Engineered stem cell-based strategy: A new paradigm of next-generation stem cell product in regenerative medicine

Natural bioactive compounds modified with mesenchymal stem cells: new hope for regenerative medicine

Mesenchymal stem cells (MSCs) have the potential to differentiate into various cell types, providing important sources of cells for the development of regenerative medicine. Although MSCs have various advantages, there are also various problems, such as the low survival rate of transplanted cells and poor migration and homing; therefore, determining how to reform MSCs to improve their utilization is particularly important. Although many natural bioactive compounds have shown great potential for improving MSCs, many mechanisms and pathways are involved; however, in the final analysis, natural bioactive compounds promoted MSC proliferation, migration and homing and promoted differentiation and antiaging. This article reviews the regulatory effects of natural bioactive compounds on MSCs to provide new ideas for the therapeutic effects of modified MSCs on diseases.

Sequential activation of osteogenic microenvironment via composite peptide-modified microfluidic microspheres for promoting bone regeneration

The osteogenic microenvironment (OME) significantly influences bone repair; however, reproducing its dynamic activation and repair processes remains challenging. In this study, we designed injectable porous microspheres modified with composite peptides to investigate cascade alterations in OME and their underlying mechanisms. Poly l-lactic acid microfluidic microspheres underwent surface modifications through alkaline hydrolysis treatment, involving heterogeneous grafting of bovine serum albumin nanoparticles with stem cell-homing peptides (BNP@SKP) and BMP-2 mimicking peptides (P24), respectively. These modifications well-organized the actions of initial release and subsequent in situ grafting of peptides. Cellular experiments demonstrated varied degrees of chemotactic recruitment and osteogenic differentiation in mesenchymal stem cells. Further biological analysis revealed that BNP@SKP targeted the Ras/Erk axis and upregulated matrix metalloproteinase (MMP)2 and MMP9 expression, thereby enhancing initial chemotaxis and recruitment. In vivo studies validated the establishment of a dynamically regulated OME centered on the microspheres, resulting in increased stem cell recruitment, sequential activation of the differentiation microenvironment, and facilitation of in situ osteogenesis without ectopic ossification. In conclusion, this study successfully fabricated composite peptide-modified microspheres and systematically explored the mechanisms of bone formation through sequential activation of OME via heterogeneous grafting of signaling molecules. This provides theoretical evidence for biomaterials based on microenvironment regulation.

Evaluating teratoma formation risk of pluripotent stem cell-derived cell therapy products: a consensus recommendation from the Health and Environmental Sciences Institute's International Cell Therapy Committee

Human pluripotent stem cells (hPSCs) can differentiate into any cell of choice and hold significant promise in regenerative medicine and for treating diseases that currently lack adequate therapies. However, hPSCs are intrinsically tumorigenic and can form teratomas. Therefore, the presence of residual undifferentiated hPSCs must be rigorously assessed using sensitive methodologies to mitigate the potential tumorigenicity risks of hPSC-derived cell therapy products (CTPs). In this comprehensive review, we describe methods for detecting residual undifferentiated hPSCs and discuss the relative value of current in vitro assays versus conventional in vivo assays. We highlight that in vitro assays such as digital PCR detection of hPSC-specific RNA and the highly efficient culture assay, have superior detection sensitivity. Additionally, we outline important considerations for validating in vitro assays when applying them to assess each product. This article lays the groundwork for guiding internationally harmonized procedures for evaluating the potential teratoma formation risk of hPSC-derived CTPs and increasing confidence in the safety of these products.

Advances in clinical translation of stem cell-based therapy in neurological diseases

Stem cell-based therapies have raised considerable interest to develop regenerative treatment for neurological disorders with high disability. In this review, we focus on recent preclinical and clinical evidence of stem cell therapy in the treatment of degenerative neurological diseases and discuss different cell types, delivery routes and biodistribution of stem cell therapy. In addition, recent advances of mechanistic insights of stem cell therapy, including functional replacement by exogenous cells, immunomodulation and paracrine effects of stem cell therapies are also demonstrated. Finally, we also highlight the adjunction approaches that has been implemented to augment their reparative function, survival and migration to target specific tissue, including stem cell preconditioning, genetical engineering, co-transplantation and combined therapy.

