Three‐dimensional (3D) bioprinting is a promising method for the fabrication of tissue engineering constructs. The bioprintable materials with cells or other biological parts, which are called bioinks, are arranged layer by layer and make multicellular structures. Not all materials can be printed, and a set of requirements should be met to formulate the appropriate bioink. Poly (ethylene glycol) (PEGDA), as a synthetic polymer, is a promising choice for regenerative medicine applications due to its biocompatibility, ease of crosslinking, and adjustability of its mechanical and chemical properties depending on the application. This review aims to guide and familiarize the reader with the PEGDA‐based bioink as a raw material of the 3D‐bioprinting method, its properties, and applications in soft and hard tissue engineering.

Amniotic membrane (AM) is a biological tissue that surrounds the fetus in the mother’s womb. It has pluripotent cells, immune modulators, collagen, cytokines with anti-fibrotic and anti-inflammatory effect, matrix proteins, and growth factors. In spite of the biological characteristics, some results have been released in preventing the adhesion on traumatized surfaces. Application of the AM as a scaffold is limited due to its low biomechanical resistance and rapid biodegradation. Therefore, for using the AM during surgery, its modification by different methods such as cross-linking of the membrane collagen is necessary, because the cross-linking is an effective way to reduce the rate of biodegradation of the biological materials. In addition, their cross-linking is likely an efficient way to increase the tensile properties of the material, so that they can be easily handled or sutured. In this regard, various methods related to cross-linking of the AM subsuming the composite materials, physical cross-linking, and chemical cross-linking with the glutraldehyde, carbodiimide, genipin, aluminum sulfate, etc. are reviewed along with its advantages and disadvantages in the current work.

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Background: Some pathogenic bacteria cause diseases under certain conditions, such as entry through the skin via a cut. Staphylococcus and Pseudomonas can be commonly found on the skin; yet, these species can potentially initiate skin infections. Considering the importance of these bacteria in skin infections and based on the world attraction to traditional treatment, the present study was conducted to determine the antibacterial effect of Pimpinella anisum polar extract on standard strains of Pseudomonas aeruginosa and Staphylococcus aureus. Methods: Antimicrobial effect of anisum's polar extract was determined by the well diffusion agar and microtitr plate for determining the minimum bactericidal concentration (MBC) and minimum inhibitory concentrations (MIC) on Staphylococcus aureus, Pseudomonas aeruginosa. Results: Inhibition zones were recorded for both bacteria in this study. The MIC/MBC assay showed that Pseudomonas aeruginosa bacteria had the highest susceptibility to the anisum's polar extract. Conclusions: Considering the antibacterial effects of the Pimpinella anisum extract, the extract of this plant can be studied as a treatment for skin infections.

Background & Aims: Pressure ulcer is a serious problem in patients admitted to the intensive care unit. It is associated with major complications such as prolonged length of stay and delayed recovery. The aim of this study was to compare the incidence and grade of pressure ulcers in smokers and non-smokers admitted to the intensive care unit. Materials & Methods:This study is an analytical cross-sectional study in which 120 patients in two groups (smokers (60) and non-smokers (60)) were selected by convenience sampling. Data were collected using a demographic questionnaire, information sheet based on the division of the National Pressure Ulcer Advisory Panel (NPUAP), and Braden's grading criteria. Data were analyzed by SPSS v.24 software. Results: The results showed that incidence of pressure ulcers in the smoker group was 46.13 ± 11.01 and in the non-smokers group was 39.2 ± 8.23 and there was a significant difference between the incidence of pressure ulcers in two groups (p≤.0/05). Also, comparing the grade of pressure ulcer, the mean and standard deviation of the smoker group was 23.32 ± 5.92 and the non-smokers group was 14.22 ± 1.21. 11/7% of patients in the smoking group had grades of four pressure ulcers, but in the nonsmoking group, none of the patients had grades of four pressure ulcers. The t-test showed a significant difference between the grades of pressure ulcers in two groups (p≤0/05). Conclusion:The results of this study showed the effect of smoking on increasing incidence and grade of pressure ulcers in patients admitted to the intensive care unit. Therefore, it is necessary for the staff of the intensive care units to pay special attention to risk factors and to identify and monitor the hospitalized patients.