % | |
| IL-10 loading eff. | 84 | % | |
| 24 h burst | 22 | % | |
| Cumulative day 21 | 85 | % | |
| Local VEGF target | 50–100 | ng/mL | Day 3–10 |
| Macrophage polarization | >65 % M2 | Day 10 |