The renoprotective efficacy and safety of genetically-engineered human bone marrow-derived mesenchymal stromal cells expressing anti-fibrotic cargo.

Background: Kidney fibrosis is a hallmark of chronic kidney disease (CKD) and compromises the viability of transplanted human bone marrow-derived mesenchymal stromal cells (BM-MSCs). Hence, BM-MSCs were genetically-engineered to express the anti-fibrotic and renoprotective hormone, human relaxin-2 (RLX) and green fluorescent protein (BM-MSCs-eRLX + GFP), which enabled BM-MSCs-eRLX + GFP delivery via a single intravenous injection.

Methods: BM-MSCs were lentiviral-transduced with human relaxin-2 cDNA and GFP, under a eukaryotic translation elongation factor-1α promoter (BM-MSCs-eRLX + GFP) or GFP alone (BM-MSCs-eGFP).

Angiotensin-(1-5) is a Potent Endogenous Angiotensin AT -Receptor Agonist.

Background: The renin-angiotensin system involves many more enzymes, receptors and biologically active peptides than originally thought. With this study, we investigated whether angiotensin-(1-5) [Ang-(1-5)], a 5-amino acid fragment of angiotensin II, has biological activity, and through which receptor it elicits effects.

Methods: The effect of Ang-(1-5) (1µM) on nitric oxide release was measured by DAF-FM staining in human aortic endothelial cells (HAEC), or Chinese Hamster Ovary (CHO) cells stably transfected with the angiotensin AT -receptor (AT R) or the receptor Mas.

A switch in N-terminal capping of β-peptides creates novel self-assembled nanoparticles.

Small tripeptides composed entirely of β-amino acids have been shown to self-assemble into fibres following acylation of the N-terminus. Given the use of Fmoc as a strategy to initiate self-assembly in α-peptides, we hypothesized that the acyl cap can be replaced by an Fmoc without perturbation to the self-assembly and enable simpler synthetic protocols. We therefore replaced the -acyl cap for an Fmoc group and herein we show that these Fmoc-protected β-peptides produce regular spherical particles, rather than fibrous structures, that are stable and capable of encapsulating cargo.

Elucidating the cell penetrating properties of self-assembling β-peptides.

Self-assembling lipopeptide hydrogels have been widely developed for the delivery of therapeutics due to their rapid gelation, injectability, and highly controlled physicochemical properties. Lipopeptides are also known for their membrane-associating and cell penetrating properties, which may impact on their application in cell-encapsulation. Self-assembling lipidated-β-peptide materials developed in our laboratory have previously been used in cell culture as 2D substrates, thus as a continuation of this work we aimed to encapsulate cells in 3D by forming a hydrogel.

Novel ATR agonist, β-ProAng III, is cardio- and vaso-protective in diabetic spontaneously hypertensive rats.

Stimulation of the angiotensin II type 2 receptor (ATR) evokes protective effects in various cardiovascular diseases. Thus, this study aimed to investigate the effects of ATR stimulation, with or without ATR blockade, in a model of hypertension with concomitant type 1 diabetes mellitus (T1DM). Spontaneously hypertensive rats (SHRs) were given either citrate or a single dose of streptozotocin (STZ; 55 mg/kg, i.

The protective effects of a novel AT receptor agonist, β-ProAng III in ischemia-reperfusion kidney injury.

Background And Purpose: This study investigated the reno-protective effects of a highly selective ATR agonist peptide, β-ProAng III in a mouse model of acute kidney injury (AKI).

Methods: C57BL/6 J mice underwent either sham surgery or unilateral kidney ischemia-reperfusion injury (IRI) for 40 min. IRI mice were treated with either β-ProAng III or perindopril and at 7 days post-surgery the kidneys analysed for histopathology and the development of fibrosis and matrix metalloproteinase (MMP)-2 and -9 activity.

A comparison of fixation methods for SEM analysis of self-assembling peptide hydrogel nanoarchitecture.

Determining the porosity of hydrogels is an important component of material characterisation. While scanning electron microscopy (SEM) is a widely used method to study hydrogel nanoarchitecture, it is well-established that SEM sample preparation methods can alter the structure of hydrogels. Herein we describe the impact of sample preparation on the SEM analysis of self-assembling β-peptide hydrogels.

