Nanofiber Carriers of Therapeutic Load: Current Trends

Abstract

The fast advancement in nanotechnology has prompted the improvement of numerous methods for the creation of various nanoscale composites of which nanofibers have gotten extensive consideration. Nanofibers are polymeric/composite fibers which have a nanoscale diameter. They vary in porous structure and have an extensive area. Material choice is of crucial importance for the assembly of nanofibers and their function as efficient drug and biomedicine carriers. A broad scope of active pharmaceutical ingredients can be incorporated within the nanofibers or bound to their surface. The ability to deliver small molecular drugs such as antibiotics or anticancer medications, proteins, peptides, cells, DNA and RNAs has led to the biomedical application in disease therapy and tissue engineering. Although nanofibers have shown incredible potential for drug and biomedicine applications, there are still difficulties which should be resolved before they can be utilized in clinical practice. This review intends to give an outline of the recent advances in nanofibers, contemplating the preparation methods, the therapeutic loading and release and the various therapeutic applications.

Keywords: biomedicine; drug loading; nanofibers; nanotechnology; therapeutic applications.

Figure 1

The overview of techniques for nanofiber fabrication. Some of the many possible nanofiber morphologies are presented in the central part: (1) Core-shell NFs obtained by microsol electrospinning loaded with liposomes (yellow arrow). Adapted from [9]. Copyright © 2020, The Author(s) under CCBY licence. (2) Janus NFs loaded with AgNP and ciprofloxacin prepared by side-by-side electrospinning. Reprinted from [10] with permission from Elsevier. (3) Hierarchical shish-kebab core-shell NF prepared for growth factor delivery. Adapted with permission from [11]. Copyright 2020 American Chemical Society. (4) and (5) Aligned and random oriented NFs. Adapted from [12] under CC BY 4.0. (6) 3D nanofibrous construct prepared by electrospinning and electrospraying. Reprinted from [13], with permission from Elsevier. In the innermost part, therapeutic agents that can be delivered by nanofibers are presented. * Reprinted with permission from [14] the Royal Society of Chemistry. ** Reprinted with permission from [15]. Copyright 2013, American Chemical Society.

Figure 2

The self-assembly of Dox-polypeptide conjugates (FDPC-NPs) and the morphologic transformation of the acid-responsive FDPC-NPs in vitro and in vivo. Change in tumor site pH causes disintegration of micelle shell (1) and subsequent assembly of nanofibers (2) driven by π–π stacking, leading to long-term drug retention in the tumor [27]. Reprinted with permission from [27], Copyright 2022, Ivyspring International Publisher.

Figure 3

Characterization of PLGA/PELA2500/CiH electrospun membranes with different contents of the second component PELA2500. (A–C) Cross-sections of PLGA/PELA2500/CiH membranes: (A) PLGA/PELA2500 (90/10); (B) PLGA/PELA2500 (93/7); (C) PLGA/PELA2500 (95/5). (D) In vitro drug release profiles of PLGA/PELA2500/CiH membranes. (E) Changes in the absorption time of PLGA/PELA2500/CiH membranes the values of the contact angles of the membranes. (F) Changes in the fiber diameter ratio of PLGA/PELA2500/CiH membranes. © 2020 The Authors. Published by Elsevier B.V, under CC-BY-NC-ND license.

Figure 4

Combination neuron therapy by NF: (A) Construction of oriented fiber scaffold loaded with nerve growth factor by microsol electrospinning is followed by condensation with pDNA-loaded liposomes. (B) Morphology of different NF scaffolds (aP: amino PLA NF; MSaP: aPLA microsol fibers; MSaP-aL/p: MSaP conjugated with pDNA-loaded liposomes where the yellow arrow indicates the position of liposome). (C) Evaluation of motor function recovery by BBB and IPT scores. * p < 0.5, ** p < 0.01. Adapted from [9]. Copyright © 2020, The Author(s) under CCBY licence.

Figure 5

Multilayer NF loaded with growth factors for bone healing ((SF/PCL)_1:5/PVA-LBL20). (1) Core-shell NFs with MBP2-loaded core is functionalized by successive layers of chitosan and the second growth factor, CTGF. (2) Time-controlled release of growth factors after intracranial implantation. (3) Temporal development of microvasculature formation. * p < 0.5 Adapted with permission from [144]. Copyright 2019 American Chemical Society.

Figure 6

Injectable biomimetic nanofiber formulation for acute myeloid leukemia treatment: (1) PCL nanofibril coated with mesenchymal stem cell membrane (MSCM) loaded with cytokine CXCL12α and lipid nanoparticles-CRISPR/Cas9 (LNP-Cas9) complex. (2) Images of naked NF and MSCM-coated NF. (3) Biodistribution of MSCM-NF/LNP-Cas9 after injection into the bone marrow of right tibia indicates prolonged localization in tibia when compared with LNP-Cas9. (4) Leukemia stem cells exhibit reduced colony formation after treatment with therapeutic MSCM-NF/LNP-Cas9. **** p < 0.0001. Adapted from [158]. Copyright © 2021, The Author(s) under CCBY 4.0 license.