In vivo Toxicity Assessment of Silver Nanoparticles in Homeostatic versus Regenerating Planarians

Abstract

Silver nanoparticles (AgNPs) currently belong to the most commercialized nanomaterials, used in both consumer products and medical applications. Despite its omnipresence, in-depth knowledge on the potential toxicity of nanosilver is still lacking, especially for developing organisms. Research on vertebrates is limited due to ethical concerns, and planarians are an ideal invertebrate model to study the effects of AgNPs on stem cells and developing tissues in vivo, as regeneration mimics development by triggering massive stem cell proliferation. Our results revealed a strong interference of AgNPs with tissue-and neuroregeneration which was related to an altered stem cell cycle. The presence of a PVP-coating significantly influenced toxicity outcomes, leading to elevated DNAdamage and decreased stem cell proliferation. Non-coated AgNPs had an inhibiting effect on stem cell and early progeny numbers. Overall, regenerating tissues were more sensitive to AgNP toxicity, and careful handling and appropriate decision making is needed in AgNP applications for healing and developing tissues. We emphasize on the importance of AgNP characterization, as we showed that changes in physicochemical properties influence toxicity.

Nanomaterial integration into the scaffolding materials for nerve tissue engineering: a review

“…It has been reported that changes in physicochemical properties of AgNPs affect their toxicity and neuroregeneration capacity. In an interesting example, Leynen et al examined non-coated AgNPs and polyvinylpyrrolidone (PVP)-coated AgNPs (30 nm in diameter) on neurodevelopment in the freshwater flatworm Schmidtea Mediterranea (Leynen et al 2019). They found that the lowest non-coated AgNPs exposure led to a markedly larger relative brain ganglia size, relative to the nonexposed worms.…”

“…Likewise, the authors mentioned that 59% of the PVP-AgNP-exposed worms showed partial eye regeneration (33%) while disruption of eye regeneration occurred in 24% of non-coated AgNPsexposed worms. Finally, they concluded that physicochemical properties and concentration of AgNPs significantly influence their regenerative capacity and toxicity (Leynen et al 2019).…”

“…Furthermore, they investigated the differentiation ability of NSCs when treated with 150 μg/mL of TiO 2 NPs (Liu et al 2010). In an interesting work, Lan et al designed TiO 2 nanotubes loaded with minocycline as antioxidant scaffolding materials on the surface of pure titanium through anodization at the voltage of 20, 30, 40 and 50 V and then soaking in minocycline solution (Lan et al 2018;Leynen et al 2019). They found that nanotubes at a voltage of 30 V had the diameter nearly 100 nm that makes them good candidates for neurogenesis.…”

“…Additionally, the authors mentioned that the TiO 2 nanotubes fabricated at the voltage of 30-50 V demonstrated a lower contact angle and stronger hydrophilic surface than others that can be attributed to the increase in surface area of nanostructures. Generally, they concluded that the optimal concentration of 5-20 μg/mL minocycline loaded in the TiO 2 nanotubes fabricated at the voltage of 30 V exerted the highest effect on the proliferation of Schwann cells and secretion of neurotrophic factors (Lan et al 2018;Leynen et al 2019). The physicochemical properties of TiO 2 nanomaterials can be modulated by surface coating to obtain the best outcomes for nerve tissue engineering.…”

Modèles alternatifs (6)

“…La planaire a également été utilisée pour étudier l'impact de nanoparticules d'argent, des nanomatériaux largement répandus dans des produits de consommation courante mais aussi dans des applications médicales, dont la toxicité reste encore méconnue. Récemment, une étude a mis en évidence une forte influence de ces nanoparticules sur la régénération de la planaire Schmidtea mediterranea avec, notamment, un retard d'apparition des taches oculaires et une altération significative de la prolifération des cellules souches pour des fragments de tête en régénération [24].…”