On-demand drug delivery systems using nanofibers have attracted significant attention owing to their controllable properties for drug release through external stimuli. Near-infrared (NIR)-responsive nanofibers provide a platform where the drug release profile can be achieved by the on-demand supply of drugs at a desired dose for cancer therapy. Nanomaterials such as gold nanorods (GNRs) exhibit absorbance in the NIR range, and in response to NIR irradiation, they generate heat as a result of a plasmon resonance effect. In this study, we designed poly (N-isopropylacrylamide) (PNIPAM) composite nanofibers containing GNRs. PNIPAM is a heat-reactive polymer that provides a swelling and deswelling property to the nanofibers. Electrospun nanofibers have a large surface-area-to-volume ratio, which is used to effectively deliver large quantities of drugs. In this platform, both hydrophilic and hydrophobic drugs can be introduced and manipulated. On-demand drug delivery systems were obtained through stimuli-responsive nanofibers containing GNRs and PNIPAM. Upon NIR irradiation, the heat generated by the GNRs ensures shrinking of the nanofibers owing to the thermal response of PNIPAM, thereby resulting in a controlled drug release. The versatility of the light-responsive nanofibers as a drug delivery platform was confirmed in cell studies, indicating the advantages of the swelling and deswelling property of the nanofibers and on–off drug release behavior with good biocompatibility. In addition, the system has potential for the combination of chemotherapy with multiple drugs to enhance the effectiveness of complex cancer treatments.

The application of near-infrared (NIR)-activated gold nanostructures, particularly gold nanostars (AuNSs) and gold nanorods (AuNRs), has emerged as a promising strategy in targeted combination cancer therapy (Figure 1). These nanostructures leverage their unique localized surface plasmon resonance (LSPR) properties, which enable effective absorption and conversion of NIR light into heat, facilitating photothermal therapy (PTT) to selectively destroy cancer cells. Recent advancements in the synthesis and functionalization of AuNSs and AuNRs have enhanced their biocompatibility, stability, and therapeutic efficacy. This review highlights the mechanisms by which these gold nanostructures can be optimized for synergistic effects when combined with other therapeutic modalities such as chemotherapy and photodynamic therapy (PDT). We discuss the importance of surface modifications that improve tumor targeting and retention, as well as the potential to overcome limitations associated with conventional therapies. The integration of AuNSs and AuNRs into multi-faceted treatment regimens represents a significant step forward in the development of effective cancer therapies, aiming to maximize therapeutic outcomes while minimizing side effects.

Dermal delivery, which delivers drugs and cosmetics through the skin, has attracted significant attention due to its non-invasive and simple administration compared with oral or injectable administration. However, delivery of the ingredients through the skin barrier is difficult because the primary function of the skin is to protect the human body by preventing the invasion of contaminants. Although various techniques have been developed to overcome skin barriers, chemical toxicity, complicated processes, and expensive equipment still remain as obstacles. Moreover, green chemistry, which minimizes or eliminates the use of toxic chemicals, is required in the cosmetic industry. Thus, the development of a new method for dermal delivery is required. In this study, we provide a new method for dermal delivery using nanobubbles (NBs). NBs generated in oil improve the delivery effect of the active ingredients through the high Brownian motion and charge-balancing effect. Franz cell experiments and depigmentation experiments using the B16F10 melanoma cells were conducted to confirm the enhanced delivery effects. The system using NBs will contribute to the advancement of the dermal delivery of drugs and cosmetics.