Biodegradable nanofibrous scaffolds as smart delivery vehicles for amino acids

Abstract

The encapsulation of amino acids (AAs) and their correct preservation before they are ingested are challenging tasks. Nonpolar (l-alanine and l-phenylalanine), polar (l-cysteine hydrochloride and l-asparagine), and charged (l-lysine hydrochloride and l-aspartic acid) AAs were loaded into biodegradable and nontoxic poly(tetramethylene succinate) (PE44) nanofibers (NFs) with electrospinning. The loading of AAs considerably affected the morphology, topography, thermal properties, and wettability of the PE44 NFs. Furthermore, although the AAs crystallized in a phase separated from the polymeric matrix, the distribution of such crystals changed into PE44 NFs and depended on their chemical nature. Release assays in enzyme-free solutions provided evidence that very significant amounts of AAs were retained in the NFs after 7 days, whereas assays in the lipase-containing solution (because lipase performs essential roles in the digestion) showed almost complete release after a few hours. Lipase preferentially attacked the PE44 regions responsible for the retention of AAs in the biphasic system and favored the almost immediate release of the biomolecules. The results displayed in this study, combined with the biocompatibility, biodegradability, and potential use of the PE44 NFs as edible nonnutritional elements, suggest that the loaded PE44–AA NFs could be used to supply essential and conditional AAs.Peer ReviewedPostprint (author's final draft

Electrospun fibers and their application in drug controlled release, biological dressings, tissue repair, and enzyme immobilization

“…In recent years, electrospun nano-bers have been widely used in the pharmaceutical eld. 11 A variety of drugs including antibiotics, 12 proteins, 13 DNA, RNA, growth factors 14 and anticancer drugs have been loaded into electrospun nanobers for disease treatment. [15][16][17] In recent years, many kinds of enzyme have also been successfully immobilized in bers by electrospinning.…”

Scaffolds for Sustained Release of Ambroxol Hydrochloride, a Pharmacological Chaperone That Increases the Activity of Misfolded β‐Glucocerebrosidase

“…These results have been attributed to the influence of AH–solvent interactions during the electrospinning process. Thus, the drug, which bears polar groups, forms crystalline domains that remain at the surface of hydrophobic PCL MFs when the electrospinning process causes the elimination of favorable AH–solvent interactions . Moreover, the flat ribbon‐like geometry of PCL/AH(TFE) fibers is probably due to the influence of unfavorable PCL–AH interactions in the chain entanglement of the solution mixture .…”

“…Thus, the drug, which bears polar groups, forms crystalline domains that remain at the surface of hydrophobic PCL MFs when the electrospinning process causes the elimination of favorable AH–solvent interactions . Moreover, the flat ribbon‐like geometry of PCL/AH(TFE) fibers is probably due to the influence of unfavorable PCL–AH interactions in the chain entanglement of the solution mixture . Thus, both the incorporation of a low molecular weight drug and the formation of such PCL–AH interactions decrease the degree of chain entanglement in the feeding solution, which is a parameter that significantly influence the fiber morphology.…”

Sustained Local Delivery of Diclofenac from Three-Dimensional Ultrafine Fibrous Protein Scaffolds with Ultrahigh Drug Loading Capacity

“…Ultrafine fibrous tissue engineering (TE) scaffolds with fibers around 50 to 500 nm can promote tissue repair due to the similarity to the extracellular matrix (ECM) structure [1,2,3,4]. However, the recent development in TE scaffolds requires not only the morphological similarity [5] but also additional functions to improve therapeutic efficacy [6,7,8,9]. In this regard, functional components were incorporated into tissue engineering scaffolds, such as anti-inflammatory drugs [8], antibiotics [10], anti-cancer drugs [11], various proteins [6,12], DNA [13], growth factors [14,15,16] and other therapeutic agents [12].…”