Preparation of pH-responsive avermectin/feather keratin-hyaluronic acid with anti-UV and sustained-release properties

In an effort to improve the utilization of pesticides, an environmentally friendly carrier material was prepared to encapsulate pesticides and to prevent pesticides from decomposing under natural conditions with sustained release effect. The carrier of feather keratin-hyaluronic acid (FK-HA) was prepared by Maillard reaction. Using avermectin (AVM) as a model drug, AVM/FK-HA was obtained by heating. Its structure and morphology were measured by SDS-PAGE, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analyzer (TGA) and dynamic light scattering (DLS). Furthermore, the encapsulation efficiency, anti-UV, sustained-release and toxicological properties were investigated. The results showed that AVM/FK-HA featured an average particle size of 473.82 nm, with nearly spherical shape. Furthermore, the material exhibited a high surface charge and was capable of homogeneous dispersion. The encapsulation efficiency was found to be as high as 81.25%. Compared to pure AVM, the pesticide encapsulated by FK-HA (i.e. AVM/FK-HA) could reduce drug decomposition by 20% after ultraviolet irradiation for 52 h. Moreover, mass ratio, temperature and varying pH values exhibited an effect on the sustained release of the drug and the release mechanism was consistent with Fick diffusion. Finally, the difference between the toxicological effects of AVM encapsulated by FK-HA and pure AVM were not significant.