Chitosan-Based Cryogels for Esterase Immobilization

OpenAlex İngilizce

Abstract Preparing chitosan (Ch) cryogels in the form of full‐interpenetrating polymer networks (IPNs) is an advantageous approach since the IPN cryogels have a more regular and tight pore distribution and durable spongy structure, including enhanced mechanical properties and more functional groups. In the present research, Ch–Ch ([Ch] cry ) and Ch‐pAAm (polyacrylamide) full‐IPN cryogels ([Ch‐pAAm] cry ) were synthesized, characterized, and then used for the immobilization of enzyme (porcine/pig liver esterase (PLE)) using the adsorption method. The results of mechanical analysis have shown that the compression elasticity modulus ( E ) value of [Ch‐pAAm] cry full‐IPN cryogel is 47 times that of [Ch] cry . The introduction of pAAm within full‐IPN cryogels increases the compression strength; however, it decreases their ability for esterase immobilization and swelling degrees ( S e ). The esterase adsorption capacity ( X L ) values are 90.7 and 13.4 mg g −1 for [Ch] cry and [Ch‐pAAm] cry , respectively. Adsorption equilibrium time of [Ch] cry is shorter (360 min) than [Ch‐pAAm] cry (600 min). According to K m values, the order of affinity for the 4‐nitrophenyl acetate (pNPA) substrate is [Ch‐pAAm] cry (6.9 mM) > [Ch] cry (22.1 mM) > free enzyme (60.4 mM). The porosity parameter, V p (cm 3 pore (g dry cryogel) −1 , was calculated to be 36.18 ± 4.77 for [Ch] cry and 5.00 ± 0.76 for [Ch‐pAAm] cry , indicating that [Ch] cry had larger pores than [Ch‐pAAm] cry .