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Background: Autologous tissues such as buccal mucosa (BM) are widely used for reconstruction of urethral strictures; however, limitations such as donor site morbidity and scarce tissue supply require the development of alternative biomaterials for urethral repair. The goals of this study were to determine the safety and efficacy of bi-layer silk fibroin (BLSF) matrices for urethral stricture repair and compare histological and functional outcomes to the standard approach, BM urethroplasty under good laboratory practices.Material and methods: A total of 13 rabbits exhibiting urethral stricture formation following electrocoagulation injury were treated with onlay urethroplasty with either acellular BLSF (N = 7) or autologous BM (N = 6) grafts for 3 months. Uninjured control rabbits were maintained in parallel (N = 4).Results and conclusion: Animals receiving BLSF implants were demonstrated to be functionally equivalent to BM grafts in their ability to restored strictured calibers, support micturition and promote tissue regeneration with minimal inflammation.

In lactating mothers, the high calcium (Ca2+) demand for milk production triggers significant bone loss1. Although oestrogen normally counteracts excessive bone resorption by promoting bone formation, this sex steroid drops precipitously during this postpartum period. Here we report that brain-derived cellular communication network factor 3 (CCN3) secreted from KISS1 neurons of the arcuate nucleus (ARCKISS1) fills this void and functions as a potent osteoanabolic factor to build bone in lactating females. We began by showing that our previously reported female-specific, dense bone phenotype2 originates from a humoral factor that promotes bone mass and acts on skeletal stem cells to increase their frequency and osteochondrogenic potential. This circulatory factor was then identified as CCN3, a brain-derived hormone from ARCKISS1 neurons that is able to stimulate mouse and human skeletal stem cell activity, increase bone remodelling and accelerate fracture repair in young and old mice of both sexes. The role of CCN3 in normal female physiology was revealed after detecting a burst of CCN3 expression in ARCKISS1 neurons coincident with lactation. After reducing CCN3 in ARCKISS1 neurons, lactating mothers lost bone and failed to sustain their progeny when challenged with a low-calcium diet. Our findings establish CCN3 as a potentially new therapeutic osteoanabolic hormone for both sexes and define a new maternal brain hormone for ensuring species survival in mammals.

Dendrites are injured in a variety of clinical conditions such as traumatic brain and spinal cord injuries and stroke. How neurons detect injury directly to their dendrites to initiate a pro-regenerative response has not yet been thoroughly investigated. Calcium plays a critical role in the early stages of axonal injury detection and is also indispensable for regeneration of the severed axon. Here, we report cell and neurite type-specific differences in laser injury-induced elevations of intracellular calcium levels. Using a human KCNJ2 transgene, we demonstrate that hyperpolarizing neurons only at the time of injury dampens dendrite regeneration, suggesting that inhibition of injury-induced membrane depolarization (and thus early calcium influx) plays a role in detecting and responding to dendrite injury. In exploring potential downstream calcium-regulated effectors, we identify L-type voltage-gated calcium channels, inositol triphosphate signaling, and protein kinase D activity as drivers of dendrite regeneration. In conclusion, we demonstrate that dendrite injury-induced calcium elevations play a key role in the regenerative response of dendrites and begin to delineate the molecular mechanisms governing dendrite repair.

Hematopoietic stem cells and multipotential progenitors emerge in multiple, overlapping waves of fetal development. Some of these populations seed the bone marrow and sustain adult B- and T-cell development long-term after birth. However, others are present transiently, but whether they are vestigial or generate B and T cells that contribute to the adult immune system is not well understood. We now report that transient fetal progenitors distinguished by expression of low levels of the PU.1 transcription factor generated activated and memory T and B cells that colonized and were maintained in secondary lymphoid tissues. These included the small and large intestines, where they may contribute to the maintenance of gut homeostasis through at least middle age. At least some of the activated/memory cells may have been the progeny of B-1 and marginal zone B cells, as transient PU.1low fetal progenitors efficiently generated those populations. Taken together, our data demonstrate the potential of B- and T-cell progeny of transient PU.1low fetal progenitors to make an early and long-term contribution to the adult immune system.

In vitro gametogenesis (IVG), the reconstitution of germ cell development in vitro, is an emerging stem cell-based technology with profound implications for reproductive science. Despite researchers' long-term goals for future clinical applications, little is currently known about the views of IVG held by the stakeholders potentially most affected by its introduction in humans. We conducted focus groups and interviews with 80 individuals with lived experience of infertility and/or LGBTQ+ family formation in the US, two intersecting groups of potential IVG users. Respondents expressed hope that IVG would lead to higher reproductive success than current assisted reproductive technology (ART), alleviate suffering associated with ART use, and promote greater social inclusion, while expressing concerns predominantly framed in terms of equity and safety. These findings underscore the importance of sustained engagement with stakeholders with relevant experience to anticipate the implications of IVG for research and clinical translation.

Tissue regeneration after damage is generally thought to involve the mobilization of adult stem cells that divide and differentiate into progressively specialized progeny. However, recent studies indicate that tissue regeneration can be accompanied by reversion to a fetal-like state. During this process, cells at the injury site reactivate programs that operate during fetal development but are typically absent in adult homeostasis. Here, we summarize our current understanding of the molecular signals and epigenetic mediators that orchestrate "fetal-like reversion" during intestinal regeneration. We also explore evidence for this phenomenon in other organs and species and highlight open questions that merit future examination.

Juvenile myelomonocytic leukemia (JMML) is a hematologic malignancy of young children caused by mutations that increase Ras signaling output. Hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment, but patients with relapsed or refractory (advanced) disease have dismal outcomes. This phase II trial evaluated the safety and efficacy of trametinib, an oral MEK1/2 inhibitor, in patients with advanced JMML. Ten infants and children were enrolled, and the objective response rate was 50%. Four patients with refractory disease proceeded to HSCT after receiving trametinib. Three additional patients completed all 12 cycles permitted on study and continue to receive off-protocol trametinib without HSCT. The remaining three patients had progressive disease with two demonstrating molecular evolution by the end of cycle 2. Transcriptomic and proteomic analyses provided novel insights into the mechanisms of response and resistance to trametinib in JMML. ClinicalTrials.gov Identifier: NCT03190915. Significance: Trametinib was safe and effective in young children with relapsed or refractory JMML, a lethal disease with poor survival rates. Seven of 10 patients completed the maximum 12 cycles of therapy or used trametinib as a bridge to HSCT and are alive with a median follow-up of 24 months.

