Collagen Scaffolds Implanted in the Palatal Mucosa

Abstract

Scar formation after repair of the cleft palate leads to growth impairment of the upper jaw and midface. The implantation of a suitable scaffold during surgery may reduce this adverse effect. However, little is known about tissue reactions to scaffolds implanted in the oral cavity. Our goal was to analyze the tissue reactions to cross-linked type I collagen scaffolds after submucoperiosteal implantation in the palate of rats. Collagen type I scaffolds were implanted in the palate of 25 male Wistar rats. Groups of 5 rats were killed consecutively after 1, 2, 4, 8, and 16 weeks and were processed for histologic and immunohistochemical analyses. After 1 and 2 weeks, 3 rats from the sham group were also killed. On hematoxylin and eosin-stained sections, the cell density and the number of giant cells were determined. Blood vessels, inflammation, and the presence of myofibroblasts were detected by immunohistochemistry. An influx of inflammatory cells started after 1 week but had completely subsided after 8 weeks. Myofibroblasts were observed within the scaffolds only in the first 2 weeks. Angiogenesis already started after 1 week and showed a peak after 4 weeks, slowly declining afterward. The scaffolds were gradually integrated within the host tissue and only elicited a mild and transient inflammatory response. The scaffolds were biocompatible and seemed to be promising for future applications in cleft palate surgery.

Collagen-Gelatin Scaffold Impregnated with bFGF Accelerates Palatal Wound Healing of Palatal Mucosa in Dogs

“…It has been reported that collagen scaffolds implanted in oral mucoperiosteal defects improve wound healing and reduce contracture and scar tissue formation [3,[14][15][16]. Recently we succeeded in developing a novel scaffold that can provide sustained release of bFGF [17].…”

Effect of collagen matrix on postoperative palatal fistula in cleft palate repair

“…It induces only a mild inflammatory reaction during degradation and has good biodegradable and biocompatible properties. The space occupied by the collagen material is replaced by host soft tissue within 4 to 12 weeks 23,25 . Excessive tension bears a risk of wound dehiscence.…”

Development and Preclinical Evaluation of Acellular Collagen Scaffolding and Autologous Artificial Connective Tissue in the Regeneration of Oral Mucosa Wounds

“…When autologous oral mucosa for grafting is scarce (e.g., large defects), tissue-engineered products can be an alternative tissue source. In fact, epithelial sheets, 15-21 acellular dermal allografts, [22][23][24][25][26][27] oral mucosa equivalents, 4,5,28 bioabsorbable polyglactin meshes, 29,30 collagen-glycosaminoglycan membranes, 31 hyaluronic acid, 32 collagen and silicon bilayer membranes, 33 and collagen scaffolds [34][35] have been preclinically and clinically evaluated. Each of the aforementioned approaches has advantages and disadvantages, and depending on the characteristics of the oral wound, one product might be preferred over the others.…”

“…44,45,54 It is important to note that a similar acute but not sustained inflammation response in oral wounds implanted with collagen-based scaffolds in palatal mucosa has been previously reported. 31,35 Although the mechanisms orchestrating this regulated immune response remain to be elucidated, a recent report suggests that acute and transient infiltration of inflammatory cells promotes the regeneration of mucosal epithelium via IL-11 and IL-22-dependent activation of epithelial STAT3. 55 It would be of great interest to determine if a similar mechanism is operative in the observed AACT and CS regenerative effects.…”