Local delivery of platelet-derived factors mitigates ischemia and preserves ovarian function through angiogenic modulation: A personalized regenerative strategy for fertility preservation.

As the most prominent and ideal modality in female fertility preservation, ovarian tissue cryopreservation, and transplantation often confront the challenge of ischemic damage and follicular loss from avascular transplantation. To surmount this impediment, we engineered a novel platelet-derived factors-encapsulated fibrin hydrogel (PFH), a paradigmatic biomaterial. PFH encapsulates autologous platelet-derived factors, utilizing the physiological blood coagulation cascade for precise local delivery of bioactive molecules. In our study, PFH markedly bolstered the success of avascular ovarian tissue transplantation. Notably, the quantity and quality of follicles were preserved with improved neovascularization, accompanied by decreased DNA damage, increased ovulation, and superior embryonic development rates under a Low-concentration Platelet-rich plasma-derived factors encapsulated fibrin hydrogel (L-PFH) regimen. At a stabilized point of tissue engraftment, gene expression analysis mirrored normal ovarian tissue profiles, underscoring the effectiveness of L-PFH in mitigating the initial ischemic insult. This autologous blood-derived biomaterial, inspired by nature, capitalizes on the blood coagulation cascade, and combines biodegradability, biocompatibility, safety, and cost-effectiveness. The adjustable properties of this biomaterial, even in injectable form, extend its potential applications into the broader realm of personalized regenerative medicine. PFH emerges as a promising strategy to counter ischemic damage in tissue transplantation, signifying a broader therapeutic prospect. (197 words).

Mitochondrial 'Birth-Death' coordinator: An intelligent hydrogen nanogenerator to enhance intervertebral disc regeneration.

Currently, mitochondrial dysfunction caused by oxidative stress is a growing concern in degenerative diseases, notably intervertebral disc degeneration (IVDD). Dysregulation of the balance of mitochondrial quality control (MQC) has been considered the key contributor, while it's still challenging to effectively harmonize different MQC components in a simple and biologically safe way. Hydrogen gas (H2) is a promising mitochondrial therapeutic molecule due to its bio-reductivity and diffusibility across cellular membranes, yet its relationship with MQC regulation remains unknown. Herein, we propose a mitochondrial 'Birth-Death' coordinator achieved by an intelligent hydrogen nanogenerator (Fe@HP-OD), which can sustainably release H2 in response to the unique microenvironment in degenerated IVDs. Both in vitro and in vivo results prove alleviation of cellular oxidative stress and restoration of nucleus pulposus cells function, thereby facilitating successful IVD regeneration. Significantly, this study for the first time proposes the mitochondrial 'Birth-Death' coordination mechanism: 1) attenuation of overactivated mitochondrial 'Death' process (UPRmt and unselective mitophagy); and 2) activation of Adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling pathway for mitochondrial 'Birth-Death' balance (mitochondrial biogenesis and controlled mitophagy). These pioneering findings can fill in the gaps in molecular mechanisms for H2 regulation on MQC homeostasis, and pave the way for future strategies towards restoring equilibrium of MQC system against degenerative diseases.

Advanced therapy with mesenchymal stromal cells for knee osteoarthritis: Systematic review and meta-analysis of randomized controlled trials.

