Human Placental Mesenchymal Stem Cells for the Treatment of ARDS in Rat.

The acute respiratory distress syndrome (ARDS) is one of the main causes of high mortality in patients with coronavirus (COVID-19). In recent years, due to the coronavirus pandemic, the number of patients with ARDS has increased significantly. Unfortunately, until now, there are no effective treatments for ARDS caused by COVID-19. Many drugs are either ineffective or have a low effect. Currently, there have been reports of efficient use of mesenchymal stem cells (MSCs) for the treatment of ARDS caused by COVID-19. We investigated the influence of freeze-dried human placenta-derived mesenchymal stem cells (HPMSCs) in ARDS rat model. All animals have received intratracheal injection of 6 mg/kg of lipopolysaccharide (LPS). The rats were randomly divided into five groups: I: LPS, II: LPS+dexamethasone, III: LPS+HPMSCs, IV: HPMSC, and V: saline. ARDS observation time was short-term and amounted to 168 hours. The study has shown that HPMSCs are able to migrate and attach to damaged lung tissue, contributing to the resolution of pathology, restoration of function, and tissue repair in the alveolar space. Studies have also shown that the administration of HPMSCs in animals with ARDS model significantly reduced the levels of key cytokines such as IL-1ß, IL-6, and TNF-α. Freeze-dried placental stem cell is a very promising biomaterial for the treatment of ARDS. The human placenta can be easily obtained because it is considered as a medical waste. At the same time, a huge number of MSCs can be obtained from the placental tissue, and there is no ethical controversy around their use. The freeze-dried MSCs from human placental tissue can be stored sterile at room temperature for a long time before use.

Local drug delivery system for the treatment of tongue squamous cell carcinoma in rats.

The present study describes a local drug delivery system with two functions, which can suppress tumor growth and accelerate wound healing. Thе system consists of a two-layer multicomponent fibrin-based gel (MCPFTG). The internal layer of MCPFTG, which is in direct contact with the wound surface, contains cisplatin placed on a CultiSpher-S collagen microcarrier. The external layer of MCPFTG consists of a CultiSpher-S microcarrier with lyophilized bone marrow stem cells (BMSCs). The efficacy of MCPFTG was evaluated in a rat model of squamous cell carcinoma of the tongue created with 4-nitroquinoline 1-oxide. The results of the study showed that, within 20-25 days, a non-healing wound of the tongue was formed in animals that underwent only 85% resection of squamous cell carcinoma, while rapid progression of the residual tumor was concomitantly observed. Immunohistochemical methods revealed high expression of cyclin D1 and low expression of E-cadherin in these animals. Additionally, high expression of p63 and Ki-67 was noted. In 80% of animals with squamous cell carcinoma of the tongue that were treated with MCPFTG after 85% tumor resection, a noticeable suppression of tumor growth was evident throughout 150 days, and tumor recurrence was not detected. Immunohistochemistry revealed low or moderate expression of cyclin D1, and high expression of E-cadherin throughout the whole observation period. The MCPFTG-based local drug delivery system was shown to be effective in suppressing tumor growth and preventing recurrence. MCPFTG decreased the toxicity of cisplatin and enhanced its antitumor activity. In addition, lyophilized paracrine BMSC factors present in MCPFTG accelerated wound healing after tumor removal. Thus, the present study suggests novel opportunities for the development of a multifunctional drug delivery system for the treatment of squamous cell carcinoma.

Oral microbiota and oral cancer: Review.

In this review, we draw attention and discuss the risk factors and causes of the development of oral squamous cell carcinoma (OSCC) focusing on oral microbiota. Recently, a breakthrough in the study of cancer has been the discovery of the relationship between the presence of certain types of bacteria and the development of cancer in the human body. Studies have shown that, Porphyromonas gingivalis (P. gingivalis) bacteria that is responsible for the destructive processes in the oral cavity, could play an important role in the development of OSCC. In our continuing search for bacteria that causes oral squamous cell carcinoma, we came across the Pseudomona aeruginosa, which due to its metabolite properties, may play important role in carcinogenesis of oral cancer. One possible mechanism is the ability of Pseudomonas to synthesize nitric oxide (NO) that modulates different cancer-related appearances such as apoptosis, cell cycle, angiogenesis, invasion, and metastasis. We think that P. aeruginosa increases the concentration of NO by converting salivary nitrite to nitric oxide, and this is how it contributes to NO-related carcinogenesis. Early diagnosis and treatment of periodontitis are very important not only for patients' oral health, but also for the prevention of OSCC development. Screening test for OSCC based on determination of salivary NO levels could be appealing and may prove to be useful assay for diagnosis and early detection of disease progression in oral cancer.

Bone Marrow Stem Cell and Decellularized Human Amniotic Membrane for the Treatment of Nonhealing Wound After Radiation Therapy.