The intricate interplay between biochemical and physical cues dictates pluripotent stem cell (PSC) differentiation to form various tissues. While biochemical modulation has been extensively studied, the role of biophysical microenvironments in early lineage commitment remains elusive. Here, we introduce a novel 3D cell culture system combining electrospun nanofibers with microfabricated polydimethylsiloxane (PDMS) patterns. This system enables the controlled formation of semispherical human induced pluripotent stem cell (hiPSC) colonies, facilitating the investigation of local mechanical stem cell niches on mechano-responsive signaling and lineage specification. Our system unveiled spatially organized RhoA activity coupled with actin-myosin cable formation, suggesting mechano-dependent hiPSC behaviors. Nodal network analysis of RNA-seq data revealed RhoA downstream regulation of YAP signaling, DNA histone modifications, and patterned germ layer specification. Notably, altering colony morphology through controlled PDMS microwell shaping effectively modulated the spatial distribution of mechano-sensitive mediators and subsequent differentiation. This study provides a cell culture platform to decipher the role of biophysical cues in early embryogenesis, offering valuable insights for material design in tissue engineering and regenerative medicine applications.

BackgroundAutologous tissues derived from bowel, buccal mucosa and skin are primarily used to repair or replace diseased vaginal segments as well as create neovaginas for male-to-female transgenders. These grafts are often limited by scarce tissue supply, donor site morbidity and post-operative complications. Bi-layer silk fibroin (BLSF) biomaterials represent potential alternatives for vaginoplasty given their structural strength and elasticity, low immunogenicity, and processing flexibility. The goals of the current study were to assess the potential of acellular BLSF scaffolds for vaginal tissue regeneration in respect to conventional small intestinal submucosal (SIS) matrices in a rat model of vaginoplasty.MethodsInlay vaginoplasty was performed with BLSF and SIS scaffolds (N = 21 per graft) in adult female rats for up to 2 months of implantation. Nonsurgical controls (N = 4) were investigated in parallel. Outcome analyses included histologic, immunohistochemical and histomorphometric evaluations of wound healing patterns; µ-computed tomography (CT) of vaginal continuity; and breeding assessments.ResultsAnimals in both scaffold cohorts exhibited 100% survival rates with no severe post-operative complications. At 2 months post-op, µ-CT analysis revealed normal vaginal anatomy and continuity in both graft groups similar to controls. In parallel, BLSF and SIS grafts also induced comparable constructive remodeling patterns and were histologically equivalent in their ability to support formation of vascularized vaginal neotissues with native tissue architecture, however with significantly less smooth muscle content. Vaginal tissues reconstructed with both implants were capable of supporting copulation, pregnancy and similar amounts of live births.ConclusionsBLSF biomaterials represent potential "off-the-shelf" candidates for vaginoplasty.

Tissue engineering can provide in vitro models for drug testing, disease modeling, and perhaps someday, tissue/organ replacements. For building 3D heart tissue, the alignment of cardiac cells or cardiomyocytes (CMs) is important in generating a synchronously contracting tissue. To that end, researchers have generated several fabrication methods for building heart tissue, but direct comparisons of pros and cons using the same cell source is lacking. Here, we derived cardiomyocytes (CMs) from human induced pluripotent stem cells (hiPSCs) and compare the assembly of these cells using three fabrication methods: cardiospheres, muscle rings, and muscle strips. All three protocols successfully generated compacted tissue comprised of hiPSC-derived CMs stable for at least 2 weeks. The percentage of aligned cells was greatest in the muscle strip (55%) and the muscle ring (50%) compared with the relatively unaligned cardiospheres (35%). The iPSC-derived CMs within the muscle strip also exhibited the greatest elongation, with elongation factor at 2.0 compared with 1.5 for the muscle ring and 1.2 for the cardiospheres. This is the first direct comparison of various fabrication techniques using the same cell source.

Osteoarthritis is characterized by enzymatic breakdown of the articular cartilage via the disruption of chondrocyte homeostasis, ultimately resulting in the destruction of the articular surface. Decades of research have highlighted the importance of inflammation in osteoarthritis progression, with inflammatory cytokines shifting resident chondrocytes into a pro-catabolic state. Inflammation can result in poor outcomes for cells implanted for cartilage regeneration. Therefore, a method to promote the growth of new cartilage and protect the implanted cells from the pro-inflammatory cytokines found in the joint space is required. In this study, we fabricate two gel types: polymer network hydrogels composed of chondroitin sulfate and hyaluronic acid, glycosaminoglycans (GAGs) known for their anti-inflammatory and prochondrogenic activity, and interpenetrating networks of GAGs and collagen I. Compared to a collagen-only hydrogel, which does not provide an anti-inflammatory stimulus, chondrocytes in GAG hydrogels result in reduced production of pro-inflammatory cytokines and enzymes as well as preservation of collagen II and aggrecan expression. Overall, GAG-based hydrogels have the potential to promote cartilage regeneration under pro-inflammatory conditions. Further, the data have implications for the use of GAGs to generally support tissue engineering in pro-inflammatory environments.

The developmental origin of blood-forming hematopoietic stem cells (HSCs) is a longstanding question. Here, our non-invasive genetic lineage tracing in mouse embryos pinpoints that artery endothelial cells generate HSCs. Arteries are transiently competent to generate HSCs for 2.5 days (∼E8.5-E11) but subsequently cease, delimiting a narrow time frame for HSC formation in vivo. Guided by the arterial origins of blood, we efficiently and rapidly differentiate human pluripotent stem cells (hPSCs) into posterior primitive streak, lateral mesoderm, artery endothelium, hemogenic endothelium, and >90% pure hematopoietic progenitors within 10 days. hPSC-derived hematopoietic progenitors generate T, B, NK, erythroid, and myeloid cells in vitro and, critically, express hallmark HSC transcription factors HLF and HOXA5-HOXA10, which were previously challenging to upregulate. We differentiated hPSCs into highly enriched HLF+ HOXA+ hematopoietic progenitors with near-stoichiometric efficiency by blocking formation of unwanted lineages at each differentiation step. hPSC-derived HLF+ HOXA+ hematopoietic progenitors could avail both basic research and cellular therapies.

During the past 20 years, gene editing has emerged as a novel form of gene therapy. Since the publication of the first potentially therapeutic gene editing platform for genetic disorders, increasingly sophisticated editing technologies have been developed. As with viral vector-mediated gene addition, inborn errors of immunity are excellent candidate diseases for a corrective autologous hematopoietic stem cell gene editing strategy. Research on gene editing for inborn errors of immunity is still entirely preclinical, with no trials yet underway. However, with editing techniques maturing, scientists are investigating this novel form of gene therapy in context of an increasing number of inborn errors of immunity. Here, we present an overview of these studies and the recent progress moving these technologies closer to clinical benefit.

Live microorganisms can be manipulated and engineered for colorectal cancer detection and treatment through methods such as faecal microbiota transplantation, native bacteria engineering and synthetic circuit engineering. Although promising, substantial effort is required to translate these approaches for clinical use.