The Novel AT2 Receptor Agonist β-Pro7-AngIII Exerts Cardiac and Renal Anti-Fibrotic and Anti-Inflammatory Effects in High Salt-Fed Mice.

A high salt (HS) diet is associated with an increased risk for cardiovascular diseases (CVDs) and fibrosis is a key contributor to the organ dysfunction involved in CVDs. The activation of the renin angiotensin type 2 receptor (ATR) has been considered as organ protective in many CVDs. However, there are limited ATR-selective agonists available.

Esterase-Mediated Sustained Release of Peptide-Based Therapeutics from a Self-Assembled Injectable Hydrogel.

A synthetic strategy for conjugating small molecules and peptide-based therapeutics, via a cleavable ester bond, to a lipidated β-tripeptide is presented. The drug-loaded β-peptide was successfully co-assembled with a functionally inert lipidated β-tripeptide to form a hydrogel. Quantitative release of lactose from the hydrogel, by the action of serum esterases, is demonstrated over 28 days.

Using conformational constraints at position 6 of Angiotensin II to generate compounds with enhanced AT2R selectivity and proteolytic stability.

The Renin-Angiotensin System (RAS) plays a crucial role in numerous pathological conditions. Two of the critical RAS players, the angiotensin receptors AT1R and AT2R, possess differential functional profiles, although they share high sequence similarity. Although the main focus has been placed on AT1R, several epidemiological studies have evidenced that activation of AT2R could operate as a multimodal therapeutic target for different diseases.

entanglement in self-assembling β-peptide nanofibres decorated with vancomycin.

The increasing resistance of pathogenic microbes to antimicrobials and the shortage of antibiotic drug discovery programs threaten the clinical use of antibiotics. This threat calls for the development of new methods for control of drug-resistant microbial pathogens. We have designed, synthesised and characterised an antimicrobial material formed the self-assembly of a population of two distinct β-peptide monomers, a lipidated tri-β-peptide (β-peptide) and a novel β-peptide conjugated to a glycopeptide antibiotic, vancomycin.

Enhancement of glioblastoma multiforme therapy through a novel Quercetin-Losartan hybrid.

Glioblastoma multiforme (GBM) is the most common and aggressive primary malignant brain tumor. Maximal surgical resection followed by radiotherapy and concomitant chemotherapy with temozolomide remains the first-line therapy, prolonging the survival of patients by an average of only 2.5 months.

Single Peptide Backbone Surrogate Mutations to Regulate Angiotensin GPCR Subtype Selectivity.

Mutating the side-chains of amino acids in a peptide ligand, with unnatural amino acids, aiming to mitigate its short half-life is an established approach. However, it is hypothesized that mutating specific backbone peptide bonds with bioisosters can be exploited not only to enhance the proteolytic stability of parent peptides, but also to tune its receptor subtype selectivity. Towards this end, four [Y] -Angiotensin II analogues are synthesized where amide bonds have been replaced by 1,4-disubstituted 1,2,3-triazole isosteres in four different backbone locations.

Transition of Nano-Architectures Through Self-Assembly of Lipidated β-Tripeptide Foldamers.

β-peptides consisting exclusively of β-amino acids adopt a variety of non-natural helical structures and can self-assemble into well-defined hierarchical structures by axial head-to-tail self-assembly resulting in fibrous materials of varying sizes and shapes. To allow control of fiber morphology, a lipid moiety was introduced within a tri-β-peptide sequence at each of the three amino acid positions and the N-terminus to gain finer control over the lateral assembly of fibers. Depending on the position of the lipid, the self-assembled structures formed either twisted ribbon-like fibers or distinctive multilaminar nanobelts.

Renal functional effects of the highly selective AT2R agonist, β-Pro7 Ang III, in normotensive rats.