Background: Advanced cell therapies emerged as promising candidates for treatment of knee articular diseases, but robust evidence regarding their clinical applicability is still lacking. Objective: To assess the efficacy and safety of advanced mesenchymal stromal cells (MSC) therapy for knee osteoarthritis (OA) and chondral lesions. Methods: Systematic review of randomized controlled trials conducted in accordance with Cochrane Handbook and reported following PRISMA checklist. GRADE approach was used for assessing the evidence certainty. Results: 25 randomized controlled trials that enrolled 1048 participants were included. Meta-analyses data showed that, compared to viscosupplementation (VS), advanced MSC therapy resulted in a 1.91 lower pain VAS score (95 % CI -3.23 to -0.59; p < 0.00001) for the treatment of knee OA after 12 months. Compared to placebo, the difference was 0.99 lower pain VAS points (95 % CI -1.94 to -0.03; p = 0.76). According to the GRADE approach, the evidence was very uncertain for both comparisons. By excluding studies with high risk of bias, there was a similar size of effect (VAS MD -1.54, 95 % CI -2.09 to -0.98; p = 0.70) with improved (moderate) certainty of evidence, suggesting that MSC therapy probably reduces pain slightly better than VS. Regarding serious adverse events, there was no difference from advanced MSC therapy to placebo or to VS, with very uncertain evidence. Conclusion: Advanced MSC therapy resulted in lower pain compared to placebo or VS for the treatment of knee OA after 12 months, with no difference in adverse events. However, the evidence was considered uncertain. The Translational Potential of this Article: Currently, there is a lack of studies with good methodological structure aiming to evaluate the real clinical impact of advanced cell therapy for knee OA. The present study was well structured and conducted, with Risk of Bias, GRADE certainty assessment and sensitivity analysis. It explores the translational aspect of the benefits and safety of MSC compared with placebo and gold-standard therapy to give practitioners and researchers support to expand this therapy in their practice. PROSPERO registration number: CRD42020158173. Access at https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=158173.

Rejuvenation of human mesenchymal stem cells using a nonintegrative and conditionally removable Sendai virus vector.

Human mesenchymal stem cells (hMSCs) with extended lifespan and differentiation potential that can recapitulate in vivo characteristics could significantly contribute to basic research, drug development, and cell therapy. Specifically, they could ensure a stable supply of specific cellular resources, and possibly extracellular vesicles. Here, we established a technology for extending the lifespan while maintaining differentiation potential, termed "rejuvenation," of hMSCs (rej-hMSCs) using nonintegrative and conditionally removable temperature-sensitive Sendai virus (SeV) vectors. Various immortalizing factors (i.e., Bmi-1, hTERT, SV40T, and/or HPV E6/E7) were first introduced by the SeV vector into the cells. A combination of three SeVs with Bmi-1, hTERT, or SV40T conferred markedly improved cell proliferation and cloning ability while maintaining differentiation potential and a normal karyotype. An extended lifespan was also demonstrated in other cell types. The rejuvenation of long-passaged or aged hMSCs was also confirmed. SeV vectors were rapidly removed as a function of cell doubling by increasing the temperature from 35 °C to 37 °C or higher, while proliferative ability was maintained. Following FACS sorting, the complete removal of SeV vectors was confirmed by qPCR analyses. Therefore, our cell rejuvenation technology could contribute to research and clinical applications by enabling the supply of modified cells without damaging host chromosomes.

Preparing the soil: Adjusting the metabolic health of patients with chronic wounds and musculoskeletal diseases.

In recent years, systemic inflammation has emerged as a pivotal player in the development and progression of various degenerative diseases. This complex, chronic inflammatory state, often undetected, can have far-reaching consequences for the body's physiology. At the molecular level, markers such as C-reactive protein, cytokines and other inflammatory mediators serve as indicators of systemic inflammation and often act as predictors of numerous musculoskeletal diseases and even certain forms of cancer. The concept of 'meta-inflammation', specifically referring to metabolically triggered inflammation, allows healthcare professionals to understand inflammatory responses in patients with metabolic syndrome. Driven by nutrient excess and the expansion of adipose tissue, meta-inflammation is closely associated with insulin resistance, further propagating the metabolic dysfunction observed in many Western societies. Wound persistence, on the other hand, exacerbates the detrimental effects of prolonged inflammation at the local level. Acute inflammation is a beneficial and essential process for wound healing and infection control. However, when inflammation fails to resolve, it can impede the healing process, leading to chronic wounds, excessive scarring and even the activation of fibrotic pathways. This approach significantly reduces the efficacy of regenerative biological therapies. Our review focuses on the vital role of proteins, vitamins and minerals in collagen synthesis and cell proliferation for tissue healing. We also examine hormonal influences on regeneration, noting the negative effects of imbalances, and emphasize glucose regulation's importance in creating a stable environment for chronic wound healing.