Schwann cells (SCs) undergo phenotypic transformation and then orchestrate nerve repair following PNS injury. The ligands and receptors that activate and sustain SC transformation remain incompletely understood. Proteins released by injured axons represent important candidates for activating the SC Repair Program. The low-density lipoprotein receptor-related protein-1 (LRP1) is acutely up-regulated in SCs in response to injury, activating c-Jun, and promoting SC survival. To identify novel LRP1 ligands released in PNS injury, we applied a discovery-based approach in which extracellular proteins in the injured nerve were captured using Fc-fusion proteins containing the ligand-binding motifs of LRP1 (CCR2 and CCR4). An intracellular neuron-specific protein, Protein Kinase C and Casein Kinase Substrate in Neurons (PACSIN1) was identified and validated as an LRP1 ligand. Recombinant PACSIN1 activated c-Jun and ERK1/2 in cultured SCs. Silencing Lrp1 or inhibiting the LRP1 cell-signaling co-receptor, the NMDA-R, blocked the effects of PACSIN1 on c-Jun and ERK1/2 phosphorylation. Intraneural injection of PACSIN1 into crush-injured sciatic nerves activated c-Jun in wild-type mice, but not in mice in which Lrp1 is conditionally deleted in SCs. Transcriptome profiling of SCs revealed that PACSIN1 mediates gene expression events consistent with transformation to the repair phenotype. PACSIN1 promoted SC migration and viability following the TNFα challenge. When Src family kinases were pharmacologically inhibited or the receptor tyrosine kinase, TrkC, was genetically silenced or pharmacologically inhibited, PACSIN1 failed to induce cell signaling and prevent SC death. Collectively, these studies demonstrate that PACSIN1 is a novel axon-derived LRP1 ligand that activates SC repair signaling by transactivating TrkC.

Because derivation of retinal organoids (ROs) and transplantation are frequently split between geographically distant locations, we developed a special shipping device and protocol capable of the organoids' delivery to any location. Human embryonic stem cell (hESC)-derived ROs were differentiated from the hESC line H1 (WA01), shipped overnight to another location, and then transplanted into the subretinal space of blind immunodeficient retinal degeneration (RD) rats. Development of transplants was monitored by spectral-domain optical coherence tomography. Visual function was accessed by optokinetic tests and superior colliculus (SC) electrophysiology. Cryostat sections through transplants were stained with hematoxylin and eosin; or processed for immunohistochemistry to label human donor cells, retinal cell types, and synaptic markers. After transplantation, ROs integrated into the host RD retina, formed functional photoreceptors, and improved vision in rats with advanced RD. The survival and vision improvement are comparable with our previous results of hESC-ROs without a long-distance delivery. Furthermore, for the first time in the stem cell transplantation field, we demonstrated that the response heatmap on the SC showed a similar shape to the location of the transplant in the host retina, which suggested the point-to-point projection of the transplant from the retina to SC. In conclusion, our results showed that using our special device and protocol, the hESC-derived ROs can be shipped over long distance and are capable of survival and visual improvement after transplantation into the RD rats. Our data provide a proof-of-concept for stem cell replacement as a therapy for RD patients.

Hematopoietic stem cell transplantation can cure various disorders but poses cardiovascular risks, especially for elderly patients and those with cardiovascular diseases. Cardiovascular evaluations are crucial in pretransplantation assessments, but guidelines are lacking. This American Heart Association scientific statement summarizes the data on transplantation-related complications and provides guidance for the cardiovascular management throughout transplantation. Hematopoietic stem cell transplantation consists of 4 phases: pretransplantation workup, conditioning therapy and infusion, immediate posttransplantation period, and long-term survivorship. Complications can occur during each phase, with long-term survivors facing increased risks for late effects such as cardiovascular disease, secondary malignancies, and endocrinopathies. In adults, arrhythmias such as atrial fibrillation and flutter are the most frequent acute cardiovascular complication. Acute heart failure has an incidence ranging from 0.4% to 2.2%. In pediatric patients, left ventricular systolic dysfunction and pericardial effusion are the most common cardiovascular complications. Factors influencing the incidence and risk of complications include pretransplantation therapies, transplantation type (autologous versus allogeneic), conditioning regimen, comorbid conditions, and patient age. The pretransplantation cardiovascular evaluation consists of 4 steps: (1) initial risk stratification, (2) exclusion of high-risk cardiovascular disease, (3) assessment of cardiac reserve, and (4) optimization of cardiovascular reserve. Clinical risk scores could be useful tools for the risk stratification of adult patients. Long-term cardiovascular management of hematopoietic stem cell transplantation survivors includes optimizing risk factors, monitoring, and maintaining a low threshold for evaluating cardiovascular causes of symptoms. Future research should prioritize refining risk stratification and creating evidence-based guidelines and strategies to optimize outcomes in this growing patient population.

The current paradigm of medicine is mostly designed to block or prevent pathological events. Once the disease-led tissue damage occurs, the limited endogenous regeneration may lead to depletion or loss of function for cells in the tissues. Cell therapy is rapidly evolving and influencing the field of medicine, where in some instances attempts to address cell loss in the body. Due to their biological function, engineerability, and their responsiveness to stimuli, cells are ideal candidates for therapeutic applications in many cases. Such promise is yet to be fully obtained as delivery of cells that functionally integrate with the desired tissues upon transplantation is still a topic of scientific research and development. Main known impediments for cell therapy include mechanical insults, cell viability, host's immune response, and lack of required nutrients for the transplanted cells. These challenges could be divided into three different steps: 1) Prior to, 2) during the and 3) after the transplantation procedure. In this review, we attempt to briefly summarize published approaches employing biomaterials to mitigate the above technical challenges. Biomaterials are offering an engineerable platform that could be tuned for different classes of cell transplantation to potentially enhance and lengthen the pharmacodynamics of cell therapies.

Spermatogonial stem cells functionality reside in the slow-cycling and heterogeneous undifferentiated spermatogonia cell population. This pool of cells supports lifelong fertility in adult males by balancing self-renewal and differentiation to produce haploid gametes. However, the molecular mechanisms underpinning long-term stemness of undifferentiated spermatogonia during adulthood remain unclear. Here, we discover that an epigenetic regulator, Polycomb repressive complex 1 (PRC1), shields adult undifferentiated spermatogonia from differentiation, maintains slow cycling, and directs commitment to differentiation during steady-state spermatogenesis in adults. We show that PRC2-mediated H3K27me3 is an epigenetic hallmark of adult undifferentiated spermatogonia. Indeed, spermatogonial differentiation is accompanied by a global loss of H3K27me3. Disruption of PRC1 impairs global H3K27me3 deposition, leading to precocious spermatogonial differentiation. Therefore, PRC1 directs PRC2-H3K27me3 deposition to maintain the self-renewing state of undifferentiated spermatogonia. Importantly, in contrast to its role in other tissue stem cells, PRC1 negatively regulates the cell cycle to maintain slow cycling of undifferentiated spermatogonia. Our findings have implications for how epigenetic regulators can be tuned to regulate the stem cell potential, cell cycle and differentiation to ensure lifelong fertility in adult males.

