Freeze-Dried Mesenchymal Stem Cells: From Bench to Bedside. Review

This review describes the freeze-dried mesenchymal stem cells (MSCs) and their ability to restore damaged tissues and organs. An analysis of the literature shows that after the lyophilization MSCs retain >80% of paracrine factors and that the mechanism of their action on the restoration of damaged tissues and organs is similar to the mechanism of action of paracrine factors in fresh and cryopreserved mesenchymal stem cells. Based on the own materials, the use of paracrine factors of freeze-dried MSCs in vivo and in vitro for the treatment of various diseases of organs and tissues has shown to be effective. The study also discusses about the advantages and disadvantages of freeze-dried MSCs versus cryopreserved MSCs. However, for the effective use of freeze-dried MSCs in clinical practice, a more detailed study of the mechanism of interaction of paracrine factors of freeze-dried MSCs with target cells and tissues is required. It is also necessary to identify possible other specific paracrine factors of freeze-dried MSCs. In addition, develop new therapeutic strategies for the use of freeze-dried MSCs in regenerative medicine and tissue bioengineering.

Intravital tumor decellularization as a new approach to cancer treatment

This study demonstrates the possibility of tumor decellularization in living animals. Subcutaneous Ehrlich tumor induced by isolated Ehrlich ascitic carcinoma cells in mice was used as a model. The study also presents methods for ex vivo decellularization of human gastric adenocarcinoma (HGA) and hepatocellular carcinoma (HCC) induced by diethylnitrosamine (DEN) in rat. Sodium dodecyl sulfate (SDS) and Triton X-100 were used as detergents for tumor decellularization. The detergents for HGA and HCC were administered through organ vessels. For intravital decellularization of Ehrlich's subcutaneous tumor, detergents were injected directly into the tumor parenchyma. The results of the study showed that the effectiveness of tumor decellularization using SDS and Triton X-100 depended on the size, structure, stiffness and density of the tumor, as well as on the concentration, route and speed of detergent administration. The study also showed that an hour after the initiation of decellularization, the central part of Ehrlich's tumor changed the color, and after three hours, it completely acquired a translucent white color. Chemical contamination of tissues surrounding the tumor with the detergents was not observed. Histological studies showed the complete absence of all cellular components of Ehrlich's tumor and a slightly deformed extracellular matrix (ECM). There were no loco-regional recurrences or metastases of Ehrlich's tumor within 150 days after decellularization. The developed intravital decellularization method allows the effective removal of the cellular components and the DNA content of Ehrlich's subcutaneous tumor without compromising animal health. Additionally, this method can destroy tumor ECM, which will significantly improve the delivery of anticancer drugs to the tumor cells. However, more detailed and extensive studies are needed to develop an in vivo technique for isolated decellularization of the tumor or a part of the organ with the tumor. It is also necessary to identify less toxic decellularization agents and to develop the most efficient route for their delivery to the tumor cells.

Challenges and Opportunities Associated With Drug Delivery for the Treatment of Solid Tumors

In this review, we discuss the effectiveness of drug delivery system based on metal nanoparticles, and also, describe the problems associated with their delivery to tumor cells. Throughout recent years, more reports have appeared in the literature that demonstrate promising results for the treatment of various types of cancer using metal-based nanoparticles. Due to their unique physical and chemical properties, metal nanoparticles are effectively being used for the delivery of drug to the tumor cells, for cancer diagnosis and treatment. They can also be synthesized allowing the control of size and shape. However, the effectiveness of the metal nanoparticles for cancer treatment largely depends on their stability, biocompatibility, and ability to selectively affect tumor cells after their systemic or local administration. Another major problem associated with metal nanoparticles is their ability to overcome tumor tissue barriers such as atypical blood vessel structure, dense and rigid extracellular matrix, and high pressure of tumor interstitial fluid. The review also describes the design of tumor drug delivery systems that are based on metal nanoparticles. The mechanism of action of metal nanoparticles on cancer cells is also discussed. Considering the therapeutic safety and toxicity of metal nanoparticles, the prospects for their use for future clinical applications are being currently reviewed.

Multifunctional hybrid hydrogel for the prevention of post-surgery tumor recurrence

In this study, we present a multifunctional hybrid hydrogel (MFHH) for the prevention of postoperative tumor recurrence. MFHH consists of two components; component A - containing a gelatin-based cisplatin, which destroys the residual cancer after surgery, and component B - containing macroporous gelatin microcarriers (CultiSpher) loaded with freeze-dried bone marrow stem cells (BMSCs), which activates the wound healing process. We also evaluated the effects of MFHH in a subcutaneous Ehrlich tumor mouse model. MFHH acted as a local delivery system by directly supplying cisplatin to the tumor environment, resulting in excellent anti-cancer effects and minimal side effects. MFHH released cisplatin gradually to destroy the residual tumors, thereby preventing loco-regional recurrence. We have also demonstrated that BMSCs are able to inhibit residual tumor growth. Moreover, CultiSpher loaded with BMSCs acted as an injection 3D scaffold and easily filled the wound defect formed by tumor removal, and the paracrine factors of the freeze-dried BMSCs accelerated the wound healing process. The components of the MFHH can be used both separately and together. However, for the successful application of MFHH in clinical practice, it is necessary to study in more detail the role of paracrine factors of freeze-dried BMSCs in the inhibition or proliferation of residual cancer. These questions will be the focus of our future research.