Recently, we designed a group of peptides by sequential substitution of the naturally occurring α-amino acid throughout the Ang III peptide sequence with the corresponding β-amino acid. β-Amino acid substitution at the proline residue of Ang III (β-Pro7-Ang III) resulted in a highly selective AT2R ligand, demonstrating remarkable selectivity for the AT2R in both binding and functional studies. To provide additional functional evidence for the suitability of β-Pro7 Ang III as a novel AT2R agonist, we tested effects of acute systemic administration of β-Pro7-Ang III on renal hemodynamic and excretory function in anesthetized normotensive male and female rats.

Migration and Differentiation of Neural Stem Cells Diverted From the Subventricular Zone by an Injectable Self-Assembling β-Peptide Hydrogel.

Neural stem cells, which are confined in localised niches are unable to repair large brain lesions because of an inability to migrate long distances and engraft. To overcome these problems, previous research has demonstrated the use of biomaterial implants to redirect increased numbers of endogenous neural stem cell populations. However, the fate of the diverted neural stem cells and their progeny remains unknown.

β-tripeptides act as sticky ends to self-assemble into a bioscaffold.

Peptides comprised entirely of β-amino acids, commonly referred to as β-foldamers, have been shown to self-assemble into a range of materials. Previously, β-foldamers have been functionalised via various side chain chemistries to introduce function to these materials without perturbation of the self-assembly motif. Here, we show that insertion of both rigid and flexible molecules into the backbone structure of the β-foldamer did not disturb the self-assembly, provided that the molecule is positioned between two β-tripeptides.

Novel Materials From the Supramolecular Self-Assembly of Short Helical β-Peptide Foldamers.

Self-assembly is the spontaneous organization of small components into higher-order structures facilitated by the collective balance of non-covalent interactions. Peptide-based self-assembly systems exploit the ability of peptides to adopt distinct secondary structures and have been used to produce a range of well-defined nanostructures, such as nanotubes, nanofibres, nanoribbons, nanospheres, nanotapes, and nanorods. While most of these systems involve self-assembly of α-peptides, more recently β-peptides have also been reported to undergo supramolecular self-assembly, and have been used to produce materials-such as hydrogels-that are tailored for applications in tissue engineering, cell culture and drug delivery.

β-Tripeptides Coassemble into Fluorescent Hydrogels for Serial Monitoring in Vivo.

β-peptides uniquely form shear thinning hydrogels which are proteolytically stable and biocompatible. Herein we describe the synthesis, material and optical characterization of a new class of fluorescently labeled hydrogelators based on a helical -acetylated β-peptide backbone. The resulting hydrogels were analyzed using fluorescence microscopy to confirm successful incorporation of the fluorophore within the fiber matrix without compromising the β-peptide self-assembly.

The use of hydrogels for cell-based treatment of chronic kidney disease.

Chronic kidney disease (CKD) is a major and growing public health concern with increasing incidence and prevalence worldwide. The therapeutic potential of stem cell therapy, including mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) holds great promise for treatment of CKD. However, there are significant bottlenecks in the clinical translation due to the reduced number of transplanted cells and the duration of their presence at the site of tissue damage.

Identifying the Coiled-Coil Triple Helix Structure of β-Peptide Nanofibers at Atomic Resolution.

Peptide self-assembly represents a powerful bottom-up approach to the fabrication of nanomaterials. β-Peptides are non-natural peptides composed entirely of β-amino acids, which have an extra methylene in the backbone, and we reported fibers derived from the self-assembly of β-peptides that adopt 14-helical structures. β-Peptide assemblies represent a class of stable nanomaterials that can be used to generate bio- and magneto-responsive materials with proteolytic stability.

Exploring Molecular-Biomembrane Interactions with Surface Plasmon Resonance and Dual Polarization Interferometry Technology: Expanding the Spotlight onto Biomembrane Structure.

The molecular analysis of biomolecular-membrane interactions is central to understanding most cellular systems but has emerged as a complex technical challenge given the complexities of membrane structure and composition across all living cells. We present a review of the application of surface plasmon resonance and dual polarization interferometry-based biosensors to the study of biomembrane-based systems using both planar mono- or bilayers or liposomes. We first describe the optical principals and instrumentation of surface plasmon resonance, including both linear and extraordinary transmission modes and dual polarization interferometry.