Placenta and Placental Derivatives in Regenerative Therapies: Experimental Studies, History, and Prospects

Exosomes in nanomedicine: a promising cell-free therapeutic intervention in burn wounds

Burn injuries are serious injuries that have a big impact on a person's health and can even cause death. Incurring severe burns can incite an immune response and inflammation within the body, alongside metabolic changes. It is of utmost importance to grasp the fact that the effects of the burn injury extend beyond the body, affecting the mind and overall well-being. Burn injuries cause long-lasting changes that need to be taken care of in order to improve their quality of life. The intricate process of skin regeneration at the site of a burn wound involves a complex and dynamic interplay among diverse cells, growth factors, nerves, and blood vessels. Exciting opportunities have arisen in the field of stem cells and regenerative medicine, allowing us to explore the development of cell-free-based alternatives that can aid in the treatment of burn injuries. These cell-free-based therapies have emerged as a promising facet within regenerative medicine. Exosomes, also referred to as naturally occurring nanoparticles, are small endosome-derived vesicles that facilitate the delivery of molecular cargo between the cells, thus allowing intercellular communication. The knowledge gained in this field has continued to support their therapeutic potential, particularly in the domains of wound healing and tissue regeneration. Notably, exosomes derived from mesenchymal stem cells (MSCs) can be safely administered in the system, which is then adeptly uptaken and internalized by fibroblasts/epithelial cells, subsequently accelerating essential processes such as migration, proliferation, and collagen synthesis. Furthermore, exosomes released by immune cells, specifically macrophages, possess the capability to modulate inflammation and effectively diminish it in adjacent cells. Exosomes also act as carriers when integrated with a scaffold, leading to scarless healing of cutaneous wounds. This comprehensive review examines the role of exosomes in burn wound healing and their potential utility in regeneration and repair.

Therapeutic implication of human placental extract to prevent liver cirrhosis in rats with metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatohepatitis (MASH) is always accompanied with hepatic fibrosis that could potentially progress to liver cirrhosis and hepatocellular carcinoma. Employing a rat model, we evaluated the role of human placental extract (HPE) to arrest the progression of hepatic fibrosis to cirrhosis in patients with MASH. SHRSP5/Dmcr rats were fed with a high-fat and high-cholesterol diet for 4 weeks and evaluated for the development of steatosis. The animals were divided into control and treated groups and received either saline or HPE (3.6 ml/kg body weight) subcutaneously thrice a week. A set of animals were killed at the end of 6th, 8th, and 12th weeks from the beginning of the experiment. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), hepatic malondialdehyde (MDA), and glutathione content were measured. Immunohistochemical staining was performed for α-smooth muscle actin (α-SMA), 4-hydroxy-2-nonenal (4-HNE), collagen type I, and type III. Control rats depicted progression of liver fibrosis at 6 weeks, advanced fibrosis and bridging at 8 weeks, and cirrhosis at 12 weeks, which were significantly decreased in HPE-treated animals. Treatment with HPE maintained normal levels of MDA and glutathione in the liver. There was marked decrease in the staining intensity of α-SMA, 4-HNE, and collagen type I and type III in HPE treated rats compared with control animals. The results of the present study indicated that HPE treatment mediates immunotropic, anti-inflammatory, and antioxidant responses and attenuates hepatic fibrosis and early cirrhosis. HPE depicts therapeutic potential to arrest the progression of MASH towards cirrhosis.

DNA Methylation Signatures in Paired Placenta and Umbilical Cord Samples: Relationship with Maternal Pregestational Body Mass Index and Offspring Metabolic Outcomes

An epigenomic approach was used to study the impact of maternal pregestational body mass index (BMI) on the placenta and umbilical cord methylomes and their potential effect on the offspring's metabolic phenotype. DNA methylome was assessed in 24 paired placenta and umbilical cord samples. The differentially methylated CpGs associated with maternal pregestational BMI were identified and the metabolic pathways and the potentially related diseases affected by their annotated genes were determined. Two top differentially methylated CpGs were studied in 90 additional samples and the relationship with the offspring's metabolic phenotype was determined. The results showed that maternal pregestational BMI is associated with the methylation of genes involved in endocrine and developmental pathways with potential effects on type 2 diabetes and obesity. The methylation and expression of HADHA and SLC2A8 genes in placenta and umbilical cord were related to several metabolic parameters in the offspring at 6 years (weight SDS, height SDS, BMI SDS, Δ BW-BMI SDS, FM SDS, waist, SBP, TG, HOMA-IR, perirenal fat; all p < 0.05). Our data suggest that epigenetic analysis in placenta and umbilical cord may be useful for identifying individual vulnerability to later metabolic diseases.

A novel multifunctional chitosan-gelatin/carboxymethyl cellulose-alginate bilayer hydrogel containing human placenta extract for accelerating full-thickness wound healing

The replication of skin's dermal and epidermal morphology within a full-thickness wound using a bi-layer hydrogel to cater to their distinct needs is a compelling pursuit. Moreover, human placenta extract (HPE), containing a diverse array of bioactive agents, has proven to be effective in promoting the wound healing process and enhancing epidermal keratinocytes. This study presents a multifunctional bi-layer hydrogel incorporating HPE for accelerating full-thickness wound healing through sustained HPE release, inhibition of bacteria invasion, and promotion of cell proliferation. The upper layer of the scaffold, known as the dressing layer, is composed of carboxymethyl cellulose and sodium alginate, serving as a supportive layer for cell proliferation. The under layer, referred to as the regenerative layer, is composed of chitosan and gelatin, providing an extracellular matrix-like, porous, moist, and antibacterial environment for cell growth. The scaffold was optimized to replicate the morphology of the dermal and epidermal layers, with suitable fibroblast infiltration and a pore size of approximately 283μm. Furthermore, the degradation rate of the samples matched the wound healing rate and persisted throughout this period. The sustained HPE release rate, facilitated by the degradation rate, was optimized to reach ~98% after 28 days, covering the entire healing period. The samples demonstrated robust antibacterial capabilities, with bacterial inhibition zone diameters of and 2.63±0.12cm for S. aureus and E. coli, respectively. The biocompatibility of the samples remained at approximately 68.33±4.5% after 21 days of fibroblast cell culture. The in vivo experiment indicated that the HPE@Bilayer hydrogel promotes the formation of new blood vessels and fibroblasts during the early stages of healing, leading to the appropriate formation of granulation tissue and a wound contraction rate of (79.31±3.1)%. Additionally, it resulted in the formation of a thick epidermal layer (keratinization) that effectively covered all the impaired areas, achieving a wound contraction rate of 95.83±6.3% at the late stage of wound healing. Furthermore, immunohistochemistry staining for CD31 and TGF-β revealed that the HPE@Bilayer group had 22 blood vessels/field and 34%-66% immunoactive cells, respectively, after 14 days of healing. However, by day 21, angiogenesis and TGF-β expression had declined, demonstrating that the wounds had been successfully treated with minimal scarring.

Placental extract suppresses lipid droplet accumulation by autophagy during the differentiation of adipose-derived mesenchymal stromal/stem cells into mature adipocytes

OBJECTIVE

Placental extract, which contains various bioactive compounds, has been used as traditional medicine. Many studies have demonstrated additional applications of placental extract and provided a scientific basis for the broad spectrum of its effects. We have previously reported that porcine placental extract (PPE) strongly suppresses adipogenesis in a 3T3-L1 preadipocyte cell line, inhibiting differentiation. This study aimed to examine the effect of PPE on the accumulation of lipid droplets (LD) in adipose-derived mesenchymal stromal/stem cells (ASC).

