Cell and Tissue Journal

Abstract Aim: Tissue engineering refers to methods that are based on the use of scaffolds, cells and biologically active molecules to produce tissues with specific functions. The purpose of tissue engineering is to build structures that can regenerate, maintain and improve damaged tissue or the whole organ. Today, by using tissue engineering methods, various natural and synthetic scaffolds have been designed that can be used for nerve grafts. The physical, chemical and biological properties of the scaffold must be similar to the extracellular matrix of the body in order to avoid adhesion, growth and support the differentiation of cells. An ideal neural scaffold should have biodegradability, biocompatibility and proper tensile strength. Recently, the use of polycaprolactan as a suitable biodegradable material has been evaluated in many fields of tissue engineering. Antioxidants are among the substances, which seem to be able to prevent neuronal death by reducing the amount of ROS. Flavonoids include many compounds that have various biological effects in the body. Silymarin (Silybum marianum) is a flavonoid that has many effects, including anti-cancer effects and antioxidant properties. Tragacanth is a known natural polymer that has excellent biological properties such as biodegradability, biocompatibility, antibacterial and wound healing ability. It is obtained from the stems and branches of the Asian species tragacanth. It has outstanding structural stability against heat and acidity. The aim of this study is to produce polycaprolactan/ tragacanth /silymarin nanoscaffolds and to investigate the viability of pc12 cells on the scaffold under oxidative stress. Considering that silymarin has antioxidant properties, the use of polycaprolactan/ tragacanth /silymarin nanoscaffolds can prevent neuropathy of nerve cells.
Material and Methods: Scaffolds used in this research were prepared using the electrophoretic method. For this purpose, an electrospinning machine was used, which is equipped with a rotary collector with a thickness of 70 mm and a width of 50 mm. In order to prepare a polycaprolactan/ tragacanth nanoscaffold and load silymarin on it, a 7% polycaprolactan solution (dissolved in acetic acid), 0.7% by weight tragacanth solution (dissolved in acetic acid) and 0.9% by weight silymarin solution were mixed by a magnetic stirrer for 20 minutes, and in order to make the solution uniform, sodium didecyl sulfate (SDS) with a concentration 1 percent by weight of the solvent was added to the solution and the suspension was homogenized for 20 minutes with an ultrasonic device, then the scaffold was prepared by an electrospinning device. . The nanofibers were collected in a period of 6 hours, the sample collection speed was 1 ml per hour, and the nanofiber samples were collected by rotating at 250 rpm. The distance between the injection needle and the scaffold is 12 cm and this process is done at a voltage of 15 kV. The morphology of the scaffold was evaluated by scanning electron microscope (SEM) and the chemical structure of the scaffold was evaluated by FTIR spectroscopy. To investigate the antioxidant properties of the scaffold, glucose 80 mg/L and H2O2, 150 macro L were used.
Results: Examining the morphology and chemical structure of the scaffold showed the proper porosity of the polycaprolactan/ tragacanth scaffold and the successful loading of silymarin on the scaffold. Evaluation of the oxidant properties of the scaffold after 24 hours of PC12 cell culture on it showed the increase in cell viability on the scaffold and the appropriate antioxidant properties of the scaffold.
Conclusion: The results of this research showed that the enrichment of polycaprolactan/ tragacanth scaffold with silymarin increased the proliferation and survival of PC12 cells under oxidative stress. Therefore, this scaffold can be a suitable candidate for tissue engineering in oxidative stress.

Abstract Aim: This study was aimed to preparation of sheep urinary bladder derived from biological scaffold by a combined (physical and chemical) method and evaluation of scaffold biocompatibility.
 Materials and Methods: Urinary bladder decellularization was performed by physical and chemical methods. In the physical method, the bladder fragments were incubated at -4 °C for 24 h and intervaled the fragments each 6 h by placing for 10 min in 0.1% sodium azide solution. After 24 h, the samples were placed at -20 and -40 °C for 2 and 1 h, respectively. The bladder fragments were held in a cryotube and emerged in liquid nitrogen by five two-minute steps, and finally washed by the PBS buffer containing 0.1% sodium azide. In the chemical decellularization, all of the physically treated bladder fragments were placed in a sodium dodecyl sulphate solution under slow stirring for 24 h. The samples were rinsed with sterile distilled water, sterilized with 75% ethanol and 0.2% peracetic acid and finally were placed in PBS for 24 h.
Results: The light and electron microscopey studies revealed the biocompatibility of seeded stem cells on the sheep bladder bioscaffold, in 3rd, 5th and 7th days. The most biocompatibility was observed in the end of 7th day.
Conclusion: Decellularized urinary bladder scaffold revealed biocompatibility which could be considered as a potential nontoxic and biocompatible bioscaffold for application in tissue engineering regenerative medicine.