Chitosan (CHT) is a polysaccharide with multiple claimed properties and outstanding biocompatibility, generally attributed to the presence of protonable amino groups rendering a cationic natural polymer. However, the effect of changes in CHT structure due to hydration is not considered in its performance. This study compares the effects on biocompatibility after drying at 25 °C and 150 °C scaffolds of chitosan, polyethylene glycol diglycidyl ether (PEGDE) crosslinked CHT (low, medium and high concentration) and glutaraldehyde (GA) crosslinked CHT. PEGDE crosslinked CHT showed a reduction in free amino groups and the amide I/II ratio, which exhaustive drying reduced further. In X-ray diffraction (DRX) analysis, PEGDE crosslinked CHT showed multiple peaks, whereas the crystallinity percentage was reduced with an increase in PEGDE concentration and thermal treatments at 150 °C. In a direct contact cell assay, high osteoblast viability was achieved at low and medium PEDGE concentrations, which was improved when the crosslinked scaffolds were thermally treated at 150 °C. This was attributed to its partial hydrophilicity, low crystallinity and low surface roughness; this in spite of the small reduction in the amount of free amino groups on the surface induced during drying at 150 °C. Furthermore, PEGDE crosslinked CHT scaffolds showed strong vinculin and integrin 1β expression, which render them suitable for bone contact applications.

Chitosan is a natural polymer that can sustain not only osteoblast adhesion and proliferation for bone regeneration purposes, but it is also claimed to exhibit antibacterial properties towards several Gram-positive and Gram-negative bacteria. In this study, chitosan was modified with sodium hyaluronate, crosslinked with polyethylene glycol diglycidyl ether (PEGDE) and both osteoblast cytotoxicity and antibacterial behavior studied. The presence of sodium hyaluronate and PEGDE on chitosan was detected by FTIR, XRD, and XPS. Chitosan (CHT) films with sodium hyaluronate crosslinked with PEGDE showed a better thermal stability than pristine hyaluronate. In addition, osteoblast cytocompatibility improved in films containing sodium hyaluronate. However, none of the films exhibit antimicrobial activity against Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus while exhibiting low to mild activity against Salmonella typhimurion.

Journal of Clinical Pediatric Dentistry (JOCPD) is an international, peer-reviewed, open access journal, which is currently indexed in SCIE, etc., aming to provide clinically relevant information to enable the practicing dentist to have access to the state of the art in pediatric dentistry.

Chitosan (CHT) and propolis (P) are natural materials with antiseptic, anti-inflammatory, antimicrobial, and mucoadhesive properties with many applications in orthopaedia dentistry. The objective of this study was to develop a low molecular weight (LMW) and medium molecular weight (MMW) chitosan polymeric system with propolis at different concentrations (0.31%, 0.62%, 1.25%, 2.5%, and 5%) and to evaluate the effect in terms of their cell interaction with dental pulp fibroblasts. FTIR spectra of both molecular weights CHT’s films with propolis show increased transmittance bands at 1730–1720 cm⁻¹ and 1460 cm⁻¹, indicating the presence of propolis ethanolic extract in the organic matrix. Contact angles test to determine hydrophobicity CHT films functionalized with propolis exhibit a more hydrophobic surface as propolis concentration increases. Cytotoxicity showed synergy between chitosan and propolis; the highest proliferation was observed in LMW CHT with 0.31% of propolis. Membranes made with CHT of both molecular weights plus propolis in an inflammatory stage (cells previously treated with LPS) can inhibit the expression of NF-k-B, MAPK, and VEGF. A polymeric system based on chitosan/ethanolic extract propolis could be a future alternative treatment for oral ulcers.