RESULTS

The study findings revealed that PPE decreased the size of LD during the differentiation of ASC into mature adipocytes. RT-qPCR analysis revealed that PPE increased the gene expression of lysosomal acid lipase A (Lipa), a lipolysis-related gene, in ASC-differentiated adipocytes. However, no differences were noted in the adipocyte differentiation markers (Pparg, Cebpa, and Adipoq), or the adipogenesis-related genes (Dgat1, Dgat2, Fasn, Soat1, and Soat2). In addition, PPE promoted autophagosome formation, which was partially co-localized with the LD, indicating that PPE accelerated the degradation of LD by inducing autophagy (termed lipophagy) during the differentiation of ASC into mature adipocytes. These results suggest that the use of PPE may be a potential novel treatment for regulating adipogenesis for the treatment of obesity.

A Randomized, Multicenter, Double-Blind, Parallel, Non-Inferiority Clinical Study to Compare the Efficacy and Safety of Unicenta and Melsmon for Menopausal Symptom Improvement

This study was conducted to evaluate the efficacy and safety of Unicenta in female subjects with menopausal symptoms by analyzing the changes in the Kupperman index (primary endpoint) and hormonal changes (secondary endpoint). It was a randomized, multi-center, double-blind, parallel, non-inferiority clinical study conducted at two different tertiary medical centers. A Unicenta injection was shown to be non-inferior to Melsmon based on the Kupperman index in both the intent-to-treat and per-protocol populations (p = 0.789 and p = 0.826, respectively). Additionally, there were no statistically significant differences in hormone levels (estradiol, follicular-stimulating hormone) or in the evaluation of facial flushes. There was no statistically significant difference in the incidence rate of adverse events between the two groups (p = 0.505). The study demonstrated that Unicenta is not inferior to Melsmon in terms of the change in the Kupperman index after 12 days of injection. The efficacy and safety of Unicenta were shown, resulting in the improvement of menopausal symptoms.

Placental-Derived Biomaterials and Their Application to Wound Healing: A Review

Chronic wounds are associated with considerable patient morbidity and present a significant economic burden to the healthcare system. Often, chronic wounds are in a state of persistent inflammation and unable to progress to the next phase of wound healing. Placental-derived biomaterials are recognized for their biocompatibility, biodegradability, angiogenic, anti-inflammatory, antimicrobial, antifibrotic, immunomodulatory, and immune privileged properties. As such, placental-derived biomaterials have been used in wound management for more than a century. Placental-derived scaffolds are composed of extracellular matrix (ECM) that can mimic the native tissue, creating a reparative environment to promote ECM remodeling, cell migration, proliferation, and differentiation. Reliable evidence exists throughout the literature to support the safety and effectiveness of placental-derived biomaterials in wound healing. However, differences in source (i.e., anatomical regions of the placenta), preservation techniques, decellularization status, design, and clinical application have not been fully evaluated. This review provides an overview of wound healing and placental-derived biomaterials, summarizes the clinical results of placental-derived scaffolds in wound healing, and suggests directions for future work.

Human placental extract: a potential therapeutic in treating osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease marked by cartilage degradation and loss of function. Recently, there have been increased efforts to attenuate and reverse OA by stimulating cartilage regeneration and preventing cartilage degradation. Human placental extract (HPE) may be an option due to its anti-inflammatory, antioxidant, and growth stimulatory properties. These properties are useful in preventing cell death and senescence, which may optimize in-situ cartilage regeneration. In this review, we discuss the anatomy and physiology of the placenta, as well as explore in vivo and in vitro studies assessing its effects on tissue regeneration. Finally, we assess the potential role of HPE in cartilage regenerative medicine and OA. The Medline database was utilized for all studies that involved the use of HPE or human placenta hydrolysate. Exclusion criteria included articles not written in English, conference reviews, editorials, letters to the editor, surveys, case reports, and case series. HPE had significant anti-inflammatory and regenerative properties in vitro and in vivo. Furthermore, HPE had a role in attenuating cellular senescence and cell apoptosis via reduction of reactive oxidative species both in vitro and in vivo. One study explored the effects of HPE in OA and demonstrated reduction in cartilage catabolic gene expression, indicating HPE's effect in attenuating OA. HPE houses favorable properties that can attenuate and reverse tissue damage. This may be a beneficial therapeutic in OA as it creates a more favorable environment for in-situ cartilage regeneration. More well designed in-vitro and in-vivo studies are needed to define the role of HPE in treating OA.

Connective tissue matrices from placental disc for wound healing: mini-review

Wound management is a complex procedure that includes multiple factors that play major roles in the healing process. Extracellular matrix-based approaches are emerging strategies for promoting wound healing. The extracellular matrix is an extensive three-dimensional molecular network comprising a variety of fibrous proteins, glycosaminoglycans, and proteoglycans. One of the rich sources of extracellular matrix components is placental tissues, which have a long history of use in tissue repair and regeneration. PURPOSE OF WORK: This mini-review focuses on essential characteristics of placental disc, comparison of four commercially available placental connective matrices (Axiofill, Dermavest, Plurivest, and Interfyl) obtained from the placental disc, and their supporting studies in the use of wound healing applications.

Plumping up a Cushion of Human Biowaste in Regenerative Medicine: Novel Insights into a State-of-the-Art Reserve Arsenal

Major breakthroughs and disruptive methods in disease treatment today owe their thanks to our inch by inch developing conception of the infinitive aspects of medicine since the very beginning, among which, the role of the regenerative medicine can on no account be denied, a branch of medicine dedicated to either repairing or replacing the injured or diseased cells, organs, and tissues. A novel means to accomplish such a quest is what is being called "medical biowaste", a large assortment of biological samples produced during a surgery session or as a result of physiological conditions and biological activities. The current paper accentuating several of a number of promising sources of biowaste together with their plausible applications in routine clinical practices and the confronting challenges aims at inspiring research on the existing gap between clinical and basic science to further extend our knowledge and understanding concerning the potential applications of medical biowaste.

Porcine placental extract increase the cellular NAD levels in human epidermal keratinocytes

Nicotinamide adenine dinucleotide (NAD) is an essential cofactor for numerous enzymes involved in energy metabolism. Because decreasing NAD levels is a common hallmark of the aging process in various tissues and organs, maintaining NAD levels has recently been of interest for the prevention of aging and age-related diseases. Although placental extract (PE) are known to possess several anti-aging effects, the NAD-boosting activity of PE remains unknown. In this study, we found that porcine PE (PPE) significantly increased intracellular NAD levels in normal human epidermal keratinocytes (NHEKs). PPE also attenuated the NAD depletion induced by FK866, an inhibitor of nicotinamide phosphoribosyltransferase (NAMPT). Interestingly, only the fraction containing nicotinamide mononucleotide (NMN), nicotinamide riboside (NR), and nicotinamide (NAM) restored NAD content in NHEKs in the absence of NAMPT activity. These results suggest that PPE increases intracellular NAD by providing NAD precursors such as NMN, NR, and NAM. Finally, we showed that the application of PPE to the stratum corneum of the reconstructed human epidermis significantly ameliorated FK866-induced NAD depletion, suggesting that topical PPE may be helpful for increasing skin NAD levels. This is the first study to report the novel biological activity of PE as an NAD booster in human epidermal cells.

