Nanosized biomimetics
prepared by the strategy of molecular imprinting,
that is, the stamping of recognition sites by means of a template-assisted
synthesis, are demonstrating potential as plastic antibodies in medicine,
proving effective for cell imaging and targeted therapies. Most molecularly
imprinted nanoparticles (MIP-NPs) are currently made of soft matter,
such as polyacrylamide and derivatives. Yet, MIP-NPs biocompatibility
is crucial for their effective translation into clinical uses. Here,
we propose the original idea to synthesize fully biocompatible molecularly
imprinted nanoparticles starting from the natural polymer silk fibroin
(MIP SF-NPs), which is nontoxic and highly biocompatible. The conditions
to produce MIP SF-NPs of different sizes (
d
mean
∼ 50 nm;
d
mean
∼ 100 nm)
were set using the response surface method. The stamping of a single,
high affinity (
K
D
= 57 × 10
–9
M), and selective recognition site per silk fibroin nanoparticle
was demonstrated, together with the confirmation of nontoxicity. Additionally,
MIP SF-NPs were used to decorate silk microfibers and silk nanofibers,
providing a general means to add entailed biofunctionalities to materials.