جستجوی مقالات مرتبط با کلیدواژه « Tissue regeneration » در نشریات گروه « پزشکی »

Human mesenchymal stromal cells are multipotent cells capable of differentiating into the mesenchymal lineage that can be isolated from bone marrow and adipose tissue or from umbilical cord blood and fetal tissues. Among the widely characterized in vitro properties, MSCs show strong anti-proliferative and anti-inflammatory effects on immune responses Exosomes derived from mesenchymal stem cells derived from different tissues are promising cell-free treatments for tissue damage repair. Exosomes serve as a potential portal for cell-free drug delivery systems, as these drugs possess the properties of the parent cell from which they are derived. Extracellular vesicles (EVs) play key roles in cell biology and may provide new clinical diagnostics and therapies. Exosomes, called extracellular vesicles (EcVs), are present in almost all cells, tissues, and body fluids. They contribute to intercellular signaling and maintain tissue homeostasis. The biogenesis of exosomes starts in the endosomal system. Researchers have identified 9769 proteins, 2838 miRNAs, 3408 and 1116 lipids present in exosome of mRNA cargo. Isolation of exosomes from cells, tissues and body fluids follows a different pattern. Exosomes interact with receptor cells through their surface receptor molecules and ligands and are internalized into receptor cells through micropinocytosis and phagocytosis. This varies depending on the origin of the EV, its physiological and pathological state, and even the exact site of cellular release. The composition of the protein inside can also indicate the presence of disease pathologies such as cancer or inflammatory diseases; However, exosomes also contain a number of common proteins as well as proteins involved in vesicle formation. Advanced technologies in regenerative medicine have caused researchers to use exosomes isolated from mesenchymal stem cells (MSCs) with high regeneration ability in diseases. Exosome cargo plays a key role in diagnosis and treatment by controlling the disease process. Various studies in laboratory conditions have shown the effectiveness and therapeutic potential of exosomes in cancer, neurodegenerative, cardiovascular and orthopedic diseases. This article describes the therapeutic role and potential of exosomes derived from mesenchymal stem cells, as well as the necessary precautions for their processing.

Nowadays, according to the advances in medical science, blood products are considered as one of the important biological tools. In this regard, the use of blood-derived biomaterials in reconstructive medicine to repair a variety of tissues has expanded. One of these products is based on platelet separation, which is obtained by different processing techniques and is used alone or in combination with a variety of synthetic or natural structures. These platelet products contain a large number of growth factors that play key roles in the process of tissue repair and regeneration. The purpose of this study was to investigate the importance of these products in the repair of different body tissues.

This study is a review one that was conducted by electronic search in PubMed and EMBASE databases from 2000 to 2021 with keywords such as platelet⸲ growth factors⸲ stem cells and regenerative medicine.

Findings from studies show that blood-derived biomaterials can be extracted by different techniques, and these products have different types of growth factors such as VEGF, PDGF, EGF, and TGF-β, which can contribute to faster tissue regeneration alone or in combination with other substances.

Studies show that blood-derived platelet products can facilitate and accelerate the healing process of various tissues. They can also help advance therapeutic goals.

War's nature is constantly changing over time with the progress in military technology and weapons of war, which has led to a diverse pattern of tissue injuries. Developments in personal protective equipment and body armor, rapid transfer from the battlefield to medical centers, improved resuscitation measures, bleeding control, and wound management have increasingly contributed to the wounded survival. However, the injured suffer tissue injuries of various degrees, thereby undergoing complicated and prolonged treatments. An increasing incidence of injuries caused by explosive devices in modern wars has more complicated treatment and recovery of the injured, highlighting the need for modern treatment methods based on stem cells in military medicine. Stem cells can be harvested from various sources such as bone marrow, adipose tissue, skeletal muscle, skin, umbilical cord blood and Wharton's jelly, placenta and amniotic fluid, and with the ability of self-renewal, proliferation, and differentiation into functional cells of different tissues, anti-inflammatory, paracrine and immune system modulating activities have been considered as a promising therapeutic approach to many battlefield injuries and their complications. Recent research in this area reveals the development of solutions to reduce critical consequences when facing the injuries caused by warfare. Thereby, in this review, in addition to outlining the most important tissue injuries in modern combat, recent developments in the use of stem cells for the regeneration of injured tissues have been highlighted.

Eye injuries are one of the most common side effects of chemical agents, especially mustard gas, which can cause many conflicts in the long time. The cornea is the most critical component of the eye, and many eye injuries somehow are related to that. Nowadays, corneal transplantation is the conventional treatment for corneal injuries, which is due to the lack of a donor, rejection of the transplant, and the possibility of transmitting the disease from the donor to the recipient, face limitations that require an alternative with high efficiency. Stem cells with the ability to proliferate and differentiate into target tissues play a crucial role in novel regeneration methods. These cells are also harvested from various non-ocular sources such as bone marrow, adipose and umbilical cord as well as ocular sources in the corneal layers. Direct and indirect transfer of stem cells with different ocular and ocular references to the cornea's damaged layers and subsequent differentiation into specific corneal cells and its regeneration has been considered a practical treatment in recent years. Due to the high progress in this field in many countries and its replacement with high-risk and time-consuming surgical methods, it needs to be studied more. In this review, in addition to introducing the challenges of current medical procedures and the structure of corneal tissue, the preclinical and clinical advances in the use of stem cells for cell therapy are highlighted.