OBJECTIVES: In this study, our aim was to create a bioactive wound dressing that combined decellularized and lyophilized human amniotic membrane and freeze-dried rat bone marrow stem cells for the treatment of nonhealing wounds. MATERIALS AND METHODS: For the decellularized human amniotic membrane, sodium dodecyl sulfate and 1% Triton X-100 were used. The mononuclear fraction of bone marrow stem cells was isolated by density gradient centrifugation using Ficoll Paque Plus (GE Healthcare Bio-Sciences, Pittsburgh, PA, USA). Investigations were conducted on Lewis inbred rats with the radiation wound model (dose of 60 Gy). On day 20 after application of radiation, the skin was excised around the radiation burn. The wound was treated with decellularized human amniotic membrane seeded with and without freeze-dried bone marrow stem cells. RESULTS: The use of a decellularized amniotic membrane for closing the burn wound increased the rate of healing by 2.5 times; the use of a decellularized amniotic membrane seeded with bone marrow stem cells or freeze-dried bone marrow stem cells increased the rate of wound healing by approximately 4 times. CONCLUSIONS: Administration of freeze-dried bone marrow stem cell may represent a novel therapeutic approach in the treatment of nonhealing wounds and other conditions. We observed no evidence of local or systemic complications related to the procedure. However, further efforts with better protocol design for future studies are needed.

Decellularized bovine placentome for portacavally-interposed heterotopic liver transplantation in rats.

Scaffolds from healthy placentae offer advantages for tissue engineering with undamaged matrix, associated cytoprotective molecules, and embedded vessels for revascularization. As size disparities in human placenta and small recipients hamper preclinical studies, we studied alternative of bovine placentomes in smaller size ranges. Multiple cow placentomes were decellularized and anatomical integrity was analyzed. Tissue engineering used inbred donor rat livers. Placentomes were hepatized and immediately transplanted in rats with perfusion from portal vein and drainage into inferior vena cava. Cows yielded 99 ±â€¯16 placentomes each. Of these, approximately 25% had 3 to 9 cm diameter and 7 to 63 ml volume, which was suitable for transplantation. After decellularization, angiography and casts documented 100% of vessels and vascular networks were well-perfused without disruptions or leaks. The residual matrix also remained intact for transplantation of placentomes. Perfusion in transplanted placentomes was maintained over up to 30 days. Liver tissue reassembled with restoration of hepatic acinar and sinusoidal structure. Transplanted tissue was intact without apoptosis, or necrosis. Hepatic functions were maintained. Preservation of hepatic homeostasis was verified by cytofluorimetric analysis of hepatocyte ploidy. The prevalence in healthy and transplanted liver of diploid, tetraploid and higher ploidy classes was similar with 57%, 41% and 2% versus 51%, 46.5% and 2.6%, respectively, p = 0.77, ANOVA. CONCLUSIONS: Cow placentomes will allow therapeutic development with disease models in small animals. This will also advance drug or toxicology studies. Portasystemic interposition of engineered liver will be particularly suitable for treating hepatic insufficiencies (metabolic, secretory or detoxification needs), including for children or smaller adults.

A three-dimensional scaffold from decellularized human umbilical artery for bile duct reconstruction.

AIM: The main purpose of the study was to create in vitro bile duct equivalent out of decellularized human umbilical cord artery and use it to reconstruct common bile duct obstruction with preservation of sphincter of Oddi. MATERIAL AND METHODS: SDS and Triton X-100 were used for decellularization of the artery. Allogeneic isolated cholangiocytes were seeded onto the inner surface of the decellularized artery. Experimental study was held and 12 domestic pigs of both sexes, weighing 25-30 kg were used. They were divided in equivalent two groups. Common bile duct obstruction model was created in all animals. Animals of the first group (n=6) received no further treatment and were under observation. Animals of the second group (n=6) underwent relaparotomy after two days of initial intervention, lesion site (2 cm) was incised and defect was reconstructed with the bile duct equivalent with the size of 2-2,5 cm. Maximum observation period was 84 days. RESULTS: Laboratory, morphologic and radiologic investigations showed good integration with the host organism. DISCUSSION: Bile duct reconstruction is still a major of HPB surgery. This fact prompted this study to assess the efficacy of the novel method for bile duct reconstruction the experimental study by using appropriate laboratory, morphologic and radiologic investigations. CONCLUSION: Preliminary results obtained with the described method allows us to say that bile duct equivalent created by us with decellularized human umbilical artery and cholangiocytes can be successfully used for bile duct reconstruction with inclusion of the sphincter of oddi. KEY WORDS: Bile Duct Obstruction, Bile Duct Reconstruction, Decellularization, Human Umbilical Artery.

Decellularized human placenta supports hepatic tissue and allows rescue in acute liver failure.

