Functionalization And Characterization Of Single-Walled Carbon Nanotubes With Soy Protein Isolate

Single-walled carbon nanotubes are one of the emerging carbon nanomaterials.Because of their unique structure and various excellent properties,they are favored by many researchers.Single-walled carbon nanotubes have a high specific surface area and good stability,and have great application prospects in biological drug loading.Many studies have reported that carbon nanotubes,drug carriers,achieved the purpose of prolonging and controlling drug release,improving drug targeting,and improving the utilization of insoluble drugs.However,single-walled carbon nanotubes,poor hydrophilicity and biocompatibility,are easily aggregated and precipitated in solution.Single-walled carbon nanotubes without any treatment can destroy the cells or tissues of organisms.Single-walled carbon nanotubes are cytotoxic.Therefore,singlewalled carbon nanotubes need to be functionally modified as a drug carrier.The functional modification of single-walled carbon nanotubes is generally divided into two kinds of covalent and non-covalent modifications.Covalent modification is a chemical reaction that occurs during functionalization,but this method usually results in structural failure and performance loss of single-walled carbon nanotubes.Non-covalent modification does not require chemical reaction to improve the hydrophilicity and biocompatibility of single-walled carbon nanotubes.Therefore,in this study,the non-covalent modification of the singlewalled carbon nanotubes was applied.At present,there are many surfactants used for non-covalent modification of single-walled carbon nanotubes,but the appplication of biosurfactants as modifying groups is rarely reported.Soybean protein isolate has strong surface activity and biocompatibility and can selfassemble at hydrophilic and hydrophobic interfaces.Therefore,soybean protein isolate has been applied to functionalize single-walled carbon nanotubes in this paper.In addition,single-walled carbon nanotubes purchased from manufacturers are usually mixed by some mixture of metal catalysts,amorphous carbon,and the length is far longer.Therefore,the acid must be purified before functional modification,which will also make single-walled carbon nanotubes short.The main content of this dissertation is to use biosurfactants to functionalize the acidified single-walled carbon nanotubes.The mechanism and dynamics of the functional modification process and the influence of external conditions have been discussed.Then,the cytotoxicity and drug-loading properties were researched.The works of this article are as followed.1.In this paper,soybean protein isolate is used as a surfac tant to functionalize acidified single-walled carbon nanotubes.In order to research the reaction mechanism and kinetics,we have used X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy to study the process of functional modification of single-walled carbon nanotubes with soybean protein isolate.Results indicated that the process is a physical adsorption reaction and the kinetics are mainly hydrophobic interactions.Raman spectroscopy was used to study the effect of soybean protein isolate on the structure and properties of single-walled carbon nanotubes.The results showed that soybean protein isolate increased the disorder of carbon atoms on the surface of single-walled carbon nanotubes.However,the damage to structure and performances is less.The MTT assay was used for investigating the cytotoxicity of modified single-walled carbon nanotubes.The results confirmed that the cytotoxicity of the modified single-walled carbon nanotubes is reduced.2.In order to improve the effect of single-walled carbon nanotubes modified by soybean protein isolate,the optimal ratio of soybean protein isolate to single-walled carbon nanotubes was studied in this body.The influence of ultrasonic time and power on the modification effect was discussed.The results showed that when the ratio of soybean protein isolate to single-walled carbon nanotubes was 30:1(mass ratio)and the ultrasonic power and time of the probe were respectively 400 W and 50 min,the modification effect was best.3.The drug-loading properties is investigated by loading curcumin,isoliquiritigenin,and doxorubicin onto soybean protein isolate modified single-walled carbon nanotubes.The data indicated that the drug-loaded single-walled carbon nanotubes modified by soybean protein isolate can prolong the releas e time of the drug and can achieve the controlled release effect by controlling the p H value.The MTT cell proliferation assay experiments showed that the single-walled carbon nanotubes modified by soybean protein isolate as carriers can enhance the medical effect of the drug.In addition,modified single-walled carbon nanotubes as drug carriers can be able to avoid the degradation of photosensitive drugs or anti-oxidative drugs.