Negative cell cycle regulation by calcineurin is necessary for proper beta cell regeneration in zebrafish.

Stimulation of pancreatic beta cell regeneration could be a therapeutic lead to treat diabetes. Unlike humans, the zebrafish can efficiently regenerate beta cells, notably from ductal pancreatic progenitors. To gain insight into the molecular pathways involved in this process, we established the transcriptomic profile of the ductal cells after beta cell ablation in the adult zebrafish. These data highlighted the protein phosphatase calcineurin (CaN) as a new potential modulator of beta cell regeneration. We showed that CaN overexpression abolished the regenerative response, leading to glycemia dysregulation. On the opposite, CaN inhibition increased ductal cell proliferation and subsequent beta cell regeneration. Interestingly, the enhanced proliferation of the progenitors was paradoxically coupled with their exhaustion. This suggests that the proliferating progenitors are next entering in differentiation. CaN appears as a guardian which prevents an excessive progenitor proliferation to preserve the pool of progenitors. Altogether, our findings reveal CaN as a key player in the balance between proliferation and differentiation to enable a proper beta cell regeneration.

Bioreactor-produced iPSCs-derived dopaminergic neuron-containing neural microtissues innervate and normalize rotational bias in a dose-dependent manner in a Parkinson rat model.

A breadth of preclinical studies now support the rationale of pluripotent stem cell-derived cell replacement therapies to alleviate motor symptoms in Parkinsonian patients. Replacement of the primary dysfunctional cell population in the disease, i.e. the A9 dopaminergic neurons, is the major focus of these therapies. To achieve this, most therapeutical approaches involve grafting single-cell suspensions of DA progenitors. However, most cells die during the transplantation process, as cells face anoïkis. One potential solution to address this challenge is to graft solid preparations, i.e. adopting a 3D format. Cryopreserving such a format remains a major hurdle and is not exempt from causing delays in the time to effect, as observed with cryopreserved single-cell DA progenitors. Here, we used a high-throughput cell-encapsulation technology coupled with bioreactors to provide a 3D culture environment enabling the directed differentiation of hiPSCs into neural microtissues. The proper patterning of these neural microtissues into a midbrain identity was confirmed using orthogonal methods, including qPCR, RNAseq, flow cytometry and immunofluorescent microscopy. The efficacy of the neural microtissues was demonstrated in a dose-dependent manner using a Parkinsonian rat model. The survival of the cells was confirmed by post-mortem histological analysis, characterised by the presence of human dopaminergic neurons projecting into the host striatum. The work reported here is the first bioproduction of a cell therapy for Parkinson's disease in a scalable bioreactor, leading to a full behavioural recovery 16 weeks after transplantation using cryopreserved 3D format.

Autologous Conditioned Serum in Knee Osteoarthritis: A Systematic Review of Current Clinical Evidence.

Knee osteoarthritis (OA) significantly impacts global health, causing pain, disability, and socioeconomic burden. Traditional treatments often provide only temporary relief and can have adverse effects. Autologous conditioned serum (ACS) therapy, which enriches a patient's own blood with growth factors and anti-inflammatory cytokines, has emerged as a promising approach to manage knee OA, potentially offering pain reduction, improved function, and tissue regeneration. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched databases such as PubMed, Web of Science, and Cochrane using terms like "Autologous Conditioned Serum" and "knee osteoarthritis." Clinical studies were selected based on their focus on ACS's efficacy in knee OA, assessing outcomes like pain relief, functional improvement, and adverse events. Eighteen studies met the inclusion criteria, including randomized controlled trials, observational studies, and comparative analyses. The review included a wide range of study designs and outcomes, highlighting ACS's efficacy in reducing pain and enhancing knee function as evidenced by various patient-reported outcome measures Visual Analog Scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Society Clinical Rating Score (KSCRS) with a follow-up of up to 11 years (range: 2-11 years). Comparative studies showed ACS to be as effective or superior to conventional treatments such as platelet-rich plasma, steroids, and hyaluronic acid, especially in cases of moderate synovitis. Minimal adverse effects such as peri-injection pain, rigidity, synovitis, transient sensation of redness/heat, and numbness in the knee/leg/toes were reported, underscoring ACS's safety. Some studies suggested ACS might also have disease-modifying effects, contributing to tissue repair and integrity. ACS therapy offers a promising alternative for knee OA management, demonstrating potential benefits in symptom alleviation, functional improvement, and safety. Indications of disease-modifying properties further highlight its therapeutic value. However, the need for standardized formulations and treatment protocols, long-term studies, and mechanistic understanding remain. Future research should focus on addressing these gaps to fully elucidate ACS's role in the treatment landscape of knee OA.

