Lysozyme-Induced Degradation of Chitosan: The Characterisation of Degraded Chitosan Scaffolds

Abstract

Up till now, chitosan has confirmed its versatile application in skin, cartilage and bone tissue engineering, as well as in drug delivery applications. This study is focused on enzymatic degradation of porous chitosan structures usually designed for mentioned purposes. In vitro degradation was monitored during four weeks of incubation at physiological temperature and in two different media, phosphate buffer saline solution and water.The scaffolds were characterised before and after enzymatic degradation using scanning electron microscopy and infrared spectroscopy with Fourier transformations (FTIR). According to the gravimetric analysis, higher weight loss of chitosan scaffolds was observed in buffered medium with respect to the water. The results implied that the total weight loss obtained in buffer involves physical dissolution of chitosan and lysozyme cleavage of glycoside bond. Importantly, FTIR identification of chitosan scaffolds after enzymatic degradation indicated the absence of lysozyme activity in water, indicating that weight loss is a result of the chitosan dissolution. This finding greatly impacts design of degradation experiments and characterisation of degradation behaviour of chitosan-based materials utilised as implants or drug delivery systems.

Incorporation of antimicrobial peptides on electrospun nanofibres for biomedical applications

“…The N-H amide II peak of the polypeptide chain is also clear at 1525 cm À1 . 56 These absorption bands typical of peptides were detected in all AMP functionalized dressings and, together with the bands corresponding to O-H and C-H stretching, increased with AMP loading as shown in Fig. 1 and S1.…”

Electrophoretic Deposition and Characterization of Functional Coatings Based on an Antibacterial Gallium (III)-Chitosan Complex

“…The degradation pattern of high initial mass loss followed by a reduced degradation rate, which was observed for all types of coatings, can be attributed to the specific action mechanism of the enzyme. Lysozyme is able to hydrolyze the glycosidic linkages between N-acetyl-glucosamine units in the CS structure [67]. The enzyme contains an hexasaccharide sequence with 3-4 or more acetylated units, which is mainly responsible for the initial degradation rate of N-acetylated CS [68].…”

Chitosan/Polycyclodextrin (CHT/PCD)-Based Sponges Delivering VEGF to Enhance Angiogenesis for Bone Regeneration

“…In order to mimic the in vivo conditions, the study of the biodegradation of the sponge was carried out using a solution of PBS enriched with 0.5 mg/mL of lysozyme. Lysozyme is the major enzyme that degrades CHT in the human body by cutting the glycosidic bonds between the polysaccharide units of CHT [ 49 ]. The study of Lončarević et al [ 50 ] demonstrated the impact of lysozyme on degradation of chitosan compared to a lysozyme-free PBS solution, and concluded that the design of degradation experiments and the characterization of degradation behavior of chitosan-based scaffolds used as implants or drug delivery systems should be studied in lysozyme-PBS solution.…”