Tissue engineering with scaffolds to form transplantable organs is of wide interest. Decellularized tissues have been tested for this purpose, although supplies of healthy donor tissues, vascular recellularization for perfusion, and tissue homeostasis in engineered organs pose challenges. We hypothesized that decellularized human placenta will be suitable for tissue engineering. The universal availability and unique structures of placenta for accommodating tissue, including presence of embedded vessels, were major attractions. We found decellularized placental vessels were reendothelialized by adjacent native cells and bridged vessel defects in rats. In addition, implantation of liver fragments containing all cell types successfully hepatized placenta with maintenance of albumin and urea synthesis, as well as hepatobiliary transport of 99m Tc-mebrofenin, up to 3 days in vitro. After hepatized placenta containing autologous liver was transplanted into sheep, tissue units were well-perfused and self-assembled. Histological examination indicated transplanted tissue retained hepatic cord structures with characteristic hepatic organelles, such as gap junctions, and hepatic sinusoids lined by endothelial cells, Kupffer cells, and other cell types. Hepatocytes in this neo-organ expressed albumin and contained glycogen. Moreover, transplantation of hepatized placenta containing autologous tissue rescued sheep in extended partial hepatectomy-induced acute liver failure. This rescue concerned amelioration of injury and induction of regeneration in native liver. The grafted hepatized placenta was intact with healthy tissue that neither proliferated nor was otherwise altered. CONCLUSION: The unique anatomic structure and matrix of human placenta were effective for hepatic tissue engineering. This will advance applications ranging from biological studies, drug development, and toxicology to patient therapies. (Hepatology 2018;67:1956-1969).

Reconstruction of mandibular defects with autogenous bone and decellularized bovine bone grafts with freeze-dried bone marrow stem cell paracrine factors.

The gold standard following segmental mandibulectomy is vascularized autologous bone graft in the form of the fibula flap. However, in bone reconstruction the use of autogenous bone does not always guarantee a successful outcome. The aim of the present investigation was to develop a novel biologically active bone (BAB) graft, and to use it for the reconstruction of large size defects of the mandible bone following tumor resection. In the first part of the present study, biologically active bone graft was developed by using human freeze-dried bone marrow stem cells (BMSCs) paracrine factors and three-dimensional bone scaffold derived from cancellous bovine bone following decellularization. In the second part of the research, one male and three female patients with primary tumors of the mandible underwent hemimandibulectomy. The mandibular bone defects following tumor resection were reconstructed with autogenous rib grafts in three patients and BAB graft was used in one patient. The graft-host interfaces were covered with decellularized human amnion/chorion membrane graft. All patients were followed-up every five months following the reconstruction of the mandible, with no complications observed. Preliminary clinical investigations demonstrated that a BAB graft containing freeze-dried BMSC paracrine factors may be used for the reconstruction of large mandibular bone defects following tumor resection.

A Novel Endoscopic Bariatric Procedure: Results of an Experimental Study.

BACKGROUND: Surgical treatment of obesity is characterized by both early and late complications, and thus, there is a need to develop safe and non-invasive techniques. Ghrelin is an orexigenic hormone produced by the fundus of the stomach, which may represent a novel target for obesity management. Unfortunately, numerous attempts to alter ghrelin levels have failed to present significant clinical results. We describe a novel procedure that involves modifying arterial blood flow to the gastric fundus for limiting plasma ghrelin levels. METHODS: A gastroscope was advanced into the gastric fundus of 13 healthy Yorkshire swine, and the fundus was clipped under direct visualization to restrict left gastric artery blood flow. Body weights and ghrelin levels were recorded before and once a week for 4 weeks after the procedure. RESULTS: Compared to controls, gastroscopic clipping of the fundus decreased plasma ghrelin levels and prevented further weight gain in the 4 weeks of follow-up. Immunohistochemistry and histomorphometry revealed reduced numbers of ghrelin-positive cells in the fundus of experimental animals. We also observed thrombosis in submucosal arteries and submucosal fibrosis. Histological studies demonstrated minimal gastric mucosal injury. CONCLUSION: Gastroscopic clipping of the fundus in an experimental porcine model resulted in sustained weight loss and a reduction in plasma ghrelin levels at 1 month post-procedure, with no adverse events. Further experimental studies in human patients are needed to examine the clinical utility of this procedure and to optimize a technique, which can facilitate adequate weight loss while minimizing the risk of mucosal injury.

Phase 1 Trial of Autologous Bone Marrow Stem Cell Transplantation in Patients with Spinal Cord Injury.

Introduction. A total of 18 patients, with complete motor deficits and paraplegia caused by thoracic and lumbar spine trauma without muscle atrophy or psychiatric problems, were included into this study. Materials and Methods. The bone marrow was aspirated from the anterior iliac crest under local anesthesia and the mononuclear fraction was isolated by density gradient method. At least 750 million mononuclear-enriched cells, suspended in 2 mL of saline, were infused intrathecally. Results and Discussion. The study reports demonstrated improvement of motor and sensory functions of various degrees observed in 9 of the 18 (50%) cases after bone marrow stem cell transplantation. Measured by the American Spinal Injury Association (ASIA) scale, 7 (78%) out of the 9 patients observed an improvement by one grade, while two cases (22%) saw an improvement by two grades. However, there were no cases in which the condition was improved by three grades. Conclusions. Analysis of subsequent treatment results indicated that the transplantation of mononuclear-enriched autologous BMSCs is a feasible and safe technique. However, successful application of the BMSCs in the clinical practice is associated with the necessity of executing more detailed examinations to evaluate the effect of BMSCs on the patients with spinal cord injury.