Selected stem cell populations in pediatric acute lymphoblastic leukemia.

Introduction: Acute lymphoblastic leukemia is characterized by a disturbed maturation of hematopoietic stem cells (HSCs) resulting in development of a malignant clone. Despite relatively positive outcome, there are still instances of disease relapse occurring due to ineffective disease eradication or primary leukemic clone alterations. Unclear significance of stem cells in the course of ALL led us to investigate and establish crucial changes in two stem cell populations - very small embryonic-like stem cells (VSELs) and HSCs during the induction phase of treatment. Methods: In a retrospective study selected stem cells in peripheral blood and bone marrow of 60 pediatric ALL subjects and 48 healthy controls were subjected to flow cytometric analysis at 4 different time points. Results: Both VSELs and HSCs were elevated at the moment of ALL diagnosis compared to healthy controls, but profoundly decline until day 15. Further observations revealed an increase in HSCs with a concomitant depletion of VSELs until week 12. ALL patients with high HSCs showed positive correlation with bone marrow blasts at diagnosis. Patients with lower VSELs or HSCs at diagnosis had slightly improved response to applied therapy. We observed higher initial bone marrow lymphoblast values in patients with lower VSELs or higher HSCs in the high-risk group. The significance of VSELs in predicting treatment outcome can be illustrated by lower day 15 MRD level of patients with lower VSELs at diagnosis. Discussion: We found HSCs and VSELs to be valid participants in pediatric ALL with possible contribution in the neoplastic process and prediction of initial treatment outcome.

Vitamin C, doxycycline, and azithromycin (VDA) targeted changes in cellular senescence-related genes in human adipose-derived mesenchymal stem cells.

Objectives: Adipose-derived Mesenchymal stem cells (ASCs) have garnered attention for their regenerative potential; therefore, their cellular senescence-related gene expression remains crucial in therapeutic contexts. Nowadays, combination therapies have shown promising results in reducing senescent cells. This study investigated the effects of vitamin C, doxycycline, and azithromycin co-treatment on the key cellular senescence-associated genes in ASCs. Materials and Methods: Human ASCs were cultured and treated for 24 hr with vitamin C, doxycycline, azithromycin, and a combination of three drugs. Total RNAs were extracted, and the expression of p21, p16, Nanog, Oct4, and Sox2 genes was assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Additionally, cell cycle alterations were analyzed via flow cytometry after treatment with these compounds. Results: Notably, vitamin C treatment resulted in a significant down-regulation of p21 gene expression (P<0.01), implicating the potential role of vitamin C in promoting cell cycle progression. Doxycycline treatment led to a significant up-regulation of p21 and p16 gene expression (P<0.05), as it has previously been shown to induce cell cycle arrest. Similarly, azithromycin treatment predominantly increased p21 expression (P<0.05). Besides, cell cycle analysis revealed that each compound had changed the distribution of cells across different phases of the cell cycle. Conclusion: The combined use of all three drugs yielded intricate interactions, suggesting a complex yet promising approach to future research. According to our findings, the major difference in the combination drug-treated group (VDA) can be explained by the neutralizing effect of these three components in the environment.

Mechanotransduction, cellular biophotonic activity, and signaling patterns for tissue regeneration.

