Modified approach of regenerative treatment for distal intrabony defect beneath non-keratinized mucosa at terminal molar:A case report

BACKGROUND Intrabony defects beneath non-keratinized mucosa are frequently observed at the distal site of terminal molars.Consequently,the application of regenerative treatment using the modified wedge-flap technique is considered impractical for these specific dental conditions.CASE SUMMARY This article proposes a modified surgical procedure aimed at exposing the distal intrabony defect by making a vertical incision in the keratinized buccal gingiva.The primary objective is to maintain gingival flap stability,thereby facilitating periodontal regeneration.The described technique was successfully employed in a case involving the left mandibular second molar,which presented with an intrabony defect without keratinized gingiva at the distal site.In this case,an incision was made on the disto-buccal gingival tissue,creating a tunnel-like separation of the distal non-keratinized soft tissue to expose the intrabony defect.Subsequently,bone grafting and guided tissue regeneration surgeries were performed,resulting in satisfactory bone fill at 9 mo postoperatively.CONCLUSION This technique offers a regenerative opportunity for the intrabony defects beneath non-keratinized mucosa and is recommended for further research.

Regenerative therapy for neuronal diseases with transplantation of somatic stem cells

Pluripotent stem cells, which are capable of differentiating in various species of cells, are hoped to be donor cells in transplantation in regenerative medicine. Embryonic stem(ES) cells and induced pluripotent stem cells have the potential to differentiate in approximately all species of cells. However, the proliferating ability of these cells is high and the cancer formation ability is also recognized. In addition, ethical problems exist in using ES cells. Somatic stem cells with the ability to differentiate in various species of cells have been used as donor cells for neuronal diseases, such as amyotrophic lateral sclerosis, spinal cord injury, Alzheimer disease,cerebral infarction and congenital neuronal diseases.Human mesenchymal stem cells derived from bone marrow, adipose tissue, dermal tissue, umbilical cord blood and placenta are usually used for intractable neuronal diseases as somatic stem cells, while neural progenitor/stem cells and retinal progenitor/stem cells are used for a few congenital neuronal diseases and retinal degenerative disease, respectively. However,non-treated somatic stem cells seldom differentiate to neural cells in recipient neural tissue. Therefore, the contribution to neuronal regeneration using non-treated somatic stem cells has been poor and various differential trials, such as the addition of neurotrophic factors,gene transfer, peptide transfer for neuronal differentiation of somatic stem cells, have been performed. Here,the recent progress of regenerative therapies using various somatic stem cells is described.

Functionality of a bicistronic construction containing HEXA and HEXB genes encoding β-hexosaminidase A for cell-mediated therapy of GM2 gangliosidoses

Tay-Sachs disease and Sandhoff disease are severe hereditary neurodegenerative disorders caused by a deficiency ofβ-hexosaminidase A(HexA)enzyme,which results in the accumulation of GM2 gangliosides in the nervous system cells.In this work,we analyzed the efficacy and safety of cell-mediated gene therapy for Sandhoff disease and Sandhoff disease using a bicistronic lentiviral vector encoding cDNA of HexAα-andβ-subunit genes separated by the nucleotide sequence of a P2A peptide(HEXA-HEXB).The functionality of the bicistronic construct containing the HEXA-HEXB genetic cassette was analyzed in a culture of HEK293T cells and human umbilical cord blood mononuclear cells(hUCBMCs).Our results showed that the enzymatic activity of HexA in the conditioned medium harvested from genetically modified HEK293T-HEXA-HEXB and hUCBMCs-HEXA-HEXB was increased by 23 and 8 times,respectively,compared with the conditioned medium of native cells.Western blot analysis showed that hUCBMCs-HEXA-HEXB secreted both completely separated HEXA and HEXB proteins,and an uncleaved protein containing HEXA+HEXB linked by the P2A peptide.Intravenous injection of genetically modified hUCBMCs-HEXA-HEXB to laboratory Wistar rats was carried out,and the HexA enzymatic activity in the blood plasma of experimental animals,as well as the number of live cells of immune system organs(spleen,thymus,bone marrow,lymph nodes)were determined.A significant increase in the enzymatic activity of HexA in the blood plasma of laboratory rats on days 6 and 9(by 2.5 and 3 times,respectively)after the administration of hUCBMCsHEXA-HEXB was shown.At the same time,the number of live cells in the studied organs remained unchanged.Thus,the functionality of the bicistronic genetic construct encoding cDNA of the HEXA and HEXB genes separated by the nucleotide sequence of the P2A peptide was shown in vitro and in vivo.We hypothesize that due to the natural ability of hUCBMCs to overcome biological barriers,such a strategy can restore the activity of the missing enzyme in the central nervous system of patients with GM2 gangliosidoses.Based on the obtained data,it can be concluded that intravenous administration of hUCBMCs with HexA overexpression is a promising method of the therapy for GM2 gangliosidoses.The animal protocol was approved by the Animal Ethics Committee of the Kazan Federal University(No.23)on June 30,2020.

