Cytidine 5′-monophosphate (5′-CMP) is an essential nucleotide for additives. In this study, enhanced production of 5′-CMP was realized by the transformation of cytidine using co-immobilized di-enzymes, uridine-cytidine kinase (UCK) and acetate kinase (AcK). The immobilization yield of the enzyme had a clear correlation with the surface charges as zeta potential ( ξ ). Among them, ε -polylysine-functionalized sepharose (SA-EPL, ξ = 9.31 mV) showed high immobilization yield (78.8%), which was 4.9-fold than that of nitrilotriacetic acid functionalized sepharose (SA-NTA, ξ = −12.6 mV). The residual activity of affinity co-immobilized enzyme (EPL-Ni/ [email protected] ) was higher than 70.6% after recycled 10 times. Thus, this study provides an effective approach for the production of 5′-CMP with the advantages of low adenosine 5′-triphosphate (ATP) consumption, reduced side reactions, and improved reusability by co-immobilized UCK and AcK on the functionalized Sepharose.
Malignant bone tumors result in high rates of disability and death and are difficult to treat in terms of killing tumors and repairing bone defects. Compared with other hyperthermia strategies, magnetic hyperthermia has become an effective therapy for treating malignant bone tumors due to its lack of depth limitations. However, tumor cells express heat shock protein (HSP) to resist hyperthermia, which reduces its curative effect. Competitive ATP consumption can reduce HSP production; fortunately, the basic principle of starvation therapy by glucose oxidase (GOx) is consuming glucose to control ATP production, thereby restricting HSP generation. We developed a triple-functional magnetic gel (Fe 3 O 4 /GOx/MgCO 3 @PLGA) as a magnetic bone repair hydrogels (MBRs) with liquid‒solid phase transition capability to drive magneto-thermal effects to simultaneously trigger GOx release and inhibit ATP production, reducing HSP expression and thereby achieving synergistic therapy for osteosarcoma treatment. Moreover, magnetic hyperthermia improves the effect of starvation therapy on the hypoxic microenvironment and achieves a reciprocal strengthening therapeutic effect. We further demonstrated that in situ MBRs injection effectively suppressed tumor growth in 143B osteosarcoma tumor-bearing mice and an in-situ bone tumor model in the rabbit tibial plateau. More importantly, our study also showed that liquid MBRs could effectively match bone defects and accelerate their reconstruction via magnesium ion release and enhanced osteogenic differentiation to augment the regeneration of bone defects caused by bone tumors, which generates fresh insight into malignant bone tumor treatment and the acceleration of bone defect repair.
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