Evaluation of Antiaging Effect of Sheep Placenta Extract Using SAMP8 Mice

Widely used in traditional medicine, sheep placenta extract (SPE) is known for its physiological effects such as wound healing, antioxidant, and anti-inflammatory properties. However, the effect of SPE on antiaging is still unclear. In this study, we investigated the effect of SPE on aging through the senescence-accelerated mouse prone 8 (SAMP8) strain. We designed an experiment using both male and female mice randomly divided into 4 groups (n = 10) as follows: Group A—control group; Group B—low-dose SPE (61.5 mg/kg BW/day); Group C—medium-dose SPE (123 mg/kg BW/day); and Group D—high-dose SPE (184.5 mg/kg BW/day). As a result of measuring the aging index parameters such as skin glossiness, spine lordosis, and kyphosis, it was found that the treatment of SPE lowered the aging index. In addition, we found that biochemical parameters such as lactic acid, glucose, ketone bodies, free fatty acids, tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) were not changed in the experimental group treated with SPE for 13 weeks. Finally, we found that lipid peroxidation (LPO) was decreased, while the activities of catalase and superoxide dismutase (SOD) were significantly increased in the brain tissues of SPE-treated male and female mice. Supplementation of SPE lowered the oxidative stress caused by the aging process in mice without toxicity and decreased the aging index, suggesting the value of SPE as an effective antiaging treatment.

Heat-Induced Proteotoxic Stress Response in Placenta-Derived Stem Cells (PDSCs) Is Mediated through HSPA1A and HSPA1B with a Potential Higher Role for HSPA1B

Placenta-derived stem cells (PDSCs), due to unique traits such as mesenchymal and embryonic characteristics and the absence of ethical constraints, are in a clinically and therapeutically advantageous position. To aid in stemness maintenance, counter pathophysiological stresses, and withstand post-differentiation challenges, stem cells require elevated protein synthesis and consequently augmented proteostasis. Stem cells exhibit source-specific proteostasis traits, making it imperative to study them individually from different sources. These studies have implications for understanding stem cell biology and exploitation in the augmentation of therapeutic applications. Here, we aim to identify the primary determinants of proteotoxic stress response in PDSCs. We generated heat-induced dose-responsive proteotoxic stress models of three stem cell types: placental origin cells, the placenta-derived mesenchymal stem cells (pMSCs), maternal origin cells, the decidua parietalis mesenchymal stem cells (DPMSCs), and the maternal–fetal interface cells, decidua basalis mesenchymal stem cells (DBMSCs), and measured stress induction through biochemical and cell proliferation assays. RT-PCR array analysis of 84 genes involved in protein folding and protein quality control led to the identification of Hsp70 members HSPA1A and HSPA1B as the prominent ones among 17 significantly expressed genes and with further analysis at the protein level through Western blotting. A kinetic analysis of HSPA1A and HSPA1B gene and protein expression allowed a time series evaluation of stress response. As identified by protein expression, an active stress response is in play even at 24 h. More prominent differences in expression between the two homologs are detected at the translational level, alluding to a potential higher requirement for HSPA1B during proteotoxic stress response in PDSCs.

Wharton jelly-derived mesenchymal stem cell exosomes induce apoptosis and suppress EMT signaling in cervical cancer cells as an effective drug carrier system of paclitaxel

Mesenchymal stem cells can be obtained and multiplied from various sources and have a very high capacity to release exosomes. Exosomes are nano-sized extracellular vesicles containing biological signaling molecules. This study aimed to determine the effect of MSC-derived exosomes as a drug delivery system for paclitaxel in cervical cancer cells. In this study, human MSC were isolated from wharton jelly of umbilical cord tissue (WJ-MSC), and cells were characterized by CD44, CD90, CD105, and CD34 staining. Exosomes were released in WJ-MSC cells with serum-starved conditions for 48 hours, and particle sizes and structures were examined with zeta-sizer and TEM. In addition, exosomes CD9, CD63, and CD81 markers were checked by western blot. Paclitaxel was loaded into exosomes (Exo-PAC) by electroporation and then incubated with Hela cervical cancer cells for 24 hours. TGF-β, SMAD, Snail, Slug, β-catenin, Notch, Caspase-3, Caspase-9, Bax, Bcl-2 protein and gene expression levels were analyzed in Hela cells. As a result, low concentration Exo-PAC induced apoptosis, and suppressed epithelial-mesenchymal transition proteins in Hela cells. In this study, it has been demonstrated that WJ-MSCs can be used as drug delivery systems for cervical cancer if exosomes are produced scalably in the future.

Platelet Rich Plasma in the Repair of Articular Cartilage Injury: A Narrative Review

OBJECTIVE

This paper reviews the research of platelet-rich plasma (PRP) in articular cartilage injury repair, to assess the mechanism, utilization, and efficacy of PRP in the treatment of articular cartilage injury, hoping to provide a theoretical basis for the clinical application of PRP in the future.

MATERIALS AND METHODS

A comprehensive database search on PRP applications in cartilage repair was performed. Among them, the retrieval time range of PRP in clinical trials of repairing knee cartilage injury was from January 1, 2021 to January 1, 2022. Non-clinical trials and studies unrelated to cartilage injury were excluded.

RESULT

PRP can affect inflammation, angiogenesis, cartilage protection, and cellular proliferation and differentiation after articular cartilage injury through different pathways. In all, 13 clinical trials were included in the analysis.

CONCLUSION

PRP is an emergent therapeutic approach in tissue engineering. Most studies reported that PRP has a positive effect on cartilage injury, improving the joint function, meanwhile there is a lack of standardized standards. The technology of PRP in the repair and treatment of articular cartilage injury is worthy of further research.

Role of Placental Extracts in Periodontal Regeneration: A Literature Review

Periodontium is a specialized tissue surrounding the teeth. It is made up of the gingiva, periodontal ligament, cementum, and alveolar bone. The healing of periodontal tissues when infected occurs through repair and regeneration. The central dogma of regenerative periodontics is to stimulate a cascade of healing events that, if coordinated well, can lead to proper tissue synthesis which in turn would play a very important part in managing periodontitis and preventing tooth loss.

Many regenerative procedures are being followed in periodontics using newer and modified barrier membranes. Placental membranes like amnion, chorion and amnion-chorion membranes are one among these that serve the purpose because of their active components and therapeutic effects. This literature review highlights the benefits of placental extracts in regenerative periodontal therapy.

