Tissue engineering and regenerative medicine最新文献

Background: Although traumatic brain injury (TBI) is a significant cause of morbidity and mortality worldwide, there have been few significant therapeutic advances in recent years. Preclinical studies have explored the potential of adipose-derived stem cells (ADSCs) to improve neural function and reduce brain damage in animal models following TBI. This systematic review aims to assess and synthesize the current evidence on the efficacy of ADSCs in animal models with induced TBI.

Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically searched Scopus, PubMed, Web of Science, and Cochrane Library from inception to July 7, 2024, for original, English-language studies on animal models of induced TBI treated with ADSCs. We excluded in vitro, in silico, studies involving humans, and conference abstracts. Risk of bias was assessed using the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool.

Results: Twenty-two studies met the inclusion criteria. The most common routes of ADSC administration were intravenous and intracerebral injections, typically given within 24 h of induced TBI. Histological and neuroimaging assessments showed reduced tissue swelling and interstitial fluid accumulation in ADSC-treated animals, indicating decreased brain vasogenic edema. ADSC treatment also reduced neuroinflammation markers, suggesting lower activation of astrocytes and microglia around the injury site associated with M2 microglial phenotype polarization. Enhanced neurogenesis was observed, particularly in the hippocampus, with markers like bromodeoxyuridine (BrdU) and neuronal nuclei (NeuN) indicating improved neuron formation. Consistent cognitive and motor improvements were also noted, with treated animals showing shorter escape times and path lengths in spatial memory tests (e.g., Morris Water Maze) and better motor coordination in beam tests.

Conclusion: The available pre-clinical in vivo evidence indicates that ADSC-based therapies have the potential to mitigate neuroinflammation, reduce brain edema, enhance neurogenesis, and improve functional outcomes following induced TBI. Clinical studies are warranted to investigate the use of ADSCs in the treatment of TBI in humans.

Background: It is well recognized that interesting biological phenomena occur in various organisms in microgravity. However, real microgravity research is limited by cost and accessibility. Furthermore, current ground-based microgravity simulators often cause shear stress and vibration, which restrict the accurate reproduction of a real microgravity environment. This study aimed to develop a simple, low-cost, and reproducible simulated microgravity system based on neutral buoyancy to reproduce an environment similar to that of real space.

Methods: A neutral buoyancy medium (NBM) was created by adjusting the density of conventional cell culture medium through mixing with density gradient medium (Ficoll-Paque™, Percoll™, and Optiprep™). The buoyancy stability of human bone marrow-derived mesenchymal stem cell (hBMSC) spheroids was examined experimentally and by computational fluid dynamics (CFD). The effects of neutral buoyancy-based simulated microgravity (3D-sim-μg) on hBMSC stemness and trilineage differentiation (osteogenic, adipogenic, and chondrogenic) were compared with normal gravity.

Results: Optiprep-based NBM (Optiprep™/cell culture medium, 20/80 v/v) maintained a stable suspension of hBMSC spheroids for 14 days. CFD analysis confirmed near-zero static pressure under neutral buoyancy, reproducing a microgravity-like environment. hBMSC spheroids in 3D-sim-μg showed enhanced expression of pluripotency markers and suppressed osteogenic differentiation, with increased adipogenic and chondrogenic expression compared to normal gravity.

Conclusion: The neutral buoyancy-based system effectively simulates key microgravity-associated cellular behaviors, including maintenance of stemness and lineage-specific differentiation. This approach provides a simple and accessible platform for various microgravity research endeavors.

Background: Polydeoxyribonucleotide (PDRN) has emerged as a promising and cost-effective biological agent in regenerative medicine due to its anti-inflammatory, angiogenic, and tissue-regenerative properties.

Methods: This review outlines the mechanisms of action of PDRN, namely activation of the A₂A receptor and nucleotide provision via the salvage pathway, and summarizes its biological roles in dental regeneration together with current preclinical and clinical evidence.

