Preparation Of Amino Acid–based Gemini Surfactants Niosome And Studies Of Their Properties In Vitro

Gemini surfactant is a new kind of surfactant with double hydrophobic and hydrophilic groups.The advantages of Gemini surfactant are as follows:higher surface activity,lower critical micelle concentration,good compatibility and synergistic effect,etc.As well as,the Gemini surfactant is widely used in many fields.The amino acid-based Gemini surfactants can be obtained with natural active amino acid as raw material.And this kind of surfactants will be used as drug carrier materials with good prospect because of the advantages of this surfactant,such as mild performance,low toxicity,good biodegradability and biocompatibility.Objective:To synthesize the cystine based Gemini surfactants with high surface activity,low toxicity and to prepare nano drug-loaded vesicles by using the obtained surfactant as capsule material.Moreveover the chlorophyll with the near-infrared fluorescence properties will be encapsulated in vesicles as model drugs.And then the near infrared fluorescence characteristics of chlorophyll Gemini surfactant vesicle system are investigated.Finally the nano vesicle system with the following properities such as high stability,uniform distribution,low toxicity,good near infrared fluorescence can be obtained,and can be used for the research of imaging system in vivo.These studies will provide the basis for the development of new pharmaceutical excipients and the research of new carrier materials for in vivo imaging.Methods:Four amino acid-based Gemini surfactants were prepared by the reaction of 12,14,16 and 18 chloride with L-cystine as initial raw material.The structure of the products were characterized by IR spectrometer,¹H-NMR and ¹³C-NMR.The surface tension of their aqueous solution were determined by surface tension instrument and the emulsification,the foam properties were also investigated.The hemolysis of cystine Gemini surfactants was studied under the conditions of below or avove the critical micelle concentration,and the influence of temperature on the hemolysis was also studied.The mixture of Gemini surfactant with 18 carbon chain,cholesterol,Span80,Tween80 with certain proportion was used as vesicle material,and the chlorophyll was used as a model drug to prepare the chlorophyll-Cystine Gemini surfactant niosome by thin-film ultrasonic dispersion method.Moreover the physicochemical properties and the fluorescence characteristics in vitro,the effects of FBS and PBS on the fluorescence characteristics of the vesicle system were investigated.Results:The obtained four cystine Gemini surfactants have high surface activity,and the surface activity decreased with the extension of double carbon chains.The CMC values of the four products is at the same order of magnitude of 10^-5g/mL.The double carbon chain is shorter,the foam performance is better,while the double carbon chain is longer and the foam stability is stronger.The four cystine Gemini surfactants have almost no hemolysis effect on red blood cells at 1mg/L?10%CMC?,which similar to Tween 80 with 10%CMC.But when the concentration exceeds the critical micelle concentration,the hemolysis effect is obviously enhanced,the HC₅₀ of the Gemini surfactants was 19.3?mol/L?C12?,31.9?mol/L?C14?.However,when the C16 concentration is 32.9?mol/L,the hemolysis rate is 10%when the C18 concentration is 30.62?mol/L,the hemolysis rate is below<10%.The spherical nuclear shell vesicles with high stability and uniform particle size were prepared by using the cystine Gemini surfactants with C12 carbon chain,Tween80?Span80 and cholesterol as the capsule material.,And the the mean particle size was of?170±10?nm,polydispersity index of?0.21±0.1?,Zeta potential?-45±5?mV.The fluorescence intensity of the system in FBS and PBS solutions was obviously enhanced and the stability was high enough.Conclusion:1.Cystine Gemini surfactant has the characteristics of low toxicity,high surface activity,low CMC value and good dispersibility.2.There is a good synergistic effect between cystine Gemini surfactants and non-ionic surfactants.3.The nano vesicle system with high dispersion and strong stability can be obtained by using cystine Gemini surfactant as the capsule material.4.The near infrared fluorescence characteristics of Gemini surfactant chlorophyll vesicle system were enhanced significantly.5.Gemini surfactants will have broad prospects in the research and development of pharmaceutical carriers and pharmaceutical excipients.Cystine Gemini surfactant vesicles with strong near infrared fluorescence characteristics are expected to be applied to the related research of imaging system in vivo.And the clinical significance is very important.