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Electrospun silk fibroin nanofibrous scaffolds (ESFNSs) were successfully prepared by electrospinning of various Bombyx mori silk fibroin concentrations (10, 12, and 14% in formic acid). After characterizing the purified silk fibroin, the morphology, porosity, fibers' diameter, and uniformity of the prepared scaffolds were examined in detail. In addition, biological responses such as effects on bone marrow cell viability, cytotoxicity, and cell adhesion were evaluated in vitro. Biocompatibility and bioactivity properties of the ESFNSs were evaluated in vitro and in vivo by cell culturing and subcutaneous implantation in rat models for 7 and 28 days, respectively. According to the obtained results, no beaded fibers were seen in any of the prepared scaffolds, whereas ESFNS-10% provided more uniformity and porosity with nanoscaled fibers (90 ± 0.021 nm). Furthermore, the scaffolds also showed good cell adhesion and spreading (68.7 ± 11.8 and 7.6 ± 3.3 total length and width, respectively) with no detectable effect on cell viability and cytotoxicity. The in vivo biocompatibility evaluation indicated that the scaffolds did not stimulate detectable cellular inflammatory response (lymphocytes) and increased the total cell number (cellularity) in the implantation area. Furthermore, the results suggest the potential use of the prepared ESFNS-10% bone marrow cell constructs in direct implantation for tissue engineering applications.

In this study, three-dimensional hydroxyapatite/silk fibroin (HAp/SF) nanocomposite scaffolds were successfully prepared through layer solvent casting combined with the freeze-drying technique for tissue engineering applications. Various SF aqueous concentrations, ranging from 2.5% to 10%, were used to control the physicochemical properties of the prepared scaffolds. Biologic responses of the rat bone marrow stromal cells (rBMSCs) to the HAp/SF scaffolds were examined by culturing the cells within them. In addition, biodegradation and biocompatibility of the scaffolds were evaluated in vitro and in vivo, respectively. Among the prepared scaffolds, HAp/SF-2.5% was the most brittle sample and showed porous structure with lowest mechanical properties. The average pore diameters were 350 ± 67 and 112 ± 89 µm and decreased with the increase in the SF concentration from 5% to 10%, respectively. The pores formed in the scaffolds, made up of the 5% SF, were more uniform and regular than those of the scaffolds made up of 5% and 10% SF. The HAp/SF scaffolds did not change the rBMSCs viability and were not cytotoxic compared with the control sample. The scanning electron microscopy micrographs showed that the cells migrated into the pores and well attached to the scaffolds and their cytoplasm was extended in all directions, indicating a promising cell adhesion, high biocompatibility, and no cytotoxicity of the HAp/SF-5% nanocomposite scaffolds. Subcutaneous implantation of the HAp/SF-5% scaffolds in rat models suggested an excellent biocompatibility. All data obtained from this study suggest the potential use of the HAp/SF-5% for hard tissue engineering.

Multiple sclerosis is a complex autoimmune disorder which characterized by demyelination and axonal loss in the central nervous system (CNS). Several evidences indicate that some new drugs and stem cell therapy have opened a new horizon for multiple sclerosis treatment, but current therapies are partially effective or not safe in the long term. Recently, herbal therapies represent a promising therapeutic approach for multiple sclerosis disease. Here, we consider the potential benefits of some herbal compounds on different aspects of multiple sclerosis disease. The medicinal plants and their derivatives; Ginkgo biloba, Zingiber officinale, Curcuma longa, Hypericum perforatum, Valeriana officinalis, Vaccinium macrocarpon, Nigella sativa,Piper methysticum, Crocus sativus, Panax ginseng, Boswellia papyrifera, Vitis vinifera, Gastrodia elata, Camellia sinensis, Oenothera biennis, MS14 and Cannabis sativa have been informed to have several therapeutic effects in MS patients.