Evaluation of nanofibril chitosan@8‐formyl‐7‐hydroxy‐coumarin hydrogel having distinct auto‐fluorescence efficiency: Structure–properties relation, improved antioxidant, and cellular imaging

Abstract

The modification at the branching of chitosan using 8‐formyl‐7‐hydroxy‐coumarin (ChCm) through chemically cross‐linked has been structured for hydrogel fabrication. ChCm produced stable mechanical properties, improved swelling capacity, and delayed degradation for new cross linking‐functionalized during experimental works. It also imparted high antioxidant potency. The swelling water ratio of this hydrogel makes it robust and elastic, providing a mechanical basis to keep the hydrogel strong and steady. A remarkable self‐fluorescence behavior has been witnessed. The distinct photo‐sensitiveness has been studied thoroughly as time, temperature, and solvent‐dependent spectral analysis to establish the ESIPT mechanism and improve stability in various conditions. Detailed instrumental‐structural evaluations are explored as required, and optimized the gel skeleton and photo activities are using DFT calculations. The effectiveness of radical scavenging using DPPH, antioxidant power using FRAP assay, and chelation ability have been observed during the evaluation of antioxidant potency for hydrogel. The role of phenolic‐OH is very significant not only for optical fluorescence enhancement by ESIPT but also for the improved antioxidant abilities. As well as being less toxic, bio‐compatible, and photostable, it could be used to image fibroblast 3T3 cells by fluorescence; current hydrogel has gained vast potential for developing dynamic biomaterials in multiple applications.

An Integrated Polysaccharide Hydrogel with Versatile Fluorescence Responses through Noncovalent Reformation of Gel Aggregation and for Bioimaging

“…Hydrogel networks, as shown in the swelling study, 33,50 are susceptible to pH. 1,22,51 The emission properties of ChCrQ gels depend on the aggregation state of the CrQ moieties (either CrQ−CrQ or ChCrQ−ChCrQ interactions). The assembly of CrQ−CrQ aggregates is affected by variations in pH due to the reformation of gel networks at lower (protonation) and higher (proton abstraction) pH values.…”

“…p -Cresol (compound a) was used to prepare p -cresol dialdehyde (compound b) from the Duff reaction in the previous procedure for forming the aromatic ring. , p- Cresol-based quinazolinone aldehyde (compound c, CrQ) was synthesized using a synthetic approach using CuO nanoparticles as a catalyst . This synthesis was carried out with compound b (1 mM) and anthranilamide (1 mM) catalyzed by 3 mol % copper oxide (CuO) nanoparticles dissolved in N , N -dimethylacetamide (DMAc, 3 mL) in air at 120 °C for 24 h. 1 H NMR for CrQ ( d 6 -DMSO, 400 MHz): δH 15.30 (1H, s), 12.73 (1H, s), 10.46 (1H, s), 8.48–8.45 (1H, m), 8.20–8.15 (1H, m), 7.92–7.82 (2H, m), 7.71–7.69 (1H, m), 7.60 (1H, t, J = 7.6 Hz), 2.33 (3H, s) (Figure S2a); ESI-MS ( m / z ): 281.08 (M+H) + (Figure S2b).…”

“…Gaussian 06 is engaged in collecting programs to analyze the geometric and electronic structures of the ChCrQ model. Density functional theory , (DFT) and time-dependent DFT (TD-DFT) calculations , were performed to optimize the ground state geometries and energies of the two models, ensuring no imaginary frequencies (indicating stable structures). , The CAM-B3LYP with the 6-31G basis set was used, incorporating a solvent model (water) using the polarizable continuum model (PCM) to account for solvation effects. These calculations not only provided insights into the electronic properties of the molecules but also yielded HOMO/LUMO levels and energy gaps.…”