Experimental bladder regeneration using a poly-l-lactide/silk fibroin scaffold seeded with nanoparticle-labeled allogenic bone marrow stromal cells

The Use of Mesenchymal Stem Cells in the Complex Treatment of Kidney Tuberculosis (Experimental Study)

In recent years, the application of mesenchymal stem cells (MSCs) has been recognized as a promising method for treatment of different diseases associated with inflammation and sclerosis, which include nephrotuberculosis. The aim of our study is to investigate the effectiveness of MSCs in the complex therapy of experimental rabbit kidney tuberculosis and to evaluate the effect of cell therapy on the reparative processes. Methods: To simulate kidney tuberculosis, a suspension of the standard strain Mycobacterium tuberculosis H37Rv (10⁶ CFU) was used, which was injected into the cortical layer of the lower pole parenchyma of the left kidney under ultrasound control in rabbits. Anti-tuberculosis therapy (aTBT) was started on the 18th day after infection. MSCs (5 × 10⁷ cells) were transplanted intravenously after the start of aTBT. Results: 2.5 months after infection, all animals showed renal failure. Conducted aTBT significantly reduced the level of albumin, ceruloplasmin, elastase and the severity of disorders in the proteinase/inhibitor system and increased the productive nature of inflammation. A month after MSC transplantation, the level of inflammatory reaction activity proteins decreased, the area of specific and destructive inflammation in kidneys decreased and the formation of mature connective tissue was noted, which indicates the reparative reaction activation.

Iron Oxide Nanoparticles in Regenerative Medicine and Tissue Engineering

In recent years, many promising nanotechnological approaches to biomedical research have been developed in order to increase implementation of regenerative medicine and tissue engineering in clinical practice. In the meantime, the use of nanomaterials for the regeneration of diseased or injured tissues is considered advantageous in most areas of medicine. In particular, for the treatment of cardiovascular, osteochondral and neurological defects, but also for the recovery of functions of other organs such as kidney, liver, pancreas, bladder, urethra and for wound healing, nanomaterials are increasingly being developed that serve as scaffolds, mimic the extracellular matrix and promote adhesion or differentiation of cells. This review focuses on the latest developments in regenerative medicine, in which iron oxide nanoparticles (IONPs) play a crucial role for tissue engineering and cell therapy. IONPs are not only enabling the use of non-invasive observation methods to monitor the therapy, but can also accelerate and enhance regeneration, either thanks to their inherent magnetic properties or by functionalization with bioactive or therapeutic compounds, such as drugs, enzymes and growth factors. In addition, the presence of magnetic fields can direct IONP-labeled cells specifically to the site of action or induce cell differentiation into a specific cell type through mechanotransduction.

Bilayer Scaffolds for Interface Tissue Engineering and Regenerative Medicine: A Systematic Reviews

PURPOSE

This systematic review focus on the application of bilayer scaffolds as an engaging structure for the engineering of multilayered tissues, including vascular and osteochondral tissues, skin, nerve, and urinary bladder. This article provides a concise literature review of different types of bilayer scaffolds to understand their efficacy in targeted tissue engineering.

METHODS

To this aim, electronic search in the English language was performed in PMC, NBCI, and PubMed from April 2008 to December 2019 based on the PRISMA guidelines. Animal studies, including the "bilayer scaffold" and at least one of the following items were examined: osteochondral tissue, bone, skin, neural tissue, urinary bladder, vascular system. The articles which didn't include "tissue engineering" and just in vitro studies were excluded.

RESULTS

Totally, 600 articles were evaluated; related articles were 145, and 35 full-text English articles met all the criteria. Fifteen articles in soft tissue engineering and twenty items in hard tissue engineering were the results of this exploration. Based on selected papers, it was revealed that the bilayer scaffolds were used in the regeneration of the multilayered tissues. The highest multilayered tissue regeneration has been achieved when bilayer scaffolds were used with mesenchymal stem cells and differentiation medium before implanting. Among the studies being reported in this review, bone marrow mesenchymal stem cells are the most studied mesenchymal stem cells. Among different kinds of multilayer tissue, the bilayer scaffold has been most used in osteochondral tissue engineering in which collagen and PLGA have been the most frequently used biomaterials. After osteochondral tissue engineering, bilayer scaffolds were widely used in skin tissue engineering.