Injuries to the musculoskeletal system are common, debilitating and expensive. In many cases, healing is imperfect, which leads to chronic impairment. Gene transfer might improve repair and regeneration at sites of injury by enabling the local, sustained and potentially regulated expression of therapeutic gene products such products include morphogens, growth factors and anti-inflammatory agents. Proteins produced endogenously as a result of gene transfer are nascent molecules that have undergone post-translational modification. In addition, gene transfer offers particular advantages for the delivery of products with an intracellular site of action, such as transcription factors and noncoding RNAs, and proteins that need to be inserted into a cell compartment, such as a membrane. Transgenes can be delivered by viral or nonviral vectors via in vivo or ex vivo protocols using progenitor or differentiated cells. The first gene transfer clinical trials for osteoarthritis and cartilage repair have already been completed. Various bone-healing protocols are at an advanced stage of development, including studies with large animals that could lead to human trials. Other applications in the repair and regeneration of skeletal muscle, intervertebral disc, meniscus, ligament and tendon are in preclinical development. In addition to scientific, medical and safety considerations, clinical translation is constrained by social, financial and logistical issues.

In the last decade, several studies have reported the isolation of stem cell population from different dental sources, while their mesenchymal nature is still controversial. The aim of this study was to introduce the isolating methods for stem cells from human dental pulp and to determine their mesenchymal nature before differentiation. One of the best sources for stem cell is dental pulp tissue. Dental Pulp Stem Cells (DPSCs) would be the most convenient source of stem cells because teeth were easy to retrieve and removed throughout life. Pulp is a specialized connective tissue including blood and lymph vessels, nerves, and the interstitial fluid. DPSCs can be found within the ‘‘cell rich zone’’ of pulp. DPSCs have been isolated for the first time in 2000 by Gronthos; these cells exhibited a differentiation potential for odontoblastic, adipogenic and neural cytotypes. Gronthos isolated stem cells in 2 different The enzymatic digestion method and the second was out growth, these cells could be cryopreserved in liquid nitrogen. It has also been shown that human DPSCs can be used for complex structures such as pulp or woven bone formation in vivo. DPSCs originate from the cranial neural crest and have neural characteristics such as the expression of neurotrophins. Therefore, DPSCs may represent a promising source in cell therapy for neurological disorders. Characterization of these cells and determination of their potentialities in terms of specificity of regenerative response will form the foundation for development of new clinical treatment modalities, whether involving directed recruitment of the cells and seeding of stem cells at sites of injury for regeneration or use of the stem cells with appropriate scaffolds for tissue engineering solutions. Such approaches will provide an innovative and novel biologically based on new generation of clinical treatments for dental disease.

Recently، bone-marrow-derived cells have introduced new therapeutic approaches to the management of wound healing in severe skin injuries. Bone marrow-derived stromal cells are described as a heterogeneous population، including mesenchymal stem cells، hematopoietic stem cells، and fibro-blast cells. Results derived from several studies indicate that these cells may contribute to tissue regeneration whether through producing variety of bioactive growth factors and/or by differentiation into mesoderm lineage. The aim of the present study was to investigate the effect of subcutaneous administration of bone marrow-derived stromal cells in repairing or regeneration of skin wounds induced by third-degree burn in a mouse model. In an experimental study that was performed in Urmia University research center from December 2011 to June 2012، The third-degree skin burn was induced on the shaved backs of healthy 7-8 week old male mice (N=18) using a metal rods heated in boiling water. After 1 hour، based on the equal physical condition mice were randomly divided into two separate groups and then subcutaneously administered with phosphate buffered saline (PBS; 400 µl) or bone marrow-derived stromal cells (106 cell in 400µl PBS) at the burn site. 7، 14 and 21 days after induction of burn injury، biopsies were taken from burn wounds and then the sections were prepared. Subsequently the prepared sections were stained with hematoxylin/eosin and Masson''s trichrome to explore histopathological changes evoke by administration of bone marrow derived stromal cells in comparison with control subjects. Considering investigated parameters including formation of granulation tissue (respectively on days 7، 14 and 21 P≤ 0/007، P≤ 0/0013 and P≤ 0/001)، angiogenesis (on day 21 P≤ 0/002) and collagen deposition، in mice treated with bone marrow-derived stromal cells the rate of healing of third-degree thermal burns was significantly accelerated when compared to the PBS-treated mice. This experimental modulation of wound healing suggests that bone marrow-derived stromal cells can significantly enhance the rate of wound healing possibly through stimulation of granulation tissue، angiogenesis، fibroblast proliferation and collagen deposition.