Engineered MSCs Break Endothelial-Myofibroblast Crosstalk in Pulmonary Fibrosis: Reconstructing the Vascular Niche

In the progress of pulmonary fibrosis (PF), the normal vascular niche plays a crucial role in alveolar regeneration by secreting angiocrine factors. However, the malignant interaction between myofibroblasts and vascular endothelial cells results in significant loss of pulmonary capillaries in fibroblast foci, which promotes continuous deterioration of fibrosis. Herein, an engineered mesenchymal stem cell (MSC) therapeutic named MSC-MM@LPHN is developed for reconstructing the vascular niche, which is formed by modifying the surface of MSC with ROS-responsive lipid polymeric hybrid nanoparticles encapsulating the metformin and macitentan. Due to the homing ability of MSC, the MSC-MM@LPHN can effectively target lung tissue, then induce myofibroblast dedifferentiation to reduce the secretion of cytokines that cause endothelial cell damage and preventing endothelial cells from turning into a fibrotic phenotype, leading to recovery of the vascular endothelial cells function. Combined with the role of MSC-secreted growth factors promoting angiogenesis, the MSC-MM@LPHN ultimately constructs normal vascular structure in the fibroblast area and reverses bleomycin-induced PF. The findings suggest targeting the cell network in the vascular niche can effectively treat PF, which provides a novel therapeutic strategy for fibrosis-related diseases.

Engineered Stem Cell Booster Breaks Pathological Barriers to Treat Chronic Pancreatitis

Chronic pancreatitis (CP) is a long-standing progressive fibrosis and has long been considered incurable, which remains a heavy health burden worldwide. Mesenchymal stem cells (MSCs) with anti-fibrosis properties are currently used in the treatment of fibroinflammatory diseases. However, its therapeutic effect is limited mainly due to two main types of pathological barriers in CP: 1) Fibrotic collagen hinders cell delivery, and 2) Malignant microenvironment attacks cell inactivation. Here, a MSCs-based exogenous nitric oxide (NO) delivery system (MSCs-Lip@RNO) is constructed. In the MSCs-Lip@RNO, NO not only can be a cell booster to regulate collagen fibers, relieve the vascular compression and enhance the accumulation of MSCs in the whole pancreas, but also can form a protective gas layer on the cell surface, which enhances the therapeutic effect of MSCs. In the CP rat model, the pancreatic injury and fibrosis are reduced with 7 days after a single dose administration of this long-acting MSCs. Collectively, this study offers a promising strategy for enhancing the delivery and therapeutic efficacy of MSCs to break pathological barriers in CP treatment.

New considerations in selecting donors for dental pulp stem cells: a pilot study

BACKGROUND/PURPOSE

Tissue engineering based on stem cell therapy necessitates a substantial quantity of high-quality stem cells. However, current sources face limitations, including narrow donor pools, compromised biological properties due to cryopreservation, and cellular senescence resulting from in vitro passaging and expansion. This study examines the impact of mild periodontitis on the biological performance of dental pulp stem cells (DPSCs) to explore the potential of broadening the donor pool for these cells.

MATERIALS AND METHODS

The experiment included two variables: age and the presence of periodontitis. DPSCs were isolated from six healthy subjects and six patients with mild periodontitis. Healthy subjects were categorized into Groups A (28-32 years) and B (52-54 years), and patients with mild periodontitis were categorized into Groups C (31-33 years) and D (50-53 years). The analyses included cell morphology, proliferation rate, multilineage differentiation capacity, apoptosis, and surface marker expression.

RESULT

No significant differences in cell morphology, pluripotency, or senescence were observed between healthy controls and periodontitis patients across age groups. Additionally, data on proliferation, pluripotency, and senescence were not significantly different. In healthy subjects, increased age was correlated with more elongated, flattened, and broader cells, alongside greater heterogeneity and intercellular granules. The proliferation and differentiation capacities decreased, whereas the degree of apoptosis increased. Similar trends were noted in patients with periodontitis.

CONCLUSION

The biological properties of DPSCs remain unchanged in teeth with mild periodontitis, providing valuable insights for addressing the shortage of DPSCs in tissue engineering. Teeth with mild periodontitis have the potential to be pulp stem cell donors.