Tissue engineering strategies show great potential for repairing osteochondral defects in osteoarthritic joints; however, these approaches often rely on passaging cells multiple times to obtain enough cells to produce functional tissue. Unfortunately, monolayer expansion culture causes chondrocyte dedifferentiation, which is accompanied by a phenotypical and morphological shift in chondrocyte properties that leads to a reduction in the quality of de novo cartilage produced. Thus, the objective of this study was to evaluate transcriptional variations during in vitro expansion culture and determine how differences in cell phenotype from monolayer expansion alter development of functional engineered cartilage. We used an unbiased approach to explore genome-wide transcriptional differences in chondrocyte phenotype at passage 1 (P1), P3, and P5, and then seeded cells into hydrogel scaffolds at P3 and P5 to assess cells' abilities to produce cartilaginous extracellular matrix in three dimensional (3D). We identified distinct phenotypic differences, specifically for genes related to extracellular organization and cartilage development. Both P3 and P5 chondrocytes were able to produce chondrogenic tissue in 3D, with P3 cells producing matrix with greater compressive properties and P5 cells secreting matrix with higher glycosaminoglycan/DNA and collagen/DNA ratios. Furthermore, we identified 24 genes that were differentially expressed with passaging and enriched in human osteoarthritis (OA) genome-wide association studies, thereby prioritizing them as functionally relevant targets to improve protocols that recapitulate functional healthy cartilage with cells from adult donors. Specifically, we identified novel genes, such as TMEM190 and RAB11FIP4, which were enriched with human hip OA and may play a role in chondrocyte dedifferentiation. This work lays the foundation for several pathways and genes that could be modulated to enhance the efficacy for chondrocyte culture for tissue regeneration, which could have transformative impacts for cell-based cartilage repair strategies.

Peripheral artery disease is an atherosclerotic disease associated with limb ischemia that necessitates limb amputation in severe cases. Cell therapies comprised of adult mononuclear or stromal cells have been clinically tested and show moderate benefits. Bioengineering strategies can be applied to modify cell behavior and function in a controllable fashion. Using mechanically tunable or spatially controllable biomaterials, we highlight examples in which biomaterials can increase the survival and function of the transplanted cells to improve their revascularization efficacy in preclinical models. Biomaterials can be used in conjunction with soluble factors or genetic approaches to further modulate the behavior of transplanted cells and the locally implanted tissue environment in vivo. We critically assess the advances in bioengineering strategies such as 3-dimensional bioprinting and immunomodulatory biomaterials that can be applied to the treatment of peripheral artery disease and then discuss the current challenges and future directions in the implementation of bioengineering strategies.

ObjectiveExtracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) are promising avenues in regenerative medicine, offering unique immunomodulatory and regenerative properties with lower immunogenicity. This study delves into the distinctive features of EVs extracted from feline adipose-derived MSCs (ASCs) and placenta-derived MSCs (PMSCs). The tissues were collected from 11 female cats aged between 4 and 7 years old.SampleEVs extracted from MSCs from discarded fetal membranes from 7 female cats and SC adipose tissue from 11 cats.MethodsWe comprehensively explored morphological characteristics, mitochondrial density, surface markers, and pro- and anti-inflammatory mediators, uncovering notable differences between ASCs and PMSCs.ResultsMorphologically, ASCs exhibit a spindle-shaped form in contrast to the spherical morphology of PMSCs. Proliferation and clonogenic potential assessments reveal the faster proliferation and robust clonogenic nature of ASCs, suggesting their potential vital role in regenerative processes. Surface marker expression analysis indicates a significantly higher expression of multipotency-associated markers in ASCs, suggesting their superior proregenerative potential. Phenotyping of EVs demonstrates distinctive features, with CD9 expression suggesting varied EV secretion patterns. Notably, PMSCs exhibit superior CD81 expression, indicating their potential as preferred donors of mitochondria. Pro- and anti-inflammatory mediators analyzed at mRNA and microRNA levels reveal higher RNA content in EVs compared to source cells, emphasizing the potential of EVs in directing regenerative processes. Differential microRNA expression in EVs derived from ASCs hints at their regulatory roles in anti-inflammatory and immunometabolic processes.Clinical relevanceThis study lays a foundation for understanding the nuances between ASCs and PMSCs, which is crucial for harnessing the full therapeutic potential of MSCs and their EVs in tissue repair and regeneration.

Mesenchymal stromal cells (MSCs) are widely used in cell-based therapies and tissue regeneration for their potent secretome, which promotes host cell recruitment and modulates inflammation. Compared to monodisperse cells, MSC spheroids exhibit improved viability and increased secretion of immunomodulatory cytokines. While mechanical stimulation of monodisperse cells can increase cytokine production, the influence of mechanical loading on MSC spheroids is unknown. Here, we evaluated the effect of controlled, uniaxial cyclic compression on the secretion of immunomodulatory cytokines by human MSC spheroids and tested the influence of load-induced gene expression on MSC mechanoresponsiveness. We exposed MSC spheroids, entrapped in alginate hydrogels, to three cyclic compressive regimes with varying stress (L) magnitudes (i.e., 5 and 10 kPa) and hold (H) durations (i.e., 30 and 250 s) L5H30, L10H30, and L10H250. We observed changes in cytokine and chemokine expression dependent on the loading regime, where higher stress regimes tended to result in more exaggerated changes. However, only MSC spheroids exposed to L10H30 induced human THP-1 macrophage polarization toward an M2 phenotype compared to static conditions. Static and L10H30 loading facilitated a strong, interlinked F-actin arrangement, while L5H30 and L10H250 disrupted the structure of actin filaments. This was further examined when the actin cytoskeleton was disrupted via Y-27632. We observed downregulation of YAP-related genes, and the levels of secreted inflammatory cytokines were globally decreased. These findings emphasize the essential role of mechanosignaling in mediating the immunomodulatory potential of MSC spheroids.

Human pluripotent stem cell-derived neural progenitor cells (NPCs) are an essential tool for the study of brain development and developmental disorders such as autism. Here, we present a protocol to generate NPCs rapidly and reproducibly from human stem cells using dual-SMAD inhibition coupled with a brief pulse of mouse neurogenin-2 (Ngn2) overexpression. We detail the 48-h induction scheme deployed to produce these cells-termed stem cell-derived Ngn2-accelerated progenitor cells-followed by steps for expansion, purification, banking, and quality assessment. For complete details on the use and execution of this protocol, please refer to Wells et al.1.