A Comparable Study of Combinational Regenerative Therapies Comprising Enamel Matrix Derivative plus Deproteinized Bovine Bone Mineral with or without Collagen Membrane in Periodontitis Patients with Intrabony Defects

Aim: The aim of the present study was to examine the effectiveness of collagen membrane (CM) in regenerative therapy with deproteinized bovine bone mineral (DBBM) and enamel matrix derivative (EMD) for periodontal intrabony defects. Methods: Eighteen periodontal intrabony defects of nine chronic periodontitis patients were evaluated. Two defects per patient with probing pocket depth (PPD) ≥ 6 mm were assigned to two different types of treatments: EMD + DBBM + CM or EMD + DBBM. Clinical parameters including Gingival Index (GI), PPD, clinical attachment level (CAL), gingival recession (GR), bleeding on probing (BOP), tooth mobility (MOB), and the filled bone volume/rate (FBV/FBR), which was measured by cone beam computed tomography, were compared at baseline and 12 months post-treatment. Differences between groups were determined by the chisquare test, McNemar’s test, and Wilcoxon signed-rank test. Results: Clinically, PPD, CAL, and FBR significantly improved in both groups (p Conclusion: Periodontal regenerative therapies comprising EMD and DBBM with and without CM resulted in positive clinical outcomes. The use of CM may result in better outcomes in MOB decrease;however, long-term prognosis must be further studied.

Therapeutic potential of urine-derived stem cells in renal regeneration following acute kidney injury:A comparative analysis with mesenchymal stem cells

BACKGROUND Acute kidney injury(AKI)is a common clinical syndrome with high morbidity and mortality rates.The use of pluripotent stem cells holds great promise for the treatment of AKI.Urine-derived stem cells(USCs)are a novel and versatile cell source in cell-based therapy and regenerative medicine that provide advantages of a noninvasive,simple,and low-cost approach and are induced with high multidifferentiation potential.Whether these cells could serve as a potential stem cell source for the treatment of AKI has not been determined.METHODS Stem cell markers with multidifferentiation potential were isolated from human amniotic fluid.AKI severe combined immune deficiency(SCID)mice models were induced by means of an intramuscular injection with glycerol.USCs isolated from human-voided urine were administered via tail veins.The functional changes in the kidney were assessed by the levels of blood urea nitrogen and serum creatinine.The histologic changes were evaluated by hematoxylin and eosin staining and transferase dUTP nick-end labeling staining.Meanwhile,we compared the regenerative potential of USCs with bone marrow-derived mesenchymal stem cells(MSCs).RESULTS Treatment with USCs significantly alleviated histological destruction and functional decline.The renal function was rapidly restored after intravenous injection of 5×105 human USCs into SCID mice with glycerol-induced AKI compared with injection of saline.Results from secretion assays conducted in vitro demonstrated that both stem cell varieties released a wide array of cytokines and growth factors.This suggests that a mixture of various mediators closely interacts with their biochemical functions.Two types of stem cells showed enhanced tubular cell prolif-eration and decreased tubular cell apoptosis,although USC treatment was not more effective than MSC treatment.We found that USC therapy significantly improved renal function and histological damage,inhibited inflammation and apoptosis processes in the kidney,and promoted tubular epithelial proliferation.CONCLUSION Our study demonstrated the potential of USCs for the treatment of AKI,representing a new clinical therapeutic strategy.

