Lignin-based sunscreen formulation using silica gel particles for UV protection

Overview

This solution addresses two major concerns with conventional chemical sunscreens: human health risks from chemicals passing through the skin into the bloodstream, and environmental damage to coral reefs from sunscreen chemicals washing off into ocean water. The approach uses aromatic compounds derived from lignin, a natural polymer found in plants, absorbed irreversibly onto small silica gel particles. The lignin-derived aromatics chemically resemble existing sunblock molecules and provide UV-blocking capability, while the silica particles serve a dual purpose: scattering light to enhance protection and preventing the active compounds from passing through skin or entering waterways when the product washes off.

This concept offers a path to effective, natural-origin sun protection that avoids the health and environmental issues driving regulatory action against chemical sunscreens in certain regions.

Technical specifications

Core approach:

• Uses monolignols (p-coumaryl, coniferyl, and sinapyl alcohols) as building blocks for the UV-absorbing component
• These lignin model compounds are commercially available and structurally similar to existing chemical sunblock molecules
• Active compounds are irreversibly absorbed onto silica gel particles, preventing release into skin or water
• Silica particles also contribute to UV protection through light scattering

Key advantages:

• Health safety: Irreversible binding to silica prevents chemicals from passing through the skin into the bloodstream
• Environmental safety: Particles do not release active compounds into water, protecting marine ecosystems including coral reefs
• Natural origin: Lignin-derived components offer a bio-based alternative to synthetic sunscreen chemicals

Validation methods:

• UV-visible spectroscopy to measure UV-blocking effectiveness
• Established characterization of irreversible molecular absorption onto silica gel
• Known light-scattering properties of silica particles

Technology readiness level

Multiple lignin model structures have been synthesized to date, and the individual components of the concept (UV absorption by lignin aromatics, irreversible silica absorption, and silica light scattering) are well-established. The integrated formulation requires further development and validation. Under a sponsored research agreement, the team can provide data and physical samples for sponsor evaluation, with a research associate completing the work in approximately six months to twelve months depending on development scope. A startup has been formed around this concept, offering partners the option to engage through the company or directly with the university laboratory.