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.

RECONSTRUCTION OF THE ABDOMINAL WALL DEFECTS USING GELATIN-COATED DECELLULARIZED AND LYOPHILIZED HUMAN AMNIOTIC MEMBRANE

Ventral hernias, with the incidence of reherniation nearly as high as 50%, still remain to be a real challenge for surgeons worldwide. The use of mesh in the repair of abdominal wall defects reduces the incidence of reherniation; however, using a prosthetic mesh can lead to complications like wound infection, hematoma, seroma, enterocutaneous fistula, small bowel obstruction, recurrent herniation and erosion into adjacent structures including the intestine. The aim of the study was to develop a method for producing gelatin-coated decellularized and lyophilized human amniotic membrane graft and to determine its effectiveness for the reconstruction of the anterior abdominal wall defects. Experiments were conducted on 40 Lewis white laboratory rats. Animals were divided into four equivalent groups. Abdominal wall defects were created in all rats and repaired using the ULTRAPROTM mesh (group I), ULTRAPROTM mesh which was covered by decellularized and lyophilized human amniotic membrane from both sides (group II), mesh from gelatin-coated decellularized and lyophilized human amniotic membrane (group III) and biological surgical mesh XI-S+® (group IV). Three months after implantation, meshes from gelatin-coated decellularized and lyophilized human amniotic membrane were integrated with host tissues so that it was difficult to distinguish it from the surrounding tissues. However, in the second group, ULTRAPROTM mesh was still detectable through the decellularized amniotic membrane. Encouraging results were also observed when using a XI-S+® graft. Three months after implantation, XI-S+® graft was surrounded by a well-defined connective tissue capsule and was tightly fixed to the host tissues. While using gelatin-coated decellularized and lyophilized human amniotic membrane grafts and XI-S+® grafts, all the defects were repaired successfully and none of the rats in these groups showed any evidence of bulging or herniation, development of wound rupture, wound infection or fistula formation in postoperative period. Gelatin-coated Decellularized human amniotic membrane can be used as anti-adhesive barrier in abdominal and pelvic surgery, as well as for the repair of the abdominal wall hernia.

EVALUATION OF NOVEL PORCINE PERICARDIAL BIOMATERIAL FOR VENTRAL AND INGUINAL HERNIA REPAIR. THE RESULTS OF A NON-RANDOMIZED CLINICAL TRIAL

Using the mesh for hernia repair is the most common type of hernia surgery. There are many types of meshes made of various synthetic materials, but all of these meshes have their own respective disadvantages. The aim of this study was to provide preliminary results of a non-randomized clinical trial evaluation of novel porcine grafts XI-S+® (Colorado Therapeutics LLC. USA) for ventral and inguinal hernia repair. All patients underwent a standardized surgical procedure. Onlay surgical repair technique has been performed in ten patients with ventral hernia and Lichtenstein tension-free method has been used for ten patients with inguinal hernia repair. The XI-S+® mesh fixation was performed with multiple simple interrupted sutures using prolene thread. The average age of the patients with ventral hernia was 54±14 years, and 30% of patients were female and 70% of patients were male. The average age of the patients with inguinal hernia was 62.5±9.4 years, and 10% of patients were female and 90% of patients were male. The average hospitalization length was 2 days. During three years of observation, no recurrence of hernia was observed in patients. The XI-S + ® mesh has anti-adhesive properties, is extremely resistant to infections, provides favorable conditions for engraftment, early activity and patient rehabilitation. The clinical studies of the patients that underwent ventral and inguinal hernia repair using XI-S+® mesh have shown that the post-operative pain was minimal and easily controlled by the use of analgesics. As for the sensation of the mesh, in some patients it has been present up until 1 month from surgery, but it fully disappeared by the end of the 3rd month.

RELATIONSHIP BETWEEN ORAL SQUAMOUS CELL CARCINOMA AND IMPLANTS (REVIEW)

In this review, we have discussed the relationships between oral squamous cell carcinoma (OSCC) and dental implants. In the last decade, dental implants have been widely used for the treatment of complete or partial edentulism. Despite the fact that they have seen incredible success and the use of dental implants increases, concerns over safety and efficiency is rising as well. The literature analysis has shown that the number of reported cases when the OSCC development is associated with peri implantitis is gradually increasing. The possibility of squamous cell carcinoma development must be considered when evaluating the peri-implantitis. We highly recommend periodic oral and radiographic examination after the implant placement. The patients with peri-implantitis that do not respond to conventional treatment methods, and the patients who have a severe or rapid progression of peri-implantitis require biopsy. The histopathological examination will aid with the differential diagnosis between peri-implantitis and OSCC, and hence, provide the correct diagnosis.

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.