Advancement of Nanomaterials- and Biomaterials-Based Technologies for Wound Healing and Tissue Regenerative Applications

Patients and healthcare systems face significant social and financial challenges due to the increasing number of individuals with chronic external and internal wounds that fail to heal. The complexity of the healing process remains a serious health concern, despite the effectiveness of conventional wound dressings in promoting healing. Recent advancements in materials science and fabrication techniques have led to the development of innovative dressings that enhance wound healing. To further expedite the healing process, novel approaches such as nanoparticles, 3D-printed wound dressings, and biomolecule-infused dressings have emerged, along with cell-based methods. Additionally, gene therapy technologies are being harnessed to generate stem cell derivatives that are more functional, selective, and responsive than their natural counterparts. This review highlights the significant potential of biomaterials, nanoparticles, 3D bioprinting, and gene- and cell-based therapies in wound healing. However, it also underscores the necessity for further research to address the existing challenges and integrate these strategies into standard clinical practice.

Polydopamine-functionalized nanohydroxyapatite coated exosomes with enhanced cytocompatibility and osteogenesis for bone regeneration

BackgroundMesenchymal stem cells-derived exosomes, crucial in regenerative medicine, have been explored for their potential for the functional modification of bone scaffolds.ObjectiveTo design a functionally modified biomimetic nanohydroxyapatite using exosomes and explore its effects on bone regeneration.MethodsA biomimetic nanohydroxyapatite (named as tHA) was fabricated as previous methods using a polydopamine (pDA) structure as a template, and exosomes (Exo) derived from periodontal ligament stem cells (PDLSCs) were used to functionally modify the tHA scaffold material through pDA. The effects of functional composite scaffold (tHA-Exo) on cells proliferation and osteogenic differentiation were investigated. Furthermore, their effect on bone regeneration was also evaluated in vivo.ResultsExosomes can be loaded onto the tHA via pDA and the tHA-Exo releases exosomes in a sustained and stable manner. tHA-Exo showed improved cytocompatibility compared to controls. Additionally, tHA-Exo significantly enhanced the proliferation and osteogenic differentiation of PDLSCs. More importantly, animal experiments have shown that tHA-Exo could dramatically promote bone regeneration.ConclusionThe tHA nanoparticles, functionally modified by the PDLSCs-Exo through pDA, significantly promoted bone regeneration by improving its cytocompatibility and osteogenic potential, which could serve as a promising material for promoting bone regeneration.

Programmable short peptides for modulating stem cell fate in tissue engineering and regenerative medicine

Recent advancements in tissue engineering and regenerative medicine have introduced promising strategies to address tissue and organ deficiencies. This review highlights the critical role of short peptides, particularly their ability to self-assemble into matrices that mimic the extracellular matrix (ECM). These low molecular weight peptides exhibit target-specific activities, modulate gene expression, and influence cell differentiation pathways. They are stable, programmable, non-cytotoxic, biocompatible, biodegradable, capable of crossing the cell membrane and easy to synthesize. This review underscores the importance of peptide structure and concentration in directing stem cell differentiation and explores their diverse biomedical applications. Peptides such as Aβ1-40, Aβ1-42, RADA16, A13 and KEDW are discussed for their roles in modulating stem cell differentiation into neuronal, glial, myocardial, osteogenic, hepatocyte and pancreatic lineages. Furthermore, this review delves into the underlying signaling mechanisms, the chemistry and design of short peptides and their potential for engineering biocompatible materials that mimic stem cell microenvironments. Short peptide-based biomaterials and scaffolds represent a promising avenue in stem cell therapy, tissue engineering, and regenerative medicine.

Association of Sexual Health and Mental Health in Erectile Dysfunction: Expert Opinion From the Indian Context

Erectile dysfunction (ED) is a common condition in men, driven by a complex interplay of organic, relational, and psychological factors, necessitating an integrated treatment approach. Psychological factors, such as anxiety, depression, and stress, are significant contributors to erectile problems. Erectile dysfunction can have severe psychological consequences, including feelings of emasculation, humiliation, reduced self-confidence, isolation, loneliness, and a decline in overall well-being. A national advisory board comprising 12 experts from India, including 9 urologists and 3 psychiatrists, convened to discuss a multidisciplinary approach to the treatment of ED. Using a modified Delphi method and literature review, the 34 panels developed evidence-based insights. Experts highlighted the importance of thorough assessments of sexual dysfunction in patients. Given the frequent comorbidity of mental health issues with ED, physicians should proactively explore patients' sexual and mental health. Creating a secure and welcoming environment is crucial for these assessments. Physicians should gather detailed information on psychological symptoms, stressors, relationship dynamics, cognitive style, and distractions. Experts highlighted the importance of thorough diagnostic assessments and recommended a multidisciplinary approach integrating pharmacological interventions (e.g., phosphodiesterase-5 inhibitors) with psychometric therapy, tailored to the age, existing comorbidities, and underlying causes of ED. A balanced, interdisciplinary approach incorporating psychosexual therapy, lifestyle modifications, and advanced therapies is crucial for the holistic management of ED. Key consensus recommendations also emphasized fostering open communication between patients and healthcare providers, routine mental health screenings in patients with ED, and early referrals to specialists when necessary. Clinicians should actively involve mental health professionals in the management of ED and prioritize individualized treatment strategies tailored to each patient's needs. This multifactorial condition requires coordinated efforts to address both organic and psychogenic causes, restore patients' quality of life, and promote open communication. By proactively engaging with patients, addressing their concerns, and facilitating referrals as needed, clinicians can significantly improve outcomes for patients with ED.