Use of priming strategies to advance the clinical application of mesenchymal stromal/stem cell-based therapy

Mesenchymal stromal/stem cells(MSCs)have garnered significant attention in the field of regenerative medicine due to their remarkable therapeutic potential.MSCs play a pivotal role in maintaining tissue homeostasis and possess diverse functions in tissue repair and recovery in various organs.These cells are charac-terized by easy accessibility,few ethical concerns,and adaptability to in vitro cultures,making them a valuable resource for cell therapy in several clinical conditions.Over the years,it has been shown that the true therapeutic power of MSCs lies not in cell engraftment and replacement but in their ability to produce critical paracrine factors,including cytokines,growth factors,and exosomes(EXOs),which modulate the tissue microenvironment and facilitate repair and regeneration processes.Consequently,MSC-derived products,such as condi-tioned media and EXOs,are now being extensively evaluated for their potential medical applications,offering advantages over the long-term use of whole MSCs.However,the efficacy of MSC-based treatments varies in clinical trials due to both intrinsic differences resulting from the choice of diverse cell sources and non-standardized production methods.To address these concerns and to enhance MSC therapeutic potential,researchers have explored many priming strategies,including exposure to inflammatory molecules,hypoxic conditions,and three-dimensional culture techniques.These approaches have optimized MSC secretion of functional factors,empowering them with enhanced immunomodulatory,angiogenic,and regenerative properties tailored to specific medical conditions.In fact,various priming strategies show promise in the treatment of numerous diseases,from immune-related disorders to acute injuries and cancer.Currently,in order to exploit the full therapeutic potential of MSC therapy,the most important challenge is to optimize the modulation of MSCs to obtain adapted cell therapy for specific clinical disorders.In other words,to unlock the complete potential of MSCs in regenerative medicine,it is crucial to identify the most suitable tissue source and develop in vitro manipulation protocols specific to the type of disease being treated.

A review of regenerative therapies as penile rehabilitation in men following primary prostate cancer treatment:Evidence for erectile restoration and cavernous nerve regeneration

Objective:The following article explores our evolving understandings of the role of regenerative technology as an effective penile rehabilitation tool in men with erectile dysfunction(ED)in the setting of prostate cancer(PCa)treatment and PCa survivorship.Methods:This narrative clinical review paper summarizes what is currently known about various modalities of regenerative therapy in restoring spontaneous erectile function(EF)in men following PCa treatment with an emphasis on penile rehabilitation strategies.Results:Conventional medical therapy often does not reverse underlying endothelial dysfunction or promote neuro-vasculogenesis to preserve penile health in men with ED.Over the past decade,there has been considerable interest in the role of regenerative therapy to restore endothelial dysfunction and ED without future dependency on medical therapy.Regenerative therapy can be classified into cellular-based(immunomodulators,stem cells,and platelet-rich plasma),biomaterials(nerve graft transfer),and device-related technology(low-intensity shockwave).Although published literature shows early promise in the role of regenerative technology for ED,there is a paucity of high-quality clinical trials in the setting of penile rehabilitation and PCa survivorship to support their use as standard care and be adopted in clinical guidelines.

Novel approaches for the development of peripheral nerve regenerative therapies

Schwann cells are the myelinating glial cells of the peripheral nervous system（PNS）.By establishing lipid-rich myelin sheaths around large-caliber axons,they ensure that electrical signal transmission is accelerated-a process referred to as saltatory signal propagation.Apart from this prominent physiological function,these cells also exert important pathophysiological roles in PNS injuries or dis- eases. In contrast to the central nervous system （CNS）, the adult PNS retains a remarkably high degree of intrinsic re- generation. As a consequence, transected axons and dam- aged myelin sheaths can be repaired and nerve functional- ity can be restored. This spontaneous regenerative capacity depends on （inter） actions of macrophages, neurons, and Schwann cells.

Regenerative Surgery for the Rehabilitation of a Patient after Surgery and Radiation Therapy for Head and Neck Cancer: A Case Report

Oral cancer is usually treated combining surgery, radiation therapy and chemotherapy, following effective therapeutic protocols. Severe maxillary and mandibular bone atrophy resulting after therapies are usually treated with autologous bone grafting procedures even though these techniques often present a significant risk of postoperative complications and disadvantages. We describe the case of a 59-year-old woman presenting severe bone defect after being treated with surgery and radiotherapy for recurrent oral verrucous squamous cell carcinoma. We performed bone regeneration using Platelet-Derived Growth Factors (PDGF) in combination with autologous bone chips. Our procedure of bone regeneration allowed the placement of dental implants and the achievement of a good aesthetic and functional result. Regenerative surgery may enable the regeneration of substantial bone defects. Moreover, PDGF application decreases the risk of implant failure in irradiated patients.

