Polycaprolactone-templated reduced-graphene oxide liquid crystal nanofibers towards biomedical applications

Here, we report a facile method to generate electrically conductive nanofibers by coating and subsequently chemically reducing graphene oxide (GO) liquid crystals on a polycaprolactone (PCL) mat.</p

Optimal human ovarian follicle isolation: A review focused on enzymatic digestion.

The damage or depletion of ovarian reserves due to aging or cancer treatment can increase the need for fertility preservation techniques. One of the most common ways of supporting fertility in prepubertal girls and women who require immediate cancer treatment is through ovarian tissue cryopreservation and re-transplantation following cancer treatment. However, a more appropriate method should be employed in diseases such as leukemia, where malignant cells may be present in cryopreserved tissue, instead of ovarian tissue transplantation. Human ovarian follicle isolation for culture or the use of artificial ovaries for their growth can decrease the risk of reintroducing cancer cells into these individuals. Here we review the methods for the isolation of human ovarian follicles

Earlier Detection of Alzheimer’s Disease Based on a Novel Biomarker <em>cis</em> P-tau by a Label-Free Electrochemical Immunosensor

Early detection of cis phosphorylated tau (cis P-tau) may help as an effective treatment to control the progression of Alzheimer’s disease (AD). Recently, we introduced for the first time a monoclonal antibody (mAb) with high affinity against cis P-tau. In this study, the cis P-tau mAb was utilized to develop a label-free immunosensor. The antibody was immobilized onto a gold electrode and the electrochemical responses to the analyte were acquired by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The immunosensor was capable of selective detection of cis P-tau among non-specific targets like trans P-tau and major plasma proteins. A wide concentration range (10 × 10−14 M–3.0 × 10−9 M) of cis P-tau was measured in PBS and human serum matrices with a limit of detection of 0.02 and 0.05 pM, respectively. Clinical applicability of the immunosensor was suggested by its long-term storage stability and successful detection of cis P-tau in real samples of cerebrospinal fluid (CSF) and blood serum collected from human patients at different stages of AD. These results suggest that this simple immunosensor may find great application in clinical settings for early detection of AD which is an unmet urgent need in today’s healthcare services

Effect of human umbilical cord blood-derived mesenchymal stem cells on the survival of skin flap in rats

Background: The use of random flaps is one of the most common methods of reconstructive surgery because they are easy to use and quick to do. However, the absence of axial vessels especially in the distal areas can cause ischemia and loss of total or part of the flap. Different methods and systemic and topical medications have been recommended to prevent ischemia in random flaps. The aim of this study was to evaluate the effect of stem cells derived from umbilical cord blood in random flap survival in rats. Methods: This experimental study was conducted in Animal Laboratory of Hazrat Fatemeh Hospital in 2012. In this study twenty Sprague-Dawley male rats weighing approximately 300 to 350 g were selected and divided randomly into two groups. In both groups after anesthesia, a flap was created in the posterior part of each rat with a size of 2 x 6 cm. In the intervention group we injected stem cells derived from umbilical cord blood into the flap, and after eight days the effects on the survival of flaps were examined by digital photography and then pathological examination was performed. Results: The mean of viable flap in the stem cell group was 6.57 cm2 and in control group 4.71 cm2. The minimum and maximum flap survival in the intervention group were 4.71 and 8.75, and the minimum and maximum flap survived in control group were 1.86 and 7.77. This difference was significant and showed that the viable parts of flap were more in the intervention group (P=0.49). In pathologic examinations epidermal and muscle necrosis of the skin were reported in 3 cases in the intervention group and 5 cases in control group. Conclusion: This study showed that cord blood stem cells can be effective somehow in reducing ischemia and increasing random flap survival. However, similar studies are recommended in order to compare the results of this drug and placebo or other proven effective drugs

Possibilities in Germ Cell Research: An Engineering Insight

Germ cells (GCs) are responsible for fertility and disruptions in their development or function cause infertility. However, current knowledge about the diverse mechanisms involved in GC development and function is still in its infancy. This is mainly because there are low numbers of GCs, especially during embryonic development. A deeper understanding of GCs would enhance our ability to produce them from stem cells. In addition, such information would enable the production of healthy gametes for infertile couples. In this regard, pluripotent stem cells (PSCs) demonstrated a promising ability to produce GCs in vitro. In this review, we highlight recent advances in the field of tissue engineering that suggest novel strategies to enhance GC research

Comparison of divided sciatic nerve growth within dermis, venous and nerve graft conduit in rat

