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

Abstract

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 m2/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). Copyright © 2012 John Wiley & Sons, Ltd.

A new, bioactive, antibacterial‐eluting, composite graft for infection‐free wound healing

“…To support the present hypothesis, the following components were selected for development of the composite graft: cytomodulin functionalized porous, Poly dl‐lactide‐co‐glycolide (PLGA) microspheres were selected to be used as scaffold material for designing this composite graft. As reported earlier by our group, cytomodulin immobilized onto the porous PLGA scaffolds resulted in better cell migration, actin production, and wound healing in rodent model . Cytomodulin is a synthetic, tumor growth factor beta (TGF‐β) mimic and acts as a substitute for cytokines in many fields particularly wound healing and skin regeneration and thus create a natural habitat within the scaffolds .…”

“…The present study indicated that uninfected wounds showed faster wound closure in comparison with the infected wounds. In all cases, the treated groups (G2 and G4) showed a faster wound closure in comparison with the control groups (G1 and G3) due to the presence of bioactive scaffolds in the composite graft, which enhanced the cell proliferation and migration and thereby tissue healing in the wound, and also inhibited the growth of bacteria in G4 by the presence of gentamicin in the graft at the wound site. Healing was also assessed by monitoring the weight change of animals during the study where an initial weight loss (after 24 hours of inoculation of bacteria) was seen only in the infected animals (Figure ), which might be due to the presence of infection in the wounds; however, infected treated animals (G4) regained their initial weight faster (day 7) as compared with infected control animals (G3).…”

“…These microspheres were hydrolyzed in the presence of alkali NaOH (0.05 M) followed by coupling cytomodulin (200 ng/mL) onto the hydrolyzed PLGA scaffolds using EDC‐NHS as coupling agents. The cytomodulin coupled particles so obtained were freeze dried to obtain cytomodulin functionalized porous microparticles (cPMS), characterized for physical properties, and evaluated in vitro in cell culture studies and in vivo in full‐thickness wound model …”

“…As reported earlier by our group, cytomodulin immobilized onto the porous PLGA scaffolds resulted in better cell migration, actin production, and wound healing in rodent model. 15 Cytomodulin is a synthetic, tumor growth factor beta (TGF-β) mimic and acts as a substitute for cytokines in many fields particularly wound healing and skin regeneration and thus create a natural habitat within the scaffolds. 15,16 Covalent immobilization of such biomimetic molecules or growth factors onto the scaffolds enabled single application by preventing its rapid degradation.…”

Polymeric Nanoparticles

“…Given the simple degradation products of PLGA, it is a popular component polymer for a variety of nanospheres, micelles, polymersomes, and nanocapsule systems [43][44][45][46][47] and has already been approved for human use [60,61]. Poly(β-amino ester) (PBAE) is an new and exciting class of biodegradable polymer.…”