Recent trends in stem cell-based therapies and applications of artificial intelligence in regenerative medicine

Stem cells are undifferentiated cells that can self-renew and differentiate into diverse types of mature and functional cells while maintaining their original identity.This profound potential of stem cells has been thoroughly investigated for its significance in regenerative medicine and has laid the foundation for cellbased therapies.Regenerative medicine is rapidly progressing in healthcare with the prospect of repair and restoration of specific organs or tissue injuries or chronic disease conditions where the body’s regenerative process is not sufficient to heal.In this review,the recent advances in stem cell-based therapies in regenerative medicine are discussed,emphasizing mesenchymal stem cell-based therapies as these cells have been extensively studied for clinical use.Recent applications of artificial intelligence algorithms in stem cell-based therapies,their limitation,and future prospects are highlighted.

The Mechanism of Burn Regenerative Therapy and Wound Healing

Objective: From molecular, cell and systemic clinical treatment three levels, this report revealed the mechanism of wound healing, the basic theory and the importance of clinical practice for the Burn Regenerative Therapy with MEBT/MEBO (BRT & MEBT/MEBO).Method: This report analyzed the importance and clinical curative effect for standardized appliance of BRT & MEBT/MEBO from two key points: 1) Liquefaction of necrotic tissue from burn wound; 2) Skin regeneration in situ . Result: There are three necessary conditions for skin physiologically repair and regeneration of burn wound: 1) The formation of moist physiological environment on burn wound; 2) The material foundation of life regenerative substances and histology for keratin-19 stem cells’ regeneration in situ ; 3) Standardized procedures and appliance of BRT & MEBT/MEBO, which is the guarantee of burn wound healing physiologically. Conclusion: The theory of “Potential Regenerative Cell" and the technique of “Stem cell in situ regeneration" are the basic theory and clinical treatment for BRT. Full-thickness burn skin can be healed physiologically and the skin tissues and organs can be regenerated ONLY by standardized procedures and timely appliance of BRT & MEBT/MEBO.

Stem cells therapy for regenerative medicine:Principles of present and future practice

The characterization and isolation of various stem cell populations, from embryonic to tissue-derived stem cells and induced pluripotent stem cells (iPSCs), have led to a rapid growth in the field of stem cell research and its potentially clinical application in the field of regenerative medicine and tissue repair. Stem cell therapy has recently progressed from the preclinical to the early clinical trial arena for a variety of diseases states, although further knowledge on action mechanisms, long-term safety issues, and standardization and characterization of the therapeutic cell products remains to be thoroughly elucidated. In this paper we summarize the current state of the art of basic and clinical research that were highlighted at the 2012 meeting of the Spanish Cell Therapy Network. This includes the current research involving in genomic and transcriptomic characterization of selected stem cell populations, studies of the role of resident and transplanted stem cells during tissue regeneration and their mechanism of action, improved new strategies of tissue engineering, transplantation of mesenchymal stem cells (MSCs) in different animal models of disease, disease correction by iPSCs, and preliminary results of cell therapy in human clinical trials.

Gingival-derived mesenchymal stem cells:An endless resource for regenerative dentistry

The gingiva, the masticatory portion of the oral mucosa, is excised and discarded frequently during routine dental treatments and following tooth extraction, dental crown lengthening, gingivectomy and periodontal surgeries. Subsequent to excision, healing eventually happens in a short time period after gingival surgery. Clinically, the gingival tissue can be collected very easily and, in the laboratory, it is also very easy to isolate gingival-derived mesenchymal stem cells (GMSCs) from this discarded gingival tissue. GMSCs, a stem cell population within the lamina propria of the gingival tissue, can be isolated from attached and free gingiva, inflamed gingival tissu-es, and from hyperplastic gingiva. Comparatively, they constitute more attractive alternatives to other dental-derived mesenchymal stem cells due to the availability and accessibility of gingival tissues. They have unique immunomodulatory functions and well-documented self-renewal and multipotent differentiation properties. They display positive signals for Stro-1, Oct-4 and SSEA-4 pluripotency-associated markers, with some co-expre-ssing Oct4/Stro-1 or Oct-4/SSEA-4. They should be considered as the best stem cell source for cell-based therapies and regenerative dentistry. The clinical use of GMSCs for regenerative dentistry represents an attrac-tive therapeutic modality. However, numerous biological and technical challenges need to be addressed prior to considering transplantation approaches of GMSCs as clinically realistic therapies for humans.

