Effect of molecular weight of chitosan degraded by microwave irradiation on lyophilized scaffold for bone tissue engineering applications

Abstract

Chitosan (CTS) is biocompatible, biodegradable, and can be formed into 3D porous structures for bone tissue engineering applications. Although studies have reported on the effects of molecular weight (MW) on CTS physicochemical properties, studies evaluating CTS biological property relationships often do not account for MW that confounds interpretation of study results. The aim of this study was to evaluate the effect of MW on CTS physicochemical and biological properties. CTS materials were treated for 6, 18, and 30 min by microwave irradiation to decrease MW without affecting deacetylation (DDA). Materials were evaluated for crystallinity using X-ray diffraction, thermal degradation using differential scanning calorimetry, water content, swelling ratio, and in vitro compatibility using Saos-2. Results showed that microwave treatments did not affect DDA but decreased MW and swelling ratio by 45.78% and 36.75%, respectively, after 30 min of microwave treatment. Microwave-treated CTS showed reduced or no crystalline peaks. Initial increase in exothermic peak temperatures with short (6 min) microwave treatment times were followed by a decrease with longer (18 and 30 min) treatment times. Cell growth over 7 days on samples was proportional to MW with the number of cells being 62% higher on CTS with the highest MW (3.71 ± 0.25 × 10(5) g/mol) when compared with the lower MW CTS (2.38 ± 0.12 × 10(5) g/mol). These results demonstrate the importance of MW of CTS to both its physicochemical characteristics and biological properties, providing researchers with another tool for the modulation and optimization of CTS for different biomedical applications.

Effects of sodium acetate buffer on chitosan sponge properties andin vivodegradation in a rat intramuscular model

“…This degradation time may not be ideal because the chitosan sponges typically release most of the loaded antibiotics early. 23 The available chitosan literature does not report many details on in vivo chitosan degradation, and the in vivo degradation and elimination mechanism is still not well understood. In the literature, there is molecular weight dependence for timely in vivo degradation and elimination, while an increase in DDA and molecular weight may provide for better biocompatibility.…”

“…The endothermic peak corresponds to water loss and the exothermic peak can be attributed to polymer decomposition, possibly of amine units. 17,23,24 The chitosan powder exhibited the highest exothermic peak temperature; after processing chitosan into a neutral sponge, the exothermic peak temperature decreased (p < 0.001). Buffering the chitosan sponges at pH 5.6 and 4.6 lowered the exothermic peak temperature by 23.4 and 30.2 C, respectively, from the neutral chitosan sponge's peak temperature (p < 0.001).…”

Biological properties of novel chitosan-based composites for medical application as bone substitute

“…Biological properties of chitosan make this polysaccharide an ideal component of calcium phosphate-based composites. Chitosan is a partially N-deacetylated derivative of chitin that naturally occurs in the exoskeleton of crustaceans [6,7]. This polysaccharide is often applied in tissue engineering because it biodegrades rapidly, is nontoxic, is prone to chemical and enzymatic modification, has similar structure to glycosaminoglycans (GAG) of bone extracellular matrix (ECM), and it stimulates cell adhesion, proliferation and osteoinduction [8][9][10].…”

Bio-scaffolds produced from irradiated squid pen and crab chitosan with hydroxyapatite/β-tricalcium phosphate for bone-tissue engineering

“…-Lower MW chitosan did not support cells. [29] a MW: Molecular weight. b DD: Degree of deacetylation.…”