Fabrication and characterization of three-dimensional poly(lactic acid-co-glycolic acid), atelocollagen, and fibrin bioscaffold composite for intervertebral disk tissue engineering application

Abstract

The use of synthetically derived poly(lactic-co-glycolic acid) scaffold and naturally derived materials in regeneration of intervertebral disks has been reported in many previous studies. However, the potential effect of poly(lactic-co-glycolic acid) in combination with atelocollagen or fibrin or both atelocollagen and fibrin bioscaffold composite have not been mentioned so far. This study aims to fabricate and characterize three-dimensional poly(lactic-co-glycolic acid) scaffold incorporated with (1) atelocollagen, (2) fibrin, and (3) both atelocollagen and fibrin combination for intervertebral disk tissue engineering application. The poly(lactic-co-glycolic acid) without any natural, bioscaffold composites was used as control. The chemical conformation, morphology, cell–scaffold attachment, porosity, water uptake capacity, thermal properties, mechanical strength, and pH level were evaluated on all scaffolds using attenuated total reflectance Fourier transform infrared, scanning electron microscope, gravimetric analysis, swelling test, differential scanning calorimetry, and Instron E3000, respectively. Biocompatibility test was conducted to assess the intervertebral disk, annulus fibrosus cells viability using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The attenuated total reflectance Fourier transform infrared results demonstrated notable peaks of amide bond suggesting interaction of atelocollagen, fibrin, and both atelocollagen and fibrin combination into the poly(lactic-co-glycolic acid) scaffold. Based on the scanning electron microscope observation, the pore size of the poly(lactic-co-glycolic acid) structure significantly reduced when it was incorporated with atelocollagen and fibrin. The poly(lactic-co-glycolic acid)–atelocollagen scaffolds demonstrated higher significant swelling ratios, mechanical strength, and thermal stability than the poly(lactic-co-glycolic acid) scaffold alone. All the three bioscaffold composite groups exhibited the ability to reduce the acidic poly(lactic-co-glycolic acid) by-product. In this study, the biocompatibility assessment using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cells proliferation assay demonstrated a significantly higher annulus fibrosus cells viability in poly(lactic-co-glycolic acid)–atelocollagen–fibrin compared to poly(lactic-co-glycolic acid) alone. The cellular attachment is comparable in poly(lactic-co-glycolic acid)–atelocollagen–fibrin and poly(lactic-co-glycolic acid)–fibrin scaffolds. Overall, these results may suggest potential use of poly(lactic-co-glycolic acid) combined with atelocollagen and fibrin bioscaffold composite for intervertebral disk regeneration.

Structural and Functional Properties of Neocartilage Construct Engineered in Poly (Lactic-co-Glycolic Acid) (PLGA) based Scaffolds

“…Fro m the ATR-FTIR spectra (result not shown), two notable peaks have been detected indicating the presence of amide bond. The amide bond demonstrated the linking between PLGA carboxyl group and atelocollagen amine group [12]. EDC/ NHS, a cross-linker wh ich is crucial to prevent the leaking of materials fro m scaffold has facilitate to the successful integration of atelocollagen and/or fibrin into PLGA.…”

“…This has been depicted with the presence of reticulated-like fibers network structure blanketing the cell clusters on the scanned surface of PAF and PA bioscaffold groups at the end of the 3-weeks culture. The use of atelocollagen has been reported to encourage the production of ECM [12,23].…”

“…Based on the result, it has been suggested that hybrid scaffolds promote better template for the cell affinity as co mpared to PLGA only scaffold [ 13,14,15,21]. Th is is perhaps to the presence of atelocollagen [12,23]. The properties of fibrin that act as glue to the cells [24,25], provide better attachment of cells [26] and act as a good transport for cells delivery [ 27] also contribute to the promotion of cell growth within the framework of scaffolds.…”

“…The previous stepwise procedure of PLGA-based hybrid formation with some modifications was adapted in this study [12,14,15]. The disk-shape 3D PLGA (65:35) scaffolds with 7mm (diameter) × 3mm (height) were formed using salt leaching and solvent casting method (mo le ratio 65:35, mo lecular weight 24,000 -38,000 g/ mole, Resomer® RG 653 H, Evonik, Boehringer Ingelheim, Germany).…”

“…Therefore, PLGA is often used in co mbination with natural bio material for instance atelocollagen and fibrin. Previous studies have successfully indicated that PLGA in co mbination with atelocollagen and/or fresh fibrin (PAF) facilitated for neo-tissues formation co mparab le to that of native t issues [12] and provide good microenvironment for cell growth and adhesion [13,14]. Hence, this current study is to characterize the structural and functional properties of hybrid biomaterial scaffold to form neo-cartilage like t issue in monolayer culture.…”