Neuroprotective Effects of gH625-lipoPACAP in an In Vitro Fluid Dynamic Model of Parkinson’s Disease

Engineering Multifunctional Peptide-Decorated Nanofibers for Targeted Delivery of Temozolomide across the Blood-Brain Barrier

A nanoplatform based on self-assembling peptides was developed with the ability to effectively transport and deliver a wide range of moieties across the blood-brain barrier (BBB) for the treatment of glioblastoma. Its surface was functionalized to have a targeted release of TMZ thanks to the targeting peptide that binds to EGFRvIII, which is overexpressed on tumor cells, and gH625, which acts as an enhancer of penetration. Furthermore, the on-demand release of TMZ was achieved through matrix metalloproteinase-9 (MMP-9) cleavage. Nanofibers were characterized for their stability, critical aggregation concentration, and morphology. Next, the effect on both 2D and 3D glioblastoma/astrocytoma (U-87) and glioma (U-118) cell lines was evaluated. The Annexin V/Propidium iodide showed an increase in necrotic and apoptotic cells, and the morphological analysis allowed to discover that both U-118 and U-87 spheroids are smaller in surface, perimeter, and Feret's diameter when treated with NF-TMZ. The developed nanofiber was demonstrated to permeate the BBB in vitro in a 3D spheroidal biodynamic BBB model. Finally, there were no cytotoxic effects of nanofibers without the drug on spheroids, while a significant decrease in viability was observed when NF-TMZ was used. Overall, these results open new opportunities for the evaluation of the efficacy and safety of this nanoplatform in in vivo studies.

Utilization of nanotechnology to surmount the blood-brain barrier in disorders of the central nervous system

Central nervous system (CNS) diseases are a major cause of disability and death worldwide. Due to the blood-brain barrier (BBB), drug delivery for CNS diseases is extremely challenging. Nano-delivery systems can overcome the limitations of BBB to deliver drugs to the CNS, improve the ability of drugs to target the brain and provide potential therapeutic methods for CNS diseases. At the same time, the choice of different drug delivery methods (bypassing BBB or crossing BBB) can further optimize the therapeutic effect of the nano-drug delivery system. This article reviews the different methods of nano-delivery systems to overcome the way BBB enters the brain. Different kinds of nanoparticles to overcome BBB were discussed in depth.

Shielding siRNA by peptide-based nanofibers: An efficient approach for turning off EGFR gene in breast cancer

Peptide-based self-assembled nanosystems show great promise as non-viral gene and siRNA delivery vectors. In the current study, we designed and functionalized nanofibers for the delivery of siRNA, targeting and silencing EGFR gene overexpressed in triple-negative breast cancer. The nanofiber-mediated siRNA delivery was characterized in terms of zeta potential, morphology, and structural stability by circular dichroism spectroscopy. In cytotoxicity studies, nanofibers presented high biocompatibility showing a negligible effect on cell viability both on healthy and cancer cell lines. The binding between nanofibers and EGFR-siRNA was investigated and ascertained by performing different biophysical studies. The complex siRNA:NF was stable over time, under fetal bovine serum, temperature and ionic strength effects. Moreover, nanofibers effectiveness in stabilizing and delivering an ad hoc selected siRNA for EGFR gene expression silencing was verified in a preclinical model of triple-negative breast cancer. Specifically, a significant gene knockdown was obtained with the complex siRNA:NF, that is comparable with the effect obtained by lipofectamine/siRNA transfection. This effective gene silencing derived from the successful internalization of nanofibers by cancer cells as observed by confocal microscopy. These results suggested that this peptide-based nanofiber could be an effective and safe systemic siRNA delivery system for application in biomedical areas.

Tuning Peptide-Based Nanofibers for Achieving Selective Doxorubicin Delivery in Triple-Negative Breast Cancer

Introduction

The design of delivery tools that efficiently transport drugs into cells remains a major challenge in drug development for most pathological conditions. Triple-negative breast cancer (TNBC) is a very aggressive subtype of breast cancer with poor prognosis and limited effective therapeutic options.

Purpose

In TNBC treatment, chemotherapy remains the milestone, and doxorubicin (Dox) represents the first-line systemic treatment; however, its non-selective distribution causes a cascade of side effects. To address these problems, we developed a delivery platform based on the self-assembly of amphiphilic peptides carrying several moieties on their surfaces, aimed at targeting, enhancing penetration, and therapy.

Methods

Through a single-step self-assembly process, we used amphiphilic peptides to obtain nanofibers decorated on their surfaces with the selected moieties. The surface of the nanofiber was decorated with a cell-penetrating peptide (gH625), an EGFR-targeting peptide (P22), and Dox bound to the cleavage sequence selectively recognized and cleaved by MMP-9 to obtain on-demand drug release. Detailed physicochemical and cellular analyses were performed.

Results

The obtained nanofiber (NF-Dox) had a length of 250 nm and a diameter of 10 nm, and it was stable under dilution, ionic strength, and different pH environments. The biological results showed that the presence of gH625 favored the complete internalization of NF-Dox after 1h in MDA-MB 231 cells, mainly through a translocation mechanism. Interestingly, we observed the absence of toxicity of the carrier (NF) on both healthy cells such as HaCaT and TNBC cancer lines, while a similar antiproliferative effect was observed on TNBC cells after the treatment with the free-Dox at 50 µM and NF-Dox carrying 7.5 µM of Dox.

Discussion

We envision that this platform is extremely versatile and can be used to efficiently carry and deliver diverse moieties. The knowledge acquired from this study will provide important guidelines for applications in basic research and biomedicine.

Hydrophobicity: The door to drug delivery

The engineering of intracellular delivery systems with the goal of achieving personalized medicine has been encouraged by advances in nanomaterial science as well as a greater understanding of diseases and of the biochemical pathways implicated in many disorders. The development of vectors able to transport the drug to a target location and release it only on demand is undoubtedly the primary issue. From a molecular perspective, the topography of drug carrier surfaces is directly related to the design of an effective drug carrier because it provides a physical hint to modifying its interactions with biological systems. For instance, the initial ratio of hydrophilic to hydrophobic surfaces and the changes brought about by external factors enable the release or encapsulation of a therapeutic molecule and the ability of the nanosystem to cross biological barriers and reach its target without causing systemic toxicity. The first step in creating new materials with enhanced functionality is to comprehend and characterize the interplay between hydrophilic and hydrophobic molecules at the molecular level. Therefore, the focus of this review is on the function of hydrophobicity, which is essential for matching the complexity of biological environments with the intended functionality.

An Overview of Supramolecular Platforms Boosting Drug Delivery

Numerous supramolecular platforms inspired by natural self-assembly are exploited as drug delivery systems. The spontaneous arrangement of single building blocks into inorganic and organic structures is determined and controlled by noncovalent forces such as electrostatic interactions, π-π interactions, hydrogen bonds, and van der Waals interactions. This review describes the main structures and characteristics of several building blocks used to obtain stable, self-assembling nanostructures tailored for numerous biological applications. Owing to their versatility, biocompatibility, and controllability, these nanostructures find application in diverse fields ranging from drug/gene delivery, theranostics, tissue engineering, and nanoelectronics. Herein, we described the different approaches used to design and functionalize these nanomaterials to obtain selective drug delivery in a specific disease. In particular, the review highlights the efficiency of these supramolecular structures in applications related to infectious diseases and cancer.