Bioactive electrospun scaffold for annulus fibrosus repair and regeneration

Abstract

Purpose Annulus fibrosus (AF) tissue engineering is gathering increasing interest for the development of strategies to reduce recurrent disc herniation (DH) rate and to increase the effectiveness of intervertebral disc regeneration strategies. This study evaluates the use of a bioactive microfibrous poly(L-lactide) scaffold releasing Transforming Growth Factor (TGF)-b1 (PLLA/TGF) for the repair and regeneration of damaged AF. Methods The scaffold was synthesized by electrospinning, with a direct incorporation of TGF-b1 into the polymeric solution, and characterized in terms of morphology and drug release profile. Biological evaluation was performed with bovine AF cells (AFCs) that were cultured on the scaffold up to 3 weeks to quantitatively assess glycosaminoglycans and total collagen production, using bare electrospun PLLA as a control. Histological evaluation was performed to determine the thickness of the deposited neo-ECM. Results Results demonstrated that AFCs cultured on PLLA/TGF deposited a significantly greater amount of glycosaminoglycans and total collagen than the control, with higher neo-ECM thickness. Conclusions PLLA/TGF scaffold induced an anabolic stimulus on AFCs, mimicking the ECM three-dimensional environment of AF tissue. This bioactive scaffold showed encouraging results that allow envisaging an application for AF tissue engineering strategies and AF repair after discectomy for the prevention of recurrent DH.

The transpedicular approach for the study of intervertebral disc regeneration strategies: in vivo characterization

“…Indeed, tissue regeneration has made rapid progresses in recent years, making possible the synthesis of constructs that closely mimic the structure and properties of native tissues. Many new promising biomaterials have been recently described [23][24][25] and need to be tested in valuable animal models. Various agencies, such as Medicines and Healthcare products Regulatory Agency (MHRA), National Institute for Health and Clinical Excellence (NICE), Central Office for Research Ethics Committees (COREC) and US Food and Drug Administration (FDA), will require evidences of successful animal works, to sanitize any permissions given to proceed to human work [3].…”

Polymer-Based Reconstruction of the Inferior Vena Cava in Rat: Stem Cells or RGD Peptide?

“…Indeed, the use of different bioactive peptides as substitutes for cell therapy has been successfully tested in cardiac regeneration and other specialties. 17,[39][40][41][42] In the present study, we selected RGD, a tripeptide composed of arginine-glycine-aspartate that mimics the integrin-binding site of cells and the extracellular matrix 43 and has already been successfully tested as a biofunctionalization motif. 44 Grafting of RGD on a polymer was compared, again in a head-to-head fashion, with ADSC selected because of their ease of procurement, richness of their secretome, and potential for human applications.…”

'Cell or Not to Cell' that is the Question: For Intervertebral Disc Regeneration?

“…Lazebnik et al, (2011) used a biomimetic strategy by combining porcine chondrocyte cell seeded agarose gel surrounded by cell seeded electrospun polycaprolactine ibres and observed that cells were viable, well distributed and orientated themselves in the direction of the ibres [128]. Successful incorporation of growth factors to enhance regeneration has also been shown in electrospun scafolds [129]. Furthermore, biphasic scafolds consisting of a hydrogel NP centre surrounded by a polymeric electrospun AF (2014) conducted an in vivo eicacy study whereby bone marrow derived MSCS were encapsulated within hydrogels, incorporated with anti-angiogenic factors and implanted into ovine disc; following 12 weeks no signiicant diference in biomechanical properties was observed between implanted and untreated discs and disc height and degeneration score deteriorated for all implant treated discs [131].…”