In vitro and in vivo evaluation of a biomimetic scaffold embedding silver nanoparticles for improved treatment of oral lesions.

BACKGROUND: New materials are currently designed for efficient treatment of oral tissue lesions by guided tissue regeneration. The aim of this study was to develop a multifunctional 3D hybrid biomaterial consisting of extracellular matrix components, collagen, chondroitin 4-sulfate and fibronectin, functionalised with silver nanoparticles, intended to improve periodontitis treatment protocols. METHODS: Structural observations were performed by autometallography, scanning and transmission electron microscopy. In vitro tests of 3D constructs of embedded gingival fibroblasts within hybrid biomaterial were performed by MTS and Live/Dead assays. Genotoxicity was assessed by comet assay. In vivo experiments using chick embryo chorioallantoic membrane (CAM) assay analysed the degradation and nanoparticles release, but also angiogenesis, new tissue formation in 3D constructs and the regenerative potential of the hybrid material. Biological activity was investigated in experimental models of inflamed THP-1 macrophages and oral specific bacterial cultures. RESULTS: Light micrographs showed distribution of silver nanoparticles on collagen fibrils. Scanning electron micrographs revealed a microstructure with interconnected pores, which favoured cell adhesion and infiltration. Cell viability and proliferation were significantly higher within the 3D hybrid biomaterial than in 2D culture conditions, while absence of the hybrid material's genotoxic effect was found. In vivo experiments showed that the hybrid material was colonised by cells and blood vessels, initiating synthesis of new extracellular matrix. Besides the known effect of chondroitin sulfate, incorporated silver nanoparticles increased the anti-inflammatory activity of the hybrid biomaterial. The silver nanoparticles maintained their antibacterial activity even after embedding in the polymeric scaffold and inhibited the growth of F. nucleatum and P. gingivalis. CONCLUSION: The novel biomimetic scaffold functionalised with silver nanoparticles presented regenerative, anti-inflammatory and antimicrobial potential for oral cavity lesions repair.

Tailored Biomaterials for Therapeutic Strategies Applied in Periodontal Tissue Engineering.

Several therapeutic strategies are currently in development for severe periodontitis and other associated chronic inflammatory diseases. Guided tissue regeneration of the periodontium is based on surgical implantation of natural or synthetic polymers conditioned as membranes, injectable biomaterials (hydrogels), or three-dimensional (3D) matrices. Combinations of biomaterials with bioactive factors represent the next generation of regenerative strategy. Cell delivery strategy based on scaffold-cell constructs showed potential in periodontitis treatment. Bioengineering of periodontal tissues using cell sheets and genetically modified stem cells is currently proposed to complete existing (pre)clinical procedures for periodontal regeneration. 3D structures can be built using computer-assisted manufacturing technologies to improve the implant architecture effect on new tissue formation. The aim of this review was to summarize the advantages and drawbacks of biomimetic composite matrices used as biomaterials for periodontal tissue engineering. Their conditioning as two-dimensional or 3D scaffolds using conventional or emerging technologies was also discussed. Further biotechnologies are required for developing novel products tailored to stimulate periodontal regeneration. Additional preclinical studies will be useful to closely investigate the mechanisms and identify specific markers involved in cell-implant interactions, envisaging further clinical tests. Future therapeutic protocols will be developed based on these novel procedures and techniques.

A bioanalytical approach of chemical composition, bioactivity and cytotoxicity of Berteroa incana L. herb.

Berteroa incana is a wild herb widespread in temperate zones which was practically not studied for its biological effects. Methanolic and aqueous extracts of B. incana were assessed for the content in polyphenols and the related antioxidant and antimicrobial activities and the polysaccharide extract for the content in saccharides and the associated cytostatic effect. The results obtained highlighted that the methanolic extracts of B. incana contain moderate amounts of polyphenols, the most representative been isoquercitrin 4.41 ± 0.02 mg100 g-1dry weight plant material (DW), quercetin 4.21 ± 0.05, sinapic acid 5.23 ± 0.12 and ferulic acid 5.05 ± 0.12 mg 100 g-1DW, with correlated moderate antioxidant activities (IC50 13.40 ± 0.01 µg mL-1) and absent antibacterial activity. The polysaccharide fraction showed high content in saccharides, especially in arabinose (312.22 ± 7.54 mg g-1 polysaccharide extract) and glucose (279.22 ± 5.59), and promising cytostatic effect.