Structure-activity Relationship Of ApoE-reconstituted High Density Lipoprotein Nanocarriers-mediated Aβ Clearance

Alzheimer’s disease(AD)is the most common form of dementia,and exerts heavy medical and economic burden for modern society.The accumulation of extracellular β-amyloid(Aβ)is crucial in AD pathogenesis and the imbalance between producing-clearing of Aβ could directly aggravate the severity of AD.Thus,the development of novel therapeutic agents that can both accelerate Aβ clearance and inhibit other subsequent pathological cascade has been taken as a brand new promising strategy for AD management.Our previous work had constructed apolipoprotein E3-reconstituted high density lipoprotein as an efficient nanoplatform that could penetrate the blood-brain barrier(BBB)and accelerated Aβ clearance for the therapy of AD.Here,to further improve its Aβ clearance activity and drug loading capacity,we hypothesed that spherical nanocarrier might serve as a more powerful multi-target and advantage-integrated nanocarrier if it owned the same Aβ clearance abilities as discoidal one does.For testing the hypothesis,this study focused on investigating the effect of nanocarrier shape on Aβ clearance and AD disease modification.We divided our work into three chapters.Chapter 1 focused on the preparation and characterization of ANC,AO,GANC and GAO.DLS,TEM and Cryo-EM results showed that nanocarriers size were around 20 nm.AO and GAO were spherical in shape while ANC and GANC were discoidal in shape.In chapter 2,SPR analysis showed that there was no obvious affinity difference between the four nanocarriers and LDLR.KD values of AO and GAO were lower than ANC and GANC,suggesting that spherical nanocarriers possessed higher binding affinity to Aβ monomers and oligomers.GAO exhibited the highest binding affinity.Cellular uptake and Aβ degradation analysis found that AO and GAO were more efficient than ANC and GANC,respectively.GAO owned the highest degradation efficiency,40.51%,which was 1.38-fold of AO and 1.38-fold of GANC.Uptake inhibitors test suggested that multi-pathways contribute to the process.In the third chapter,biodistribution analysis in mice showed that AO and GAO more efficiently distributed into the brain than ANC and GANC.The disease modification effect of GAO was evaluated in an AD model animal-senescence-accelerated mice P8(SAMP8).49.67% Aβ was digested in situ,which was 1.2-fold of AO.Morris water maze test showed that the cognitive function of SAMP8 was significantly improved.Ameliorated neurologic changed while no observable cytotoxicity was noted.The nesting result of GAO group were closer to R1 group(normal control).All in all,our work here illustrated the significant effect of shape on Apo E-reconstituted high density lipoprotein nanocarriers-mediated Aβ clearance and AD disease modification,in which spherical nanocarriers exhibited better effect,and GAO behaved the best.Hopefully,spherical lipoprotein-mimic nanocarriers might serve as a more efficient multi-functional nanoplatform for AD therapy.