Organic and inorganic nanoparticles (NPs) have shown promising outcomes in transdermal drug delivery. NPs can not only enhance the skin penetration of small/biomacromolecule therapeutic agents but can also impart control over drug release or target impaired tissue. Thanks to their unique optical, photothermal, and superparamagnetic features, NPs have been also utilized for the treatment of skin disorders, imaging, and biosensing applications. Despite the widespread transdermal applications of NPs, their delivery across the stratum corneum, which is the main skin barrier, has remained challenging. Microneedle array (MN) technology has recently revealed promising outcomes in the delivery of various formulations, especially NPs to deliver both hydrophilic and hydrophobic therapeutic agents. The present work reviews the advancements in the application of MNs and NPs for an effective transdermal delivery of a wide range of therapeutics in cancer chemotherapy and immunotherapy, photothermal and photodynamic therapy, peptide/protein vaccination, and the gene therapy of various diseases. In addition, this paper provides an overall insight on MNs’ challenges and summarizes the recent achievements in clinical trials with future outlooks on the transdermal delivery of a wide range of nanomedicines.

Nowadays, green synthesis methods have gained growing attention in nanotechnology owning to their versatile features including high efficiency, cost-effectiveness, and eco-friendliness. Here, the aqueous extract of Chlorophytum comosum leaf was applied for the preparation of iron nanoparticles (INPs) to obtain spherical and amorphous INPs with a particle size below 100 nm as confirmed by TEM. The synthesized INPs managed to eliminate methyl orange (MO) from the aqueous solution. The concentration of MO can be easily checked via ultraviolet-visible (UV-Vis) spectroscopy throughout the usage of INPs at the presence of H2O2. The synthesized INPs exhibited MO degradation efficiency of 77% after 6 h. Furthermore, the synthesized INPs exhibited antibacterial activity against both Gram-negative and Gram-positive bacteria. The prepared INPs have an impressive effect on Staphylococcus aureus at concentrations below 6 μg/ml. Overall, the synthesized INPs could considerably contribute to our combat against organic dyes and bacteria.

Green synthesis of materials have received increasing attentions in the field of nanotechnology due to its characteristics of low-cost, high-efficiency, non-toxicity, and eco-friendly manner. In the present study, iron oxide nanoparticles (IONPs) were successfully synthesized using aqueous leaf extract of Teucrium polium as a low-cost and simple green technique to evaluate their effective applicability as dye degradation nanomaterial. The synthesis part comprises the reaction of Fe ³⁺ to obtain spherical-shaped iron oxide nanoparticles with sizes in the range of 5.68 to 30.29 nm, which were further characterized using various techniques such as transmission electron microscopy (TEM), particle size analysis (PSA), x-ray diffraction pattern (XRD), Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA). Additionally, the dye degradation activity of these nanoparticles was studied with the degradation of model dye methyl orange (MO). Remarkably, the results showed that the green synthesized IONPs were able to decolorize MO dye with 73.6% efficiency in a 6-h reaction, and so have the potential to serve as effective catalyst for environmental remediation.