1. N-(9-Fluorenylmethoxycarbonyl)-L-Phenylalanine/nano-hydroxyapatite hybrid supramolecular hydrogels as drug delivery vehicles with antibacterial property and cytocompatibility
Wan Li, Xueying Hu, Jiawei Chen, Zhengnan Wei, Chengwu Song, Rongzeng Huang J Mater Sci Mater Med. 2020 Jul 29;31(8):73. doi: 10.1007/s10856-020-06410-9.
The intrinsic fragility of hydroxyapatite (HAP) restricts its wider applications for local delivery of antibiotics. The composites formed by integrating HAP with hydrogels can improve the properties of HAP. However, these reported composites not only require tedious preparation and employ organic solvent and toxic reagents, but also hardly have inherent antimicrobial property. In this study, N-(9-Fluorenylmethoxycarbonyl)-L-Phenylalanine/nano-hydroxyapatite (Fmoc-L-Phe/nHAP) hybrid supramolecular hydrogels with antibacterial property and cytocompatibility was prepared by integrating nHAP as reinforcement with Fmoc-L-Phe supramolecular hydrogels. The results showed that nHAP bounds in the chamber of the gel network and adheres to the fiber of Fmoc-L-Phe due to intermolecular interaction, remarkably improving the mechanical strength of Fmoc-L-Phe supramolecular hydrogels. The results of inhibition zone experiment and MTT experiment showed that the Fmoc-L-Phe/nHAP hybrid supramolecular hydrogels possess antimicrobial property and cytocompatibility. In vitro release experiment of chlorogenic acid (CGA) from the hybrid supramolecular hydrogels was performed. The study of the release kinetics indicated that the release behavior of CGA from the hybrid supramolecular hydrogels is following Weibull model and release mechanism involved Fickian diffusion and erosion of the surface of hydrogel matrix. The release of CGA shows a good inhibition effect on S. aureus. The results show that the Fmoc-L-Phe/nHAP hybrid hydrogels with antibacterial property and cytocompatibility have promising applications as drug delivery carrier. Due to the intrinsic fragility of hydroxyapatite (HAP), the properties of HAP could be improved by incorporation into hydrogels. However, these reported composites not only require tedious preparation and employ organic solvent and toxic reagents, but also hardly have inherent antimicrobial property. We prepared N-(9-Fluorenylmethoxycarbonyl)-L-Phenylalanine/nano-hydroxyapatite (Fmoc-L-Phe/nHAP) hybrid supramolecular hydrogels by integrating nHAP as reinforcement with Fmoc-L-Phe supramolecular hydrogels. The results showed that nHAP bounds in the chamber of the gel network and adheres to the fiber of Fmoc-L-Phe due to intermolecular interaction, remarkably improving the mechanical strength of Fmoc-L-Phe supramolecular hydrogels. The results of inhibition zone experiment and MTT experiment showed that the Fmoc-L-Phe/nHAP hybrid supramolecular hydrogels possess antibacterial property and cytocompatibility. In vitro release experiment of chlorogenic acid (CGA) from the hybrid supramolecular hydrogels was performed. The study of the release kinetics indicated that the release behavior of CGA from the hybrid supramolecular hydrogels is following Weibull model and release mechanism involved Fickian diffusion and erosion of the surface of hydrogel matrix. The release of CGA shows a good inhibition effect on S. aureus. The results show that the Fmoc-L-Phe/nHAP hybrid hydrogels with antibacterial property and cytocompatibility have promising applications as drug delivery carrier.
2. Self-assembling N-(9-Fluorenylmethoxycarbonyl)-l-Phenylalanine hydrogel as novel drug carrier
Kirti Snigdha, Brijesh K Singh, Abijeet Singh Mehta, R P Tewari, P K Dutta Int J Biol Macromol. 2016 Dec;93(Pt B):1639-1646. doi: 10.1016/j.ijbiomac.2016.04.072. Epub 2016 Apr 25.
Supramolecular hydrogel as a novel drug carrier was prepared from N-(9-Fluorenylmethoxycarbonyl) (Fmoc) modified l-phenylalanine. Its different properties like stability at different pH, temperature and rheology were evaluated in reference to salicylic acid (SA) as a model drug, entrapped in the supramolecular hydrogel network. The release behaviour of SA drug in supramolecular hydrogel was investigated by UV-vis spectroscopy. The influence of hydrogelator, pH values of the accepting media, temperature and concentration of SA drug on the release behaviour was investigated under static conditions. The results indicated that the release rate of SA in the supramolecular hydrogels was slightly retarded with an increase of the hydrogelator concentration. Also, the release rates of SA increased with an increase of temperature and its concentration. Furthermore, the release behaviour of SA was found to be different at various pH values in buffers. The study of the release kinetics indicated that the release behaviour of SA from the carrier was in accord with the Peppas model and the diffusion controlled mechanism involved in the Fickian model.
3. Multigram Synthesis of 1- O-Acetyl-3- O-(4-methoxybenzyl)-4- N-(9-fluorenylmethoxycarbonyl)-4- N-methyl-L-pyrrolosamine
Matthew Burk, Nolan Wilson, Seth B Herzon Tetrahedron Lett. 2015 Jun 3;56(23):3231-3234. doi: 10.1016/j.tetlet.2014.12.073.
A synthesis of 1-O-acetyl-3-O-(4-methoxybenzyl)-4-N-(9-fluorenylmethoxycarbonyl)-4-N-methyl-L-pyrrolosamine (7), which constitutes a protected form of the N,N-dimethyl-L-pyrrolosamine residues found within the antiproliferative bacterial metabolites (-)-lomaiviticins A and B (1 and 2, respectively), is reported. The synthetic route to 7 proceeds in eight steps and 13% overall yield from (E)-crotyl alcohol. The protected carbohydrate 7 is envisioned to be a useful derivative for syntheses of 1 and 2.
