Genipin‐cross‐linked chitosan‐based hydrogels: Reaction kinetics and structure‐related characteristics

Abstract

The main aim of this work is the synthesis and characterization of cross-linked chitosan systems. Chitosan hydrogels can be prepared by physical or chemical cross-linking of polymer chains. Chemical cross-linking, leading to the creation of hydrogel networks possessing improved mechanical properties and chemical stability, can be achieved using either synthetic agents or naturalbased agents. In this work, the cross-linker Genipin, a naturally derived compound, was selected because of the lower acute toxicity compared to many other commonly used synthetic cross-linking reagents. In particular, the chemical stabilization of chitosan through genipin cross-linking molecules was performed and characterized by calorimetric analyses (differential scanning calorimetry), swelling measurements in different pHs, and ionic strength. The reaction kinetics was carried out by means of rheological measurements, and both the activation energy (E a ) and the reaction order (m) were calculated. The hydrogel analyses were carried out at different concentrations of genipin (GN1 and GN2). The results were used to evaluate the possibility to use the chemical cross-linked chitosangenipin hydrogel for biomedical applications.

Effects of Genipin Concentration on Cross-Linked Chitosan Scaffolds for Bone Tissue Engineering: Structural Characterization and Evidence of Biocompatibility Features

“…These features suggest that the carboxymethyl group of genipin reacted with the amino group of chitosan to form a secondary amide according to the literature [28].…”

“…In a previous work, the polymerization reaction of a CS/genipin system, induced in the presence of oxygen radicals, was investigated. The reaction was strongly affected by temperature and by the presence of H + [28]. The aim of this research is to assess the effect of genipin on morphology, degradation, and mechanical properties of CS/genipin scaffolds and to describe the potential applications in bone tissue engineering by assessing cellular responses.…”

Core/shell cellulose‐based microspheres for oral administration of Ketoprofen Lysinate

“…After one hour, the weight was measured and the mass variation was calculated according to the following equation: where was the mass of the samples after dipping in water bath and the dry mass of the same type. Then, the dynamic mass variation was investigated, so as to measure the water absorption due to the external chitosan coating. To this aim, the weight of the samples extracted from the water bath after 1 h, was recorded continuously.…”

Cellulose‐based porous scaffold for bone tissue engineering applications: Assessment of hMSC proliferation and differentiation

“…The nature of the biomaterial and the fabrication process are the major aspects that influence the scaffold properties . Over the years, different materials (such as metals, ceramics, glass, synthetic and natural polymers) have been used to produce scaffold . Biodegradable polymers including poly(glycolic acid) (PGA), poly(lactic acid) (PLA), poly[lactic‐co‐(glycolic acid)] (PLGA), polyethylene glicol, chitosan, collagen, hyaluronic acid, and alginate have been widely used in the tissue engineering of cartilage, bone, skin, ligament, and so forth.…”

“…8 Over the years, different materials (such as metals, ceramics, glass, synthetic and natural polymers) have been used to produce scaffold. 9,10 Biodegradable polymers including poly(glycolic acid) (PGA), poly(lactic acid) (PLA), poly[lactic-co-(glycolic acid)] (PLGA), polyethylene glicol, chitosan, collagen, hyaluronic acid, and alginate have been widely used in the tissue engineering of cartilage, 11 bone, 12 skin, 13 ligament, and so forth. In order to produce the porous structure, the most common foaming techniques are based on salt leaching, gas foaming, phase separation, freeze-drying, electrospinning techniques.…”