A supramolecular crosslinked structure was incorporated to improve the performance of highly deformable and flexible polymeric soft materials like hydrogels, making them more elastic and enabling self-healing capability as maintenance-free property. This structure contains two photo-responsive guest molecules inside a host cavity, forming a host-guest inclusion complex. Using this supramolecular formation, we show that the viscoelasticity of hydrogels can be controlled in response to photo-stimuli. In addition, we provide an example of achieving self-healing properties in water-based solid coating prepared through a water medium.

We have focused on petroleum (widely used as a moisturizer in creams and other products) as a novel approach to maintain the water-holding capacity of stratum corneum (SC), with the aim of developing ingredients that further enhance moisturization. Petroleum is an extremely low polarity compound that is water-insoluble and oily with very low skin permeability. Additionally, its moisturizing effect is exclusively achieved by covering the skin surface to prevent moisture loss. In contrast, petroleum is easily eliminated from the skin surface by contact or rubbing, and its effects are short-lived.

The newly developed nanoemulsion of petroleum (nano-petroleum) enhances penetration into the SC by reducing the particle size to approximately ≤ 80 nm. Additionally, it was confirmed that the product had post-penetration moisture retention and swelling effects on SC. The skin permeability of low-polarity molecules is thought to be extremely low.

However, nanosizing enhances the texture by stably dissolving them in an aqueous system, making it possible to combine the usefulness of the moisture retention effect with skin permeability. We believe that this research has uncovered novel potential applications for petroleum, enabling its use in various cosmetic formulations.

Enzymes can reduce the energy required for cleaning while effectively breaking down and removing stains. Additionally, enzymes have the advantage of exerting low environmental impact even when released into the environment. For these reasons, incorporating enzymes into cleaning agents has become an important consideration from the perspectives of the Sustainable Development Goals (SDGs) and environmental consciousness. However, it is not easy to fully realize the performance of enzyme-containing products while maintaining their quality. For example, Most amylase is often deactivated by the oxidative effects of chlorine (such as sodium hypochlorite), which is commonly added to tap water for disinfection. As a result, simply blending amylase into a cleaning agent and diluting it with tap water may lead to the enzyme’s deactivation, rendering the product ineffective in removing starchy stains such as those from cooked rice. To address this issue of enzyme deactivation, it is necessary to incorporate chlorine inactivator-such as amine compounds or reducing agents-into the cleaning formulation to protect amylase from chlorine. However, most of these additives have some drawbacks, including poor storage stability of the enzyme, reduced appearance of the detergent, or increased risk of metal corrosion. This review presents our efforts to resolve these issues.