Synthesis, characterization and cytotoxicity of photo-crosslinked maleic chitosan-polyethylene glycol diacrylate hybrid hydrogels.

Synthetic hydrogels are important biomaterials for many biomedical applications and hydrogels produced via photo-gelation have shown particular promise. In this paper, we describe a new family of biodegradable hybrid hydrogels fabricated in aqueous solution via long wavelength UV photo-crosslinking using maleic chitosan and polyethylene glycol diacrylate (PEGDA) as precursors. The maleic chitosan precursor was prepared by a simple one-step chemical modification of chitosan, with high yields, and characterized by Fourier transform infrared spectroscopy, (1)H NMR and (13)C NMR. Maleic chitosan and PEGDA precursors at a wide range of weight feed ratios were mixed in aqueous solution and directly photo-crosslinked for 10 min under a long wavelength UV light (365 nm) using 4-(2-hydroxyethoxy) phenyl-(2-hydroxy-2-propyl) ketone (Irgacure 2959) as photoinitiator. It was observed that as the weight feed ratio of maleic chitosan to PEGDA decreased the pore sizes of the hydrogel samples decreased, thereby increasing the densities of the hydrogel networks and producing a lower swelling ratio and a higher compressive modulus. The molecular weight of PEGDA had a similar effect. Preliminary cell cytotoxicity tests of both the maleic chitosan precursor and maleic chitosan/PEGDA hydrogels, based on the MTT assay and live-dead assay, respectively, showed that these new chitosan-based biodegradable biomaterials were relatively non-toxic to bovine aortic endothelial cells at low dosages.

Zhong C ，Wu J ，Reinhart-King CA ，Chu CC ... -  《-》

Synthesis and characterization of in situ chitosan-based hydrogel via grafting of carboxyethyl acrylate.

We developed and characterized a novel in situ chitosan-poly(ethylene oxide) (PEO) hydrogel via two steps: 2-carboxyethyl acrylate molecules were grafted to the primary amine functional groups in chitosan in the first step and then Michael type addition reaction was processed between the grafted acrylate end groups and the thiol end groups in the PEO. Grafting of acrylate molecules to the amine groups in the deacetylated water soluble chitosan was confirmed by observing the new acrylate peaks by the FTIR and NMR spectra of the acrylated chitosan samples, as well as changes in relative viscosities of chitosan and acrylated chitosan. Formation of the chitosan-PEO hydrogel was visually observed with digital images after both gelation and hydration. Rheological analyses of the hydrogel formation were performed to detect its gelation time, phase angle changes, and visco-elastic properties over frequency and strain percentage. Their results indicated that the gelation process was completed within 10 min after mixing the precursor liquid solutions. An extent of water swelling, mechanical strength against compression and the morphologies of the hydrogel surface and cross sections after dehydration process were analyzed by microbalance measurement, texture analyzer, and scanning electron microscopy observation, respectively. Biological activities of the hydrogels were evaluated by observing smooth muscle cell behaviors such as cell adhesion and viability as well as by measuring the number of adhered cells on their surfaces.

Kim MS ，Choi YJ ，Noh I ，Tae G ... -  《JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A》

Effect of crosslinking density on swelling and mechanical properties of PEGDA400/PCLTMA900 hydrogels.

Metz J ，Gonnerman K ，Chu A ，Chu TM ... -  《-》

Synthesis and characterization of photo-cross-linked hydrogels based on biodegradable polyphosphoesters and poly(ethylene glycol) copolymers.

Du JZ ，Sun TM ，Weng SQ ，Chen XS ，Wang J ... -  《BIOMACROMOLECULES》

Synthesis and evaluation of novel biodegradable hydrogels based on poly(ethylene glycol) and sebacic acid as tissue engineering scaffolds.

Kim J ，Lee KW ，Hefferan TE ，Currier BL ，Yaszemski MJ ，Lu L ... -  《-》