Use of magnetic nanoparticles for biofunctionalization of alginate hydrogel: experimental study findings

Introduction. The use of naturally occurring hydrocolloids and hydrogels as components of biomimetic materials has a significant advantage because such biopolymers are highly biocompatible. At the same time, the large-scale introduction of natural hydrogels in tissue engineering and practical medicine is hampered by the complexity of the structure standardization and chemical composition of this class of biopolymers, and, consequently, difficulties in predicting the cellular response to hydrogel biomaterials. One way to solve this problem may be the integration of magnetic nanoparticles into the structure of hydrogel biomaterials. Aim. To evaluate the effect of magnetite nanoparticles on the biocompatibility and adhesion of fibroblasts to the surface of alginate hydrogel. Materials and methods. A 2 % aqueous solution of sodium alginate was used to prepare the alginate hydrogel film. Magnetite nanoparticles treated with citric acid were used to modify the biofunctional properties of alginate hydrogel. Biocompatibility of materials was evaluated by light and luminescence microscopy using fluorescent dyes (DAPI, Rhodamine) and a kit for assessing metabolic activity of cell using a tetrazolium dye (MTT assay). Results and discussion. It was found that the introduction of magnetite nanoparticles into the alginate film increases the biocompatibility of the hydrogel material. After 48 hours of incubation, the number of cells increases from 30 ± 5 to 60 ± 7 pcs/200 μm2, and the metabolic activity of fibroblasts is 93 % of the control values. The surface of the hybrid film acquires the ability to maintain the adhesion and viability of fibroblasts, the number of cells on the surface of the hybrid film is more than 10 times greater than the number of cells adhered to the alginate film. Thus, magnetite nanoparticles modified with citric acid can be used to regulate functional cellular responses to plant-derived hydrogel biomaterials. Conclusion. A new method for the biofunctionalization of alginate hydrogel by including magnetite nanoparticles in its composition is proposed. The integration of magnetite nanoparticles with natural hydrogels and the creation of biomaterials with controlled structural and mechanical properties can be a solution to the problem of predictable cellular response to biopolymers heterogeneous in composition and structure.