β-Alanine enhancing the crosslink of chitosan/poly-(γ-glutamic acid) hydrogel for a potential alkaline-adapted wound dressing

• Published in: International journal of biological macromolecules 2023-03, Vol.231, p.123157-123157, Article 123157
• Main Authors: Hu, Ziwei, Liu, Dandan, Wang, Mengmeng, Yu, Chenrui, Han, Zhenxing, Xu, Maodong, Yue, Wenjin, Nie, Guangjun
• Format: Article
• Language: English
• Subjects: Bandages; beta-Alanine; Chitosan; Chitosan - chemistry; Glutamic Acid; Hydrogel; Hydrogels - chemistry; Poly-(γ-glutamic acid); Polyglutamic Acid - chemistry; Water; Wound dressing; β-Alanine
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2023.123157

Tiny crosslink in chitosan (CS)/poly-(γ-glutamic acid) (γ-PGA) hydrogel leads to some disadvantages including low mechanical strength and high swelling. To enhance the crosslink of CS/γ-PGA hydrogel, amino acid (AA) was introduced to remove the drawbacks. The results indicated that AA can dramatically increase the crosslink and mechanical properties of CS/γ-PGA hydrogel, and AA chain length and concentration have a drastic effect on them. Particularly, 0.5 % β-Alanine (β-Ala) decreased the hydrogel by 70 % in porosity, 52 % in water solubility, and 30 % in swelling, but increased by 2.2-fold in elastic modulus, 2.08-fold in stress, and 1.53-fold in water retention. The porosity of the hydrogel correlates positively with the elastic modulus but negatively with the crosslinking degree. The effect of pH on CS/β-Ala/γ-PGA hydrogel was investigated in the load and release of benzalkonium chlorides (BAC). β-Ala strengthened pH response of the hydrogel in BAC load and release. The loading capacity increased with pH value, and 0.5 % β-Ala increased the hydrogel by 1.25-fold in the release capacity in alkaline environment, suggesting a good buffering effect of β-Ala on pH variation to accelerate the transportation of BAC. CS/β-Ala/γ-PGA hydrogel will be competently applied as a potential material for wound dressing in alkaline environment. •β-Ala as a buffer can counteract the detrimental effect of pH variation on the structure and behavior of CS/γ-PGA hydrogel.•β-Ala as a bridge can enhance the crosslinking degree of CS/γ-PGA hydrogel and increase the elastic modulus by 2.2-fold.•β-Ala as a carrier can increase the capacity of CS/γ-PGA hydrogel to release BAC by 25 % in alkaline environment.