Preparation, characterization, and performance analysis of starch-based nanomicelles.

A novel amphiphilic starch-based polymer carrier (R-St-PEG; R = hexadecyl, St = starch, PEG = polyethylene glycol) was prepared using tapioca starch. It was then applied as an effective carrier for encapsulated drug, and used for sustained drug release. First, tapioca starch was made to react with hexadecane bromide (R16) for hydrophobic modification, and then the hydrophobically-modified tapioca starch molecules were grafted onto hydrophilic carboxyl-terminated PEG (mPEG-COOH). The drug-loading capacity and drug release behavior of R-St-PEG were systematically evaluated using curcumin as drug. The results show that the polymer has good drug-loading capacity and sustained-release properties, and it can act as an effective drug carrier. Thus, this study provides a suitable platform for preparing stable amphiphilic polymer carriers and broadens the application range of tapioca starch.

Preparation and application of a polymer with pH/temperature-responsive targeting.

Targeted drug carrier systems not only prolong the long-term circulation of drugs, but also improve their bioavailability. To obtain a pH/temperature synergistically responsive polymer carrier, temperature and pH-sensitive groups were chemically grafted onto a cassava starch backbone. Secondly, the structure of the polymer micelle carrier was characterized, and finally the drug loading performance and capacity of the drug carrier were explored. It was observed that cumulative drug release was low when the temperature and pH values met one of two conditions. Only at a high temperature and low pH (T = 38 °C, pH = 5.5, as in tumor tissue) did cumulative drug release reach its maximum value. The design of the polymer carrier described in the present study represents a novel paradigm in precision release drug carriers.