Signaling molecules exhibit mechanical oscillations, entailing precise vibrational directionalities. These steering signatures have profound functional implications, and are intimately connected with the onset of molecular electric oscillations and biophoton emission. We discuss biophotonic activity as a form of endogenous photobiomodulation, orchestrating the mechano-sensing/-transduction in signaling players. We focus on exogenous photobiomodulation in the form of pulsed wave modulation of selected light wavelengths to direct endogenous biophotonic activity and molecular cellular dynamics. We highlight the relevance of this strategy to target and reprogram the developmental potential of tissue resident stem cells in damaged tissues, affording a precision regenerative medicine without the needs for cell or tissue transplantation.

Past Trends and Future Directions of Cardiac Regenerative Medicine - A Systematic Analysis of Clinical Trial Registries.

Cell therapy, gene therapy, and tissue engineering have been explored as potential strategies to repair or regenerate damaged cardiac tissue. Despite the presence of encouraging preclinical data, clinical trials of regenerative cardiac therapies have yielded mixed results. Our study aimed to investigate the fate of all registered clinical trials within regenerative cardiac medicine, with the purpose of exploring the potential role of publication bias (or trial-completion bias), how published and unpublished research affects the field, and to draw lessons and recommendations for future clinical trials. In this analysis, we show that only a third of all registered trials has yielded results and that a significant number of trials are not completed. Furthermore, we identified significant heterogeneity in study design, study phase, funding, specific therapies used, primary outcome measures and methods of outcome assessment. These observations might hinder the successful translation of cardiac regenerative therapies into clinical practice.

Effects of human amniotic membrane on the angiogenesis and healing of ischemic wounds in a rat model.

Although the human amniotic membrane (hAM) has been demonstrated to promote angiogenesis, its efficacy in healing ischemic wounds remains unknown. Therefore, the current study aimed to evaluate the potential of hAM as a dressing for treating ischemic wounds. The inferior abdominal wall arteries and veins of male rats were divided, and an ischemic wound was created on each side of the abdominal wall. Of the two ischemic wounds created, only one was covered with hAM, and its wound healing effect was determined by measuring the wound area. Angiogenesis was assessed by measuring microvessel density (MVD). On day 5, the mean wound area changed from 400 mm2 to 335.4 (260-450) mm2 in the hAM group and to 459 (306-570) mm2 in the control group (p = 0.0051). MVD was 19.0 (10.4-24.6) in the hAM group and 15.1 (10.6-20.8) in the control group (p = 0.0026). No significant differences in local pro- and anti-inflammatory cytokine levels were observed between the two groups. Histological examination revealed no rejection of the transplanted hAM. Therefore, the hAM may serve as a novel wound dressing that can promote angiogenesis and healing in ischemic wounds.

Advances in Tissue Engineering and Its Future in Regenerative Medicine Compared to Traditional Reconstructive Techniques: A Comparative Analysis.

Tissue engineering represents a revolutionary approach in regenerative medicine, offering promising alternatives to traditional reconstructive techniques. This systematic review explores recent advances in tissue engineering, comparing their efficacy, postoperative outcomes, and patient satisfaction to conventional methods. A comprehensive literature search was conducted across PubMed, Cochrane Library, and Google Scholar, covering studies published from 2000 to 2024. Fourteen studies were selected for final analysis based on inclusion criteria focusing on outcomes such as scar quality, postoperative pain, and patient satisfaction. The review demonstrated that tissue engineering techniques consistently provided superior cosmetic outcomes with minimal scarring compared to traditional methods. Patients undergoing tissue-engineered procedures experienced mild-to-moderate postoperative pain with rapid resolution, whereas traditional techniques resulted in moderate to severe pain requiring extended management. Furthermore, patients treated with tissue engineering reported high satisfaction rates due to improved cosmetic and functional outcomes. Despite challenges such as ensuring adequate vascularization, controlling scaffold degradation, and overcoming regulatory and cost barriers, ongoing research and development are essential to fully realize the potential of these innovative therapies. Tissue engineering offers significant advantages over traditional reconstructive techniques and has the potential to profoundly improve patient care in regenerative medicine.

