Fabircation And Propetries Of The Composite Nanofiber Scaffolds Loaded With Drugs

Sustained and control release preparation are pointed to be a new kind of drug dose,which can delaythe release velocity of the drugs, reduce the absorbing velocity of the drugs entrancing into the organismand targetedly delivery the drugs.Because this kind of preparation can reduce the administration times,prolong the acting time and lower the toxic and sides effects of absoring drugs, it is arousing generalinterest in clinic. This article studied how to incorporate the antibiotic,compound antihypertensive andanticarcinogen into the PLLA nanofibers by eletrospinning,analyzed the distribution state of drugs inelectrospun fibers and discussed the loaded drugs release mechanisms,which established the firmfoundation for developing a new kind of sustained and control release preparation.our main work andresults are included as follows:The solubility parameters theory was applied to choose the applicable solvent system to dissolvePLLA,the solvent of acetone/dichloromethane(1/2) was determined because of their low toxic and goodsolubility. It was found that the average fiber diameters were exponential growing with the mass fraction ofPLLA, but were linear growing with spinning voltages, flow mount and receiving distance by analyzing therelation of the electrospun fibers morphology and spinning parameters such as the polymer mass fraction,spinning voltages, flow mount and receiving distance. It was also found that the chemical structure of thepolymer was not changed,but its crystallinity degree decreased and hydrophilic property was poorer than itscast film, which would lay a foundation for preparing the applicable carrier forms to be beneficial forloading and releasing all kinds of drugs.Clarithromycin was chosen to be model drug and PLLA/Clarithromycin composite nanofibers wereprepared,their morphology and property were analyzed. The result showed the average fibers’ diameterswere decreased with the increase of the drug concentration,their relationship were compatible with theexponential decreasing rules. There were some physical actions between the drug and the carrier and thedrug were distributed into the nanofibers at the amorphous state. The drug release test showed that theincorporated drug was released by logistic model at the action of protein K.The compound antihypertensive drugs contained captopril and hydrochlorothiazide were chosen to bemodel drugs and PLLA/captopril/hydrochlorothiazide composite nanofibers were prepared,theirmorphology and property were analyzed.The result showed the average fibers’ diameters were decreasedwith the increase of the drug concentration, but the decrease content was less than the effect ofClarithromycin content in PLLA nanofibers’ diameters.There were also some physical actions between thedrugs and the carrier, both the drugs were distributed into the nanofibers at the amorphous state. The drugrelease test showed that the incorporated drugs was released by Peppas model without the action of proteinK.Fluorouracil was chosen to be model drug, Fe3O4nanoparticles was synthetized by using chemicalcoprecipitation method and PLLA/Fluorouracil/Fe3O4composite nanofibers were prepared,theirmorphology and property were analyzed. The result showed the average fibers’ diameters were decreased with the increase of the drug concentration,but increased with the addition of Fe3O4nanoparticles.Therewere also some physical actions between the drugs,the carrier and Fe3O4nanoparticles,the drug wasdistributed into the nanofibers at the amorphous state and the composite showed some magnetic with theaddition of Fe3O4nanoparticles. The drug release test showed that the incorporated drugs was released byPeppas model att the action of protein K.