Responsive drug-delivery microcarriers based on the silk fibroin inverse opal scaffolds for controllable drug release

Tumor has always been a major threat to human health due to its high morbidity and mortality. Among many cancer treatments, drug delivery microcarriers as a newly emerging method has attracted much attention. Here, we present a novel kind of multifunctional drug-delivery microcarriers formed from silk fibroin inverse opal scaffold and temperature-responsive poly (N-isopropylacrylamide) (PNIPAM) hydrogel for controllable and sustained drug release. Because of their uniform porous microstructure and interconnected nanopores, the PNIPAM hydrogel loaded with therapeutic drug can fill into the inverse opal scaffolds. It was demonstrated that these microcarriers had the ability to release drugs controllably and sustainably with temperature changes, which could not only reduce the drug waste but improve the effect of oncotherapy as well. In addition, due to the excellent biocompatibility of the silk fibroin, the inverse opal scaffolds could also support the adhesion and growth of normal cells, which was contributed to the tissue regeneration in the lesions. These features indicate that the designed drug-delivery microcarriers are ideal for oncotherapy and tissue engineering.