l-Diphenylalanine Microtubes As a Potential Drug-Delivery System: Characterization, Release Kinetics, and Cytotoxicity

Abstract

Microtubes obtained from the self-assembly of L-diphenylalanine (FF-MTs) were evaluated as potential vehicles for drug delivery. The biological marker Rhodamine B (RhB) was chosen as a model drug and conjugated to the peptide arrays during self-organization in the liquid phase. Microscopy and X-ray studies were performed to provide morphological and structural information. The data revealed that the cargo was distributed either in small aggregates at the hydrophobic surface of the FF-MTs or homogeneously embedded in the structure, presumably anchored at polar sites in the matrix. Raman spectroscopy revealed notable shifts of the characteristic RhB resonance peaks, demonstrating the successful conjugation of the fluorophore and peptide assemblies. In vitro assays were conducted in erythrocytes and fibroblast cells. Interestingly, FF-MTs were found to modulate the release of the load. The release of RhB from the FF-MTs followed first-order kinetics with a steady-state profile, demonstrating the potential of these carriers to deliver drugs at constant rates in the body. Cytotoxicity investigations revealed high cell viability up to concentrations of 5 mg mL(-1), demonstrating the low toxicity of the FF-MTs.

Amyloid-based nanosensors and nanodevices

“…Applying the microtubes to erythrocytes and fibroblast cells, had no impact on cell viability, demonstrating the potential of these carriers to deliver drugs at a constant rate. 129 …”

Peptide Self-Assembled Nanostructures for Drug Delivery Applications

“…These solvents can make the -stacking more dominant than other self-assembly effects [40]. For the dipeptide FF self-assembly process, -stacking from the aromatic groups and hydrogen bonding stabilized the selfassembled FF nanostructures, which have been demonstrated for various applications including drug delivery [43,113].…”

“…Peptide self-assembled hydrogel with injectable properties could also be used to directly come into contact with the tumor sites to enhance the efficacy and safety of tumor therapy [118]. Peptide selfassembled nanotubes also could be utilized for cancer therapy through conjugation with doxorubicin in high efficiency [113]. There are many different anticancer agents including doxorubicin, curcumin, fluorouracil, and paclitaxel that have been loaded in the peptide self-assembled nanostructures and investigated in preclinical or clinical trials for cancer therapy.…”

Thin and ordered hydrogel films deposited through electrospinning technique; a simple and efficient support for organic bilayers

“…To understand surface sample morphology and variations according to increasing temperature, a Digital Instruments nanoscope III atomic force microscope (AFM) was used to obtain surface micrographies. This instrument had the ability to scan an area of 125x125 µm 2 , coupled with a zaxis length of 5.5 µm, with a resolution of 0.03 nm [28]. AFM images were recorded with a supersharp silicon probe of 10 nm radius, 330 kHz resonance frequency and spring constant of 42 Nm -1 .…”