Photocross-Linkable and Shape-Memory Biomaterial Hydrogel Based on Methacrylated Cellulose Nanofibres

Emerging roles of hydrogel in promoting periodontal tissue regeneration and repairing bone defect

Periodontal disease is the most common type of oral disease. Periodontal bone defect is the clinical outcome of advanced periodontal disease, which seriously affects the quality of life of patients. Promoting periodontal tissue regeneration and repairing periodontal bone defects is the ultimate treatment goal for periodontal disease, but the means and methods are very limited. Hydrogels are a class of highly hydrophilic polymer networks, and their good biocompatibility has made them a popular research material in the field of oral medicine in recent years. This paper reviews the current mainstream types and characteristics of hydrogels, and summarizes the relevant basic research on hydrogels in promoting periodontal tissue regeneration and bone defect repair in recent years. The possible mechanisms of action and efficacy evaluation are discussed in depth, and the application prospects are also discussed.

Methacrylated Cellulose Nanocrystals as Fillers for the Development of Photo-Cross-Linkable Cytocompatible Biosourced Formulations Targeting 3D Printing

Cellulose nanocrystals (CNCs) from cotton were functionalized in aqueous medium using methacrylic anhydride (MA) to produce methacrylated cellulose nanocrystals (mCNCs) with a degree of methacrylation (DM) up to 12.6 ± 0.50%. Dispersible as-prepared CNCs and mCNCs were then considered as reinforcing fillers for aqueous 3D-printable formulations based on methacrylated carboxymethylcellulose (mCMC). The rheological properties of such photo-cross-linkable aqueous formulations containing nonmodified CNCs or mCNCs at 0.2 or 0.5 wt% in 2 wt% mCMC were fully investigated. The influence of the presence of nanoparticles on the UV-curing kinetics and dimensions of the photo-cross-linked hydrogels was probed and 13C CP-MAS NMR spectroscopy was used to determine the maximum conversion ratio of methacrylates as well as the optimized time required for UV postcuring. The viscoelasticity of cross-linked hydrogels and swollen hydrogels was also studied. The addition of 0.5 wt% mCNC with a DM of 0.83 ± 0.040% to the formulation yielded faster cross-linking kinetics, better resolution, more robust cross-linked hydrogels, and more stable swollen hydrogels than pure mCMC materials. Additionally, the produced cryogels showed no cytotoxicity toward L929 fibroblasts. This biobased formulation could thus be considered for the 3D printing of hydrogels dedicated to biomedical purposes using vat polymerization techniques, such as stereolithography or digital light processing.