Material Characterization of PCL:PLLA Electrospun Fibers Following Six Months Degradation In Vitro

The annulus fibrosus—one of the two tissues comprising the intervertebral disc—is susceptible to injury and disease, leading to chronic pain and rupture. A synthetic, biodegradable material could provide a suitable scaffold that alleviates this pain and supports repair through tissue regeneration. The transfer of properties, particularly biomechanical, from scaffold to new tissue is essential and should occur at the same rate to prevent graft failure post-implantation. This study outlines the effect of hydrolytic degradation on the material properties of a novel blend of polycaprolactone and poly(lactic acid) electrospun nanofibers (50:50) over a six-month period following storage in phosphate buffered saline solution at 37 °C. As expected, the molecular weight distribution for this blend decreased over the 180-day period. This was in line with significant changes to fiber morphology, which appeared swollen and merged following observation using Scanning Electron Microscopy. Similarly, hydrolysis resulted in considerable remodeling of the scaffolds’ polymer chains as demonstrated by sharp increases in percentage crystallinity and tensile properties becoming stiffer, stronger and more brittle over time. These mechanical data remained within the range reported for human annulus fibrosus tissue and their long-term efficacy further supports this novel blend as a potential scaffold to support tissue regeneration.

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Synthesis, Processing and Testing of a Poly (DL-Lactide-co-ε-Caprolactone) Resorbable Electrospun Membrane for Guided Tissue Regeneration

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.506.110 ◽

2012 ◽

Vol 506 ◽

pp. 110-113 ◽

Cited By ~ 1

Author(s):

P. Piyakunakorn ◽

B. Khumraksa ◽

B. Thapsukhon ◽

S. Rassameemasmaung ◽

Robert Molloy ◽

...

Keyword(s):

Weight Loss ◽

Tissue Regeneration ◽

Hydrolytic Degradation ◽

Guided Tissue Regeneration ◽

Electrospun Membrane ◽

3 Dimensional ◽

Agar Diffusion Test ◽

The Media ◽

Phosphate Buffered Saline

The aim of this study was to fabricate 75:25 poly(DL-lactide-co-e-caprolactone), poly(DLL-co-CL) membranes for used in guided tissue regeneration (GTR). The copolymer was synthesized by ring-opening polymerization (ROP) in bulk. The 3-dimensional fiber networks with built-in microporosity membranes were prepared by electrospinning. The pore size was varied between 5-30 μm and the porosity of membrane was 69%. After immersing in phosphate buffered saline (PBS), the membranes were degradable with time, as indicated by molecular weight loss, mass weight loss, reduction of pH of the media and changes in the surface topography and shape of the membranes. However, the in vitro hydrolytic degradation of the membranes was too fast for use as periodontal GTR. The membranes maintained their original shape for the first 4 weeks and the porous structure disappeared within 2 weeks. Results from agar diffusion test suggest the membranes to be non-cytotoxic. In conclusion, the electrospun membrane was non-cytotoxic but the degradation rate was too fast to be used as GTR membrane in periodontal treatment.

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Effect of TGF-β3 on the Gene Expression of Intervertebral Disc Cells in 3D Pellet Cultures

ASME 2010 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2010-19246 ◽

2010 ◽

Author(s):

C. Houseman ◽

M. Scro ◽

S. Belverud ◽

D. Chen ◽

P. Razzano ◽

...

Keyword(s):

Intervertebral Disc ◽

Tissue Regeneration ◽

Annulus Fibrosus ◽

Culture System ◽

Tissue Repair ◽

Tissue Type ◽

Disc Cells ◽

Ivd Degeneration

Intervertebral disc (IVD) degeneration typically involves changes in the multiple constitutive tissues of the IVD. Many tissue repair efforts have focused on the use of differentiated disc cells or stem cells for the regeneration of an IVD in vitro. Consequently, successful long term culture of human disc cells is pivotal for tissue regeneration of the IVD. The aim of this study is to establish a long-term in vitro culture system for the growth of disc cells that maintain their phenotype based on the anatomical origin (annulus fibrosus (AF), nucleus pulposus (NP), or the vertebral end-plates (EP)). This maintenance of phenotype is crucial for examination of treatment efficacy, which is typically designed to induce regeneration of a single tissue type (i.e. injection of growth factors into the NP or anti-inflammatory treatment of the EPs).

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Drug-Eluting Biodegradable Implants for the Sustained Release of Bisphosphonates

Polymers ◽

10.3390/polym12122930 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2930

Author(s):

Cintya Dharmayanti ◽

Todd A. Gillam ◽

Desmond B. Williams ◽

Anton Blencowe

Keyword(s):

Drug Release ◽

Release Profile ◽

Polymer Chains ◽

Poly Lactic Acid ◽

Initial Surface ◽

Sustained Drug Release ◽

Drug Eluting ◽

Release In Vitro ◽

Poor Absorption

Despite being one of the first-line treatments for osteoporosis, the bisphosphonate drug class exhibits an extremely low oral bioavailability (<1%) due to poor absorption from the gastrointestinal tract. To overcome this, and to explore the potential for sustained drug release, bioerodible poly(lactic acid) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) implants loaded with the bisphosphonate alendronate sodium (ALN) were prepared via hot-melt extrusion. The rate of drug release in vitro was modulated by tailoring the ratio of lactide to glycolide in the polymer and by altering the ALN-loading of the implants. All investigated implants exhibited sustained ALN release in vitro between 25 to 130 days, where implants of greater glycolide composition and higher ALN-loadings released ALN more rapidly. All PLGA implants demonstrated a sigmoidal release profile, characterised by an initial surface dissolution phase, followed by a period of zero-order drug diffusion, then relaxation or erosion of the polymer chains that caused accelerated release over the subsequent days. Contrastingly, the PLA implants demonstrated a logarithmic release profile, characterised by a gradual decrease in ALN release over time.

