Ocular injectable formulation assessment for oxidized dextran-based hydrogels

Abstract

Initiator-free injectable hydrogels are very interesting for drug and/or cell delivery applications, since they can be administered in a minimally invasive way, and avoid the use of potentially harmful chemical initiators. In the current work, oxidized dextran crosslinked with adipic acid dihydrazide hydrogels were further characterized and tuned to produce formulations, with the aim of producing an injectable formulation for the possible treatment of posterior eye diseases. The gelation rate and the hydrogel dissolution profile were shown to be dependent on the balance between the degree of dextran oxidation, and the concentration of both components. For the in vitro studies, rabbit corneal endothelial cells were seeded on the hydrogels to assess cytotoxicity. Hydrogels prepared with low oxidized dextrans were able to promote cell adhesion and proliferation to confluence in just 24h, while more highly oxidized samples promoted cell adhesion and proliferation, but without achieving confluence. Cell viability studies were performed using MTS assays to verify the non-cytotoxicity of hydrogels and their degradation byproducts, rendering these formulations attractive for further in vivo studies.

In situgelling polysaccharide‐based hydrogel for cell and drug delivery in tissue engineering

“…Precipitation formation may complicate NMR readings after reaction between DA and tert ‐butyl carbazate (tBC) due to the bulky butyl group of tBC. For this reason, DO was determined by TNBS assay instead of NMR . Under the described reaction condition, the DO of DA was determined to be 59 ± 1.4% ( n = 3).…”

“…DA was prepared using oxidative cleavage, based on previously reported protocols . In brief, 2.5 g dextran was dissolved in 100 mL DI water.…”

“…The degree of oxidization (DO) of DA was determined using a TNBS titration method, as described previously . The DO of DA is defined as the number of oxidized residues per 100 glucose residues.…”

In vitro genotoxicity assessment of an oxidized dextrin‐based hydrogel for biomedical applications

“…Despite extensive research on cytotoxicity (effects on cell proliferation/viability) of aldehyde-modified polysaccharides and ADH, genotoxicity studies are still scarce, in particular, on ADHreticulated polyaldehyde-based hydrogels (Bouhadir, Hausman, & Mooney, 1999;Hu et al, 2017;Maia et al, 2009;Schramm et al, 2012;Su, Chen, & Lin, 2010). Genotoxicity is an important endpoint of the safety assessment of regulated products, but no single test is available to detect all types of genotoxicity.…”

Sodium hyaluronate/chitosan polyelectrolyte complex scaffolds for dental pulp regeneration: Synthesis and characterization

“…Hereafter, cells were kept in culture at 37 • C in a 5% CO 2 humidified atmosphere, inside an incubator. To evaluate cell behaviour in the presence of the scaffolds, MSCs were seeded with materials in 96-well plates at a density of 2 × 10 4 cells per well, for 72 h. Previously to cell seeding, plates and materials were sterilized by UV irradiation for 30 min [14,21]. Cell growth was monitored using an Olympus CX41 inverted light microscope (Tokyo, Japan) equipped with an Olympus SP-500 UZ digital camera.…”