ObjectiveNumerous pharmacological and cell-based treatments have shown promise in preventing vocal fold (VF) scarring when applied at the time of injury. A common clinical scenario, however, is the finding of mature scar impeding voicing. Many treatments are less effective in remodeling existing scar tissue. This objective of this study is to determine if a cell-based outer vocal fold replacement (COVR) effectively restores VF function when applied to existing scar.MethodsEighteen rabbits were allocated to three groups: unilateral COVR implant at the time of cordectomy (acute COVR); unilateral cordectomy followed by COVR implant 2 months later (chronic COVR); and unilateral cordectomy followed by sham implant surgery 2 months later (chronic scar). Larynges were harvested 2 months after implant or sham surgery.ResultsAll larynges in the COVR groups demonstrated human leukocyte antigen labeling on immunohistochemistry (IHC). COVR groups had increased hyaluronic acid content compared with normal. VF stiffness as measured by elastic moduli in acute COVR and chronic COVR were similar to their contralateral unoperated VF.ConclusionCOVR implantation in both acutely injured and chronically scarred VF demonstrate persistence of implanted cells, restored tissue biomechanics, and increased hyaluronic acid content.Level of evidenceNA Laryngoscope, 134:764-772, 2024.

Effective cellular therapy using CD19 chimeric antigen receptor T-cells for the treatment of advanced B-cell malignancies raises the question of whether the administration of adoptive cellular therapy (ACT) posttransplant could reduce relapse and improve survival. Moreover, several early phase clinical studies have shown the potential beneficial effects of administration of tumor-associated antigen-specific T-cells and natural killer cells posttransplant for high-risk patients, aiming to decrease relapse and possibly improve survival. In this article, we present an in-depth review of ACT after transplantation, which has the potential to significantly improve the efficacy of this procedure and revolutionize this field.

Spheroids exhibit enhanced cell-cell interactions that facilitate improved survival and mimic the physiological cellular environment in vivo. Cell spheroids have been successfully used as building blocks for engineered tissues, yet the viability of this approach with skeletal muscle spheroids is poorly understood, particularly when incorporated into three-dimensional (3D) constructs. Bioprinting is a promising strategy to recapitulate the hierarchical organization of native tissue that is fundamental to its function. However, the influence of bioprinting on skeletal muscle cell spheroids and their function are yet to be interrogated. Using C2C12 mouse myoblasts and primary bovine muscle stem cells (MuSCs), we characterized spheroid formation as a function of duration and cell seeding density. We then investigated the potential of skeletal muscle spheroids entrapped in alginate bioink as tissue building blocks for bioprinting myogenic tissue. Both C2C12 and primary bovine MuSCs formed spheroids of similar sizes and remained viable after bioprinting. Spheroids of both cell types fused into larger tissue clusters over time within alginate and exhibited tissue formation comparable to monodisperse cells. Compared to monodisperse cells in alginate gels, C2C12 spheroids exhibited greater MyHC expression after 2 weeks, while cells within bovine MuSC spheroids displayed increased cell spreading. Both monodisperse and MuSC spheroids exhibited increased expression of genes denoting mid- and late-stage myogenic differentiation. Together, these data suggest that skeletal muscle spheroids have the potential for generating myogenic tissue via 3D bioprinting and reveal areas of research that could enhance myogenesis and myogenic differentiation in future studies.

Retinitis pigmentosa (RP), a heterogenous group of inherited retinal disorder, causes slow progressive vision loss with no effective treatments available. Mutations in the rhodopsin gene (RHO) account for ~25% cases of autosomal dominant RP (adRP). In this study, we describe the disease characteristics of the first-ever reported mono-allelic copy number variation (CNV) in RHO as a novel cause of adRP. We (a) show advanced retinal degeneration in a male patient (68 years of age) harboring four transcriptionally active intact copies of rhodopsin, (b) recapitulated the clinical phenotypes using retinal organoids, and (c) assessed the utilization of a small molecule, Photoregulin3 (PR3), as a clinically viable strategy to target and modify disease progression in RP patients associated with RHO-CNV. Patient retinal organoids showed photoreceptors dysgenesis, with rod photoreceptors displaying stunted outer segments with occasional elongated cilia-like projections (microscopy); increased RHO mRNA expression (quantitative real-time PCR [qRT-PCR] and bulk RNA sequencing); and elevated levels and mislocalization of rhodopsin protein (RHO) within the cell body of rod photoreceptors (western blotting and immunohistochemistry) over the extended (300 days) culture time period when compared against control organoids. Lastly, we utilized PR3 to target NR2E3, an upstream regulator of RHO, to alter RHO expression and observed a partial rescue of RHO protein localization from the cell body to the inner/outer segments of rod photoreceptors in patient organoids. These results provide a proof-of-principle for personalized medicine and suggest that RHO expression requires precise control. Taken together, this study supports the clinical data indicating that RHO-CNV associated adRPdevelops as a result of protein overexpression, thereby overloading the photoreceptor post-translational modification machinery.

Platelets are the terminal progeny of megakaryocytes, primarily produced in the bone marrow, and play critical roles in blood homeostasis, clotting, and wound healing. Traditionally, megakaryocytes and platelets are thought to arise from multipotent hematopoietic stem cells (HSCs) via multiple discrete progenitor populations with successive, lineage-restricting differentiation steps. However, this view has recently been challenged by studies suggesting that (1) some HSC clones are biased and/or restricted to the platelet lineage, (2) not all platelet generation follows the "canonical" megakaryocytic differentiation path of hematopoiesis, and (3) platelet output is the default program of steady-state hematopoiesis. Here, we specifically investigate the evidence that in vivo lineage tracing studies provide for the route(s) of platelet generation and investigate the involvement of various intermediate progenitor cell populations. We further identify the challenges that need to be overcome that are required to determine the presence, role, and kinetics of these possible alternate pathways.

Stem cells exist in vitro in a spectrum of interconvertible pluripotent states. Analyzing hundreds of hiPSCs derived from different individuals, we show the proportions of these pluripotent states vary considerably across lines. We discover 13 gene network modules (GNMs) and 13 regulatory network modules (RNMs), which are highly correlated with each other suggesting that the coordinated co-accessibility of regulatory elements in the RNMs likely underlie the coordinated expression of genes in the GNMs. Epigenetic analyses reveal that regulatory networks underlying self-renewal and pluripotency are more complex than previously realized. Genetic analyses identify thousands of regulatory variants that overlapped predicted transcription factor binding sites and are associated with chromatin accessibility in the hiPSCs. We show that the master regulator of pluripotency, the NANOG-OCT4 Complex, and its associated network are significantly enriched for regulatory variants with large effects, suggesting that they play a role in the varying cellular proportions of pluripotency states between hiPSCs. Our work bins tens of thousands of regulatory elements in hiPSCs into discrete regulatory networks, shows that pluripotency and self-renewal processes have a surprising level of regulatory complexity, and suggests that genetic factors may contribute to cell state transitions in human iPSC lines.