Unveiling the molecular blueprint of SKP-SCs-mediated tissue engineering-enhanced neuroregeneration

Peripheral nerve injury poses a significant challenge to the nervous system's regenerative capacity. We previously described a novel approach to construct a chitosan/silk fibroin nerve graft with skin-derived precursor-induced Schwann cells (SKP-SCs). This graft has been shown to promote sciatic nerve regeneration and functional restoration to a level comparable to that achieved by autologous nerve grafts, as evidenced by behavioral, histological, and electrophysiological assessments. However, the underlying molecular mechanisms based on SKP-SCs mediated tissue engineering-aid regeneration remain elusive. In the present work, we systematically identified gene modules associated with the differentiation of SKPs into SCs by employing weighted gene co-expression network analysis (WGCNA). By integrating transcriptomic data from the regenerated nerve segment, we constructed a network that delineated the molecular signatures of TENG aid neuroregeneration. Subsequent quantitative PCR (qPCR) validation was performed to substantiate the WGCNA findings. Our WGCNA approach revealed a robust molecular landscape, highlighting hub genes pivotal for tissue engineering-aid regeneration. Notably, the upregulation of specific genes was observed to coincide with the acquisition of SC characteristics. The qPCR validation confirmed the expression patterns of these genes, underscoring their role in promoting neuroregeneration. The current study harnesses the power of WGCNA to elucidate the molecular blueprint governing tissue engineering-aid regeneration. The identified gene modules and validated targets offer novel insights into the cellular and molecular underpinnings of tissue engineering-augmented neuroregeneration. These findings pave the way for developing targeted therapeutics and advanced tissue engineering grafts to enhance peripheral nerve repair.

Advances in drug delivery systems utilizing blood cells and their membrane-derived microvesicles

The advancement of drug delivery systems (DDSs) in recent decades has demonstrated significant potential in enhancing the efficacy of pharmacological agents. Despite the approval of certain DDSs for clinical use, challenges such as rapid clearance from circulation, toxic accumulation in the body, and ineffective targeted delivery persist as obstacles to successful clinical application. Blood cell-based DDSs have emerged as a popular strategy for drug administration, offering enhanced biocompatibility, stability, and prolonged circulation. These DDSs are well-suited for systemic drug delivery and have played a crucial role in formulating optimal drug combinations for treating a variety of diseases in both preclinical studies and clinical trials. This review focuses on recent advancements and applications of DDSs utilizing blood cells and their membrane-derived microvesicles. It addresses the current therapeutic applications of blood cell-based DDSs at the organ and tissue levels, highlighting their successful deployment at the cellular level. Furthermore, it explores the mechanisms of cellular uptake of drug delivery vectors at the subcellular level. Additionally, the review discusses the opportunities and challenges associated with these DDSs.

Modulating Fibrotic Mechanical Microenvironment for Idiopathic Pulmonary Fibrosis Therapy

