Bioactive Hydrogels: Design and Characterization of Cellulose-Derived Injectable Composites

Abstract

Cellulose represents a low cost, abundant, and renewable polysaccharide with great versatility; it has a hierarchical structure composed of nanofibers with high aspect ratio (3–4 nm wide, hundreds of μm long). TEMPO-mediated oxidation represents one of the most diffused methods to obtain cellulose nanofibers (CNFs): It is possible to obtain physically crosslinked hydrogels by means of divalent cation addition. The presence of inorganic components, such as calcium phosphates (CaP), can improve not only their mechanical properties but also the bioactivity of the gels. The aim of this work is to design and characterize a TEMPO-oxidized cellulose nanofibers (TOCNFs) injectable hydrogel embedded with inorganic particles, CaP and CaP-GO, for bone tissue regeneration. Inorganic particles act as physical crosslinkers, as proven by rheological characterization, which reported an increase in mechanical properties. The average load value registered in injection tests was in the range of 1.5–4.4 N, far below 30 N, considered a reasonable injection force upper limit. Samples were stable for up to 28 days and both CaP and CaP-GO accelerate mineralization as suggested by SEM and XRD analysis. No cytotoxic effects were shown on SAOS-2 cells cultured with eluates. This work demonstrated that the physicochemical properties of TOCNFs-based dispersions could be enhanced and modulated through the addition of the inorganic phases, maintaining the injectability and bioactivity of the hydrogels.

An Electroconductive, Thermosensitive, and Injectable Chitosan/Pluronic/Gold-Decorated Cellulose Nanofiber Hydrogel as an Efficient Carrier for Regeneration of Cardiac Tissue

“…Figure 4 A shows FT-IR spectra of OBC and Au@OBC samples. The results indicate that, after oxidation, a new peak at 1729 cm −1 has emerged that can be attributed to the C=O stretching vibration of carboxylic acid groups [ 50 ]. The peak located at around 3400 cm −1 is assigned to the stretching vibration of hydroxyl groups (OH).…”

Point of care-based design and developement of liposome-anchored Teriparatide incorporated gallic acid-grafted gelatin injectable hydrogel for osteoarthritis treatment

“…The morphology of Lipo@PTH NPs was observed with the transmission electron microscope (TEM) (Hitachi, HT7800, Japan) and the sample was negatively stained with 2% phosphotungstic acid 35,36 .…”

Smart Biomaterials in Biomedical Applications: Current Advances and Possible Future Directions

“…Adding bioactive compounds to hydrogels is an enabling way to boost their bioactivity, which is crucial for cell adhesion and proliferation. [133] Many biomaterials have been investigated to control drug release; however, hydrogels show two distinct advantages among these biomaterials. First, the drug release rate can be controlled in numerous ways, such as changing the crosslinking density, preparing the hydrogel with the controlled hydrophilicity monomers, or containing the proportion to the hydrophilic and hydrophobic monomers.…”