RESUMEN
Despite the widespread central nervous system injuries, treatment of these disorders is still an issue of concern due to the complexities. Natural recovery in these patients is rarely observed, which calls for developing new methods that address these problems. In this study, natural polymers of polyhydroxybutyrate (PHB) and gelatin were electrospun into scaffolds and cross-linked. In order to modify the PHB-based scaffold for nerve tissue engineering, the scaffold surface was modified by exposure to the ammonium gas plasma under controlled conditions, and the laminin as a promoter for neural cells was coated on the sample surface. Then, polyaniline nanoparticles were inkjet-printed on a sample surface as parallel lines to induce the differentiation of stem cells into neural cells. Infrared spectroscopy, absorption of PBS, AFM, degradation rate, contact angle, electron microscopy and optical microscopy, thermal and mechanical behavior, and analysis of the viability of L929 cells were investigated for the scaffolds. The results showed gelatin decreased the contact angle from 106.2° to 38° and increased the residual weight after PBS incubation from 82 % to 38 %. The moduli of the scaffold increased from 8.78 MPa for pure PHB to 28.74 for the modified scaffold. In addition, performed methods increased cell viability from 69 % for PHB to 89 % for modified scaffold and also had a favorable effect on cell adhesion. Investigation of culturing P19 stem cells demonstrated that they successfully differentiated into neural cells. Results show that the scaffolds prepared in this study were promising for nerve tissue engineering.
Asunto(s)
Gelatina , Ingeniería de Tejidos , Humanos , Ingeniería de Tejidos/métodos , Gelatina/química , Andamios del Tejido/química , Laminina , Poliésteres/químicaRESUMEN
The reconstruction of the nerve tissue engineering scaffold is always of particular interest due to the inability to recover and repair neural tissues after being damaged by diseases or physical injuries. The primary purpose of this study was obtaining a model used to predict the diameter of the fibers of electrospun polyhydroxybutyrate (PHB) scaffolds. Accordingly, the range of operating parameters, namely the applied voltage, the distance between the nozzle to the collector, and solution concentration, was designed for the electrospinning process at three different levels, giving seventeen experiments. These data were modeled utilizing response surface methodology and artificial neural network method using Design Expert and Matlab software.The effect of process parameters on the diameter, as well as their interactions were investigated in detail, and the corresponding models were suggested. Both the RSM and ANN models showed an excellent agreement between the experimental and predicted response values. In the second phase of the study, PHB natural polymer was electrospun into scaffolds with high biocompatibility, resulting in a 224-360 nm diameter range .To further modify the scaffold in order to improve the compatibility of PHB, the fibrous surface of scaffolds was exposed to oxygenated plasma gas radiation under controlled conditions. Next, polyaniline (PANI) nanoparticles were then synthesized and printed on the surface of scaffolds as parallel lines. Then samples were exposed to the electric field. Fourier-transform infrared spectroscopy, water contact angle, optical and electron microscopy, tensile test, and cell viability analysis were performed to study properties of resulting scaffolds. The results indicated the fact that modification of the scaffolds by oxygen plasma and printing PANI nanoparticles in particular patterns had a favorable impact on cell adhesion and direction of cell growth, showing the potential of resulting scaffolds for nerve tissue engineering applications.
Asunto(s)
Ingeniería de Tejidos , Andamios del Tejido , Compuestos de Anilina , Adhesión Celular , PoliésteresRESUMEN
BACKGROUND: Polytetrafluoroethylene (PTFE) is poorly biocompatible due to its low surface energy and hydrophobicity, which cause weak cell attachment and proliferation and complicate its use in implants. OBJECTIVE: NH3 plasma was used for surface modification and binding of amine groups on the PTFE surface. Collagen was immobilized on the plasma-treated PTFE in order to enable it to support enhanced cell adhesion and growth. METHODS: PTFE was exposed to NH3 plasma and collagen was immobilized on the NH3 plasma-treated surface. ATR-IR, SEM, EDXA and contact angle were conducted to determine the composition, microstructure and wettability of samples. The cytocompatibility of the samples was assessed via the growth HUVEC cells using MTT assay. RESULTS: Plasma treatment resulted in an incorporation of functional groups, containing N2 and O2 that caused the PTFE surface to become hydrophilic with contact angle 68°. Also, a reduction in F/C ratio was observed after collagen immobilization that indicates the presence of collagen. Cells proliferated in greater numbers on the collagen immobilized-PTFE as compared to the plasma-treated one. CONCLUSIONS: Plasma treatment incorporates functional polar moieties on the PTFE surface, causing enhanced wettability, collagen immobilization and cell viability. Collagen-immobilized PTFE may offer a valuable solution in biomedical applications such as vessel grafts.