# Environmentally Friendly UV Absorbers: Synthetic Characterization and Biosecurity Studies of the Host–Guest Supramolecular Complex

## TL;DR

This study creates a safer UV absorber by combining IMC with cyclodextrin, improving its environmental and biological safety while maintaining UV protection.

## Contribution

A novel host–guest supramolecular complex is proposed to enhance the eco-friendliness and performance of UV absorbers.

## Key findings

- IMC-SBE-β-CD achieved an 84.45% encapsulation rate and optimal stability at 30 °C.
- The supramolecular complex promoted cell growth without disrupting oxidative stress or apoptosis pathways.
- IMC-SBE-β-CD improved water solubility and maintained UV absorption properties.

## Abstract

Isoamyl 4-methoxycinnamate (IMC) is widely used in various fields because of its exceptional UV-filter properties. However, due to its cytotoxicity and anti-microbial degradability, the potential eco-environmental toxicity of IMC has become a focus of attention. In this study, we propose a host–guest supramolecule approach to enhance the functionality of IMC, resulting in a more environmentally friendly and high-performance materials. Sulfobutyl-β-cyclodextrin sodium salt (SBE-β-CD) was used as the host molecule. IMC-SBE-β-CD supramolecular substances were prepared through the “saturated solution method”, and their properties and biosecurity were evaluated. Meanwhile, we conducted the AOS tree evaluation system that surpasses existing evaluation approaches based on apoptosis, oxidative stress system, and signaling pathways to investigate the toxicological mechanisms of IMC-SBE-β-CD within human hepatoma SMMC-7721 cells as model organisms. The AOS tree evaluation system aims to offer the comprehensive analysis of the cytotoxic effects of IMC-SBE-β-CD. Our findings showed that IMC-SBE-β-CD had an encapsulation rate of 84.45% and optimal stability at 30 °C. Further, IMC-SBE-β-CD promoted cell growth and reproduction without compromising the integrity of mitochondria and nucleus or disrupting oxidative stress and apoptosis-related pathways. Compared to IMC, IMC-SBE-β-CD is biologically safe and has improved water solubility with the UV absorption property maintained. Our study provides the foundation for the encapsulation of hydrophobic, low-toxicity organic compounds using cyclodextrins and offers valuable insights for future research in this field.