Nanocellulose/metal–organic framework (MOF) with broad-spectrum UV protection for sunblock creams on earthworms†

Skin protection from hazardous radiation, such as ultraviolet (UV) rays, is paramount. An investigation was conducted on a nanocomposite consisting of nanocellulose and metal–organic frameworks (MOFs) as a protective material against UV radiation with a wavelength of 254 nm. As the MOF model, the zeolitic imidazolate framework (ZIF-8) was in situ synthesized within cellulose materials, resulting in a milky white cream composed of nanocellulose/ZIF-8. The nanocellulose/ZIF-8 composite was characterized utilizing several analytical techniques, including X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and diffuse reflectance spectroscopy (DRS). The nanocellulose/ZIF-8 (50–200 nm) nanoparticles exhibit extensive UV light absorption over the UV-A, UV-B, and UV-C regions. Consequently, earthworms were used as a model for human skin to test the effectiveness of UV protection. The material's performance was assessed using several tests, including SEM, optical microscopy, histology (hematoxylin and eosin stain (H&E)), and photomicrographs of semithin slices. The mortality assessment conducted on earthworms demonstrates that the composite exhibits a significantly high level of biocompatibility. These findings may pave the way for developing a marketable sunscreen lotion or cream incorporating nanocellulose and ZIF-8 nanoparticles.