ABSTRACT
Aptamers are DNA or RNA fragments that can specifically bind to target substances.Because of the excellent properties such as strong binding force,high specificity,small physical size,chemical synthesis and modification,good biocompatibility,and low immunogenicity aptamers show wide application propects in biomedical researches.Aptamers can also bind specifically to receptors on the surface of cell membranes,and mediate the endocytosis of nanoparticles into cells,making them ideal drug targeting ligands.Organic nanomaterials have excellent application value in nanodrug delivery system because of their good biocompatibility and degradability.In this paper,the recent research progress of aptamers and organic nanomaterials drug delivery systems was reviewed.
ABSTRACT
OBJECTIVE: To synthesize low molecular weight chitosan-acetylcysteine (LMWC-NAC) conjugate and investigate its renal targeting profile and the rapeutic effects in model mice with acute kidney injury (AKI).METHODS: NAC was conjugated to LMWC by EDC/NHS reaction and the LMWC-NAC conjugate was identified by 1H-NMR. The cellular uptake of LMWC-NAC conjugate and megalin receptor involved in this process was investigated in vitro. In addition, the tissue distribution of ICG-labelled LMWC-NAC conjugate was investigated in nude mice. AKI were induced by LPS intraperitoneal injection (20 mg·kg-1).The parameters including Scr, BUN, inflammatory factors (TNF-α and IL-1β), and oxidative stress (MDA) were determined and renal histology was observed. RESULTS: LMWC-NAC conjugate was successfully synthesized by the amide interaction.The in vitrostudies demonstrated that the uptake of LMWC-NAC conjugate was mediated by the megalin receptor on HK-2 cells, and the tissue distribution experiment indicated that LMWC-NAC conjugate was mainly accumulated in the kidney.LMWC-NAC conjugate significantly suppressed Scr, BUN, inflammatory factors and oxidative stress (P<0.01) and improved kidney injury. CONCLUSION: LMWC-NAC conjugate showed good renal targeting profile and effect in recovering renal functions, which indicates the potential of LMWC-NAC conjugate as a safe and efficient drug delivery system for the treatment of AKI.
ABSTRACT
Polymeric micelles as effective drug carriers have been paid wide attention. They have many considerable advantages in cancer therapy, such as high efficiency, long acting and high drug loading etc. The paper reviewed the type, preparation materials and drug lording methods of polymeric micelles, especially discussed the targeting strategy of tumor-targeting drug delivery systems and the ap-plication examples of polymeric micelles in targeting drug delivery systems.