Results: In dentistry, PDRN has been shown to enhance osteogenesis and vascularization when used with bone graft scaffolds, to exert anti-inflammatory and chondroprotective effects in temporomandibular joint disorders, and to modulate pain pathways in neuropathic conditions. It has also demonstrated adjunctive benefits in managing inflammatory oral diseases such as peri-implantitis and medication-related osteonecrosis of the jaw, where its dual regenerative and anti-inflammatory actions support both soft- and hard-tissue healing.

Conclusion: Although these findings highlight broad therapeutic potential, current evidence remains limited. Most reports derive from preclinical experiments or small-scale clinical studies, and well-designed randomized controlled trials are needed to validate efficacy of PDRN and define its optimal clinical indications in evidence-based dental protocols.

Background: Bacteriophage mixtures have been explored as biomaterials to promote tissue repair. In this study, we tested the hypothesis that incorporating a phage mixture into a wound dressing could modulate immune cell responses and skin cell migration within the wound environment.

Methods: Phage strains specific to three common bacterial pathogens-Escherichia coli, Salmonella enterica, and Pseudomonas aeruginosa-were embedded in an alginate hydrogel (E-Alg) or grafted onto its surface (S-Alg). The viability of the phages released from the samples were tested. 3T3 fibroblasts in a transwell system were co-cultured with Raw 264.7 macrophages seeded on the dressing samples containing the phage mixture. The cytokine release and fibroblast migration through the transwell membrane were measured.

Results: The phages remained lytic to their hosts after incorporation in the dressing samples (p < 0.001). Macrophages internalized similar numbers of phages, regardless of whether they were stimulated with lipopolysaccharide (LPS) or not (p > 0.05). In the presence of the phage mixture, the resting macrophage produced significantly more nitric oxide (NO), interleukin 1ß (IL-1ß) and tumor necrosis factor α (TNF-α) (p < 0.001). In contrast, the phage mixture significantly reduced the production of these inflammatory mediators in LPS-stimulated macrophages (p < 0.001). The numbers of fibroblast migrating through the membrane toward the macrophages positively correlated with the concentrations of TNF-α and IL-10 released by the macrophages.

Conclusion: A nonhealing wound-common in diabetic patients-is often a result of weakened immune responses. A phage-releasing dressing may not only alleviate bacterial infection but also attract and stimulate immune responses that promote skin repair.

Backround: Human-induced pluripotent stem cells (hiPSCs) have emerged as a promising source of transplantable insulinproducing cells (IPCs) to restore insulin levels in Type 1 Diabetes (T1D) patients. Despite progress, obtaining fully functional β cells from hiPSCs remains challenging, underscoring the need to better understand the intracellular mechanisms involved. We investigated here the potential role of Vav1, a multidomain protein that we identified as crucial for the maturation of human biliary stem cells (hBTSCs) into β-like cells and in the trans-differentiation of pancreatic adenocarcinoma (PDAC) cells into IPCs; METHODS: Levels and subcellular localization of Vav1 were investigated throughout a seven-step differentiation process of hiPSCs to β cells. Vav1expression was forcedly modulated in pancreatic progenitors, and the potential effects were evaluated on insulin production and on PDX1, miR-375, and Akt, key regulators of β cells generation; RESULTS. Vav1 showed dynamic modulation, with pancreatic precursor cells requiring adequate levels of the protein to generate IPCs.

Results: Vav1 sustains the expression of PDX1, a primary regulator of insulin expression, and of its target miR-375, essential for determining β cell mass. Furthermore, Vav1 reduction correlated with increased activation of Akt, which regulates cell survival and insulin secretion in β cells and is down-regulated by miR- 375.

Conclusion: Our findings suggest the existence of a Vav1/PDX1/miR-375/Akt axis as part of the complex network orchestrating the generation of functional β cells. These insights indicate that strategies aimed at specifically modulating Vav1 levels may positively impact the generation of IPCs in vitro and, ultimately, β cell replacement therapy for T1D.

