Development of protein-based biomimetic particles for drug recovery

Abstract

A cytotoxic anticancer agent (CAA) that has the ability to enter aquatic environments via urinary excretion and is only partially removed by conventional wastewater-treatment units. In this study, the authors designed and synthesized serum protein (SP)-functionalized styrene–methylmethacrylate–poly(ethylene glycol) methacrylate (SMGP) based biomimetic particles (PSP) for the capture and recovery of CAA from aqueous solution and from real human urine. The particle shape, chemical functional groups, dry-state textural properties, particle-size distribution, and swelling characteristics were investigated by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett– Teller (BET) analysis, particle-size measurements, and swelling experiments, respectively. The adsorption was found to increase with the initial concentration of CAA and attain a maximum value of 9.39 mg/g at the selected condition of CAA concentration around 0.8 mg/mL. The adsorption capacity of both the modified polymer (PSP) and the unmodified polymer (UMP) was determined and compared. The adsorption capacity of the PSP was 8.76 mg/g, which is 6.14 times more than that of the UMP at 1.43 mg/g. The particles retained effectiveness in real human urine, with CAA removal and adsorption capacity of 73.73% and 8.59 mg/g, respectively, and with significantly higher CAA capture than commercial cation exchange (CE) and anion exchange (AE) resins. A global model for filmtransfer/intraparticle-diffusion simultaneously described seven different adsorption profiles using a common set of model parameters and yielded qmax=10.92 mg/g with an RMSE of 0.01 mg/mL. Molecular docking also suggested an optimal CAA-binding region at the SP IB–IIA interface, which is stabilized by complementary non-covalent interactions. The desorption efficiency was 97.13–98.90% for the regeneration performed with 0.50 M inorganic salt (IS), and CAA removal was 73.59–73.93% for five repeated adsorption– regeneration cycles with the same batch of particles. The findings here show a molecular recognition intraparticle transport protein adsorption platform for the capture of CAA in complex aqueous matrices that can be regenerated.