The nerve injury-induced protein 1 (NINJ1) and NINJ2 constitute a family of homophilic adhesion molecules and are involved in nerve regeneration. Previously, we showed that NINJ1 and p53 are mutually regulated and the NINJ1-p53 loop plays a critical role in p53-dependent tumor suppression. However, the biology of NINJ2 has not been well-explored. By using multiple in vitro cell lines and genetically engineered mouse embryo fibroblasts (MEFs), we showed that NINJ2 is induced by DNA damage in a p53-dependent manner. Moreover, we found that the loss of NINJ2 promotes p53 expression via mRNA translation and leads to growth suppression in wild-type p53-expressing MCF7 and Molt4 cells and premature senescence in MEFs in a wild-type p53-dependent manner. Interestingly, NINJ2 also regulates mutant p53 expression, and the loss of NINJ2 promotes cell growth and migration in mutant p53-expressing MIA-PaCa2 cells. Together, these data indicate that the mutual regulation between NINJ2 and p53 represents a negative feedback loop, and the NINJ2-p53 loop has opposing functions in wild-type p53-dependent growth suppression and mutant p53-dependent growth promotion.

Mesenchymal stem cells (MSCs) are novel therapeutics for the treatment of Crohn's disease. However, their mechanism of action is unclear, especially in disease-relevant chronic models of inflammation. Thus, we used SAMP-1/YitFc (SAMP), a chronic and spontaneous murine model of small intestinal inflammation, to study the therapeutic effects and mechanism of action of human bone marrow-derived MSCs (hMSC). hMSC dose-dependently inhibited naïve T lymphocyte proliferation via prostaglandin E2 (PGE2) secretion and reprogrammed macrophages to an anti-inflammatory phenotype. We found that the hMSCs promoted mucosal healing and immunologic response early after administration in SAMP when live hMSCs are present (until day 9) and resulted in a complete response characterized by mucosal, histological, immunologic, and radiological healing by day 28 when no live hMSCs are present. hMSCs mediate their effect via modulation of T cells and macrophages in the mesentery and mesenteric lymph nodes (mLN). Sc-RNAseq confirmed the anti-inflammatory phenotype of macrophages and identified macrophage efferocytosis of apoptotic hMSCs as a mechanism that explains their long-term efficacy. Taken together, our findings show that hMSCs result in healing and tissue regeneration in a chronic model of small intestinal inflammation and despite being short-lived, exert long-term effects via sustained anti-inflammatory programming of macrophages via efferocytosis.

Purpose of Review: Describe the rationale for preconditioning MSCs prior to use as therapy and the state-of-the-art of using preconditioning of MSCs in clinical settings. Recent Findings: Mounting preclinical data supports preconditioning of mesenchymal stromal cells (MSCs) to enhance their therapeutic efficacy. Most research has focused on cytokine priming and hypoxic preconditioning, while other approaches, such as glycoengineering, remain relatively understudied. Despite strong preclinical data, clinical evidence supporting preconditioning strategies are limited to six Phase I clinical trials (most of them in progress). Summary: Here, we succinctly discuss the rationale for preconditioning using cytokines, hypoxia, and glycoengineering, while elaborating on the respective clinical experiences. Overall, we note that preconditioning is highly dependent on the desired application, and therefore requires elucidating the mechanism of action of the MSCs used for therapy. Preconditioning may also help mitigate heterogeneity of MSC lots. Based on the remarkable safety profile of MSCs, even when used in allogeneic settings, the role of preconditioning prior to their final formulation might be the key to reach expected therapeutic outcomes.

Background: Fibroblast cells have the ability to improve skin conditions through regenerative medicine and cell-based therapies. The purpose of this scoping review is to assess the contribution of fibroblast cells to skin homeostasis and extracellular matrix deposition in clinical trials involving skin disorders and cosmetic applications. Methods: Using targeted search terms, published publications from January 2000 to August 2023 that addressed fibroblast uses in clinical trials of skin conditions were obtained from bibliographic databases like PubMed, Scopus, and Web of Science (WoS). Precise inclusion and exclusion criteria were used during the screening process. The potential benefits of induction treatment with fibroblasts lead to the choosing of clinical trials for this kind of treatment. Results: Out of the 820 published ppapers initially identified, only 35 studies fulfilled our meticulous eligibility criteria after careful screening. To ensure clarity, we methodically eliminated any duplicate or irrelevant published papers, thereby offering a transparent account of our selection process. Conclusion: This study highlights the advantages of fibroblast therapy in treating skin conditions such as diabetic foot, venous leg ulcers, and cosmetic reasons. Fibroblasts possess remarkable regenerating capabilities, making dermal fibroblast therapy crucial in cell-based and skin regenerative treatments. Nevertheless, additional research is required for more disorders and cosmetic applications. [ABSTRACT FROM AUTHOR]

Chronic kidney disease poses a significant threat to public health. Renal replacement therapy is the primary treatment option for end-stage kidney disease. However, there is a promising and relatively new method in regenerative medicine for creating a functional organ known as whole kidney decellularization. This method uses the intrinsic vasculature to perfuse the decellularizing agent into the tissue, effectively penetrating and removing cellular material. The regenerated bioscaffolds could serve as a source of organ donation. This study is focused on evaluating the effectiveness of various SDS exposures in decellularizing human fetal kidneys. The study included human fetal kidneys harvested from fetuses terminated before 14 weeks of gestational age. Kidneys were divided into six treatment groups based on SDS concentration and duration of perfusion. Decellularization, scanning electron microscopy, histopathological staining, immunofluorescent staining, and immunohistochemistry staining were performed to evaluate the adequacy of the process. The statistical analysis revealed that the SDS 0.1% treatment group had the highest collagen deposition after 24 h, significantly greater than the SDS 0.5% treatment group at 24 and 48 h. No significant differences were observed among the other treatment groups. The study concludes that the SDS 0.1% treatment group for 24 h was the most effective in terms of ECM content preservation and effective cell removal. This treatment showed better results than the other treatment groups and can be considered for future whole kidney decellularization studies. [ABSTRACT FROM AUTHOR]

Stem cells, ideal for the tissue repair and regeneration, possess extraordinary capabilities of multidirectional differentiation and self‐renewal. However, the limited spontaneous differentiation potential makes it challenging to harness them for tissue repair without external intervention. Although conventional approaches using biomolecules, small organic molecules, and ions have shown specific and effective functions, they face challenges such as in vivo diffusion and degradation, poor internalization, and side effects on adjacent cells. Nanoengineered biomaterials offer a solution by solidifying and nanosizing these soluble regulating molecules and ions, facilitating their uptake by stem cells. Once inside lysosomes, these nanoparticles release their contents in a controlled “molecule or ion storm,” efficiently altering the intracellular biological and chemical microenvironment to tune the differentiation of stem cells. This newly emerged approach for regulating stem cell fate has attracted much attention in recent years. This method has shown promising results and is poised to enhance clinical stem cell therapy. This review provides an overview of the design principles for nanoengineered biomaterials, discusses the categories and characteristics of nanoparticles, summarizes the application of nanoparticles in tissue repair and regeneration, and discusses the direction of nanoparticle‐enhanced stem cell therapy and prospects for its clinical application in regenerative medicine. [ABSTRACT FROM AUTHOR]