CONCLUSION

The current review aimed to manifest the researcher and surgeons to use a more sophisticated bilayer scaffold in combinations of appropriate stem cells, and different can improve multilayer tissue regeneration. This systematic review can pave a way to design a suitable bilayer scaffold for a specific target tissue and conjunction with proper stem cells.

Almost 40 Years of Tissue Engineering in Russia: Where Are We Now?

This review describes achievements of Russian cell-based regenerative medicine in different periods of time depending on the legislation and politics, and future prospects for its commercialization and wide application with an emphasis on products devised for skin regeneration. The world’s experience in tissue engineering began with the development of living skin equivalents, utilizing a biopolymer matrix and cells at the very beginning of the 1980s. During this period, the USSR kept abreast with the times and also conducted studies on skin wound healing, implementing modern cell techniques. However, there soon emerged a gap between scientific advancement and practical application. After the breakup of the USSR, there were no institutions that could implement scientific inventions into full-scale manufacturing for clinical application. At the same time, accumulating scientific and practical experience allowed for the maintenance of biomedical research and its readiness for market entry at present. Recently developed legislation opens up new opportunities in this field in Russia. There are a growing number of studies on the development of novel products for regenerative medicine, bringing hope for its rapid progress.

Review of clinical experience on biomaterials and tissue engineering of urinary bladder

PURPOSE

In recent pre-clinical studies, biomaterials and bladder tissue engineering have shown promising outcomes when addressing the need for bladder tissue replacement. To date, multiple clinical experiences have been reported. Herein, we aim to review and summarize the reported clinical experience of biomaterial usage and tissue engineering of the urinary bladder.

METHODS

A systematic literature search was performed on Feb 2019 to identify clinical reports on biomaterials for urinary bladder replacement or augmentation and clinical experiences with bladder tissue engineering. We identified and reviewed human studies using biomaterials and tissue-engineered bladder as bladder substitutes or augmentation implants. The studies were then summarized for each respective procedure indication, technique, follow-up period, outcome, and important findings of the studies.

RESULTS

An extensive literature search identified 25 studies of case reports and case series with a cumulative clinical experience of 222 patients. Various biomaterials and tissue-engineered bladder were used, including plastic/polyethylene mold, preserved dog bladder, gelatine sponge, Japanese paper with Nobecutane, lypholized human dura, bovine pericardium, amniotic membrane, small intestinal mucosa, and bladder tissue engineering with autologous cell-seeded biodegradable scaffolds. However, overall clinical experiences including the outcomes and safety reports were not satisfactory enough to replace enterocystoplasty.

CONCLUSION

To date, several clinical experiences of biomaterials and tissue-engineered bladder have been reported; however, various studies have reported non-satisfactory outcomes. Further technological advancements and a better understanding is needed to advance bladder tissue engineering as a future promising management option for patients requiring bladder drainage.

Incorporation of nanoparticles into transplantable decellularized matrices: Applications and challenges

Decellularization of tissues can significantly improve regenerative medicine and tissue engineering by producing natural, less immunogenic, three-dimensional, acellular matrices with high biological activity for transplantation. Decellularized matrices retain specific critical components of native tissues such as stem cell niche, various growth factors, and the ability to regenerate in vivo. However, recellularization and functionalization of these matrices remain limited, highlighting the need to improve the characteristics of decellularized matrices. Incorporating nanoparticles into decellularized tissues can overcome these limitations because nanoparticles possess unique properties such as multifunctionality and can modify the surface of decellularized matrices with additional growth factors, which can be loaded onto the nanoparticles. Therefore, in this minireview, we highlight the various approaches used to improve decellularized matrices with incorporation of nanoparticles and the challenges present in these applications.