Regenerative treatment of canine osteogenic lesions with Platelet-Rich Plasma and hydroxyapatite: a case report.

Introduction: This study examined the efficacy of a therapy based on a combination of Platelet Rich Plasma and hydroxyapatite nanoparticles in a severe clinical case involving a young Rottweiler with a complex spiral fracture of the tibia. Method: Following a worsening of the lesion after traditional surgical intervention, the subject was treated with the combined therapy. X-rays were taken at the following stages: immediately post-surgery, four weeks post-surgery, and 10 days post-treatment. Fracture gap and callus density measurements were obtained using ImageJ analysis, allowing for a detailed quantitative assessment of bone regeneration over time. Results: Post-operative radiographs indicated a clinical worsening of the fracture, revealing an increased fracture gap due to bone loss. However, significant improvements were observed ten days following the treatment, with a marked reduction in fracture gaps and increased callus density. These results demonstrated a notable acceleration in bone healing and callus formation compared to typical recovery times for similar lesions. Conclusion: The method showed potential for enhancing osteogenic regeneration, facilitating faster healing of serious orthopedic injuries compared to traditional methods.

Development of HEMA-Succinic Acid-PEG Bio-Based Monomers for High-Performance Hydrogels in Regenerative Medicine.

In recent years, hydrogels have found a special place in regenerative medicine for tissue repair, rehabilitation, and drug delivery. To be used in regenerative medicine, hydrogels must have desirable physical, chemical, and biological properties. In this study, a new biomonomer based on hydroxyethyl methacrylate-succinic acid-polyethylene glycol 200 (HEMA-Suc-PEG) was synthesized and characterized. Then, using the synthesized monomers and different ratios of polyethylene glycol diacrylate (PEGDA) as a crosslinker, biocompatible hydrogels were synthesized through thermal and UV curing methods. The mechanical, physical, chemical, and biological properties of the hydrogels and the behavior of endothelial cells, an essential component of the cardiovascular system, were evaluated. The results showed that the hydrogel synthesized with 0.2 g of PEGDA (UV curing) has desirable mechanical and physical properties. Biological tests showed that these hydrogels are not only nontoxic to cells but also enhance cell adhesion. Therefore, the hydrogel containing the synthesized monomer HEMA-Suc-PEG and 0.2 g of PEGDA has the potential to be used in the cardiovascular system.

Regenerative Medicine in Orthopedic Surgery: Expanding Our Toolbox.

Regenerative medicine leverages the body's inherent regenerative capabilities to repair damaged tissues and address organ dysfunction. In orthopedics, this approach includes a variety of treatments collectively known as orthoregeneration, encompassing modalities such as prolotherapy, extracorporeal shockwave therapy, pulsed electromagnetic field therapy, therapeutic ultrasound, and photobiomodulation therapy, and orthobiologics like platelet-rich plasma and cell-based therapies. These minimally invasive techniques are becoming prominent due to their potential for fewer complications in orthopedic surgery. As regenerative medicine continues to advance, surgeons must stay informed about these developments. This paper highlights the current state of regenerative medicine in orthopedics and advocates for further clinical research to validate and expand these treatments to enhance patient outcomes.

Aging: Disease or "natural" process? A glimpse from regenerative medicine.

We explore aging as a global phenomenon, questioning whether it constitutes a treatable condition or follows a natural course. Acknowledging its multifactorial nature, we delve into the challenges and opportunities inherent in this intricate biological process. The inclusion of old age in the 11th International Classification of Diseases sparks debate, categorizing it as a disease based on mechanistic explanations, blood-based biomarkers, and anti-aging products. Ethical dilemmas arise, emphasizing the difficulty of defining the transition from normal to pathological states during this process. We suggest that aging should be regarded as a treatable condition without necessarily labeling it a 'disease.' While anti-aging research unveils promising interventions like Metformin, Rapamycin, and cellular therapy, achieving biological immortality remains a formidable challenge. The future promises to prolong life and enhance quality by comprehensively understanding aging's implications for human health.