Osteochondral defects are common orthopedic conditions that can lead to osteoarthritis and severe joint pain. Recently, smart biohydrogels have been widely applied in osteochondral repair and regeneration, owing to their 3D structural resemblance to osteochondral tissues and their remarkable responsiveness to external stimuli. Glucosamine hydrochloride (GH) has been proved to stimulate the proliferation and chondrogenic differentiation of bone mesenchymal stem cells (BMSC), thereby accelerating wound healing and tissue regeneration. Herein, double-crosslinked smart hydrogels SPA 5 -Mg/GH/FP are fabricated using sodium alginate, acrylamide and N-Isopropylacrylamide (NIPAM) as the substrates. Simultaneously, the incorporation of Mg 2+ and Polydopamine (PDA)-coated Fe 3 O 4 NPs into the system further enhanced its properties. The results emphasized the favorable microenvironment created by the 3D architecture of the hydrogel, which effectively facilitated tissue repair and regeneration of the defects. Notably, the controlled release of GH aligned with the repair process is achieved through the responsiveness of Fe 3 O 4 @PDA NPs to near-infrared light. Moreover, in vivo assessments have demonstrated the effectiveness of the smart hydrogel in repairing osteochondral defects, highlighting its structural similarities to native tissue. This promising outcome underscores the potential of SPA 5 -Mg/GH/FP as a sophisticated solution for addressing the challenges associated with osteochondral repair.
Bi Yanhong,Wang Zhaoyu,Tian Yaoqi,Fan Haoran,Huang Shuo,Lu Yihui,Jin Zhengyu
The immobilization of Thermomyces lanuginosus lipase on polydopamine-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@PDA-TLL) as a nanobiocatalyst was successfully performed for the first time, and the Fe3O4@PDA-TLL was used for regioselective acylation of natural hyperoside with vinyl decanoate. The effects of several crucial factors, such as the reaction solvent, substrate molar ratio, temperature, and immobilized enzyme dosage, were investigated. Under optimum conditions, the reaction rate, 6″-regioselectivity, and maximum substrate conversion were as high as 12.6 mM/h, 100%, and 100%, respectively. An operational stability study demonstrated that the immobilized enzyme could maintain 90.1% of its initial maximum conversion even after reusing it five times. In addition, further investigations on the kinetic parameters, like Vmax, Km, Vmax/Km, and Ea, also revealed that the biocompatible Fe3O4@PDA could act as an alternative carrier for the immobilization of different enzymes.
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