Background: This study focuses on addressing the challenges associated with temporomandibular joint osteoarthritis (TMJOA), a condition currently considered incurable. Osteoarthritis (OA) is a degenerative disease of cartilage and tissues that affects the temporomandibular joint (TMJ). The potential of interferon-γ (IFN-γ)-primed three-dimensional (3D) spheroids of umbilical cord-derived mesenchymal stem cells (UC-MSCs) was investigated as a therapeutic intervention for TMJOA. This research aims to confirm that enhanced 3D UC-MSC spheroids are more effective than their two-dimensional (2D) counterparts.

Methods: Effective conditions for IFN-γ-primed 3D spheroids in the treatment of temporomandibular joint osteoarthritis (TMJOA) were determined. The therapeutic potential was confirmed by co-culturing with synovium-derived cells from patients with temporomandibular disorder (TMD-SDCs). The therapeutic efficacy was confirmed by injecting IFN-γ-primed 3D spheroids into rats with TMJOA.

Results: Co-culturing TMD-SDCs with IFN-γ-primed 3D UC-MSC spheroids resulted in significantly improved regenerative and anti-inflammatory effects compared to co-cultures with 2D UC-MSCs. Validation in TMJOA rats further supported the promising effects of IFN-γ-primed 3D spheroids of UC-MSCs. The 3D spheroids group showed rapid recovery based on micro-computed tomography images, histology images, and pain response.

Conclusion: MSCs were enhanced using cytokine priming and 3D spheroid culture. We successfully established the effective priming conditions for the therapeutic application of IFN-γ-primed 3D spheroids. The findings suggest their potential benefits in the treatment of TMJOA which is currently incurable and inform further advancements in regenerative medicine.

Introduction: It is estimated that more than 27 million people worldwide suffer from spinal cord injury (SCI) due to road traffic accidents, falls, and other causes, with 1 million new cases occurring each year. The primary objectives of SCI repair are to prevent further damage to nerves, inhibit glial scar and inflammatory responses, and facilitate nerve regeneration. However, at present, there is no curative therapy available. Despite the long-standing utilization of conventional pharmaceutical interventions and surgical approaches in clinical settings, these approaches have not yielded optimal therapeutic outcomes. Recent research based on regenerative medicine suggests that biomaterials containing cells, drugs, and bioactive molecules, especially hydrogels, have tremendous potential to repair SCI.

Methods: This paper summarizes the pathogenesis and current treatments of SCI, and provides a systematic review of the physicochemical properties and classification of hydrogels. It also explores the combination of hydrogels with therapeutic cells, as well as various small molecules and drug delivery strategies based on hydrogels.

Results: Hydrogels can facilitate the restructuring of axons, the promotion of nerve function recovery, and the delivery of drugs or cells to the lesion, which provides novel insights into the treatment of SCI.

Conclusion: The employment of hydrogel, encompassing both natural and synthetic hydrogels or hydrogel combinations, has emerged as a novel and effective approach to treating SCI. We are grateful for the suggestions on this manuscript and sincerely thank the reviewers for their attention and support.

Background: The renal glomerulus, a capillary network between two arterioles, is essential for urine production in mammals. While it partially regenerates after renal injury, its precise mechanisms remain unclear, and stereological studies on post-injury glomerular structural changes are limited.

Methods: Therefore, this study aims to investigate three-dimensional glomerular alterations over time following ischemia-reperfusion injury (IRI) in adult mouse kidneys. Synchrotron radiation micro-computed tomography (SR-MCT) and immunohistochemical analyses were employed to visualize and quantify three-dimensional glomerular structures and nephron numbers from 1 to 21 days post-IRI.

Results: A unique "twin glomeruli" structure, linked to three arterioles through an atypical "aefferent" arteriole, appeared between 3 and 21 days post-IRI, peaked on day 9, and exhibited features distinct from both degenerating and developing glomeruli. SR-MCT revealed a time-dependent increase in nephron numbers between 1 and 21 days post-IRI, while immunohistochemistry revealed significant elevated glomerular and tubular densities from days 9 to 21. These findings suggest that twin glomeruli are transient structures induced by IRI and may contribute to nephron expansion.

