Spun Biotextiles in Tissue Engineering and Biomolecules Delivery Systems

Abstract

Nowadays, tissue engineering is described as an interdisciplinary field that combines engineering principles and life sciences to generate implantable devices to repair, restore and/or improve functions of injured tissues. Such devices are designed to induce the interaction and integration of tissue and cells within the implantable matrices and are manufactured to meet the appropriate physical, mechanical and physiological local demands. Biodegradable constructs based on polymeric fibers are desirable for tissue engineering due to their large surface area, interconnectivity, open pore structure, and controlled mechanical strength. Additionally, biodegradable constructs are also very sought-out for biomolecule delivery systems with a target-directed action. In the present review, we explore the properties of some of the most common biodegradable polymers used in tissue engineering applications and biomolecule delivery systems and highlight their most important uses.

Keywords: local and systemic biomolecule delivery; micro- and nanofibers; regenerative medicine; soft and hard tissue substitution; tissue engineering.

Figure 1

Chemical structure of PGA, PLA, PLGA and the enantiomers D- and L-lactide.

Figure 2

Depiction of acute and chronic wound scenarios with dysregulated matrix metalloproteinases (MMPs) and infiltration of bacteria (used with permission from [126]).

Figure 3

(a) Endothelial progenitor cell growth from 1 to 7 days (PLCL-W, control without biomolecules; 15Hep, 15 wt% heparin; 10, 20 and 30 vascular endothelial growth factors (VEGF) represent 10, 20 and 30 μg/mL of VEGF) and visual detection of the cells via (b) immunofluorescent microscopy (scale 200 µm) and (c) scanning electron microscopy (SEM, scale 100 µm) (adapted with permission from [162]).

Figure 4

Masson’s trichrome-stained images of the newly formed bone within the repaired tissue eight weeks after surgery, using scaffolds made of PLA/gelatin (GEL), nano-hydroxyapatite (nHA)/PLA/GEL and nHA/PLA/GEL/BMP-2 peptide (-PEP). Red arrows indicate new bone, green arrows indicate host bone and black arrows indicate residual scaffolds. Residual scaffolds were all clearly filled with intercellular collagen fibers stained blue, and the newly formed bone tissue was dark blue because of the existence of abundant and compact collagen. New bone regenerated in the nHA/PLA/GEL-PEP group existed both in the middle and limbic of the defects (used with permission from [171]).

Figure 5

Chondrogenic differentiation of mesenchymal stem cells derived from Wharton’s jelly of human umbilical cord on two different nanofibrous scaffolds, the PLLACL and collagen, here referred to as PC; and the PLLACL, collagen and rhTGF-β3, here named PC@rhTGF. (a) Real time-qPCR analysis of chondrogenic markers SRY-box transcription factor 9 (So × 9) and collagen type II (COL2) after culturing for 14 days (n = 3, * P < 0.05). (b) Histological staining of glycosaminoglycans synthesized by the mesenchymal stem cells derived from Wharton’s jelly of human umbilical cord with Toluidine and Safranin O after culturing for 21 days (used with permission from [178]).

Figure 6

Evidence of accelerated wound closure in diabetic rat models (in vivo testing) promoted by curcumin-loaded biotextiles (adapted with permission from [230]).