Mesenchymal stem cell-derived exosomes: Toward cell-free therapeutic strategies in regenerative medicine

Mesenchymal stem cells(MSCs)are multipotent stem cells with marked potential for regenerative medicine because of their strong immunosuppressive and regenerative abilities.The therapeutic effects of MSCs are based in part on their secretion of biologically active factors in extracellular vesicles known as exosomes.Exosomes have a diameter of 30-100 nm and mediate intercellular communication and material exchange.MSC-derived exosomes(MSC-Exos)have potential for cell-free therapy for diseases of,for instance,the kidney,liver,heart,nervous system,and musculoskeletal system.Hence,MSC-Exos are an alternative to MSCbased therapy for regenerative medicine.We review MSC-Exos and their therapeutic potential for a variety of diseases and injuries.

Improved guided bone regeneration by combined application of unmodified, fresh autologous adipose derived regenerative cells and plasma rich in growth factors:A first-in-human case report and literature review

BACKGROUND Novel strategies are needed for improving guided bone regeneration(GBR) in oral surgery prior to implant placement, particularly in maxillary sinus augmentation(GBR-MSA) and in lateral alveolar ridge augmentation(LRA). This study tested the hypothesis that the combination of freshly isolated, unmodified autologous adipose-derived regenerative cells(UA-ADRCs), fraction 2 of plasma rich in growth factors(PRGF-2) and an osteoinductive scaffold(OIS)(UAADRC/PRGF-2/OIS) is superior to the combination of PRGF-2 and the same OIS alone(PRGF-2/OIS) in GBR-MSA/LRA.CASE SUMMARY A 79-year-old patient was treated with a bilateral external sinus lift procedure as well as a bilateral lateral alveolar ridge augmentation. GBR-MSA/LRA was performed with UA-ADRC/PRGF-2/OIS on the right side, and with PRGF-2/OIS on the left side. Biopsies were collected at 6 wk and 34 wk after GBRMSA/LRA. At the latter time point implants were placed. Radiographs(32 mo follow-up time) demonstrated excellent bone healing. No radiological or histological signs of inflammation were observed. Detailed histologic,histomorphometric, and immunohistochemical analysis of the biopsies evidenced that UA-ADRC/PRGF-2/OIS resulted in better and faster bone regeneration than PRGF-2/OIS.CONCLUSION GBR-MSA with UA-ADRCs, PRGF-2, and an OIS shows effectiveness without adverse effects.

Adipose stromal/stem cells in regenerative medicine:Potentials and limitations

This article presents the stem and progenitor cells from subcutaneous adipose tissue,briefly comparing them with their bone marrow counterparts,and discussing their potential for use in regenerative medicine.Subcutaneous adipose tissue differs from other mesenchymal stromal/stem cells(MSCs)sources in that it contains a pre-adipocyte population that dwells in the adventitia of robust blood vessels.Pre-adipocytes are present both in the stromal-vascular fraction(SVF;freshly isolated cells)and in the adherent fraction of adipose stromal/stem cells(ASCs;in vitro expanded cells),and have an active role on the chronic inflammation environment established in obesity,likely due their monocyticmacrophage lineage identity.The SVF and ASCs have been explored in cell therapy protocols with relative success,given their paracrine and immunomodulatory effects.Importantly,the widely explored multipotentiality of ASCs has direct application in bone,cartilage and adipose tissue engineering.The aim of this editorial is to reinforce the peculiarities of the stem and progenitor cells from subcutaneous adipose tissue,revealing the spheroids as a recently described biotechnological tool for cell therapy and tissue engineering.Innovative cell culture techniques,in particular 3D scaffold-free cultures such as spheroids,are now available to increase the potential for regeneration and differentiation of mesenchymal lineages.Spheroids are being explored not only as a model for cell differentiation,but also as powerful 3D cell culture tools to maintain the stemness and expand the regenerative and differentiation capacities of mesenchymal cell lineages.