Conclusion: This study challenges current understanding by demonstrating that twin glomeruli represent an atypical glomerular structure occurring during kidney repair and suggesting possible neonephrogenesis in the adult mouse kidney, a phenomenon previously considered impossible after birth. If similar results are observed in humans, it could lead to significant changes in the approaches and objectives for treating renal diseases. Additionally, a comprehensive investigation into the numerical response of glomerular counts to various stimuli could provide valuable insights into kidney regeneration and repair.

Background: Electric field (EF) stimulation is an emerging biophysical approach that enhances stem cell function by mimicking endogenous wound currents. However, its effects on tonsil-derived mesenchymal stem cells (TMSCs) remain poorly understood.

Methods: A low-intensity EF stimulation system (0-12 mV; potential difference between parallel electrodes, 5 mm apart; 5 min on/5 s off for 38 h) was established to examine the effects of EF on TMSC viability, proliferation, stemness, and chondrogenic differentiation. Young and senescent TMSCs were evaluated for metabolic activity, cell cycle distribution, and expression of stemness- and chondrogenesis-related markers. For differentiation assays, cells were preconditioned with EF stimulation before chondrogenic induction.

Results: Moderate EF intensities (4-8 mV) enhanced the viability, metabolic activity, and proliferation of both young and senescent TMSCs, whereas excessive stimulation (12 mV) reduced these functions without causing cell death. In senescent TMSCs, EF stimulation promoted S-phase entry and upregulated Cyclin A2 and Cyclin B1 expression, suggesting partial restoration of proliferative potential. In young TMSCs, EF stimulation increased NANOG, OCT4, and SOX2 expression, thereby supporting stemness maintenance. EF stimulation enhanced glycosaminoglycan deposition and chondrogenic marker expression (Aggrecan, COL2A1, and SOX9) when applied before chondrogenic induction but exerted an inhibitory effect when applied during the differentiation phase.

Conclusion: Low-intensity EF stimulation serves as a tunable bioelectric cue that enhances the proliferation, stemness, and early chondrogenic potential of TMSCs in an intensity- and state-dependent manner, providing a non-invasive strategy to improve mesenchymal stem cell function for regenerative applications.

Background: The perichondrium-a natural fibrous membrane encasing cartilage-plays a pivotal role in nutrient delivery and matrix regulation; however, it is often overlooked in engineered constructs. This study aimed to fabricate a perichondrium-mimicking three-dimensional (3D) bioprinted auricular cartilage construct utilizing a hybrid bioink and to assess the effects of adipose-derived stem cell (ADSC) outer layers on cartilage matrix formation, vascularization, and construct stability.

Methods: Chondrocyte spheroids and ADSCs were isolated from New Zealand white rabbits and embedded in bioinks composed of either alginate alone or alginate/GelMA composites. A dual-mode printing strategy facilitated the fabrication of constructs with 3 and 10 layers. ADSCs were printed as outer "perichondrium-mimicking" layers in designated groups (G2, G4, and G6). Constructs were implanted subcutaneously in nude mice for 6 weeks. Histological analyses, immunohistochemical assessments (CD31), and image-based quantitative analyses were conducted.

Results: The inclusion of ADSC layers significantly enhanced cartilage matrix synthesis and decreased calcification, particularly in constructs containing GelMA. Group G4 exhibited the highest levels of glycosaminoglycan and collagen content, as well as the lowest calcium deposition. Ten-layer constructs (G6) preserved structural integrity and supported neovascularization; however, the final cartilage thickness did not proportionally scale with the initial print height.

Conclusion: The incorporation of ADSC-laden perichondrium-mimicking layers in conjunction with a hybrid alginate/GelMA bioink synergistically enhances cartilage formation, matrix quality, and vascular integration in large constructs. This biomimetic approach is a promising platform for developing clinically relevant cartilage grafts for auricular reconstruction and other cartilage repair applications.