Opening the Soul Window Manually: Limbal Tissue Scaffolds with Electrospun Polycaprolactone/Gelatin Nanocomposites

Abstract

Restricted by the difficulty in fabricating scaffolds suitable for cell proliferation, the use of ex vivo expanded limbal stem cell (LSC) for LSC transplantation, an effective treatment method for patients with limb stem cell deficiency (LSCD), is hard to be widely used in clinical practice. To tackle these challenges, a novel electrospun polycaprolactone (PCL)/gelatin nanocomposite is proposed to make 3D scaffolds for limbal niche cells (LNC) proliferation in vitro, which is a milestone in the treatment of diseases such as LSCD. PCL and gelatin in different weight ratios are dissolved in a mixed solvent, and then electrospinning and cross‐linking are performed to prepare a scaffold for cell proliferation. The characterizations of the nanocomposites indicate that the gelatin content has a significant effect on its micro‐morphology, thermal properties, crystallinity, degradation temperature, hydrophilicity, and mechanical properties. P8G2‐C (PCL: gelatin = 80: 20, cross‐linked), with smooth fibers and homogeneous pores, has better hydrophilicity, mechanical properties, and flexibility, so it can support LNC as cell proliferation assays revealed. This detailed investigation presented here demonstrates the feasibility of using PCL/gelatin nanocomposites electrospun fiber membranes as a limbus tissue engineering scaffold, which undoubtedly provide a new perspective for the development of tissue engineering field.

Limbal Bio‐Engineered Tissue Employing 3D Nanofiber‐Aerogel Scaffold to Facilitate LSCs Growth and Migration

“…[17] To fab-ricate a biomimetic framework, homogenization and lyophilization facilitated smooth and uniform PCL-GEL nanofibers (Figure 2a,b) to form a 3D structure possessing desired biocompatibility, in agreement with our previous study. [10] The obtained 3D nanofiber-aerogel scaffolds can serve as the basal membrane for cell adhesion and migration, and featured the advantages of micropores structure to facilitate the exchange of nutrient and metabolic waste. Under the influence of inflammatory and vascular epithelium growth factors, the 3D nanofiber-aerogel scaffolds eventually vascularized and became part of the host tissue.…”

“…The electrospun polycaprolactone-gelatin (PCL-GEL) nanocomposites were prepared as described in a previous study. [10] The PCL (average molecule weight = 80 kg mol −1 , Shanghai yuanye biotechnology Co., Ltd., China) solution (12% w/v) and GEL solution (20% w/v) was obtained by dissolving in 2,2,2-trifluroethanol (TFE) and glacial acetic acid (Shanghai aladdin bio-chem technology Co., Ltd., China) solvent at a volume ratio of 1:1. Then, the PCL-GEL solution was prepared by mixing PCL solution with GEL solution at a mass ratio of 5:5 and stirred for at least 8 h at room temperature to obtain the PCL/GEL nanocomposites.…”

“…In this work, by integrating 3D nanofibers and micron-nano structure, we propose an innovative method to fabricate limbal bio-engineered tissue which efficiently provides limbal niche for LSCs growth and migration (Scheme 1). [10] Precisely speaking, PCL and GEL were mixed to prepare a 3D nanofiber-aerogel scaffold through an electrospinning, freeze-drying, and crosslinking method. To enable this scaffold suitable for cell proliferation and transplantation, the ratio of mat and tert-butanol solution (3 wt%) had been accurately adjusted to regulate the aperture (50-100 μm) and morphology (3D interconnected porous structure).…”

Chain-End Functionalization of Poly(ε-caprolactone) for Chemical Binding with Gelatin: Binary Electrospun Scaffolds with Improved Physico-Mechanical Characteristics and Cell Adhesive Properties

“…Comparison of PCL2 /Gt-based ES fiber materials to PCL/Gt composites prepared with the use of [PCL ES]→[PCL grafting]→[Gt binding] [ 22 , 23 , 24 , 44 , 52 ] and [PCL ES]→[Gt cross-linking] [ 26 , 28 , 29 , 30 , 40 , 42 , 42 , 45 , 55 ] shows the following with regard to the most important characteristics of ES films: PCL2 /Gt-based ES fiber demonstrates higher hydrolytic stability and retains the integrity of the structure longer; more importantly, the mechanical characteristics of PCL2 /Gt-based ES scaffolds differ significantly from the characteristics of Gt-grafted or Gt-cross-linked PCL-based scaffolds.…”

“…In early and following studies, preparation of PCL/Gt ES films was accomplished by chemical grafting of the PCL fibers, followed by the treatment with Gt [ 22 , 23 , 24 , 44 , 52 ] ( Scheme 1 b). The task of the ‘stabilization’ of Gt in binary ES scaffolds was also solved via the treatment of PCL/Gt ES films by gelatin cross-linker reagents such as glutaraldehyde [ 28 , 45 ], genipin [ 26 , 30 , 42 ] ( Scheme 1 c), and other active organic compounds [ 29 , 40 , 42 , 55 ], employing recent progress in cross-linking of ES Gt nanofibers [ 56 ]. In this way, known methods of the preparation of PCL/Gt ES scaffolds with chemically bonded Gt have used chemical linking between macromolecules after ES molding.…”