In Vivo Evaluation of Collagen and Chitosan Scaffold, Associated or Not with Stem Cells, in Bone Repair

Abstract

Natural polymers are increasingly being used in tissue engineering due to their ability to mimic the extracellular matrix and to act as a scaffold for cell growth, as well as their possible combination with other osteogenic factors, such as mesenchymal stem cells (MSCs) derived from dental pulp, in an attempt to enhance bone regeneration during the healing of a bone defect. Therefore, the aim of this study was to analyze the repair of mandibular defects filled with a new collagen/chitosan scaffold, seeded or not with MSCs derived from dental pulp. Twenty-eight rats were submitted to surgery for creation of a defect in the right mandibular ramus and divided into the following groups: G1 (control group; mandibular defect with clot); G2 (defect filled with dental pulp mesenchymal stem cells—DPSCs); G3 (defect filled with collagen/chitosan scaffold); and G4 (collagen/chitosan scaffold seeded with DPSCs). The analysis of the scaffold microstructure showed a homogenous material with an adequate percentage of porosity. Macroscopic and radiological examination of the defect area after 6 weeks post-surgery revealed the absence of complete repair, as well as absence of signs of infection, which could indicate rejection of the implants. Histomorphometric analysis of the mandibular defect area showed that bone formation occurred in a centripetal fashion, starting from the borders and progressing towards the center of the defect in all groups. Lower bone formation was observed in G1 when compared to the other groups and G2 exhibited greater osteoregenerative capacity, followed by G4 and G3. In conclusion, the scaffold used showed osteoconductivity, no foreign body reaction, malleability and ease of manipulation, but did not obtain promising results for association with DPSCs.

Use of Plant Extracts in Polymeric Scaffolds in the Regeneration of Mandibular Injuries

“…In the FT-IR spectrum of the scaffolds ( Figure 3 ), the characteristic bands of the precursors were observed, in agreement with other studies [ 25 , 75 ]. The values of the characteristic bands for collagen in the infrared region were directly linked to its extraction source, with only small displacements observed [ 76 ].…”

“…In addition, the operated areas were lined with integral local musculature and adhered well to the mandible, with no clinical signs of complications such as infections, purulent secretion, tissue necrosis, or any other signs that would also indicate clinical signs of rejection of the scaffolds used in G2 and G3 ( Figure 7 ). Therefore, the protocol used in the surgical procedure was within the expected standards as described in the experimental literature on mandibular regeneration [ 75 ].…”

Viability of Collagen Matrix Grafts Associated with Nanohydroxyapatite and Elastin in Bone Repair in the Experimental Condition of Ovariectomy

“…These findings confirm the affinity of collagen with the ECM in in-vivo therapies [17]. It is worth mentioning that the experimental protocol adopted in this study applied the principles of the ARRIVE guidelines of the National Center for the Replacement, Refinement and Reduction of Animals in Research-NC3Rs, with due preand post-operative care with analgesic control measures and good aseptic practices for carrying out the procedures [70].…”

Evaluation of Different Decellularization Protocols for Obtaining and Characterizing Canine Cardiac Extracellular Matrix

“…Due to its high biocompatibility and low immunogenicity, collagen is still the protein of choice for preparing biomaterials. The use of collagen as a scaffold has led to the development of bioengineered tissues as substitutes for various tissues [ 52 , 53 , 54 ].…”