The Design And Application Of Self-driving Micro/nano Motors Based On Polyaspartic Acid

Artificial micro/nanomotors are micro/nanoscale devices or equipment capable of converting chemical energy,solar energy and other different energy into mechanical energy to achieve the self-propulsion.Micro/nanomotors have some advantages such as lower weight,smaller dimensions,larger propulsion,and lower power consumption etc.Over the past decade,researchers have shown increased interest in micro/nanomotors from proof of concept to motion mechanisms,and have fabricated different sizes or shapes of micro/nanomotors with rod,spherical,helical and tubular.These artificial micro/nano motors are widely used in such applications as cargo transport,biosensing,environmental renovation and biomedicine.In this thesis,we used polyamino acid as the novel surface material of microrockets.Two strategies in this thesis are designed for the fabrication and application of the polyaspartic acid based microrockets:1.The decontamination of heavy metal ions in wastewater with self-propellant polyaspartic acid/platinum microrocketsPolyaspartic acid/platinum microrocket?PASP/Pt MR?was designed for the decontamination of heavy metal ions based on the complexation reaction between the carboxyl group in PASP and heavy metal ions.The PASP/Pt MRs were prepared by electrodeposition using cyclopore polycarbonate membranes as templates.The MRs can self-propel at low hydrogen peroxide levels?0.3%?and form a macromolecule metal complex with heavy metal ions such as Cd²⁺and Pb²⁺.The decontamination rate of Cd²⁺and Pb²⁺was detected by the stripping voltammogram with the bismuth membrane modified electrode which exhibited high sensitivity and wide linear range?5-500?g/L?.It is the self-propulsion of microrockets that reduced the time of decontaminating heavy metal ions?from 30 min with MRs in concussion state to 4min with MRs in self-propelling state?.The experimental results showed that PASP/Pt MRs had the advantages of short decontamination time??4 min?,high adsorption capacity and high removal rate?close to 100%?.As a novel micro/nanomotors material,PASP has important significance for the extension of the development of micro/nanomotors.2.Self-propellant and selective drug delivery of polyaspartic acid/iron-zinc microrocket?PASP/Fe-Zn MR?in the stomach.A novel drug-loading polyaspartic acid/iron-zinc microrocket?PASP/Fe-Zn MR?was designed through the electrostatic interaction between the carboxyl group in polyaspartic acid and the amino group of doxorubicin?DOX?,a common chemotherapeutic drug.It could realize the load,transport and release process of DOX in vivo.DOX is easily banded onto the surface of microrocket by one-step process through the electrostatic interaction to produce a single PASP iron-zinc microrocket loading with DOX?DOX/PASP/Fe-Zn MR?.The experiments showed that under the guidance of magnet,DOX/PASP/Fe-Zn MR could achieve the directional movement and the penetration of mouse gastric tissue sections in vitro.The in vivo experiments showed that DOX/PASP/Fe-Zn MRs could remain on the gastric mucosa and prolong the release time of DOX.From the results of the toxic test,the oral administration of the PASP/Fe-Zn MRs would show no obvious toxic effects on mice,and the gastric tissue section experiments showed that the PASP/Fe-Zn MRs had no cytotoxicity and no apparent immunological response.The PASP polymer and Zn,Fe would leave no harmful products following their movement,cargo delivery,and self-destruction in vivo.In short,the novel drug-loading microrocket is expected to have great potential for many applications such as green self-propelled targeted drug delivery and biochemistry.