مقالات پذیرفته شده در هشتمین کنگره بین المللی زیست پزشکی
The effect of hydroxyapatite and bioactive glass nanoparticles on the physicochemical and biological properties of enzymatically-crosslinked gelatin hydrogel: A comparative study
The effect of hydroxyapatite and bioactive glass nanoparticles on the physicochemical and biological properties of enzymatically-crosslinked gelatin hydrogel: A comparative study
Maryam Alizadeh,1Mohammad Jafar Abdekhodaie,2,*
1. Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran 2. Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
Introduction: The increasing average age of the global population, coupled with the rising prevalence of conditions such as osteoporosis, has resulted in a growing incidence of bone defects. Current treatment modalities, including autografts, allografts, and metal implants, present several limitations, including the induction of additional defects, the risk of graft rejection, and the potential necessity for re-surgery. These challenges highlight the urgent need for alternative therapeutic options.
Tissue engineering scaffolds have emerged as promising substitutes for bone repair to address these challenges. Hydrogel scaffolds provide an optimal environment for bone regeneration by providing a three-dimensional structure supporting cell survival and proliferation. Osteoinduction and osteoconduction are two essential features that must be considered in the design of these hydrogels to ensure effective bone regeneration. To enhance these properties, a variety of inorganic nanoparticles have been incorporated into hydrogels. Notably, hydroxyapatite (nHAp) and mesoporous bioactive glass (MBG) nanoparticles have shown great promise. Although these nanoparticles have been extensively employed to fabricate different types of nanocomposite hydrogels, their comparative effects on the overall properties of these hydrogels remain insufficiently investigated.
This study aimed to develop nanocomposite hydrogels by incorporating nHAp and MBG nanoparticles into an enzymatically crosslinked gelatin-based hydrogel. The objective was to evaluate and compare the effects of these two nanoparticles on the physicochemical and biological properties of the gelatin-based hydrogel.
Methods: Mesoporous bioactive glass nanoparticles were synthesized utilizing a sol-gel method. The morphology of the nanoparticles was assessed through scanning electron microscopy (SEM), while the porous structure was evaluated using the Brunauer-Emmett-Teller (BET) method. Gelatin was modified with tyramine groups via carbodiimide chemistry to facilitate enzymatic crosslinking of the hydrogel. Two groups of nanocomposite hydrogels were fabricated by incorporating nHAp and MBG into the hydrogel precursor solution at a final concentration of 1% w/v. Additionally, a nanoparticle-free hydrogel was prepared as the control group. The biodegradation rate, microstructure, and compressive modulus of the three hydrogel groups were investigated and compared. To assess the effect of nHAp and MBG nanoparticles on the biocompatibility of the hydrogels, mesenchymal stem cells (MSCs) were seeded onto the hydrogels, and metabolic activity was evaluated after 48 hours of culture. In all tests, the nanoparticle-free hydrogel served as the control group.
Results: The successful synthesis of MBG nanoparticles was confirmed through SEM images and BET test. The presence of peaks associated with tyramine groups was observed in the 1H NMR spectra of modified gelatin indicating successful modification of the gelatin molecules. Biodegradation test revealed a decrease in the degradation rate of hydrogels containing nHAp and MBG nanoparticles compared to the nanoparticle-free hydrogel (control group). Notably, the addition of nHAp had a more pronounced effect on the degradation rate than MBG nanoparticles. Analysis of the SEM images showed that incorporating nHAp significantly reduced the pore size of the gelatin hydrogel. Although the addition of MBG also decreased pore size, the difference compared to the control group was not statistically significant. The results of the compression tests demonstrated a similar trend: the nHAp-containing hydrogel exhibited a significantly higher compressive modulus than the control, while the increase in modulus for the MBG-containing hydrogel was not significant compared to the control group. In terms of metabolic activity, the nHAp-containing hydrogel showed no significant difference from the control group. However, the MBG-containing hydrogels exhibited a significant decrease in cell viability, likely due to the elevated pH resulting from ion release from the MBG nanoparticles.
Conclusion: The results indicate that fabricating nanocomposite hydrogels with nHAp or MBG nanoparticles at the same concentrations can lead to significantly different effects on the physicochemical properties of gelatin-based hydrogels. Although both nHAp and MBG nanoparticles are recognized in the literature as promising bioactive materials for bone regeneration, the choice of nanoparticles for creating an effective nanocomposite hydrogel should be based on the specific scaffold type, composition, and crosslinking method. These factors can significantly influence the mechanical and biological properties of the hydrogels. Therefore, this study emphasizes the need for preliminary optimization before finalizing the composition of the proposed nanocomposite hydrogels.