title: Neurotensin-loaded collagen dressings reduce inflammation and improve wound healing in diabetic mice.
abstract: Impaired wound healing is an important clinical problem in diabetes mellitus and results in failure to completely heal diabetic foot ulcers (DFUs), which may lead to lower extremity amputations. In the present study, collagen based dressings were prepared to be applied as support for the delivery of neurotensin (NT), a neuropeptide that acts as an inflammatory modulator in wound healing. The performance of NT alone and NT-loaded collagen matrices to treat wounds in streptozotocin (STZ) diabetic induced mice was evaluated. Results showed that the prepared dressings were not-cytotoxic up to 72h after contact with macrophages (Raw 264.7) and human keratinocyte (HaCaT) cell lines. Moreover, those cells were shown to adhere to the collagen matrices without noticeable change in their morphology. NT-loaded collagen dressings induced faster healing (17% wound area reduction) in the early phases of wound healing in diabetic wounded mice. In addition, they also significantly reduced inflammatory cytokine expression namely, TNF-α (p<0.01) and IL-1β (p<0.01) and decreased the inflammatory infiltrate at day 3 post-wounding (inflammatory phase). After complete healing, metalloproteinase 9 (MMP-9) is reduced in diabetic skin (p<0.05) which significantly increased fibroblast migration and collagen (collagen type I, alpha 2 (COL1A2) and collagen type III, alpha 1 (COL3A1)) expression and deposition. These results suggest that collagen-based dressings can be an effective support for NT release into diabetic wound enhancing the healing process. Nevertheless, a more prominent scar is observed in diabetic wounds treated with collagen when compared to the treatment with NT alone.
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal; CIEPQPF, Chemical Engineering Department, FCTUC-University of Coimbra, Coimbra, Portugal.
authors.forename: Liane I F
authors.initials: LI
authors.lastname: Moura
authors.forename: Ana M A
authors.initials: AM
authors.lastname: Dias
authors.forename: Edward
authors.initials: E
authors.lastname: Suesca
authors.forename: Sergio
authors.initials: S
authors.lastname: Casadiegos
authors.forename: Ermelindo C
authors.initials: EC
authors.lastname: Leal
authors.forename: Marta R
authors.initials: MR
authors.lastname: Fontanilla
authors.forename: Lina
authors.initials: L
authors.lastname: Carvalho
authors.forename: Hermínio C
authors.initials: HC
authors.lastname: de Sousa
authors.forename: Eugénia
authors.initials: E
authors.lastname: Carvalho
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001458:Bandages; D002465:Cell Movement; D003094:Collagen / Q000737:chemistry; D024042:Collagen Type I / Q000235:genetics / Q000276:immunology; D024061:Collagen Type III / Q000235:genetics / Q000276:immunology; D003921:Diabetes Mellitus, Experimental / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007249:Inflammation / Q000276:immunology / Q000473:pathology / Q000517:prevention & control; D015603:Keratinocytes / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D009496:Neurotensin / Q000494:pharmacology*; D012867:Skin / Q000187:drug effects* / Q000276:immunology / Q000293:injuries / Q000378:metabolism; D013311:Streptozocin; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; C439971:COL3A1 protein, human; D024042:Collagen Type I; D024061:Collagen Type III; D014409:Tumor Necrosis Factor-alpha; D009496:Neurotensin; D013311:Streptozocin; D003094:Collagen; D020780:Matrix Metalloproteinase 9
keywords: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; AUC; COL1A1; COL1A2; COL3A1; Collagen; DFU; Diabetic foot ulcer; ECM; EGF; FBS; IL-1β; IL-6; KC; MMP-9; MTT; NO; NT; Neurotensin; PBS; PDGF; PMN; SEM; STZ; TGF β1; TGF β3; TNF-α; VEGF; Wound dressing; Wound healing; area under the curve; collagen type I, alpha 1; collagen type I, alpha 2; collagen type III, alpha 1; diabetic foot ulcer; endothelial growth factor; extracellular matrix; fetal bovine serum; interleukin-1β; interleukin-6; interleukin-8; metalloproteinase 9; neurotensin; nitric oxide; phosphate buffer solution; platelet-derived growth factor; polymorphonuclear leukocytes; scanning electron microscopy; streptozotocin; transforming growth factor β1; transforming growth factor β3; tumor necrosis factor-α; vascular endothelial growth factor