Core/Shell Glycine-Polyvinyl Alcohol/Polycaprolactone Nanofibrous Membrane Intended for Guided Bone Regeneration: Development and Characterization

Abstract

Glycine (Gly), which is the simplest amino acid, induces the inflammation response and enhances bone mass density, and particularly its β polymorph has superior mechanical and piezoelectric properties. Therefore, electrospinning of Gly with any polymer, including polyvinyl alcohol (PVA), has a great potential in biomedical applications, such as guided bone regeneration (GBR) application. However, their application is limited due to a fast degradation rate and undesirable mechanical and physical properties. Therefore, encapsulation of Gly and PVA fiber within a poly(ε-caprolactone) (PCL) shell provides a slower degradation rate and improves the mechanical, chemical, and physical properties. A membrane intended for GBR application is a barrier membrane used to guide alveolar bone regeneration by preventing fast-proliferating cells from growing into the bone defect site. In the present work, a core/shell nanofibrous membrane, composed of PCL as shell and PVA:Gly as core, was developed utilizing the coaxial electrospinning technique and characterized morphologically, mechanically, physically, chemically, and thermally. Moreover, the characterization results of the core/shell membrane were compared to monolithic electrospun PCL, PVA, and PVA:Gly fibrous membranes. The results showed that the core-shell membrane appears to be a good candidate for GBR application with a nano-scale fiber of 412 ± 82 nm and microscale pore size of 6.803 ± 0.035 μm. Moreover, the wettability of 47.4 ± 2.2° contact angle (C.A) and mechanical properties of 135 ± 3.05 MPa average modulus of elasticity, 4.57 ± 0.04 MPa average ultimate tensile stress (UTS), and 39.43% ± 0.58% average elongation at break are desirable and suitable for GBR application. Furthermore, the X-ray diffraction (XRD) and transmission electron microscopy (TEM) results exhibited the formation of β-Gly.

Dual-Modal Imaging and Synergistic Spinal Tumor Therapy Enabled by Hierarchical-Structured Nanofibers with Cascade Release and Postoperative Anti-adhesion

“…As expected, the trilayered electrospun nanofibers with the slightest degradation degree played a mechanical role to bear physiological loading through maintaining well-organized original structure after 14 days, so as to prevent postsurgical adhesion during the membrane degradation process. 37…”

A Review on Electrospun Poly(amino acid) Nanofibers and Their Applications of Hemostasis and Wound Healing

“…For this reason, glycine is often used to improve immunity and anti-inflammation, promote wound healing, and even improve neurological function, and has good biocompatibility, biodegradability, and excellent mechanical properties [ 115 ]. Alazzawi et al [ 116 ] prepared nanofibers by electrospinning by blending PVA with an aqueous glycine solution. Such nanofibers with high specific surface area can be well used in applications such as bio-scaffolds and drug transport.…”

“…The nanofibrous membranes were implanted into intracranial bone defects in rats, and their ability to promote bone growth and repair was evaluated, as shown in Figure 9 F. The zeatin nanofibrous membrane modified with polyaspartic acid has low cytotoxicity and provides a good microenvironment for promoting osteogenicity, which is a good biomaterial for coping with bone repair and has promising applications. Alazzawi et al [ 116 ] prepared core-shell structured nanofibers using PCL as the shell and glycine and PVA as the core and wrapped glycine as the core part in them by coaxial electrospinning. This core-shell structured nanofiber is able to guide bone regeneration and promote the growth of bone defects, which is an ideal membrane for bone regeneration and can alleviate the rapid degradability of glycine.…”

Potential of uniaxial electrospun composite nanofibers based on polycaprolactone and polyvinyl alcohol in guided bone regeneration

“…Guided bone regeneration (GBR) membrane, as a biological barrier, is usually used in implant surgery to block the colonization of cells that are not conducive to osteogenesis, thus ensuring the reconstruction of bone defects 5 . In literatures, barrier function, good mechanical properties, biocompatibility, and biodegradability are consistent with the basic elements of an absorbable GBR membrane construction 2,6 .…”

“…As for mechanical properties, for one thing, it can ensure that the barrier function is strengthened in the process of tissue regeneration. For another, it can also ensure that the membrane is not easy to move and tear when it is placed and fixed 5 . In addition, when the membrane is in the body, it is not easy to dissolve in body fluid, excessive thickening, and contraction are also necessary for the barrier membrane 7 …”