Effect of genipin‐crosslinked chitin‐chitosan scaffolds with hydroxyapatite modifications on the cultivation of bovine knee chondrocytes

Abstract

Chitin and chitosan were hybridized in various weight percentages by genipin crosslinkage under various prefreezing temperatures to form tissue-engineering scaffolds via lyophilization. In addition, deposition of hydroxyapatite (HA) on the surface of the porous scaffolds was performed by precipitation method to achieve modified chemical compositions for chondrocyte attachments and growths. The experimental results revealed that a lower prefreezing temperature or a higher weight percentage of chitin in the chitin-chitosan scaffolds would yield a smaller pore diameter, a greater porosity, a larger specific surface area, a higher Young's modulus, and a lower extensibility. Moreover, a higher chitin percentage could also result in a higher content of amine groups after crosslink and a lower onset temperature for the phase transition after thermal treatment. A decrease in the prefreezing temperature from -4 degrees C to -80 degrees C, an increase in the chitin percentage from 20% to 50%, and an increase in the cycle number of alternate immersion for HA deposition from 1 to 5 generated positive effects on the cell number, the content of glycosaminoglycans, and the collagen level over 28-day cultivation of bovine knee chondrocytes.

Application of polyethyleneimine‐modified scaffolds to the regeneration of cartilaginous tissue

“…25,27,30,31 Briefly, 3% PEO was prepared by mixing 3 g PEO in 100 mL of ultrapure water. 3% chitin was prepared by dissolving 3 g acidolysed and centrifuged chitin in 100 mL of ultrapure water.…”

“…26 Application of chitin/chitosan matrices with the surface modification of hydroxyapatite also accelerated the regeneration of cartilaginous tissue. 27 For synthetic biopolymers, polyethylene oxide (PEO) is a linear, hydrophilic, and uncharged substance. Residue of PEO in animal tissue normally induced few immune responses owing to its extremely low toxicity.…”

Physical Limitations to Tissue Engineering of Intervertabral Disc Cells

“…The different maneuvers which have been tried to increase glycosaminoglycan production all have limitations. An increase in glycosaminoglycan production rate per cell can be induced by addition of growth factors, by providing mechanical or ultrasound stimulation or through alterations to scaffold properties (Blunk et al, 2002, Richmon et al, 2005, van der Kraan et al, 2002, Kuo & Lin, 2006, but the relative increase which can be achieved is limited (usually two-threefold under optimal conditions) and the consequent increase in metabolic demand can lead to a fall in pH in the construct center (Razaq et al, 2004) and thus severely limit growth factor efficacy. Indeed, addition of growth factors to constructs was found to have little effect on the concentration of accumulated glycosaminoglycan although it increased construct size (Walsh et al, 2002, Yoon et al, 2003a, Yoon et al, 2003b, Masuda et al, 2003, Malda et al, 2004.…”

Chitosan Electrodeposition for Microrobotic Drug Delivery

“…Intravitreal injections offer several advantages over conventional methods by increasing the drug level without causing systemic side effects. These injections are routinely applied in clinical settings, though repeated sessions are needed in order to compensate for the elimination of the drugs from the vitreous, thus causing patient discomfort and leading, 6.5) allows for the formation of pH responsive and functionalizable hydrogel fi lms for a large variety of applications, such as drug delivery systems, [21][22][23] scaffolds for tissue engineering, [ 24 ] and targeted radiotherapy. [ 25 ] These functions can be incorporated into lab-on-a-chip devices by different fabrication methods, including casting, printing and self-assembly.…”