Highly elastic 3D-printed gelatin/HA/placental-extract scaffolds for bone tissue engineering

Bioengineering scaffolds have been improved to achieve efficient regeneration of various damaged tissues. In this study, we attempted to fabricate mechanically and biologically activated 3D printed scaffold in which porous gelatin/hydroxyapatite (G/H) as a matrix material provided outstanding mechanical properties with recoverable behavior, and human placental extracts (hPE) embedded in the scaffold were used as bioactive components. Methods: Various cell types (human adipose-derived stem cells; hASCs, pre-osteoblast; MC3T3-E1, human endothelial cell line; EA.hy926, and human dermal fibroblast; hDFs) were used to assess the effect of the hPE on cellular responses. High weight fraction (~ 70 wt%) of hydroxyapatite (HA) in a gelatin solution supplemented with glycerol was used for the G/H scaffold fabrication, and the scaffolds were immersed in hPE for the embedding (G/H/hPE scaffold). The osteogenic abilities of the scaffolds were investigated in cultured cells (hASCs) assaying for ALP activity and expression of osteogenic genes. For the in vivo test, the G/H and G/H/hPE scaffolds were implanted in the rat mastoid obliteration model. Results: The G/H/hPE scaffold presented unique elastic recoverable properties, which are important for efficient usage of implantable scaffolds. The effects of G/H and G/H/hPE scaffold on various in vitro cell-activities including non-toxicity, biocompatibility, and cell proliferation were investigated. The in vitro results indicated that proliferation (G/H = 351.1 ± 13.3%, G/H/hPE = 430.9 ± 8.7% at day 14) and expression of osteogenic markers (ALP: 3.4-fold, Runx2: 3.9-fold, BMP2: 1.7-fold, OPN: 2.4-fold, and OCN: 4.8-fold at day 21) of hASCs grown in the G/H/hPE scaffold were significantly enhanced compared with that in cells grown in the G/H scaffold. In addition, bone formation was also observed in an in vivo model using rat mastoid obliteration. Conclusion:In vitro and in vivo results suggested that the G/H/hPE scaffold is a potential candidate for use in bone tissue engineering.

Placental Tissues as Biomaterials in Regenerative Medicine

Placental tissues encompass all the tissues which support fetal development, including the placenta, placental membrane, umbilical cord, and amniotic fluid. Since the 1990s there has been renewed interest in the use of these tissues as a raw material for regenerative medicine applications. Placental tissues have been extensively studied for their potential contribution to tissue repair applications. Studies have attributed their efficacy in augmenting the healing process to the extracellular matrix scaffolds rich in collagens, glycosaminoglycans, and proteoglycans, as well as the presence of cytokines within the tissues that have been shown to stimulate re-epithelialization, promote angiogenesis, and aid in the reduction of inflammation and scarring. The compositions and properties of all birth tissues give them the potential to be valuable biomaterials for the development of new regenerative therapies. Herein, the development and compositions of each of these tissues are reviewed, with focus on the structural and signaling components that are relevant to medical applications. This review also explores current configurations and recent innovations in the use of placental tissues as biomaterials in regenerative medicine.

Efficacy of extracts from cryopreserved placenta on third-degree burns in rats

Human placenta extracts have anti-inflammatory, antioxidant and wound-healing properties, so they are promising drugs for the treatment of wounds of various origins, including burns. Cryopreservation methods are widely used to preserve the biological activity of placental drugs for a long time. The aim of this work was to study the effect of low-temperature storage of the placenta on the regenerative properties of its extracts. Fragments of freshly obtained placentas were cooled by immersion in liquid nitrogen and stored at –196 °C for 6 months. The placenta was warmed in a water bath at 37 °C. The effect of low-temperature preservation of the placenta on the ability of its extracts to positively affect the wound healing process was studied in a model of thermal burn of III B degree in rats. The effectiveness of wound treatment with extracts from cryopreserved placenta was evaluated by planimetric and histological methods at 3, 7, 14, 21 and 28 days after the burn. The activity of antioxidant enzymes in the serum of animals was also determined. superoxide dismutase activity was assessed by inhibition of adrenaline autooxidation in carbonate buffer, catalase activity was assessed by the degree of inhibition of ammonium peroxide formation. It has been shown that the treatment of burns with extracts from cryopreserved placenta helped to accelerate the regeneration processes and the rate of wound healing. The formation of granulation tissue was detected on the 7th day of treatment with extracts, and on the 14th day in the control. The area of burn wounds during treatment with extracts probably differed from the control starting from 14 days after application of the burn. It was found that the dynamics of recovery of catalase activity after burns is probably higher on the 7th day of treatment with extracts. The obtained data testify to the high efficiency of application of placenta stored at low-temperature for the purpose of obtaining extracts from it with preservation of regenerative properties.

Systematic Review of the Application of Perinatal Derivatives in Animal Models on Cutaneous Wound Healing

Knowledge of the beneficial effects of perinatal derivatives (PnD) in wound healing goes back to the early 1900s when the human fetal amniotic membrane served as a biological dressing to treat burns and skin ulcerations. Since the twenty-first century, isolated cells from perinatal tissues and their secretomes have gained increasing scientific interest, as they can be obtained non-invasively, have anti-inflammatory, anti-cancer, and anti-fibrotic characteristics, and are immunologically tolerated in vivo. Many studies that apply PnD in pre-clinical cutaneous wound healing models show large variations in the choice of the animal species (e.g., large animals, rodents), the choice of diabetic or non-diabetic animals, the type of injury (full-thickness wounds, burns, radiation-induced wounds, skin flaps), the source and type of PnD (placenta, umbilical cord, fetal membranes, cells, secretomes, tissue extracts), the method of administration (topical application, intradermal/subcutaneous injection, intravenous or intraperitoneal injection, subcutaneous implantation), and the type of delivery systems (e.g., hydrogels, synthetic or natural biomaterials as carriers for transplanted cells, extracts or secretomes). This review provides a comprehensive and integrative overview of the application of PnD in wound healing to assess its efficacy in preclinical animal models. We highlight the advantages and limitations of the most commonly used animal models and evaluate the impact of the type of PnD, the route of administration, and the dose of cells/secretome application in correlation with the wound healing outcome. This review is a collaborative effort from the COST SPRINT Action (CA17116), which broadly aims at approaching consensus for different aspects of PnD research, such as providing inputs for future standards for the preclinical application of PnD in wound healing.

Anti-arthritic effect of chicken embryo tissue hydrolyzate against adjuvant arthritis in rats (X-ray microtomographic and histopathological analysis)

Finding new, safe strategies to prevent and control rheumatoid arthritis is an urgent task. Bioactive peptides and peptide-rich protein hydrolyzate represent a new trend in the development of functional foods and nutraceuticals. The resulting tissue hydrolyzate of the chicken embryo (CETH) has been evaluated for acute toxicity and tested against chronic arthritis induced by Freund's full adjuvant (modified Mycobacterium butyricum) in rats. The antiarthritic effect of CETH was studied on the 28th day of the experiment after 2 weeks of oral administration of CETH at doses of 60 and 120 mg/kg body weight. Arthritis was evaluated on the last day of the experiment on the injected animal paw using X-ray computerized microtomography and histopathology analysis methods. The CETH effect was compared with the non-steroidal anti-inflammatory drug diclofenac sodium (5 mg/kg). Oral administration of CETH was accompanied by effective dose-dependent correction of morphological changes caused by the adjuvant injection. CETH had relatively high recovery effects in terms of parameters for reducing inflammation, inhibition of osteolysis, reduction in the inflammatory reaction of periarticular tissues, and cartilage degeneration. This study presents for the first time that CETH may be a powerful potential nutraceutical agent or bioactive component in the treatment of rheumatoid arthritis.

Food and Drug Administration's Position on Commonly Injected Biologic Materials in Orthopaedic Surgery

The use of biologically based therapies is becoming a popular less-invasive therapy for relieving pain and promoting tissue regeneration. The most commonly used biologics are autologous adipose-derived products, bone marrow aspirations, and platelet-rich plasma (PRP). Birth tissue is a common allogenic source of biologics, including umbilical cord, placental membranes, and amniotic fluid. Injected biologics, depending on the indication and how they are processed, formulated, delivered, and promoted, can be subject to different regulatory pathways. The aim of this review is to provide an overview of these products and procedures and educate the musculoskeletal community about the relevant current Food and Drug Administration (FDA) regulations.

