Functionalization with TAT-Peptide Enhances Blood-Brain Barrier Crossing In vitro of Nanoliposomes Carrying a Curcumin-Derivative to Bind Amyloid-Β Peptide

Abstract

# These authors contributed equally to this work preventing high-molecular weight molecules from passing through [25]. Indeed, the design and engineering of NP with high specificity for brain capillary endothelial cells have been proposed as promising strategy for AD diagnosis and treatment [26][27][28][29].The aim of the present investigation was to design NP able to bind Aβ peptide and to cross the BBB. To reach this goal we developed nanoliposomes (NL) double-functionalized with a curcuminderivative and with a modified HIV Transactivating Transcriptional Activator (TAT) peptide. Preparation of NL covalently decorated with curcumin-derivative was previously carried out, starting from a curcumin alkyne-derivative showing a very high affinity for Aβ peptide [30], suitable for NL decoration by click chemistry and with improved features of stability with respect to curcumin itself [31]. On the other side, TAT-peptide could enhance NP BBB crossing [32,33] based on the evidence that its coupling to NP may facilitate their efficient translocation through the cell membrane, bypassing the endocytic pathway [34][35][36]. TAT-peptide was covalently attached to NL surface via a thiol-maleimide reaction. The ability of NL to bind Aβ after AbstractProduction of abnormally high amounts of amyloid-β peptide in the brain plays a central role in the onset and development of Alzheimer's disease, a neurodegenerative disorder affecting millions of individuals worldwide. Nanoparticles have been proposed as promising tools to treat the disease by delivering drugs and contrast agents to the brain. Here, nanoliposomes decorated with a curcumin-derivative, displaying high affinity for amyloid-β, were functionalized with a modified cell-penetrating TAT-peptide, with the aim of conferring on such nanoliposomes the ability to cross the blood-brain barrier. Functionalization with TAT-peptide did not modify the ability of curcumindecorated nanoliposomes to bind amyloid-β fibrils, as assessed by surface plasmon resonance. Confocal microscopy, mass spectrometry and radioactivity experiments with [3 H]-sphingomyelin showed about 3-fold increase in the uptake of nanoliposomes by human brain capillary endothelial cells (hCMEC/D3) after the functionalization with TATpeptide, with no alterations in cell viability. Moreover, TAT functionalization increased the permeability of curcuminnanoliposomes across a blood-brain barrier model made with the same cells. The similar permeabilities of curcuminderivative and [3 H]-sphingomyelin suggested that nanoliposomes were transported intact. Considering these results, nanoliposomes functionalized with the curcumin-derivative and TAT-peptide represent a promising tool for targeting amyloid-β directly in the brain parenchyma.

Curcumin’s Nanomedicine Formulations for Therapeutic Application in Neurological Diseases

“…Among all CPPs, the modified HIV-1 transactivating transcriptional activator (TAT) peptide (having positive charges that can interact with negative charges of the BBB) has been successfully used for specific endocytosis delivery of liposome nanoparticles into the brain [224]. It has been demonstrated that nanoliposomes double-functionalized with a CUR derivative and with a TAT peptide enhances BBB crossing in vitro, carrying a CUR-derivative to bind Aβ peptide [225]. Also, CUR derivatives containing lipid ligands can be exploited for targeted drug delivery for brain diseases.…”

Nanoformulations of Herbal Extracts in Treatment of Neurodegenerative Disorders

“…In vitro, nanoliposomes of Cur or Cur derivatives were able to control or decrease the Aβ oligomers or the fibril formation (Taylor et al, 2011). A double-functionalized nanoliposomes of a Cur derivative in modified HIV Trans-activating Transcriptional Activator (TAT) peptide (TATCur-NL) could cross the BBB in vitro and illustrated high affinity for Aβ peptides (Sancini et al, 2013). In another in vitro study, apolipoprotein E3 mediated poly(butyl) cyanoacrylate NPs containing Cur (ApoE3-C-PBCA), enhanced the photostability and the cellular uptake of Cur due to a sustained drug release (Mulik et al, 2010).…”

Amphiphilic Nanocarrier Systems for Curcumin Delivery in Neurodegenerative Disorders

“…Liposomes functionalized with TAT-peptide In vitro Permeability across the BBB enhanced [98]. Increased entrapment efficiency of NGF and CU, of NGF release and cell viability, Decreased release of CU, Permeability of NGF and CU across the blood-brain barrier [102].…”