Synthesis and Characterization of Phenylalanine Nanotubes as Green pH‐Responsive Drug Nanocarriers

Abstract

The present study is aiming to investigate the potential of phenylalanine amino acid nanotubes (PhNTs) synthesized by a self‐assembly process as an efficient and pH‐responsive green drug nanocarrier for the treatment of oral disease. Phenylalanine was used for the preparation of solutions with three different concentrations (0.1, 0.5 and 2.5 mg/ml). Scanning electron microscopy (SEM) and Field emission scanning electron microscopy (FESEM) images showed that low and high concentrations of phenylalanine solution creates nanospheres and nanowires, respectively rather than tubular‐shaped nanostructures. In contrast, phenylalanine nanotubes were synthesized by medium concentration (0.5 mg/ml). The tubular shape and nanoscale diameter of the synthesized PhNTs were characterized by FESEM, Transmission Electron microscopy (TEM), Dynamic Light Scattering (DLS) and Fourier Transform Infrared Spectroscopy (FTIR). These characterization tests confirmed the synthesis of PhNTs with a tubular shape and nanoscale diameter. In the second stage, metronidazole was loaded into the phenylalanine‐based nanostructures as an effective drug for oral disorders. The results indicated that nanospheres and nanowires show drug loading efficiency of 49 % and 58 %, respectively, after 48 h of incubation time. Whereas, the drug loading efficiency for nanotubes was 91 %. The results from the FTIR analysis and UV‐vis spectroscopy verified the presence of metronidazole into the hollow structure of PhNT. While a burst drug release was observed for nanospheres and nanowires, PhNTs showed a well‐controlled release of metronidazole up to 95 % at oral pH, which is best fitted to the Weibull model. Subsequently, the cell viability of phenylalanine‐based nanostructures was assessed by MTT test on L929 fibroblast cell line.

Fabrication of multifunctional mucoadhesive buccal patch for drug delivery applications

“…After 24 hr, the solution was centrifuged at 6,000 rpm for 20 min. The synthesized metronidazole‐encapsulated nanocarrier was used for electrospraying process 36 …”

A comparison between solvent casting and electrospinning methods for the fabrication of neem extract-containing buccal films

“…According to our recent research, PhNT was synthesized as a drug nanocarrier via a self-assembly technique with an approximate diameter of 22 nm. All the synthesis methods and results were reported in our previous study [23]. Neem extract as a sedative and antibacterial agent was loaded into the synthesized PhNTs.…”

“…To determine the release kinetics of neem extract from samples, different commonly used mathematical models including zero order, first order, Higuchi, Hixson-Crowell, Korsmeyer–Peppas, and Weibull were used. The values of the kinetic parameters were obtained by analyzing the data in the Excel software [23,34]. Table 1 shows the related equations for each drug release model.…”

“…Phenylalanine and its derivatives are cyclic pH-responsive amino acids which can be synthesized via a self-assembly process. These types of biomaterials show reversible changes in their conformational characteristics as a function of pH and are considered to be a promising drug nanocarrier for an effective oral drug delivery [23]. Therefore, phenylalanine nanotube (PhNT) was chosen as a promising nanocarrier for a high efficient drug loading and delivery.…”

Bio-piezoelectric phenylalanine-αβ-dehydrophenylalanine nanotubes as potential modalities for combinatorial electrochemotherapy in glioma cells

“…33 Owing to the great chemical adaptability presented by peptides, varying sequences of amino acids can be incorporated into the peptide design for enabling site-specific targeting along with achieving controlled amphiphilicity for an effective delivery of drugs with different polarities. 34 Shirvan et al demonstrated enhanced drug penetrability into hollow phenylalanine nanotubular structures, which resulted in high loading efficiencies of the drug molecules into nanotubes (91%) compared to nanospheres (58%), following an incubation period of 48 h. 35 Redox-responsive, Dox loaded oxidized cysteine–phenylalanine (CFO) NPs were fabricated by Chibh et al , which depicted an enhanced uptake and higher toxicity against both C6 glioma and B16F10 melanoma cells. Glutathione-triggered release and high anti-proliferative efficacy of the Dox–CFO NPs make them prospective anti-cancer therapeutics.…”