An Experimental Study of the Cryopreserved Placenta Extract Effect On the Sodium Diclofenac Anti-Inflammatory Activity

Background. As a means of correcting the ulcerogenic effect of nonsteroidal anti-inflammatory drugs, our attention was attracted by a cryopreserved extract of the human placenta, which has a multivector spectrum of biological activity. To date, there is no information about its effect on the specific activity of this class of medicines (anti-inflammatory, analgesic, etc.) in published sources. Objective. We are aimed to characterize the effect of cryopreserved placenta extract on the anti-inflammatory activity of diclofenac sodium when administered separately in a model of acute exudative inflammation. Methods. Experimental studies in vivo were conducted on 28 nonlinear male laboratory rats. The model of acute exudative inflammation was reproduced by subplantar injection of 0.1 ml of 1.0% aqueous solution of λ-karagenin into the right hind limb of rats. Cryopreserved placenta extract was administered intramuscularly at a dose of 0.16 ml/kg 60 minutes before diclofenac sodium (8 mg/kg). Results. Preventive administration of diclofenac sodium caused an antiexudative effect as early as 30 minutes after administration of λ-karagenin – its anti-inflammatory activity was 11.0%, which is 4.6 times higher than similar indicators at the same time in rats injected with placental cryoextract. At 60 minutes of observation, diclofenac sodium was comparable in anti-inflammatory activity with cryopreserved placenta extract: 28.6% and 22.2%, respectively, but at 120 and 180 minutes, diclofenac sodium exceeded the studied cryoextract in antiphlogistic effect by 1.6 times in both periods of observation. The anti-inflammatory effect of the combined separate administration of placenta cryoextract and diclofenac sodium before λ-karagenin for 30 and 60 minutes was 12.7% and 32.3%, respectively, which is comparable with analogous indicators against the background of diclofenac sodium monotherapy. However, at 120 minutes of observation, the group of combined use of placenta cryoextract and diclofenac sodium showed the greatest anti-inflammatory effect among rats of all the studied groups – 52.6%, which was 2.2 times higher than the indicators of the placenta cryoextract monotherapy group and 1.4 times lower than the indicators of the rats of the diclofenac sodium monotherapy group. Conclusions. 4 hours after administration, placental cryoextract had a suppressive effect on kinins like diclofenac sodium, and in the prostaglandin period of caragenin-induced inflammation against the background of combined use of the studied cryoextract and diclofenac sodium, the anti-inflammatory activity was 46.4 %. This suggests a suppressive effect on the production of prostaglandins as a possible mechanism of anti-exudative action of cryopreserved placenta extract.

Intratracheal transplantation of trophoblast stem cells attenuates acute lung injury in mice

Background

Acute lung injury (ALI) is a common lung disorder that affects millions of people every year. The infiltration of inflammatory cells into the lungs and death of the alveolar epithelial cells are key factors to trigger a pathological cascade. Trophoblast stem cells (TSCs) are immune privileged, and demonstrate the capability of self-renewal and multipotency with differentiation into three germ layers. We hypothesized that intratracheal transplantation of TSCs may alleviate ALI.

Methods

ALI was induced by intratracheal delivery of bleomycin (BLM) in mice. After exposure to BLM, pre-labeled TSCs or fibroblasts (FBs) were intratracheally administered into the lungs. Analyses of the lungs were performed for inflammatory infiltrates, cell apoptosis, and engraftment of TSCs. Pro-inflammatory cytokines/chemokines of lung tissue and in bronchoalveolar lavage fluid (BALF) were also assessed.

Results

The lungs displayed a reduction in cellularity, with decreased CD45⁺ cells, and less thickening of the alveolar walls in ALI mice that received TSCs compared with ALI mice receiving PBS or FBs. TSCs decreased infiltration of neutrophils and macrophages, and the expression of interleukin (IL) 6, monocyte chemoattractant protein-1 (MCP-1) and keratinocyte-derived chemokine (KC) in the injured lungs. The levels of inflammatory cytokines in BALF, particularly IL-6, were decreased in ALI mice receiving TSCs, compared to ALI mice that received PBS or FBs. TSCs also significantly reduced BLM-induced apoptosis of alveolar epithelial cells in vitro and in vivo. Transplanted TSCs integrated into the alveolar walls and expressed aquaporin 5 and prosurfactant protein C, markers for alveolar epithelial type I and II cells, respectively.

Conclusion

Intratracheal transplantation of TSCs into the lungs of mice after acute exposure to BLM reduced pulmonary inflammation and cell death. Furthermore, TSCs engrafted into the alveolar walls to form alveolar epithelial type I and II cells. These data support the use of TSCs for the treatment of ALI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02550-z.

Extracellular Vesicles (Secretomes) from Human Trophoblasts Promote the Regeneration of Skin Fibroblasts

To date, placental trophoblasts have been of interest in the fields of obstetrics and gynecology, mainly due to their involvement in the formation of a connection between the mother and fetus that aids in placental development and fetal survival. However, the regenerative capacities of trophoblasts for application in regenerative medicine and tissue engineering are poorly understood. Here, we aim to determine the skin regeneration and anti-aging capacities of trophoblast-derived conditioned medium (TB-CM) and exosomes (TB-Exos) using human normal dermal fibroblasts (HNDFs). TB-CM and TB-Exos treatments significantly elevated the migration and proliferation potencies of HNDF cells in a dose- and time-dependent manner. When RNA sequencing (RNA-seq) was used to investigate the mechanism underlying TB-CM-induced cell migration on scratch-wounded HNDFs, the increased expression of genes associated with C-X-C motif ligand (CXCL) chemokines, toll-like receptors, and nuclear factor-kappa B (NF-κB) signaling was observed. Furthermore, treatment of intrinsically/extrinsically senescent HNDFs with TB-CM resulted in an enhanced rejuvenation of HNDFs via both protection and restoration processes. Gene expression of extracellular matrix components in the skin dermis significantly increased in TB-CM- and TB-Exos-treated HNDFs. These components are involved in the TB-CM and Exo-mediated regeneration and anti-aging of HNDFs. Thus, this study demonstrated the regenerative and anti-aging efficacies of trophoblast-derived secretomes, suggesting their potential for use in interventions for skin protection and treatment.

Dried bovine placenta improves spermatozoa count in a rat model of male reproductive aging

Background and Aim:

In the male reproductive system, the aging process can lead to infertility. Recently, placenta and its derivatives have been researched as regenerative agents. This study aimed to describe the basic components of dried bovine placenta powder and its potential effects as a regenerative agent in a rat model of male reproductive aging with D-galactose induction.

Materials and Methods:

We divided 15 male Wistar rats, 2 months of age, into three groups: A, the health control group; B, the D-galactose induction group, and C, the D-galactose induction and 10% dried bovine placenta supplementation group. We measured epididymal sperm concentration and testicular weight and volume and analyzed these using one-way analysis of variance.

Results:

Dried bovine placenta was rich in nutrients, with 61.98% protein, 21.25±2.07 carbohydrates, 8.58% water, 4.93% ash, and 3.27% fat. The mean epididymal spermatozoa concentration of the rats in Groups A, B, and C was 3026×10⁶/mL, 1492.8×10⁶/mL, and 2732.5×10⁶/mL, respectively. The average total testicle weights were 2.44 g, 2.72 g, and 2.57 g, respectively. The average total testicle volumes were 2.29 cm³, 2.49 cm³, and 2.33cm³, respectively.

