N-(furfural) chitosan hydrogels based on Diels-Alder cycloadditions and application as microspheres for controlled drug release.
In this study, chitosan was chemically modified by reductive amination in a two-step process. The synthesis of N-(furfural) chitosan (FC) was confirmed by FT-IR and (1)H NMR analysis, and the degrees of substitution were estimated as 8.3 and 23.8%. The cross-linkable system of bismaleimide (BM) and FC shows that FC shared properties of furan-maleimide chemistry. This system produced non-reversible hydrogel networks by Diels-Alder cycloadditions at 85 °C. The system composed of BM and FC (23.8% substitution) generated stronger hydrogel networks than those of FC with an 8.3% degree of substitution. Moreover, the FC-BM system was able to produce hydrogel microspheres. Environmental scanning electron microscopy revealed the surface of the microspheres to be non-porous with small protuberances. In water, the microspheres swelled, increasing their volume by 30%. Finally, microspheres loaded with methylene blue were able to release the dye gradually, obeying second-order kinetics for times less than 600 min. This behavior suggests that diffusion is governed by the relaxation of polymer chains in the swelled state, thus facilitating drug release outside the microspheres.
['Montiel-Herrera|Marcelino|M|', 'Gandini|Alessandro|A|', 'Goycoolea|Francisco M|FM|', 'Jacobsen|Neil E|NE|', 'Lizardi-Mendoza|Jaime|J|', 'Recillas-Mota|Maricarmen|M|', 'Argüelles-Monal|Waldo M|WM|']
D048271:Chitosan D057930:Click Chemistry D061565:Cycloaddition Reaction D003692:Delayed-Action Preparations D005662:Furaldehyde D020100:Hydrogels D009682:Magnetic Resonance Spectroscopy D008301:Maleimides D008863:Microspheres D017550:Spectroscopy, Fourier Transform Infrared
Chitosan Hydrogels Reductive amination Click chemistry Diels–Alder Furans