Preparation, Characterization And Fluidity Research Of Water-soluble L-cysteine Carbon Microspheres Derivatives

Pharmaceutical biomaterial is a new developed subject in recent years. It is the development and intersectant product of modern pharmaceutics and material science. In all of the targeted drug delivery systems (TDDSs), the materials (carriers) used must be particular and special. Therefore, nano-carrier materials transporting in drug and gene had been widely applied. TDDSs can selectively react with the targeted tissue at cell and subcell level, release the drugs slowly while selectively reaching the diseased issue, which maintain the drug concentration above an efficaciously critical value for a longer duration of time. For TDDSs of anticancer drugs, such kind of preparations can efficiently minimize the side effects to the undesired tissues or organs, consequently augmenting curative effects of chemotherapy. Although it is great difficulty for widely clinical application of TDDSs, they play an important role in overcoming the toxic side effects of cancer treatment and improve curative effect.In this paper, a kind of novel carbon microspheres (CMS) derivatives were prepared by chemically bonding L-cysteine which is an important amino acid to human liver. CMS were synthesized under 1000℃temperature by CVD method using acetylene as carbon source, argon as carrier gas and ferrocene as catalyst. Then the pristine samples were treated with nitrate and chemically modified with L-cysteine to prepare water-soluble L-cysteine CMS derivatives. The samples were analyzed and characterized by XRD, SEM, IR, UV, TGA, XPS, AFM and Optical Photos as followed. In addition, the fluidity and solubility of water-soluble L-cysteine CMS derivatives in mouse tumor cells were investigated creatively.The results showed that:(1)The CVD method prepared CMS which had smooth surface and uniform particle size; the following pickling treatment improved the graphitizational degree of CMS; pickling treatment and water-solublization did not damage the structure of pristine CMS, thus demonstrating chemical stability of the sample.(2)Hydrophilic groups added onto the surface of pristine CMS such as—OH,—NH₃ made L-cysteine CMS derivatives good water-soluble derivatives.(3)XPS and AFM results showed that the formation of L-cysteine CMS drug carriers owed to the co-activation of chemical grafting and physical coating mechanisms.(4)Mouse tumor cells'photos in electron microscopy showed that black carbon particles after water-soluble modification evenly distributed, indicating that L-cysteine CMS derivatives had a high dispersion and solubility in animal body fluid.(5)Some CMS particles whose diameter ranges from 350nm to 500nm primarily went into the organism cells by the way of endocytosis; corresponsively played an important role of drug carriers.