In a recent article published in the journal Scientific Reports, researchers present a novel nanobiocomposite (NBC) made of agar, tragacanth gum, silk fibroin, and metal–organic framework-5 (MOF-5) for potential biomedical applications. The hydrogel was investigated for its biological activity, including antimicrobial properties and potential for cancer therapy and wound healing.
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Background
Hydrogels are versatile cross-linked network matrices of polymers that offer unique physicochemical properties, such as hydrophilicity, super absorbency, and softness. These properties make them valuable in various fields, including drug delivery, tissue engineering, and wound dressing. Natural hydrogels, derived from polymers like chitosan and alginate, stand out for their low cytotoxicity and biocompatibility, making them ideal for biomedical applications.
The combination of natural polymers like agar (Ag) and tragacanth gum (TG) facilitates the formation of multi-polymeric hydrogels, leveraging their abundant hydroxyl functional groups for cross-linking. Silk fibroin (SF), derived from the Bombyx mori silkworm, is a natural protein renowned for its biocompatibility, antibacterial properties, and mechanical strength, making it a promising material in biomedicine.
The Current Study
The chemical synthesis process began with the preparation of Ag-TG hydrogel, where Ag and TG were dissolved in distilled water and mixed under specified conditions. SF was extracted from silkworm cocoons through a series of steps, including boiling, washing, and dissolution in LiBr solution, followed by dialysis. The Ag-TG hydrogel was then combined with extracted SF and stirred. MOF-5 was synthesized separately and activated.
The final NBC, Ag-TG hydrogel on SF combined with MOF-5, was prepared by dispersing the components in water. The resulting solution underwent freeze-drying and dehydration to yield the NBC for further analysis.
The following biological assays were conducted to assess the NBC’s properties:
- The Trypan blue exclusion test evaluated its biocompatibility and anticancer activity using HEK293T, MCF-7, and K-562 cell lines.
- A hemolysis assay was used to measure blood compatibility by assessing human red blood cell lysis percentage.
- An antibacterial assay determined the inhibition rate of E. coli and S. aureus bacteria cultures.
- Statistical analysis using SPSS Statistics 22.0 provided insights into the significance of the results.
Characterization was performed using various techniques. Biological assays were conducted using an ELISA reader to evaluate the biocompatibility, anticancer activity, blood compatibility, and antibacterial properties of the NBC.
Results and Discussion
The results of the synthesis and characterization of the NBC are detailed below:
Fourier-transform infrared (FT-IR) analysis: FT-IR analysis was conducted to examine the chemical bonds and functional groups of the synthesized NBC components at each stage of preparation. Spectra revealed characteristic signals corresponding to the Ag-TG hydrogel, Ag-TG hydrogel/SF, and Ag-TG hydrogel/SF/MOF-5, indicating successful synthesis and incorporation of components.
Field-emission scanning electron microscopy (FE-SEM) imaging: FE-SEM imaging was employed to analyze the morphology of the NBC. Microscopic images showed the porous structure of Ag-TG hydrogel, the addition of SF biopolymer strands, and the presence of MOF-5 within the composite, confirming the successful synthesis and uniform distribution of components.
Energy-dispersive X-Ray (EDX) analysis: EDX provided insights into the elemental composition of the synthesized NBC. The spectra exhibited peaks corresponding to carbon (C), oxygen (O), nitrogen (N), and zinc (Zn), confirming the presence of Ag, TG, SF, and MOF-5 components, respectively.
X-Ray diffraction analysis (XRD): XRD analysis was conducted to examine the crystallinity of MOF-5 and the NBC. Patterns revealed characteristic peaks corresponding to MOF-5 and a combination of crystalline MOF-5 and amorphous polymer components in the NBC.
Thermogravimetric analysis (TGA): TGA was performed to evaluate the thermal stability and decomposition behavior of the NBC. Thermograms showed distinct mass loss stages, followed by the degradation of TG, Ag, and SF individual components.
Cell lines proliferation assay: Biological assays were conducted to assess the NBC’s biocompatibility and anti-cancer properties using HEK293T, MCF-7, and K-562 cell lines. Results demonstrated significant inhibition of MCF-7 and K-562 cancer cell proliferation, while HEK293T cell proliferation remained unaffected, indicating the NBC’s potential as an anti-cancer agent.
Blood compatibility: Hemolysis assay results showed a significant lytic effect of the NBC extract on red blood cells (RBCs), indicating potential blood compatibility concerns.
Bacteria growth inhibition: The NBC exhibited significant antibacterial activity against E. coli and S. aureus strains (with inhibition rates of 76.08 % and 69.19 %, respectively), suggesting its potential application as an antibacterial agent.
Conclusion
These findings highlight the potential of Ag-TG hydrogel/SF/MOF-5 NBC for wound healing and cancer therapy applications. The biocompatible and non-toxic nature of the NBC, along with its enhanced antibacterial properties, make it a promising material for future biomedical studies.
Overall, the study advances our understanding of nanomaterials' potential applications in biomedical and related fields. Further research is recommended to explore the full potential of this NBC in various biomedical applications.
Journal Reference
Lalebeigi, F., et al. (2024). Agar-tragacanth/silk fibroin hydrogel containing Zn-based MOF as a novel nanobiocomposite with biological activity. Scientific Reports. doi.org/10.1038/s41598-024-61329-3