Current status of cell-mediated regenerative therapies for human spinal cord injury

During the past decade, significant advances have been made in refinements for regenerative therapies following human spinal cord injury （SCI）. Positive results have been achieved with different types of cells in various clinical studies of SCI. In this review, we summarize recently-completed clinical trials using cell- mediated regenerative therapies for human SCI, together with ongoing trials using neural stem cells. Specifically, clinical studies published in Chinese journals are included. These studies show that current transplantation therapies are relatively safe, and have provided varying degrees of neurological recovery. However, many obstacles exist, hindering the introduction of a specific clinical therapy, including complications and their causes, selection of the target population, and optimization of transplantation material. Despite these and other challenges, with the collaboration of research groups and strong support from various organizations, cell-mediated regenerative therapies will open new perspectives for SCI treatment.

Melatonin,tunneling nanotubes,mesenchymal cells,and tissue regeneration

Mesenchymal stem cells are multipotent stem cells that reside in many human tissues and organs.Mesenchymal stem cells are widely used in experimental and clinical regenerative medicine due to their capability to transdifferentiate into various lineages.However,when transplanted,they lose part of their multipotency and immunomodulatory properties,and most of them die after injection into the damaged tissue.In this review,we discuss the potential utility of melatonin in preserving mesenchymal stem cells’survival and function after transplantation.Melatonin is a pleiotropic molecule regulating critical cell functions including apoptosis,endoplasmic reticulum stress,and autophagy.Melatonin is also synthesized in the mitochondria where it reduces oxidative stress,the opening of the mitochondrial permeability transition pore and the downstream caspase activation,activates uncoupling proteins,and curtails the proinflammatory response.In addition,recent findings showed that melatonin also promotes the formation of tunneling nanotubes and the transfer of mitochondria between cells through the connecting tubules.As mitochondrial dysfunction is a primary cause of mesenchymal stem cells death and senescence and a critical issue for survival after transplantation,we propose that melatonin by favoring mitochondria functionality and their transfer through tunneling nanotubes from healthy to suffering cells could improve mesenchymal stem cellbased therapy in a large number of diseases for which basic and clinical trials are underway.

Mesenchymal stem cells in ischemic tissue regeneration

Diseases caused by ischemia are one of the leading causes of death in the world.Current therapies for treating acute myocardial infarction,ischemic stroke,and critical limb ischemia do not complete recovery.Regenerative therapies opens new therapeutic strategy in the treatment of ischemic disorders.Mesenchymal stem cells(MSCs)are the most promising option in the field of cell-based therapies,due to their secretory and immunomodulatory abilities,that contribute to ease inflammation and promote the regeneration of damaged tissues.This review presents the current knowledge of the mechanisms of action of MSCs and their therapeutic effects in the treatment of ischemic diseases,described on the basis of data from in vitro experiments and preclinical animal studies,and also summarize the effects of using these cells in clinical trial settings.Since the obtained therapeutic benefits are not always satisfactory,approaches aimed at enhancing the effect of MSCs in regenerative therapies are presented at the end.

Single-Center Study of 83 Horses with Suspensory Injuries Treated with Adipose-Derived Stem and Regenerative Cells

Adipose-derived stem and regenerative cells (ADRCs), concentrated from autologous fat tissue, have the ability to differentiate into various specific cell types including tenocytes. In this retrospective study, clinical data are presented from 83 horses with 176 suspensory ligament injuries, treated with ADRCs, given a strictly enforced standardized rehabilitation program, and followed up for at least one year after returning to work. Assessment for a successful outcome was return to full work (RFW) at a previous or higher level of performance for one year or more without re-injury. RFW numbers were 84.6% for horses with fore-limb ligament injuries and 82.1% for horses with hind-limb injuries. RFW outcomes were slightly better in cases with proximal suspensory ligament desmitis (86.7%) compared to horses with lesions of the body and branches. The ADRC injection procedure was well tolerated;no treatment-related adverse events, including injection flares, were detected in any of the 83 horses. The demonstrated long term stability of healed lesions strongly supports the therapeutic use of regenerative cells extracted from adipose tissue for treatment of acute and chronic, fore- and hind-limb suspensory ligament injuries in horses of various athletic sport disciplines.