Background: Exosomes are cell-derived nanovesicles that transport proteins, nucleic acids, and lipids and play a significant role in almost every physiological process in the human body. They have generated great interest, especially in the field of tissue regeneration. Studies in the last decade support their great regenerating and rejuvenating potential. However, the lack of standardized procedures, limited knowledge regarding their action mechanism, and little clinical evidence impair their implementation and approval in the medical setting. This review aimed to identify published studies and clinical trials using exosomes in human patients for clinical treatments in aesthetic medicine. Materials and Methods: A systematic search was conducted in the PubMed database using the search term "exosomes" and 25 terms related to aesthetic medicine treatments in human patients. Additionally, a search was conducted in the ClinicalTrials.gov database for interventional clinical trials using exosomes for aesthetic treatments in adults 18 to ≥ 65 years of age. Results: Nine articles were selected after debugging the initial list of published articles in which exosomes were related to Aesthetic Medicine (633 articles). Nine studies were identified from the initial search on ClinicalTrial.gov (104 trials with exosomes). Conclusions: There is no doubt about the scientific basis of exosome regenerative potential and the growing interest in exosomes in Aesthetic Medicine. However, companies must spend more on research to develop standardized and reliable procedures to obtain exosomes for their approval and application in clinical practice. Level of Evidence III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. This review highlights the large amount of published research on exosomes related to aesthetic medicine and, at the same time, the lack of products approved by regulatory agencies. Several issues have been suggested to elucidate a response, such as the need for standardized protocols and more knowledge to ensure safe treatments. It also highlights the few clinical trials conducted to evaluate exosome properties in aesthetic medicine treatments. [ABSTRACT FROM AUTHOR]

Bioresorbable shape memory polymers (SMP) are an emerging class of polymers that can help address several challenges associated with minimally invasive surgery by providing a solution for structural tissue repair. Like most synthetic polymer networks, SMPs require additional biorelevance and modification for biomedical applications. Methodologies used to incorporate bioactive ligands must preserve SMP thermomechanics and ensure biofunctionality following in vivo delivery. We have previously described the development of a novel thermoresponsive bioresorbable SMP, poly (glycerol dodecanedioate) (PGD). In this study, cell-adhesive peptide sequences RGD and YIGSR were conjugated with PGD. We investigated 1) the impact of conjugated peptides on the fixity (R f), recovery (R r), and recovery rate (dR r /dT), 2) the impact of conjugated peptides on cell binding, and 3) the impact of the shape memory cycle (T prog) on conjugated peptide functionality towards binding human bone marrow stromal cells (BMSC). Peptide conjugation conditions impact fixity but not the recovery or recovery rate (p < 0.01). Peptide-conjugated substrates increased cell attachment and proliferation compared with controls (p < 0.001). Using complementary integrin binding cell-adhesive peptides increased proliferation compared with using single peptides (p < 0.05). Peptides bound to PGD substrates exhibited specificity to their respective integrin targets. Following the shape memory cycle, peptides maintained functionality and specificity depending on the shape memory cycle conditions (p < 0.001). The dissipation of strain energy during recovery can drive differential arrangement of conjugated sequences impacting functionality, an important design consideration for functionalized SMPs. Shape memory elastomers are an emerging class of polymers that are well-suited for minimally invasive repair of soft tissues. Tissue engineering approaches commonly utilize biodegradable scaffolds to deliver instructive cues, including cells and bioactive signals. Delivering these instructive cues on biodegradable shape memory elastomers requires modification with bioactive ligands. Furthermore, it is necessary to ensure the specificity of the ligands to their biological targets when conjugated to the polymer. Moreover, the bioactive ligand functionality must be conserved after completing the shape memory cycle, for applications in tissue engineering. [Display omitted] [ABSTRACT FROM AUTHOR]

With the size of the aging population increasing worldwide, the effective diagnosis and treatment of neurodegenerative diseases (NDDs) has become more important. Two-dimensional (2D) materials offer specific advantages for the diagnosis and treatment of NDDs due to their high sensitivity, selectivity, stability, and biocompatibility, as well as their excellent physical and chemical characteristics. As such, 2D materials offer a promising avenue for the development of highly sensitive, selective, and biocompatible theragnostics. This review provides an interdisciplinary overview of advanced 2D materials and their use in biosensors, drug delivery, and tissue engineering/regenerative medicine for the diagnosis and/or treatment of NDDs. The development of 2D material-based biosensors has enabled the early detection and monitoring of NDDs via the precise detection of biomarkers or biological changes, while 2D material-based drug delivery systems offer the targeted and controlled release of therapeutics to the brain, crossing the blood–brain barrier and enhancing treatment effectiveness. In addition, when used in tissue engineering and regenerative medicine, 2D materials facilitate cell growth, differentiation, and tissue regeneration to restore neuronal functions and repair damaged neural networks. Overall, 2D materials show great promise for use in the advanced treatment of NDDs, thus improving the quality of life for patients in an aging population. [ABSTRACT FROM AUTHOR]

Bone diseases such as osteoporosis and osteoarthritis have become important human health problems, requiring a deeper understanding of the pathogenesis of related diseases and the development of more effective treatments. Bone organoids are three-dimensional tissue masses that are useful for drug screening, regenerative medicine, and disease modeling because they may mimic the structure and physiological activities of organs. Here, we describe various potential methods for culturing bone-related organoids from different stem cells, detailing the construction processes and highlighting the main applications of these bone organoid models. The application of bone organoids in different skeletal diseases is highlighted, and current and promising bone organoids for drug screening and regenerative medicine as well as the latest technological advancements in bone organoids are discussed, while the future development of bone organoids is discussed. Looking forward, it will provide a reference for constructing bone organoids with more complete structures and functions and applying them to biomedical research. [ABSTRACT FROM AUTHOR]

Background: Acute cholecystitis, inflammation of the gallbladder, can lead to serious complications if not promptly diagnosed and managed. Conventional therapies have limitations, necessitating newer personalized approaches. This review examines recent advances transforming cholecystitis care. Diagnostically, molecular techniques like next-generation sequencing rapidly identify causative microbes from gallbladder specimens, enabling targeted antimicrobial therapy. Regarding treatment, phage therapy uses viruses to lyse pathogenic bacteria. RNA interference and CRISPR-Cas9 gene editing silence microbial virulence factors. Probiotics competitively exclude pathogens. Robotics and fluorescence imaging refine surgical techniques. Additional emerging modalities include biosensors detecting inflammatory mediators, regenerative gallbladder tissue engineering using stem cells, and artificial intelligence for real-time decision support. However, the optimal integration of novel technologies with current best practices remains unknown. Further research is needed to validate and optimize personalized diagnostics and therapeutics for cholecystitis. Short conclusions: Advances in next-generation sequencing, CRISPR gene editing, robotics, and other biotechnologies promise to transform the precision and personalized management of cholecystitis when thoughtfully implemented. However, controlled trials are still required to define optimal integration with conventional supportive care and antibiotics. [ABSTRACT FROM AUTHOR]

