Cytomodulin-functionalized porous PLGA particulate scaffolds respond better to cell migration, actin production and wound healing in rodent model.

In the present study, porous PLGA microparticulate scaffolds (PMS_P), surface-hydrolysed scaffolds (PMS_Hyd) and cytomodulin-coupled scaffolds (PMS_CM) were prepared and characterized. After coupling the particles with cytomodulin, the size was reduced from 334 µm (span 0.53) to 278 µm due to hydrolysis, and contact angle also decreased from 70.87 ± 8.56 to 31.43 ± 7.43, indicating an increase in hydrophilicity. Surface roughness and pore density increased, along with an increase in surface area from 9.59 ± 0.36 to 16.82 ± 0.064 m(2) /g after attaching the biomolecule CM onto the PLGA particles. In vitro cell culture experiments on human dermal fibroblasts (HDFs) were performed for 21 days, in which MTT assay indicated two-fold higher cell proliferation on PMS_Hyd than on PMS_CM; however, cell distribution, cell spreading and actin production were significantly higher on PMS_CM than on other scaffolds. Migration of cells from PMS_CM to a 2D plate was gradual but the migrated cells attained early confluence, indicating the preservation of normal cellular functions. In a full-thickness wound mouse model, PMS_CM exhibited 80% wound closure within 2 weeks. Further, at the end of week 3, the inflammatory cell count in the PMS_CM group was reduced to one-third of the control group, while in PMS_P and PMS_Hyd the extent of inflammation was much higher and more severe. In the case of PMS_CM, abundant fibroblast proliferation, early formation of the scar tissue, eschar formation and inward movement of the wound margins (a zipper-like movement) towards the deeper layers of the skin suggested advanced wound healing. Cytomodulin-coupled scaffolds ensured better cell spreading and migration and thus enabled rapid wound healing (see Supporting information, Figure S1).