Evaluation of the temporary effect of physical vapor deposition silver coating on resistance to infection in transdermal skin and bone integrated pylon with deep porosity

Periprosthetic infection via skin-implant interface is a leading cause of failures and revisions in direct skeletal attachment of limb prostheses. Implants with deep porosity fabricated with skin and bone integrated pylons (SBIP) technology allow for skin ingrowth through the implant's structure creating natural barrier against infection. However, until the skin cells remodel in all pores of the implant, additional care is required to prevent from entering bacteria to the still nonoccupied pores. Temporary silver coating was evaluated in this work as a means to provide protection from infection immediately after implantation followed by dissolution of silver layer in few weeks. A sputtering coating with 1 µm thickness was selected to be sufficient for fighting infection until the deep ingrowth of skin in the porous structure of the pylon is completed. In vitro study showed less bacterial (Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa) growth on silver coated tablets compared to the control group. Analysis of cellular density of MG-63 cells, fibroblasts, and mesenchymal stem cells (MSCs) showed that silver coating did not inhibit the cell growth on the implants and did not affect cellular functional activity. The in vivo study did not show any postoperative complications during the 6-month observation period in the model of above-knee amputation in rabbits when SBIP implants, either silver-coated or untreated were inserted into the bone residuum. Three-phase scintigraphy demonstrated angiogenesis in the pores of the pylons. The findings suggest that a silver coating with well-chosen specifications can increase the safety of porous implants for direct skeletal attachment. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 169-177, 2019.

Application of the allogenic mesenchymal stem cells in the therapy of the bladder tuberculosis

Urogenital tuberculosis (TB) often leads to contraction of the bladder, a reduction of the urinary reservoir capacity, and, in the latest stage, to real microcystitis up to full obliteration. Bladder TB Stage 4 is unsuitable for conservative therapy, and cystectomy with subsequent enteroplasty is indicated. In this study, using a model of bladder TB in New Zealand rabbits, the therapeutic efficacy of the interstitial injection of autologous bone-derived mesenchymal stem cells (MSCs) combined with standard anti-TB treatment in the restoration of the bladder function was demonstrated. For analysis of the MSC distribution in tissues, the latter were labelled with superparamagnetic iron oxide nanoparticles. In vitro studies demonstrated the high intracellular incorporation of nanoparticles and the absence of cytotoxicity on MSC viability and proliferation. A single-dose administration of MSCs into the bladder mucosal layer significantly reduced the wall deformation and inflammation and hindered the development of fibrosis, which was proven by the subsequent histological assay. Confocal microscopy studies of the bladder cryosections confirmed the presence of superparamagnetic iron oxide nanoparticle-labelled MSCs in different bladder layers of the treated animals, thus indicating the role of stem cells in bladder regeneration.

Stromal Cell-Derived Factor-1 Accelerates Cartilage Defect Repairing by Recruiting Bone Marrow Mesenchymal Stem Cells and Promoting Chondrogenic Differentiation<sup/>

Chemokine stromal cell-derived factor-1 (SDF-1) is a powerful chemoattractant for the localization of CXCR4-positive bone marrow mesenchymal stem cells (BMSCs) into the bone marrow. We studied the effects of SDF-1 on the cartilage defect repair by recruiting BMSCs and promoting its chondrogenic differentiation in vitro and in vivo. Chemotaxis analysis with Transwell plate showed that SDF-1 could recruit BMSCs through SDF-1/CXCR4 axis. Real-time polymerase chain reaction, enzyme-linked immunosorbent assays, and Western blot results suggested that the levels of type II collagen and GAG were increased after incubating BMSCs with SDF-1 compared with the without SDF-1 group. More positive BrdU-labeled BMSCs were detected at the cartilage defect region in the SDF-1 + poly [lactide-co-glycolide] (PLGA) scaffold group (SP) in which those animals showed a smooth and transparent cartilage tissue with a strong staining of toluidine blue and type II collagen compared with the no-SDF-1 groups. ICRS score suggested that the repair effect in the SDF-1 + PLGA-treated animals was improved compared with PLGA scaffold group alone at 4 and 8 weeks after surgery; the repair effect from the SDF + PLGA-treated animals was significantly improved compared with the PLGA alone at 12 weeks after surgery. Our in vitro and in vivo results indicated the following: (1) SDF-1 could recruit the BMSCs into cartilage defect area. (2) SDF-1 induces BMSCs expressing type II collagen and GAG, which may accelerate the BMSCs transforming into chondrocytes under the cartilage microenvironment in vivo. (3) PLGA scaffold attached with SDF-1 remarkably promoted the cartilage defect repairing. The defected cartilage was filled with transparent cartilage 12 weeks after the surgery, which shared a similar structure with the adjacent normal cartilage. Taken together, this research provides a new strategy for cartilage defect repairing.

