Study On BFGF Nanoparticles-Nanopartical Drug Delivery System

With the booming development and widely application of polypeptide and protein as an important method using in clinic, more and more urgent request are put through for a new drug delivery system of this kind of medicine instead of traditional pharmaceutical dosage form. To overcome the disadvantage of traditional form of medication, such as the pain has to suffer and the expensive fees in the curing process, a new drug new drug delivery system has to be found. It is necessary and full of esperance for both the medicine society and the pharmaceutical manufactures.Nanoparticle has been regarded as a useful vector for targeted drug delivering system recent years. Many people pay attention to on the nanoparticles formed of biodegraded materials, such as polylactide (PLA), chitosan and butyl-2-cyanoacrylate (BCA), et al. We use them to protect drug form being degraded and delivery the drug into blood circle.The basic fibroblast growth factors (bFGF) is a type of the fibroblast growth factors (FGF), it brought effect in many fieds. The ectogenesis basic fibroblast growth factors can promote the cell division and chemotaxis, and induce the normal growth of embryo, and promote the growth of blood vessel, create to regeneration of nerve and healing of wound. But the half-life of bFGF is about 3-5 minutes in bodys. If it is applied to whole body ,it is quickly caused to inactivation and hard to develope its valid function. The bFGF is unstability in solutions. It is very difficult to effect that it is applied many times though local puncture, and bFGF is not suitable for over a long period of time to the medicine. So it is very important significance that to study on sustained release bFGF nanoparticle of maintenancing the local effect of drug and promoting the the growth of blood vessel.By using enzyme linked immunosorbent assay (ELISA) method , we studied the effect of different temperature,pH value and the rotation speed upon bFGF under the preparation condition. The optimum maintaining condition is to be preserved by freezing. No matter bathed in 37℃water for 24 hours or kept in tri-hydroxyl aminomethane buffer solution (Tris) (pH2.0) under 15℃for 1 hours, bFGF can not degraded. And the rotation speed of 880 revolutions per minute for 2 hours is safe for the preparation. The experiment indicates that bFGF is stable enough to survive through the whole preparation process.The effects of different concentration of surfactant and polymer, the drug: polymer ratio and the pH value in the nanoparticle forming process were investigated. All these factors influence the size and entrapment efficiency obviously. Respectively, we use three kinds of method to optimize the formulation of the prescription and obtained PLA-bFGF-NP, which diameter is 89.9 nm and EE is28.13% , CS-bFGF-NP that diameter is 453nm and EE is 48% , and PBCA-bFGF-NP with 120.5nm of diameter, 89.35%of entrapment efficiency. And the experiment design method we used in these three prescription selecting we compared, the last composed design seemed more alluring than others.Drug release test in vitro indicated that the drug release law of PBCA-bFGF-NP accorded with double-phase kinetical equation and Polynomial equation, and had obvious sustained-release specific property compared with the original drug. The observation to the reserving sample maintained frozen for three months showed that the stability of PBCA-bFGF-NP was bad, but the nanoparticle physicochemical properties had no evident difference.To detect the biological activity of PBCA-bFGF-NP in vitro, chorioallantoic membrane (CAM) test were employed. The nanoparticles of the high and middle-dose groups had the same biological activity as bFGF did. At the meanwhile, there is obvious discrepancy between high-dose group and low-dose group.According to all the above studies, Application new type high polymer material, and the preparation techniques of nanoparticle, we obtain PBCA-bFGF-NP that have sustained-release effect. bFGF nanoparticle study indicated that using nanoparticle as vector in injection drug delivery system is feasible. It has fairly high academic significance and special prospect in the administration peptide and protein.