Idiopathic pulmonary fibrosis (IPF) is exacerbated by injurious mechanical forces that destabilize the pulmonary mechanical microenvironment homeostasis, leading to alveolar dysfunction and exacerbating disease severity. However, given the inherent mechanosensitivity of fibrotic lungs, where type II alveolar epithelial cells (AEC IIs) are subjected to persistent stretching and overactivated myofibroblasts experience malignant interactions during mechanotransduction, it becomes imperative to develop effective strategies to modulate the pulmonary mechanical microenvironment. Herein, cyclo (RGDfC) peptide-decorated zeolitic imidazolate framework-8 nanoparticles (named ZDFPR NPs) are constructed to target and repair the aberrant mechanical force levels in pathological lungs. Specifically, reduces mechanical tension in AEC IIs by pH-responsive ZDFPR NPs that release zinc ions and 7, 8-dihydroxyflavone to promote alveolar repair and differentiation. Meanwhile, malignant interactions between myofibroblast contractility and extracellular matrix stiffness during mechanotransduction are disrupted by the fasudil inhibition ROCK signaling pathway. The results show that ZDFPR NPs successfully restored pulmonary mechanical homeostasis and terminated the fibrosis process in bleomycin-induced fibrotic mice. This study not only presents a promising strategy for modulating pulmonary mechanical microenvironment but also pioneers a novel avenue for IPF treatment.

Surface-engineered mesenchymal stem cell for refractory asthma therapy: Reversing airway remodeling

In the development of asthma, subepithelial fibrosis and vascular proliferation cause airway remodeling and narrowing, leading to disease deterioration and respiratory failure. In the clinic, the treatment of asthma was aimed at reducing the frequency of acute asthma attacks through inhaled corticosteroids (ICSs). However, ICSs cannot prevent the progression into refractory asthma due to the formation of airway remodeling mainly by subepithelial fibrosis and angiogenesis surrounding the tracheal lumen. Herein, we constructed surface-engineered mesenchymal stem cells (MSCs/PVLA) via the bioconjugation of MSCs and reactive oxygen species-responsive polymeric micelles loaded with vactosertib (VST) and linifanib (LFN) for treating refractory asthma through reversing airway remodeling. MSCs/PVLA migrated to the tracheal lumen due to the inflammation tropism of MSCs, and subsequently released VST and LFN could inhibit the formation of airway remodeling by preventing subepithelial fibrosis and angiogenesis. Meanwhile, MSCs reduced inflammatory cell infiltration and cytokine secretion to regulate the pathological microenvironment. Our results suggested that MSCs/PVLA could serve as a promising candidate to prevent disease exacerbations and treat refractory asthma.

A 30-Year Review on Nanocomposites: Comprehensive Bibliometric Insights into Microstructural, Electrical, and Mechanical Properties Assisted by Artificial Intelligence

From 1990 to 2024, this study presents a groundbreaking bibliometric and sentiment analysis of nanocomposite literature, distinguishing itself from existing reviews through its unique computational methodology. Developed by our research group, this novel approach systematically investigates the evolution of nanocomposites, focusing on microstructural characterization, electrical properties, and mechanical behaviors. By deploying advanced Boolean search strategies within the Scopus database, we achieve a meticulous extraction and in-depth exploration of thematic content, a methodological advancement in the field. Our analysis uniquely identifies critical trends and insights concerning nanocomposite microstructure, electrical attributes, and mechanical performance. The paper goes beyond traditional textual analytics and bibliometric evaluation, offering new interpretations of data and highlighting significant collaborative efforts and influential studies within the nanocomposite domain. Our findings uncover the evolution of research language, thematic shifts, and global contributions, providing a distinct and comprehensive view of the dynamic evolution of nanocomposite research. A critical component of this study is the "State-of-the-Art and Gaps Extracted from Results and Discussions" section, which delves into the latest advancements in nanocomposite research. This section details various nanocomposite types and their properties and introduces novel interpretations of their applications, especially in nanocomposite films. By tracing historical progress and identifying emerging trends, this analysis emphasizes the significance of collaboration and influential studies in molding the field. Moreover, the "Literature Review Guided by Artificial Intelligence" section showcases an innovative AI-guided approach to nanocomposite research, a first in this domain. Focusing on articles from 2023, selected based on citation frequency, this method offers a new perspective on the interplay between nanocomposites and their electrical properties. It highlights the composition, structure, and functionality of various systems, integrating recent findings for a comprehensive overview of current knowledge. The sentiment analysis, with an average score of 0.638771, reflects a positive trend in academic discourse and an increasing recognition of the potential of nanocomposites. Our bibliometric analysis, another methodological novelty, maps the intellectual domain, emphasizing pivotal research themes and the influence of crosslinking time on nanocomposite attributes. While acknowledging its limitations, this study exemplifies the indispensable role of our innovative computational tools in synthesizing and understanding the extensive body of nanocomposite literature. This work not only elucidates prevailing trends but also contributes a unique perspective and novel insights, enhancing our understanding of the nanocomposite research field.