Conclusion:

Dried bovine placenta powder is rich in nutrients, especially protein. Supplementation with dried bovine placenta can improve epididymal spermatozoa concentration that is important in fertility.

Placenta: A gold mine for translational research and regenerative medicine

Stem cell therapy has gained much impetus in regenerative medicine due to some of the encouraging results obtained in the laboratory as well as in translational/clinical studies. Although stem cells are of various types and their therapeutic potential has been documented in several studies, mesenchymal stromal/stem cells (MSCs) have an edge, as in addition to being multipotent, these cells are easy to obtain and expand, pose fewer ethical issues, and possess immense regenerative potential when used in a scientifically correct manner. Currently, MSCs are being sourced from various tissues such as bone marrow, cord, cord blood, adipose tissue, dental tissue, etc., and, quite often, the choice depends on the availability of the source. One such rich source of tissue suitable for obtaining good quality MSCs in large numbers is the placenta obtained in a full-term delivery leading to a healthy child's birth. Several studies have demonstrated the regenerative potential of human placenta-derived MSCs (hPMSC), and most show that these MSCs possess comparable, in some instances, even better, therapeutic potential as that shown by human bone marrow-derived (hBMSC) or human umbilical cord-derived (hUC-MSC) MSCs. The placenta can be easily sourced from the OB/GYN department of any hospital, and if its derivatives such as hPMSC or their EVs are produced under GMP conditions, it could serve as a gold mine for translational/clinical research. Here, we have reviewed recent studies revealing the therapeutic potential of hPMSC and their extracellular vesicles (EVs) published over the past three years.

Placental DNA methylation profiles in opioid-exposed pregnancies and associations with the neonatal opioid withdrawal syndrome

Opioid abuse during pregnancy can result in Neonatal Opioid Withdrawal Syndrome (NOWS). We investigated genome-wide methylation analyses of 96 placental tissue samples, including 32 prenatally opioid-exposed infants with NOWS who needed therapy (+Opioids/+NOWS), 32 prenatally opioid-exposed infants with NOWS who did not require treatment (+Opioids/-NOWS), and 32 prenatally unexposed controls (-Opioids/-NOWS, control). Statistics, bioinformatics, Artificial Intelligence (AI), including Deep Learning (DL), and Ingenuity Pathway Analyses (IPA) were performed. We identified 17 dysregulated pathways thought to be important in the pathophysiology of NOWS and reported accurate AI prediction of NOWS diagnoses. The DL had an AUC (95% CI) =0.98 (0.95-1.0) with a sensitivity and specificity of 100% for distinguishing NOWS from the +Opioids/-NOWS group and AUCs (95% CI) =1.00 (1.0-1.0) with a sensitivity and specificity of 100% for distinguishing NOWS versus control and + Opioids/-NOWS group versus controls. This study provides strong evidence of methylation dysregulation of placental tissue in NOWS development.

Comprehensive Comparison of Amnion Stromal Cells and Chorion Stromal Cells by RNA-Seq

Mesenchymal stromal cells derived from the fetal placenta, composed of an amnion membrane, chorion membrane, and umbilical cord, have emerged as promising sources for regenerative medicine. Here, we used next-generation sequencing technology to comprehensively compare amniotic stromal cells (ASCs) with chorionic stromal cells (CSCs) at the molecular and signaling levels. Principal component analysis showed a clear dichotomy of gene expression profiles between ASCs and CSCs. Unsupervised hierarchical clustering confirmed that the biological repeats of ASCs and CSCs were able to respectively group together. Supervised analysis identified differentially expressed genes, such as LMO3, HOXA11, and HOXA13, and differentially expressed isoforms, such as CXCL6 and HGF. Gene Ontology (GO) analysis showed that the GO terms of the extracellular matrix, angiogenesis, and cell adhesion were significantly enriched in CSCs. We further explored the factors associated with inflammation and angiogenesis using a multiplex assay. In comparison with ASCs, CSCs secreted higher levels of angiogenic factors, including angiogenin, VEGFA, HGF, and bFGF. The results of a tube formation assay proved that CSCs exhibited a strong angiogenic function. However, ASCs secreted two-fold more of an anti-inflammatory factor, TSG-6, than CSCs. In conclusion, our study demonstrated the differential gene expression patterns between ASCs and CSCs. CSCs have superior angiogenic potential, whereas ASCs exhibit increased anti-inflammatory properties.

Bioengineered Skin Substitutes: Advances and Future Trends

As the largest organ in the human body, the skin has the function of maintaining balance and protecting from external factors such as bacteria, chemicals, and temperature. If the wound does not heal in time after skin damage, it may cause infection or life-threatening complications. In particular, medical treatment of large skin defects caused by burns or trauma remains challenging. Therefore, human bioengineered skin substitutes represent an alternative approach to treat such injuries. Based on the chemical composition and scaffold material, skin substitutes can be classified into acellular or cellular grafts, as well as natural-based or synthetic skin substitutes. Further, they can be categorized as epidermal, dermal, and composite grafts, based on the skin component they contain. This review presents the common commercially available skin substitutes and their clinical use. Moreover, the choice of an appropriate hydrogel type to prepare cell-laden skin substitutes is discussed. Additionally, we present recent advances in the field of bioengineered human skin substitutes using three-dimensional (3D) bioprinting techniques. Finally, we discuss different skin substitute developments to meet different criteria for optimal wound healing.

Characteristics and Therapeutic Potential of Human Amnion-Derived Stem Cells

Stem cells including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and adult stem cells (ASCs) are able to repair/replace damaged or degenerative tissues and improve functional recovery in experimental model and clinical trials. However, there are still many limitations and unresolved problems regarding stem cell therapy in terms of ethical barriers, immune rejection, tumorigenicity, and cell sources. By reviewing recent literatures and our related works, human amnion-derived stem cells (hADSCs) including human amniotic mesenchymal stem cells (hAMSCs) and human amniotic epithelial stem cells (hAESCs) have shown considerable advantages over other stem cells. In this review, we first described the biological characteristics and advantages of hADSCs, especially for their high pluripotency and immunomodulatory effects. Then, we summarized the therapeutic applications and recent progresses of hADSCs in treating various diseases for preclinical research and clinical trials. In addition, the possible mechanisms and the challenges of hADSCs applications have been also discussed. Finally, we highlighted the properties of hADSCs as a promising source of stem cells for cell therapy and regenerative medicine and pointed out the perspectives for the directions of hADSCs applications clinically.

Platelet Rich Plasma in Orthopedic Surgical Medicine

There is a global interest in optimizing post-surgical tissue repair strategies, leading to better patient outcomes and fewer complications, most ideally with reduced overall cost. In this regard, in recent years, the interest in autologous biological treatments in orthopedic surgery and sports medicine has increased greatly, and the addition of platelet-rich plasma (PRP) to the surgical armamentarium is of particular note. Unfortunately, the number of PRP preparation devices has also grown immensely over the recent decades, raising meaningful concern for the considerable variation in the qualities of currently available PRP preparations. The lack of consensus on the standardization of PRP preparation and of agreement on condition specific PRP formulations is largely responsible for the sometimes contradictory outcomes in the literature. Furthermore, the full potential of PRP technology, the concept of individualized treatment protocols based on bioformulation options, and platelet dosing, angiogenesis, and antimicrobial and painkilling effects of PRP relevant to orthopedic surgery have rarely been addressed. In this review, we will discuss recent developments regarding PRP preparations and potential therapeutic effects. Additionally, we present a synopsis of several published data regarding PRP applications in orthopedic surgery for treating tendon injuries, inducing bone repair, strengthening spinal fusion outcomes, and supporting major joint replacements.