This study aimed to assess the role of the combination of design techniques of the engineered substrates, and the effect of encapsulating Marjoram (Origanum Majorana L.) into the matrix network was studied. To this end, PVA-PEG matrices were designed through 3 techniques of freeze–thaw (FT), the combination of both methods of freeze-drying and freeze-thawing(FT-FD), and ternary technique(freeze-drying,freeze-thawing,cross-linking(FT-FD/CL)), by combining equal volume ratios of both polymers. The results indicated the ternary technique can provide better physicochemical properties(porosity: 96%, lower degradation rate, higher modulus) compared to FT and FT-FD methods. Afterward, encapsulation of Marjoram-extracted bio-actives in the matrix network designed with the ternary technique demonstrated that the increase in the extract concentration up to 3% can increase encapsulation efficiency. The encapsulation also caused a more cohesive network by better bonding between functional groups in herbal biomolecules and polymer chains of the matrix. Mass transport mechanisms and release kinetics of matrix-encapsulated bio-actives indicated a deviation from Fickian diffusion and the release by diffusion and swelling process. Biologically, matrix-loaded herbal carbohydrate(Epi-alpha-Cadinol) improved fibroblast adhesion and distribution on the substrate surface, and led to the better synthesis of collagen fibers, especially in 3% herbal extract, and antibacterial activities owing to the controlled release of sesquiterpenoids and N-Acetyl-l-proline. [ABSTRACT FROM AUTHOR]

Background: Neural cell-electrode coupling is crucial for effective neural and retinal prostheses. Enhancing this coupling can be achieved through surface modification and geometrical design to increase neuron-electrode proximity. In the current research, we focused on designing and studying various biomolecules as a method to elicit neural cell-electrode adhesion via cellspecific integrin mechanisms. Methods: We designed extracellular matrix biomimetic molecules with different head sequences (RGD or YIGSR), structures (linear or cyclic), and spacer lengths (short or long). These molecules, anchored by a thiol (SH) group, were deposited onto gold surfaces at various concentrations. We assessed the modifications using contact angle measurements, fluorescence imaging, and X-ray Photoelectron Spectroscopy (XPS). We then analyzed the adhesion of retinal cells and HEK293 cells to the modified surfaces by measuring cell density, surface area, and focal adhesion spots, and examined changes in adhesion-related gene and integrin expression. Results: Results showed that YIGSR biomolecules significantly enhanced retinal cell adhesion, regardless of spacer length. For HEK293 cells, RGD biomolecules were more effective, especially with cyclic RGD and long spacers. Both cell types showed increased expression of specific adhesion integrins and proteins like vinculin and PTK2; these results were in agreement with the adhesion studies, confirming the cell-specific interactions with modified surfaces. Conclusion: This study highlights the importance of tailored biomolecules for improving neural cell adhesion to electrodes. By customizing biomolecules to foster specific and effective interactions with adhesion integrins, our study provides valuable insights for enhancing the integration and functionality of retinal prostheses and other neural implants. [ABSTRACT FROM AUTHOR]

Platelet-rich plasma (PRP) has emerged as a promising therapeutic approach in regenerative medicine. It contains various growth factors and bioactive molecules that play pivotal roles in tissue repair, regeneration, and inflammation modulation. This comprehensive narrative review delves into the therapeutic potential of PRP in experimental goat and sheep research, exploring recent advancements, challenges, and future prospects in the field. PRP has been explored for its application in musculoskeletal injuries, wound healing, and orthopedic conditions. Studies have demonstrated the ability of PRP to accelerate tissue healing, reduce inflammation, and improve the overall quality of healing. Recent advancements in PRP technology have led to the development of novel formulations and delivery methods to enhance its therapeutic efficacy. PRP has shown promise in tendon and ligament injuries, osteoarthritis, and bone fractures in experimental goat and sheep research. Despite these advancements, several challenges and opportunities exist to harness the full therapeutic potential of PRP in regenerative medicine. Standardizing PRP preparation protocols, including blood collection techniques, centrifugation parameters, and activation methods, is essential to ensure consistency and reproducibility of the findings. Moreover, further research is needed to elucidate the optimal dosing, frequency, and timing of PRP administration for different clinical indications. Research conducted in goat and sheep models provides evidence supporting the translational potential of PRP in tissue engineering and regenerative medicine. By harnessing the regenerative properties of PRP and leveraging insights from preclinical studies, researchers can develop innovative therapeutic strategies to address unmet clinical needs and improve patient outcomes in diverse medical specialties. [ABSTRACT FROM AUTHOR]

Bioelectronics is a hot research topic, yet an important tool, as it facilitates the creation of advanced medical devices that interact with biological systems to effectively diagnose, monitor and treat a broad spectrum of health conditions. Electrical stimulation (ES) is a pivotal technique in bioelectronics, offering a precise, non-pharmacological means to modulate and control biological processes across molecular, cellular, tissue, and organ levels. This method holds the potential to restore or enhance physiological functions compromised by diseases or injuries by integrating sophisticated electrical signals, device interfaces, and designs tailored to specific biological mechanisms. This review explains the mechanisms by which ES influences cellular behaviors, introduces the essential stimulation principles, discusses the performance requirements for optimal ES systems, and highlights the representative applications. From this review, we can realize the potential of ES based bioelectronics in therapy, regenerative medicine and rehabilitation engineering technologies, ranging from tissue engineering to neurological technologies, and the modulation of cardiovascular and cognitive functions. This review underscores the versatility of ES in various biomedical contexts and emphasizes the need to adapt to complex biological and clinical landscapes it addresses. [ABSTRACT FROM AUTHOR]

AbstractOral diseases are a prevalent global issue, causing significant health and economic burdens that greatly diminish the quality of life for affected individuals. Tissue engineering strategies employing scaffolds offer a promising approach to restoring the original structures and biological functions of dental and dentoalveolar tissues. Among the various building materials, polysaccharides, known for their inherent biocompatibility, have gained significant attention. Topical advances in tissue engineering have led to the fabrication of composite scaffolds with the greatest utilization of favorable properties of each material. This review aims to explore the application of polysaccharide-based composite scaffolds for regenerating dental and dentoalveolar tissues, including both hard and soft tissues, as well as tissue complexes. To begin, we will provide a brief overview to commonly used polysaccharides. Subsequently, we will introduce the commonly used forms of composite polysaccharide scaffolds together with fabricating, engineering, and optimizing methods for dental and dentoalveolar tissue regeneration. Next, we will examine the latest progress and the potential of polysaccharide composite scaffolds in dental and dentoalveolar tissue regeneration applications. To conclude, this review will reflect on the limitations and prospects associated with polysaccharide composite scaffolds for dental and dentoalveolar tissue regeneration. By addressing these aspects, we aim to contribute to the understanding and development of effective strategies for improving oral health outcomes. [ABSTRACT FROM AUTHOR]