Three-Dimensional Evaluation of the Cytotoxicity and Antibacterial Properties of Alpha Lipoic Acid-Capped Silver Nanoparticle Constructs for Oral Applications

There is a need to develop bifunctional scaffolds that provide antibacterial protection while encouraging host cell attachment/proliferation. This study evaluates HyStem(R)-C, and photo-cross-linked GelMA hydrogels for encapsulation and stabilisation of silver nanoparticles (AgNPs). We studied the behaviour of AgNPs and matrix interactions within both hydrogel systems. The cell viability of encapsulated human gingival fibroblasts (HGFs) was determined by Prestoblue(R) assay and live/dead staining. The release of AgNPs was monitored by inductively coupled plasma-mass spectroscopy. The antibacterial properties of the GelMA-AgNP constructs were determined using disc diffusion. Even distribution of AgNPs in GelMA induced a significant decrease in cell viability (p < 0.0001), whereas AgNP aggregates did not induce cytotoxicity in HyStem((R))-C. AgNPs doses >= 0.5 mu g/mL in GelMA were significantly toxic to the HGFs (p < 0.0001). The release of AgNPs from GelMA after 48 h was 20% w/w for 0.1 mu g/mL and 51% for 100 mu g/mL of AgNPs. At >= 5 mu g/mL, a significant intra-construct bactericidal effect was observed. The disc diffusion assay shows that GelMA-incorporated AgNPs were found to be effective against both Escherichia coli and Staphylococcus aureus at 50 and 100 mu g/mL, respectively. Visible photo-cross-linked GelMA stably incorporated AgNPs to provide an antimicrobial regenerative construct for oral applications.

Automated summary

This study evaluates the encapsulation and stabilization of silver nanoparticles (AgNPs) in HyStem(R)-C and photo-cross-linked GelMA hydrogels. The results show that even distribution of AgNPs in GelMA significantly decreases cell viability, while AgNP aggregates in HyStem((R))-C do not induce cytotoxicity. The release rate of AgNPs from GelMA after 48 hours is 20% w/w for 0.1μg/mL and 51% for 100μg/mL. GelMA-incorporated AgNPs exhibit antibacterial effects against Escherichia coli and Staphylococcus aureus.