The concerns regarding microplastics and nanoplastics pollution stimulate studies on the uptake and biodistribution of these emerging pollutants in vitro. Atomic force microscopy in nanomechanical PeakForce Tapping mode was used here to visualise the uptake and distribution of polystyrene spherical microplastics in human skin fibroblast. Particles down to 500 nm were imaged in whole fixed cells, the nanomechanical characterization allowed for differentiation between internalized and surface attached plastics. This study opens new avenues in microplastics toxicity research.
Topical administration of drugs is required for the treatment of parasitic diseases and insect infestations; therefore, fabrication of nanoscale drug carriers for effective insecticide topical delivery is needed. Here we report the enhanced immobilization of halloysite tubule nanoclay onto semiaquatic capybaras which have hydrophobic hair surfaces as compared to their close relatives, land-dwelling guinea pigs, and other agricultural livestock. The hair surface of mammals varies in hydrophobicity having a cortex surrounded by cuticles. Spontaneous 1–2 µm thick halloysite hair coverages on the semi-aquatic rodent capybara, non-aquatic rodent guinea pig, and farm goats were compared. The best coating was found for capybara due to the elevated 5 wt% wax content. As a result, we suggest hair pretreatment with diluted wax for enhanced nanoclay adsorption. The formation of a stable goat hair coverage with a 2–3 µm halloysite layer loaded with permethrin insecticide allowed for long-lasting anti-parasitic protection, enduring multiple rain wettings and washings. We expect that our technology will find applications in animal parasitosis protection and may be extended to prolonged human anti-lice treatment.
Halloysite is a promising building block in nanoarchitectonics of functional materials, especially in the development of novel biomaterials and smart coatings. Understanding the behavior of materials produced using halloysite nanotubes within living organisms is essential for their safe applications. In this study, quantum dots of different compositions were synthesized on the surface of modified clay nanotubes, and the biodistribution of this hybrid material was monitored within Caenorhabditis elegans nematodes. The influence of the modification agent as well as the particles’ composition on physicochemical properties of hybrid nanomaterials was investigated. Several microscopy techniques, such as fluorescence and dark-field microscopy, were compared in monitoring the distribution of nanomaterials in nematodes’ organisms. The effects of QDs-halloysite composites on the nematodes’ life cycle were investigated in vivo. Our fluorescent hybrid probes induced no acute toxic effects in model organisms. The stable fluorescence and low toxicity towards the organisms suggest that the proposed synthesis procedure yields safe nanoarchitectonic materials that will be helpful in monitoring the behavior of nanomaterials inside living cells and organisms.
A simple method for producing a nanocomposite based on halloysite nanotubes modified with carboxymethylcellulose and trypsin and lysozyme enzymes was developed. Fourier transform infrared spectroscopy confirmed the presence of enzymes in the samples. Chitosan-based coatings were subsequently produced from the nanocomposites. Atomic force microscopy visualization revealed the formation of globular structures consisting of enzymes and carboxymethylcellulose on the halloysite surface. An analysis of the coatings revealed a uniform distribution of halloysite throughout the matrix. The antibacterial activity of the nanocomposite containing lysozyme against Escherichia coli OP 50-1 was 47.2% and 63.9% at a concentration of 0.5 and 1 mg/mL, respectively. The antibacterial activity of the nanocomposite containing trypsin against Escherichia coli OP 50-1 was 44.4 and 55.5% at concentrations of 0.5 and 1 mg/mL, respectively. The antibacterial activity of the nanocomposite containing lysozyme against Staphylococcus aureus 6583 was 26.1 and 50.7% at concentrations of 0.5 and 1 mg/mL, respectively. The antibacterial activity of the nanocomposite containing trypsin against Staphylococcus aureus 6583 was 53.6 and 75.4% at concentrations of 0.5 and 1 mg/mL, respectively. The antibacterial activity of coatings based on chitosan and the nanocomposites containing trypsin and lysozyme against Escherichia coli OP 50-1 and Staphylococcus aureus 6583 was observed.