Balu Kolathupalayam Shanmugam

Presently, alumina‐zirconia nanoparticles are prominently used in biomedical applications because of their valuable properties and augmented biological interactions. Amorphous (AZA) and tetragonal phase (AZT) nanoparticles are synthesized by spray pyrolysis. Three concentrations (10/15/20 mg) of synthesized alumina‐zirconia nanoparticles were mixed separately with 4 wt% of chitosan‐sodium alginate composite and developed as scaffolds using solvent casting. The physico‐chemical and in vitro biological properties of the prepared samples are evaluated using appropriate techniques. The physico‐chemical characteristics of AZT (tetragonal phase) nanoparticles and their scaffolds enhances in vitro biocompatibility, improve antibacterial activity against S. aureus and E. coli and also possess better in vitro cytotoxicity against human osteosarcoma (MG‐63) cells compare than amorphous nanoparticles (AZA) and their scaffolds. From the analysis, AZT nanoparticles and AZT scaffolds are fit for biomedical applications, including tissue engineering and nano theranostics.

Nanomaterials play a vital role in textile industries due to their unique properties and applications. There is an increase in the use of nanoscale phyto products in textiles to control the bacterial infection in fabrics. Here, natural herbal nanoparticles of different sizes were prepared from shade‐dried Aloe vera plant leaves using ball milling technique without any additives. The amorphous herbal A. vera nanoparticles possess an average particle size of 40 ± 2 nm and UV‐absorption maximum at 269 nm. A. vera nanopowders–chitosan nanocomposites were prepared and coated on cotton fabrics using pad‐dry cure method. The evaluation of antibacterial activity against Escherichia coli (22.05 ± 0.06 mm) and Staphylococcus aureus (27.17 ± 0.02 mm), UV‐protection properties (UV‐protection factor = 57.2 ± 0.1), and superhydrophobic nature (155 ± 3°) of the prepared herbal nanoparticles and their composites were analysed by disc diffusion, UV–visible spectral analysis, and contact angle analysis. Understanding the functional properties of herbal nanoparticles, coated particles on fabrics highlights their potential applications in protective clothing with better antimicrobial properties, hydrophobicity, and UV‐protection properties. This study of using A. vera herbal nanoparticles in textiles significantly enhances the fabric performance to develop protective textile fabrics in defence and biomedical fields.

The herbal nanoparticles were prepared from shade dried Tridax procumbens plant leaves employing ball milling technique using different process parameters, like ball ratio/size and milling time. The obtained nanoparticles were comprehensively characterised using X‐ray diffraction, Fourier transform infrared spectroscopy, UV–visible spectroscopy, dynamic light scattering, scanning electron microscopy and antimicrobial analysis techniques. The crystallinity of the nanoparticles was retained without altering even though the particle size changes due to milling periods. The antibacterial activities of the prepared herbal nanoparticles against Staphylococcus aureus and Escherichia coli were explored to understand the influence of particle size on antimicrobial activities and their functional properties. The increase in ball ratio and milling time periods leads to a decrease in nanoparticle size from 114 to 45 nm which in turn increases the antimicrobial activities. The above study confirms that antimicrobial activity relies on nanoparticle size. The observed knowledge on influence of particle size on antimicrobial activities will help to optimise the production of potential herbal nanoparticles for different biomedical applications.