Synthesis, characteristics, and applications of modified starch nanoparticles: A review

Nowadays, starch nanoparticles (SNPs) are drawing attention to the scientific community due to their versatility and wide range of applications. Although several works have extensively addressed the SNP production routes, not much is discussed about the SNPs modification techniques, as well as the use of modified SNPs in typical and unconventional applications. Here, we focused on the SNP modification strategies and characteristics and performance of the resulting products, as well as their practical applications, while pointing out the main limitations and recommendations. We aim to guide researchers by identifying the next steps in this emerging line of research. SNPs esterification and oxidation are preferred chemical modifications, which result in changes in the functional groups. Moreover, additional polymers are incorporated into the SNP surface through copolymer grafting. Physical modification of starch has demonstrated similar changes in the functional groups without the need for toxic chemicals. Modified SNPs rendered differentiated properties, such as size, shape, crystallinity, hydrophobicity, and Zeta-potential. For multiple applications, tailoring the aforementioned properties is key to the performance of nanoparticle-based systems. However, the number of studies focusing on emerging applications is fairly limited, while their applications as drug delivery systems lack in vivo studies. The main challenges and prospects were discussed.