Placenta-derived mesenchymal stem cells (P-MSCs) for COVID-19 pneumonia-a regenerative dogma

With a robust rise in the number of COVID-19 cases, the World Health Organization (WHO) has declared COVID-19 as a pandemic on 11^th March 2020. COVID-19 pandemic has invited global researchers from various biomedical and biotechnological researchers to plan various treatment modalities for combating this pandemic crisis. At present, there is the unavailability of specific treatment modality; however, researchers have thrown light into the exploration of mesenchymal stem cells (MSCs) to therapeutically perquisite in ameliorating immune-mediated progressive worsening in COVID-19 infected patients. Cellular therapy (CT) has revolutionized the treatment of untreatable diseases with a better clinical and functional outcome. Placenta, being considered as medical waste, contains a variety of stem cells, and hence placenta-derived MSCs (P-MSCs) owe potentiality for extrapolation to combat COVID-19 pandemic. The usage of P-MSCs in combating the COVID-19 pandemic has plausible challenges in terms of isolation, harvesting, expansion, characterization, and involvement of ethical concerns. This article provides an insight into dealing COVID-19 pandemic with P-MSCs as cell-based therapy embracing immunomodulatory and immune-privileged potentials and future prospects. Advocating prospective randomized controlled clinical trials ethically will concretely supplement for its efficacy and safety concerns.

A Review of Placenta and Umbilical Cord-Derived Stem Cells and the Immunomodulatory Basis of Their Therapeutic Potential in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a devastating lung disorder of preterm infants as a result of an aberrant reparative response following exposures to various antenatal and postnatal insults. Despite sophisticated medical treatment in this modern era, the incidence of BPD remains unabated. The current strategies to prevent and treat BPD have met with limited success. The emergence of stem cell therapy may be a potential breakthrough in mitigating this complex chronic lung disorder. Over the last two decades, the human placenta and umbilical cord have gained increasing attention as a highly potential source of stem cells. Placenta-derived stem cells (PDSCs) and umbilical cord-derived stem cells (UCDSCs) display several advantages such as immune tolerance and are generally devoid of ethical constraints, in addition to their stemness qualities. They possess the characteristics of both embryonic and mesenchymal stromal/stem cells. Recently, there are many preclinical studies investigating the use of these cells as therapeutic agents in neonatal disease models for clinical applications. In this review, we describe the preclinical and clinical studies using PDSCs and UCDSCs as treatment in animal models of BPD. The source of these stem cells, routes of administration, and effects on immunomodulation, inflammation and regeneration in the injured lung are also discussed. Lastly, a brief description summarized the completed and ongoing clinical trials using PDSCs and UCDSCs as therapeutic agents in preventing or treating BPD. Due to the complexity of BPD, the development of a safe and efficient therapeutic agent remains a major challenge to both clinicians and researchers.

Current Status and Future Prospects of Perinatal Stem Cells

The placenta is a temporary organ that is discarded after birth and is one of the most promising sources of various cells and tissues for use in regenerative medicine and tissue engineering, both in experimental and clinical settings. The placenta has unique, intrinsic features because it plays many roles during gestation: it is formed by cells from two individuals (mother and fetus), contributes to the development and growth of an allogeneic fetus, and has two independent and interacting circulatory systems. Different stem and progenitor cell types can be isolated from the different perinatal tissues making them particularly interesting candidates for use in cell therapy and regenerative medicine. The primary source of perinatal stem cells is cord blood. Cord blood has been a well-known source of hematopoietic stem/progenitor cells since 1974. Biobanked cord blood has been used to treat different hematological and immunological disorders for over 30 years. Other perinatal tissues that are routinely discarded as medical waste contain non-hematopoietic cells with potential therapeutic value. Indeed, in advanced perinatal cell therapy trials, mesenchymal stromal cells are the most commonly used. Here, we review one by one the different perinatal tissues and the different perinatal stem cells isolated with their phenotypical characteristics and the preclinical uses of these cells in numerous pathologies. An overview of clinical applications of perinatal derived cells is also described with special emphasis on the clinical trials being carried out to treat COVID19 pneumonia. Furthermore, we describe the use of new technologies in the field of perinatal stem cells and the future directions and challenges of this fascinating and rapidly progressing field of perinatal cells and regenerative medicine.

Perinatal Derivatives: Where Do We Stand? A Roadmap of the Human Placenta and Consensus for Tissue and Cell Nomenclature

Progress in the understanding of the biology of perinatal tissues has contributed to the breakthrough revelation of the therapeutic effects of perinatal derivatives (PnD), namely birth-associated tissues, cells, and secreted factors. The significant knowledge acquired in the past two decades, along with the increasing interest in perinatal derivatives, fuels an urgent need for the precise identification of PnD and the establishment of updated consensus criteria policies for their characterization. The aim of this review is not to go into detail on preclinical or clinical trials, but rather we address specific issues that are relevant for the definition/characterization of perinatal cells, starting from an understanding of the development of the human placenta, its structure, and the different cell populations that can be isolated from the different perinatal tissues. We describe where the cells are located within the placenta and their cell morphology and phenotype. We also propose nomenclature for the cell populations and derivatives discussed herein. This review is a joint effort from the COST SPRINT Action (CA17116), which broadly aims at approaching consensus for different aspects of PnD research, such as providing inputs for future standards for the processing and in vitro characterization and clinical application of PnD.

Human Amniotic Membrane: A review on tissue engineering, application, and storage

Human amniotic membrane (hAM) has been employed as scaffolding material in a wide range of tissue engineering applications, especially as a skin dressing and as a graft for corneal treatment, due to the structure of the extracellular matrix and excellent biological properties that enhance both wound healing and tissue regeneration. This review highlights recent work and current knowledge on the application of native hAM, and/or production of hAM-based tissue-engineered products to create scaffolds mimicking the structure of the native membrane to enhance the hAM performance. Moreover, an overview is presented on the available (cryo) preservation techniques for storage of native hAM and tissue-engineered products that are necessary to maintain biological functions such as angiogenesis, anti-inflammation, antifibrotic and antibacterial activity.

Repeated Freezing Procedures Preserve Structural and Functional Properties of Amniotic Membrane for Application in Ophthalmology

For decades, the unique regenerative properties of the human amniotic membrane (hAM) have been successfully utilized in ophthalmology. As a directly applied biomaterial, the hAM should be available in a ready to use manner in clinical settings. However, an extended period of time is obligatory for performing quality and safety tests. Hence, the low temperature storage of the hAM is a virtually inevitable step in the chain from donor retrieval to patient application. At the same time, the impact of subzero temperatures carries an increased risk of irreversible alterations of the structure and composition of biological objects. In the present study, we performed a comprehensive analysis of the hAM as a medicinal product; this is intended for a novel strategy of application in ophthalmology requiring a GMP production protocol including double freezing–thawing cycles. We compared clinically relevant parameters, such as levels of growth factors and extracellular matrix proteins content, morphology, ultrastructure and mechanical properties, before and after one and two freezing cycles. It was found that epidermal growth factor (EGF), transforming growth factor beta 1 (TGF-β1), hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), hyaluronic acid, and laminin could be detected in all studied conditions without significant differences. Additionally, histological and ultrastructure analysis, as well as transparency and mechanical tests, demonstrated that properties of the hAM required to support therapeutic efficacy in ophthalmology are not impaired by dual freezing.

