Tissue engineering aims at fabricating biological substitutes to improve, repair, and regenerate failing human tissues or organs. Designing a nanocomposite scaffolds with tailored properties that enhance the development of functional tissue can be an appropriate approach to achieve this purpose. In this study, the uniform and bead-free nanofibers of poly(ε-caprolactone) composited with different graphene oxide nanosheet contents (ranging from 0.5 to 2 wt%) were successfully fabricated through electrospinning process. A decrease in the average diameter of poly(ε-caprolactone) nanofibers was observed with the addition of graphene oxide nanosheets. Moreover, the nanocomposite scaffolds containing 2 wt% of graphene oxide nanosheets exhibited superior mechanical properties compared to that of pure poly(ε-caprolactone). Compared with pure poly(ε-caprolactone) scaffold, the degradation rate of poly(ε-caprolactone)-graphene oxide nanosheet nanofibers was enhanced, while the integrity of fibers was preserved. The presence of graphene oxide nanosheets in poly(ε-caprolactone) fibers promoted in vitro biomineralization, indicating bioactive features of the nanocomposite scaffolds. Compared to the pure one, nanocomposite fibers also showed better ability in protein adsorption. The in vitro cell culture studies showed that the addition of graphene oxide nanosheets did not diminish the biocompatibility of the electrospun poly(ε-caprolactone) nanofiber. Furthermore, the adhesion and proliferation of MG63 cells were increased. Altogether, the results demonstrated that electrospun poly(ε-caprolactone)-graphene oxide nanosheet nanofiber may be a suitable candidate for tissue engineering scaffold applications.

Biological tissues hinge on blood perfusion and mechanical toughness to function. Injectable hydrogels that possess both high permeability and toughness have profound impacts on regenerative medicine but remain a long‐standing challenge. To address this issue, injectable, pore‐forming double‐network hydrogels are fabricated by orchestrating stepwise gelation and phase separation processes. The interconnected pores of the resulting hydrogels enable direct medium perfusion through organ‐sized matrices. The hydrogels are amenable to cell encapsulation and delivery while promoting cell proliferation and spreading. They are also pore insensitive, tough, and fatigue resistant. When tested in biomimetic perfusion bioreactors, the hydrogels maintain physical integrity under prolonged, high‐frequency biomechanical stimulations (>6000 000 cycles at 120 Hz). The excellent biomechanical performance suggests the great potential of the new injectable hydrogel technology for repairing mechanically dynamic tissues, such as vocal folds, and other applications, such as tissue engineering, biofabrication, organs‐on‐chips, drug delivery, and disease modeling.

The ability of inkjet-based 3D printing (3DP) to fabricate biocompatible ceramics has made it one of the most favorable techniques to generate bone tissue engineering (BTE) scaffolds. Calcium sulfates exhibit various beneficial characteristics, and they can be used as a promising biomaterial in BTE. However, low mechanical performance caused by the brittle character of ceramic materials is the main weakness of 3DP calcium sulfate scaffolds. Moreover, the presence of certain organic matters in the starting powder and binder solution causes products to have high toxicity levels. A post-processing treatment is usually employed to improve the physical, chemical, and biological behaviors of the printed scaffolds. In this study, the effects of heat treatment on the structural, mechanical, and physical characteristics of 3DP calcium sulfate prototypes were investigated. Different microscopy and spectroscopy methods were employed to characterize the printed prototypes. The in vitro cytotoxicity of the specimens was also evaluated before and after heat treatment. Results showed that the as-printed scaffolds and specimens heat treated at 300°C exhibited severe toxicity in vitro but had almost adequate strength. By contrast, the specimens heat treated in the 500°C–1000°C temperature range, although non-toxic, had insufficient mechanical strength, which was mainly attributed to the exit of the organic binder before 500°C and the absence of sufficient densification below 1000°C. The sintering process was accelerated at temperatures higher than 1000°C, resulting in higher compressive strength and less cytotoxicity. An anhydrous form of calcium sulfate was the only crystalline phase existing in the samples heated at 500°C–1150°C. The formation of calcium oxide caused by partial decomposition of calcium sulfate was observed in the specimens heat treated at temperatures higher than 1200°C. Although considerable improvements in cell viability of heat-treated scaffolds were observed in this study, the mechanical properties were not significantly improved, requiring further investigations. However, the findings of this study give a better insight into the complex nature of the problem in the fabrication of synthetic bone grafts and scaffolds via post-fabrication treatment of 3DP calcium sulfate prototypes.

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In the present study, the antibacterial activity effect of methanolic root extracts of Euphorbia Condylocarpa was evaluated against five Gram positive, three Gram negative bacterial strains. The antibacterial activity was determined by agar disk diffusion method. The most susceptible bacteria to Euphorbia Condylocarpa root extracts were Bacillus subtillis, B. pumilis and Staphylococcus epidermidis and displayed larger inhibition zones than Gram negative bacteria. Minimum inhibition concentrations (MIC) of extract against these bacteria strains were determined. The lowest MIC values were obtained with B. pumilis, B. subtillis and S. epidermidis (1.87 mg/mL), followed by Staphylococcus aureus and Escherichia coli (7.50 mg/mL) and the highest were obtained with Pseudomonas aeruginosa, Klebsiella pneumoniae and Enterococcus faecalis (15.00 mg/mL). The cell proliferation and standard cytotoxicity assays of Euphorbia Condylocarpa root extract were revealed that there is no toxic against L929 normal cell line. Based on the current investigation, it is potentially suggested that methanolic Euphorbia Condylocarpa root extract can be proposed as an antibacterial agent and it can be further assessed to discover bioactive natural products involved in its activity.

Background: Spurge family is a large family of plants that contains more than 300 genera and 800 species of which 5 genera and 72 species are native to Iran. This important family of plants can be used in various disease treatments such as cancer, arthritis, asthma, bacterial infections, and neuralgia. This study investigated the anticancer effects of the alcoholic extract of Euphorbia condylocarpa whose native Iranian Kurdish name is "Shoalehkolah".