Background: Considering the common origin of skin and peripheral nervous system, a tube of dermal layer of skin hypothetically can be an ideal conduit for nerve reconstruction. An experimental study performed to evaluate the nerve regeneration of efficacy into a dermal tube. Methods: Sixty male Wistar rats were used. A 10 mm gap was produced in right sciatic nerves. In group A the autogenous nerve grafts were used to bridge the defects. In group B vein conduit were use to reconstruct the gaps. In group C dermal tube were used to bridge the defects. Morphologic studies were carried out after 3 month. Results: The density of nerve fibers was significantly higher in autogenous nerve graft group. The efficacy of nerve growth into the dermal tube group was significantly poor in comparison to other groups. Conclusions: In the present study, dermis was used as the nerve conduit for the first time. This study indicates that the dermal tube is not a suitable conduit for nerve regeneration till further studies to resolve the problems before clinical application

Effect of β-Mercaptoethanol with and without BSO (DL-Buthionine Sulfoximine) on Resumption of Meiosis, in vitro Maturation and Embryo Development of Immature Mouse Oocytes

Introduction: The purpose of this study was to evaluated the effect of β-mercaptoethanol on resumption of meiosis, in vitro maturation of immature mouse oocytes and resulting embryo development with and without BSO (DL-Buthionine sulfoximine). Material and Methods: Germinal vasicle (GV) were recovered from 6-8 weeks old NMRI ovaries and cultured in maturation medium in MEMα supplemented with 7.5IU/ml hCG, 100mIU/ml rhFSH, 5% FCS (control group) and adding 100μm β-mercaptoethanol (group 1) or with 5mM BSO + 100μm β-mercaptoethanol (group 2) for 24h. The matured oocytes then were fertilized and cultured for 5 days. Fertilization and development were accomplished in T6 medium. Results: The percentage of GV oocytes reaching to metaphase I (or undergo GVBD) were 78.5%, 85%, 86% in control group, group 1 and group 2 respectively, that no significant difference was detected between groups. The proportion of oocytes that progressed to the metaphase II (MII) stage was minimum within 5mM BSO group (group 2) and maximum within β-mercaptoetanol group (group 1) with significant difference comparing with control and each other (P≤0.05). The percentage of embryos reaching to morula stage within β-mercaptoetanol group was significantly higher than the control group (5% and 12.2% respectively). None of oocytes treated with BSO could pass the 8 cell stage. Conclusion: β-mercaptoetanol enhances IVM and improves embryo development. While adding BSO into the maturation medium even with β-mercaptoetanol decreases maturation and declines the embryo development

Ethics of research on stem cells and regenerative medicine: ethical guidelines in the Islamic Republic of Iran

BackgroundRegenerative medicine plays a major role in biomedicine, and given the ever-expanding boundaries of this knowledge, numerous ethical considerations have been raised.Main textRapid advancement of regenerative medicine science and technology in Iran, emerged the Iranian National Committee for Ethics in Biomedical Research to develop a comprehensive national ethical guideline. Therefore, the present ethical guideline which comprises eleven chapters was developed in 2019 and approved in early 2020. The titles of these chapters were selected based on the ethical considerations of various aspects of the field of regenerative medicine: (1) ethical principles of research on stem cells and regenerative medicine; (2) ethical considerations for research on stem cells (embryonic stem cells, epiblast stem cells, tissue-specific stem cells, stem cells derived from transdifferentiation, induced pluripotent stem cells [iPSCs], germline pluripotent stem cells, germline stem cells, and somatic cell nuclear transfer [SCNT] stem cells); (3) ethical considerations for research on somatic cells in regenerative medicine (adult somatic cells, fetal tissue somatic cells, and somatic cells derived from pregnancy products [other than fetus]); (4) ethical considerations for research on gametes in regenerative medicine; (5) ethical considerations for research related to genetic manipulation (human and animal) in regenerative medicine; (6) ethical considerations for research on tissue engineering in regenerative medicine; (7) ethical considerations for pre-clinical studies in regenerative medicine; (8) ethical considerations for clinical trials in regenerative medicine; (9) ethical considerations for stem cells and regenerative medicine bio-banks; (10) ethical considerations for privacy and confidentiality; and (11) ethical considerations for obtaining informed consent.ConclusionThis article discusses the process of developing the present ethical guidelines and its practical points. We hope that it can play an important worldwide role in advancing ethics of research on stem cells and regenerative medicine