Ethical and Practical Considerations for Integrating Cellular ("Stem Cell") Therapy into Clinical Practice

PURPOSE OF REVIEW

Cellular therapies, also known as "stem cell" interventions (SCI), have undergone a rapid popularization in the USA and worldwide. The current review aimed at outlining (1) the ethical challenges facing the implementation of SCI; (2) the applicability of the currently available SCI; and (3) recommendations to achieve ethical, well-regulated incorporation of SCI in the clinical setting.

RECENT FINDINGS

Concerns regarding the inadequate characterization, poor adverse effects disclosure, and unorthodox, often inappropriate, market practices have engendered a genuine concern regarding the SCI compliance with ethical standards. Six instances of litigation on the basis of misrepresentation or inappropriate informed consent were recorded between 2012 and 2018. Such concerns have been furthered by the loopholes in the regulatory aspect governing the use of SCI coupled with the unclear literature-reported efficacy and diverse spectrum of profess indications. Similarly, the application of SCI in the clinical field is yet to prove its value. The uncertain efficacy, coupled with obscure true-costs of utilization, impedes a value-based assessment. A multidisciplinary approach involving legislative and medical professional societies should continue to advance regulations that govern SCI. A well-regulated system that allows for the ethical integration of SCI with appositely evidenced-based described benefits and risks should be sought.

Multipotency of mouse trophoblast stem cells

BACKGROUND

In a number of disease processes, the body is unable to repair injured tissue, promoting the need to develop strategies for tissue repair and regeneration, including the use of cellular therapeutics. Trophoblast stem cells (TSCs) are considered putative stem cells as they differentiate into other subtypes of trophoblast cells. To identify cells for future therapeutic strategies, we investigated whether TSCs have properties of stem/progenitor cells including self-renewal and the capacity to differentiate into parenchymal cells of fetal organs, in vitro and in vivo.

METHODS

TSCs were isolated using anti-CD117 micro-beads, from embryonic day 18.5 placentas. In vitro, CD117+ TSCs were cultured, at a limiting dilution in growth medium for the development of multicellular clones and in specialized medium for differentiation into lung epithelial cells, cardiomyocytes, and retinal photoreceptor cells. CD117+ TSCs were also injected in utero into lung, heart, and the sub-retinal space of embryonic day 13.5 fetuses, and the organs were harvested for histological assessment after a natural delivery.

RESULTS

We first identified CD117+ cells within the labyrinth zone and chorionic basal plate of murine placentas in late pregnancy, embryonic day 18.5. CD117+ TSCs formed multicellular clones that remained positive for CD117 in vitro, consistent with self-renewal properties. The clonal cells demonstrated multipotency, capable of differentiating into lung epithelial cells (endoderm), cardiomyocytes (mesoderm), and retinal photoreceptor cells (ectoderm). Finally, injection of CD117+ TSCs in utero into lungs, hearts, and the sub-retinal spaces of fetuses resulted in their engraftment on day 1 after birth, and the CD117+ TSCs differentiated into lung alveolar epithelial cells, heart cardiomyocytes, and retina photoreceptor cells, corresponding with the organs in which they were injected.

CONCLUSIONS

Our findings demonstrate that CD117+ TSCs have the properties of stem cells including clonogenicity, self-renewal, and multipotency. In utero administration of CD117+ TSCs engraft and differentiate into resident cells of the lung, heart, and retina during mouse development.

Placental mesenchymal stromal cells as an alternative tool for therapeutic angiogenesis

Dysregulation of angiogenesis is a phenomenon observed in several disorders such as diabetic foot, critical limb ischemia and myocardial infarction. Mesenchymal stromal cells (MSCs) possess angiogenic potential and have recently emerged as a powerful tool for cell therapy to promote angiogenesis. Although bone marrow-derived MSCs are the primary cell of choice, obtaining them has become a challenge. The placenta has become a popular alternative as it is a highly vascular organ, easily available and ethically more favorable with a rich supply of MSCs. Comparatively, placenta-derived MSCs (PMSCs) are clinically promising due to their proliferative, migratory, clonogenic and immunomodulatory properties. PMSCs release a plethora of cytokines and chemokines key to angiogenic signaling and facilitate the possibility of delivering PMSC-derived exosomes as a targeted therapy to promote angiogenesis. However, there still remains the challenge of heterogeneity in the isolated populations, questions on the maternal or fetal origin of these cells and the diversity in previously reported isolation and culture conditions. Nonetheless, the growing rate of clinical trials using PMSCs clearly indicates a shift in favor of PMSCs. The overall aim of the review is to highlight the importance of this rather poorly understood cell type and emphasize the need for further investigations into their angiogenic potential as an alternative source for therapeutic angiogenesis.

Cell Therapy-a Basic Science Primer for the Sports Medicine Clinician

PURPOSE OF REVIEW

The emergence of cell-based therapies has brought much excitement to the field of orthopedic sports medicine. However, the significant inconsistency of reporting has led to the poor understanding, misinformation, and false expectations for patients and clinicians alike. In this paper, we aim to clarify the available cell-therapy treatments and summarize some of the latest research.

RECENT FINDINGS

Although this technology is in early development, our understanding of cell biology has grown significantly over the last decade. Furthermore, it is becoming evident that tissue specificity may play a significant role in determining the effectiveness and overall clinical benefit attributed to cell therapy. Cell therapy is an emerging field with tremendous potential for clinically significant benefit. However, in its current state, clinical application of these treatments is limited by federal regulations, variability in formulation, and limited understanding of the biologic activity of various cell formulations.

Human placental extract ameliorates cytokine and cytokine receptor signaling in the rat hippocampus upon Benzo[a]Pyrene exposure

Benzo[alpha]Pyrene (B[a]P) causes toxicity via Cytochrome P450 1A1 (CYP1A1) metabolic activity in the brain. Studies have shown that neuronal IL-2 and TNF-α are associated with the hippocampus development and regulation, but their association with the CYP1A1 activity remains unidentified. Limited action of human placental extract (HPE) in the activation of tissue repair and wound healing is known, but their role in B[a]P clearance in the hippocampus is not known so far. Our study has focused on two novel concepts: (1) association of CYP1A1 activity with the inflammatory response in the brain hippocampus and (2) role of HPE in the immunomodulatory mechanisms in the hippocampus upon B[a]P exposure at cytokine receptor and nuclear level. Intrathecal administration of different concentrations of B[a]P and HPE into male wistar rat pups has been conducted. An increased CYP1A1 activity was observed in the presence of 0.25 μM B[a]P alone but in case of HPE followed by 0.25 μM B[a]P, it was equal to control. Herein we report that 5 μl of 0.1 gm HPE followed by 0.25 μM B[a]P administration enabled down-regulation of IL-2 and TNF-α levels in the hippocampus thereby modulating TNFR2 and IL2Rγ_c signals via NF-κB activation. Besides, localization of IL-2, TNF-α, IL2Rγ_c, TNFR1 and TNFR2 in the CA1, CA3 and DG regions of the hippocampus are also depicted. Altogether, these findings will project the clinical importance of HPE in the neuroinflammation suppression in the hippocampus developed due to B[a]P toxicity.