Self-Assembled Amino Acid Microstructures as Biocompatible Physically Unclonable Functions (BPUFs) for Authentication of Therapeutically Relevant Hydrogels.

Counterfeited biomedical products result in significant economic losses and pose a public health hazard for over a million people yearly. Hydrogels, a class of biomedical products, are being investigated as alternatives to conventional biomedical products due to their superior physicochemical properties. Most hydrogels are in contact with the patient to be treated and are equally susceptible to counterfeiting. Here, we develop a biocompatible, physically unclonable function (BPUF) to verify the authenticity of therapeutically relevant hydrogels. The principle of the BPUF relies on the self-assembly of tyrosine into fibril-like structures. These structures are incorporated into the therapeutically relevant hydrogel resulting in their random dispersion. This unclonable arrangement of the structures leads to distinctive optical micrographs that are captured using an optical microscope. These optical micrographs are transformed into a unique security code through cryptographic techniques which is then used to authenticate the hydrogel. We demonstrate the temporal stability of the BPUFs and additionally, exploit the dissolution propensity of the structures upon exposure to an adulterant to identify the tampering of the hydrogel. Finally, we developed a platform to demonstrate the translational potential of this technology in validating and detecting tampering of therapeutically relevant hydrogels. The potential of this technology to combat hydrogel counterfeiting in the future is exemplified by its various benefits, which include its simplicity in production, ease of use and readout, biocompatibility, and cost-effectiveness. This article is protected by copyright. All rights reserved.