Speaker
Description
Introduction:
Globally, almost two million bone transplants are performed using traditional methods like metallic implants and bone grafts that have their limitations. In this scenario, BTE has emerged as an advanced field to replace the conventional method by allowing a living tissue to be created within biological framework. Over the past few years, GelMA based hydrogels have been widely used to build scaffold material due to their exceptional biological and physiological properties. However, GelMA faces several limitations like mechanical strength and reduced immunogenicity. In this aspect, CQDs, 0-D carbon nanoparticles have become a promising solution to enhance the bioactivity and physical properties of GelMA by acting as a nanofiller [1]. Thus, this study focuses on dispersing green source derived and flavonoid based CQDs in the GelMA’s matrix to synthesize a composite based hydrogel with tunable and enhanced bioactivity and physiological properties.
Methods:
In this study CQDs are synthesized using microwave-based approach. It focuses on using mandarin orange juice as a carbon source, enriched with flavonoids which play a role in promoting bone formation and preventing bone resorption. In addition to this, L-arginine is used as a source of nitrogen to induce nitrogen doping in the CQDs due to its role in promoting osteogenesis, reducing inflammation and oxidative stress. The structural, chemical and optical properties of microwaves synthesized blue luminescent CQDs is confirmed using UV-Visible spectroscopy, FTIR, TEM and PL spectroscopy. Further, CQDs are dispersed in GelMA’s matrix in different concentrations to study their effect in the matrix. The morphological feature of the composite is analyzed using SEM and mechanical properties are assessed by DMA, the behavior in buffers is tested by swelling test. Moreover, biocompatibility of CQDs is revealed using MTT assay and staining. Lastly, 3D printing is done to check the effect of composite hydrogel on printing.
Results:
The characterization reveals the presence of various flavonoids on the surface of the CQDs having size around ~4-10 nm with spherical shape and exhibit blue fluorescence [2]. SEM reveals a slight decrease in pore size after addition of CQDs. An increase in compressive modulus is recorded in the composite hydrogel using DMA and the decrease in swelling degree is observed which shows their effect on crosslinking degree of GelMA. Cellular studies reveal the role of composite lack of cytotoxicity of CQDs. Thus, the enhancement in bioactivity, crosslinking and mechanical properties of GelMA after addition of flavonoids based and nitrogen doped CQDs, exhibit their potential to be a promising candidate for bioink to build bioactive scaffold for BTE.
References:
[1] Geng B, et al. Antibacterial and osteogenic carbon quantum dots for regeneration of bone defects infected with multidrug-resistant bacteria. Carbon N Y 2021;184:375–85.
[2] Bandi R, et al. Green synthesis of highly fluorescent nitrogen – Doped carbon dots from Lantana camara berries for effective detection of lead(II) and bioimaging. J Photochem Photobiol B 2018;178:330–8.