Adipose-derived stem cells-seeded bladder acellular matrix graft-silk fibroin enhances bladder reconstruction in a rat model

The unfavourable clinical outcomes of host cell-seeded scaffolds for bladder augmentation warrant improved bioactive biomaterials. This study aimed to examine the feasibility of adipose-derived stem cells (ASCs)-seeded bilayer bladder acellular matrix graft (BAMG)-silk fibroin (SF) scaffold in enhancing bladder reconstruction. Sprague Dawley rats were randomly divided into three groups: the BAMG-SF-ASCs group, the acellular BAMG-SF group and the cystotomy group. The BAMG-SF-ASCs group was sampled at 2, 4 and 12 weeks, and compared with the other groups at 12 weeks. In the BAMG-SF-ASCs group, the normal bladder contour was reformed similar to that in the cystotomy group, with abundant urothelium and smooth muscle regeneration, as well as a suitable scaffold degradation speed, and trivial fibrosis and inflammation. The ASCs seeded in BAMG-SF were maintained in the regenerated region during the 12-week experimental period and significantly enhanced the vessel density, nerve regeneration and bladder function compared with acellular BAMG-SF. In addition, the BAMG-SF-ASCs group presented elevated levels of SDF-1α, VEGF and their receptors, with an obvious increase in ERK 1/2 phosphorylation. BAMG-SF is a promising biomaterial for ASCs seeding to facilitate bladder augmentation and demonstrated an enhanced angiogenic potential possibly related to the SDF-1α/CXCR4 pathway via ERK 1/2 activation.

The morphological regeneration and functional restoration of bladder defects by a novel scaffold and adipose-derived stem cells in a rat augmentation model

Background

Due to the multilineage differentiation ability and paracrine role of adipose-derived stem cells (ASCs) for bladder defect repair, various scaffolds have been applied in combination with ASCs to promote bladder regeneration and restore bladder function. However, the low survival rate of ASCs and the difficulty of promoting bladder functional recovery are still unsolved. To explore these problems, we investigated the feasibility of a novel scaffold seeded with ASCs in a rat model of bladder augmentation.

Methods

A novel autologous myofibroblast (AM)-silk fibroin (SF) scaffold was harvested after subcutaneously prefabricating the bladder acellular matrix grafts (BAMG) and SF by removing the BAMG. The AM-SF scaffolds were then seeded with ASCs (AM-SF-ASCs). Fifty percent supratrigonal cystectomies were performed followed by augmenting the cystectomized defects with AM-SF scaffolds or AM-SF-ASCs. The histological and functional assessments of bladders were performed 2, 4, and 12 weeks after surgery while the ASCs were tracked in vivo.

Results

For bladder tissue regeneration, immunofluorescence analysis revealed that AM-SF-ASCs (the experimental group) promoted better morphological regeneration of the urothelium, vessels, bladder smooth muscle, and nerve than AM-SF scaffolds (the control group). Regarding functional restoration, the AM-SF-ASC group exhibited higher bladder compliance and relatively normal micturition pattern compared to the AM-SF group. In addition, a certain number of surviving ASCs could be found in vivo 12 weeks after implantation, and some of them had differentiated into smooth muscle cells.

Conclusions

The AM-SF scaffolds with ASCs could rapidly promote bladder morphological regeneration and improved bladder urinary function. In addition, the bag-shaped structure of the AM-SF scaffold can improve the survival of ASCs for at least 12 weeks. This strategy of AM-SF-ASCs has a potential to repair large-scale bladder defects in the clinic in the future.

Effect of PET graft coated with silk fibroin via EDC/NHS crosslink on graft-bone healing in ACL reconstruction

SF coating via EDC/NHS crosslink improved the osseointegration of PET ligaments within the bone tunnel.