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Electrospun nanofibers facilitate better alignment, differentiation, and long-term culture in an in vitro model of the neuromuscular junction (NMJ)

Biomaterials Science ◽

10.1039/c8bm00720a ◽

2018 ◽

Vol 6 (12) ◽

pp. 3262-3272 ◽

Cited By ~ 15

Author(s):

Baiwen Luo ◽

Lingling Tian ◽

Nuan Chen ◽

Seeram Ramakrishna ◽

Nitish Thakor ◽

...

Keyword(s):

Neuromuscular Junction ◽

Culture System ◽

In Vitro Model ◽

Electrospun Nanofibers ◽

Nanofibrous Scaffold ◽

Long Term Culture ◽

Vitro Model

An electrospun nanofibrous scaffold is used as a novel in vitro culture system to provide long-term support for NMJ formation.

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Porous membranes of quaternized chitosan composited with strontium-based nanobioceramic for periodontal tissue regeneration

Journal of Biomaterials Applications ◽

10.1177/08853282211050271 ◽

2021 ◽

pp. 088532822110502

Author(s):

Adarsh Rajeswari Krishnankutty ◽

Shamna Najeema Sulaiman ◽

Arun Sadasivan ◽

Roy Joseph ◽

Manoj Komath

Keyword(s):

Tensile Strength ◽

Tissue Regeneration ◽

Porous Membrane ◽

Periodontal Ligament Cells ◽

Porous Membranes ◽

Pull Out ◽

Periodontal Tissue Regeneration ◽

Phosphate Buffered Saline ◽

Pull Out Strength

This report demonstrates the development of a degradable quaternary ammonium derivative of chitosan (QC) composited with strontium-containing nanoapatite (SA) for bioactivity. The material was made as porous membrane by solution casting and freeze drying, for guided tissue regeneration (GTR) applications. The micromorphology, tensile strength, suture pull-out strength, degradation ( in vitro, in phosphate buffered saline), and cytocompatibility (using human periodontal ligament cells) were tested to investigate the effect of derivatization and SA addition. The porosity of the membranes increased with increasing SA content and so did the tensile strength and the degradation. The suture pull-out strength, however, showed a decrease. The cell culture evaluation endorsed biocompatibility. The composite with 1.5 mg SA per 1 mL QC was found to have optimal qualities for GTR applications.

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In Vitro Biodegradability of Poly(lactic Acid)/Hydroxyapatite Biocomposites Prepared by Solvent-Blending Technique

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.626.631 ◽

2012 ◽

Vol 626 ◽

pp. 631-635 ◽

Cited By ~ 3

Author(s):

Mujtahid Kaavessina ◽

Fitriani Khanifatun ◽

Imtiaz Ali ◽

Saeed M. Alzahrani

Keyword(s):

Lactic Acid ◽

Hydrolytic Degradation ◽

Phosphate Buffer Solution ◽

Weight Fraction ◽

Poly Lactic Acid ◽

Buffer Solution ◽

Before And After ◽

Micro Holes ◽

Thermal Stability Of

Poly (lactic acid) was solvent-blended and formed as thin ribbons with different weight fraction of hydroxyapatite, namely 5, 10 and 20wt%. In-vitro biodegradability of biocomposites was performed in phosphate buffer solution (PBS) at 37°C. The presence of hydroxyapatite tended to increase biodegradability of poly (lactic acid) in its biocomposites. Thermal stability of biocomposites was always higher than that neat poly (lactic acid) either before and after hydrolytic degradation tests. After biodegradation tests, some micro-holes and cracks were appeared in the surface morphology of biocomposites as well as the increasing crystallinity occurred.

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Multi-laminate Annulus Fibrosus Repair Scaffold with an Interlamellar Matrix Enhances Impact Resistance, Prevents Herniation and Assists in Restoring Spinal Kinematics

10.1101/418103 ◽

2018 ◽

Author(s):

Ryan Borem ◽

Allison Madeline ◽

Ricardo Vela ◽

Sanjitpal Gill ◽

Jeremy Mercuri

Keyword(s):

Impact Strength ◽

Tissue Regeneration ◽

Material Properties ◽

Annulus Fibrosus ◽

Impact Resistance ◽

Closure Device ◽

Mechanical Function ◽

Defect Closure ◽

Spinal Kinematics

AbstractFocal defects in the annulus fibrosus (AF) of the intervertebral disc (IVD) from herniation or surgical injury have detrimental impacts on IVD mechanical function. Thus, biomaterial-based repair strategies, which can restore the mechanical integrity of the AF and support long-term tissue regeneration are needed. Accordingly, a collagen-based multi-laminate scaffold with an underlying “angle-ply” architecture has been previously reported demonstrating similar mechanical properties to native AF tissue. The objectives of this work were to: 1) enhance the biomaterials impact strength, 2) define its contribution to spinal kinematics, and 3) assess its ability to prevent IVD herniation. First, AFRP’s were enriched with a glycosaminoglycan-based (GAG) interlamellar matrix (ILM), and then tested for its radially-directed impact resistance under physiological stresses. Subsequent kinematic testing was conducted using a characterized GAG-enriched AFRP as an AF focal defect closure device. In summary, AFRPs demonstrated 1) incorporation of a GAG-based ILM significantly increased radial impact strength, 2) restoration of axial FSU kinematics and 3) ability to prevent herniation of native IVD tissues. Together, these results suggest that the AFRP demonstrates the mechanical robustness and material properties to restore an IVD’s physiological mechanical function through the adequate closure of an AF focal defect.

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