Skin derived precursors induced Schwann cells mediated tissue engineering-aided neuroregeneration across sciatic nerve defect

Transcriptomic and proteomic integrated analysis reveals molecular mechanisms of 3D bioprinted vaginal scaffolds in vaginal regeneration

3D Bioprinting technology has been applied to vaginal reconstruction with satisfactory results. Understanding the transcriptome and proteome of regenerated vaginas is essential for knowing how biomaterials and seed cells contribute to vaginal regeneration. There are no reports on the systemic analysis of vaginal regeneration transcriptomes or proteomes. This study aims to explore the transcriptomic and proteomic features of vaginal tissue reconstructed with 3D bioprinted scaffolds. The scaffolds were made with biomaterials and bone marrow-derived mesenchymal stem cells (BMSCs) and then transplanted into a rabbit model.rna sequencing was used to analyze the transcriptomes of reconstructed and normal vaginal tissues, identifying 11,956 differentially expressed genes (DEGs). Proteomic analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and data-independent acquisition (DIA) identified 7,363 differentially expressed proteins (DEPs). Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses were performed on DEGs and deps. Results showed that DEGs and deps.were involved in extracellular matrix remodeling, angiogenesis, inflammatory response, epithelialization, and muscle formation. This study shows that 3D bioprinted scaffolds are feasible for vaginal reconstruction and offers new insights into the molecular mechanisms involved.

Optimally Aligned Nerve Scaffolds with Sustained Astaxanthin Release Improve the Inflammatory Microenvironment through Mitophagy Activation

Effective repair of peripheral nerve injury (PNI) depends on the scaffold orientation and immunomodulatory capabilities of functionalized scaffolds, both of which substantially influence nerve regeneration. In this study, composite nerve scaffolds incorporating astaxanthin (AXT) and polycaprolactone (PCL) are developed to investigate the influence of scaffold orientation and blend concentration on cellular behavior, including adhesion, migration, and proliferation. In vitro analysis identifies 0.2% AXT/PCL fabricated at a rotational speed of 400 rpm as the optimal configuration for facilitating directed cell growth and guiding nerve repair. Moreover, the controlled release of AXT improves the microenvironment by preserving mitochondrial homeostasis, promoting mitophagy, and reducing oxidative stress and inflammation. In vivo assessments reveal that the AXT/PCL group (0.2% AXT/PCL-400) achieves better morphological, histological, electrophysiological, and functional recovery than the PCL, AXT/PCL+M0, and AXT/PCL+M4 groups, approaching the outcomes observed in the autograft (Auto) group. Moreover, the AXT/PCL+M4 group demonstrates better regenerative outcomes than the PCL and AXT/PCL+M0 groups, underscoring the critical role of mitophagy in regulating the regenerative microenvironment.

Chitosan conduits for peripheral nerve repair: a systematic review of animal studies

Peripheral nerve injuries are major causes of disability worldwide. The current standard treatment, autologous nerve grafting, puts the donor region at risk and has limited availability. A systematic search of MEDLINE, EMBASE, and Web of Science databases for studies published between January 1, 2008, and September 04, 2024, was performed to compare interventions using chitosan tubes with non-intervention or autologous nerve grafts in rats with artificially injured sciatic nerves. Twenty-one experimental studies including 738 animals were selected. Nerve repair using chitosan conduits resulted in a higher sciatic functional index compared to non-intervention. Higher conduction velocity and a greater number of myelinated fibers were observed in nerve fibers treated with chitosan compared to the no intervention or primary repair groups. However, compound muscle action potentials and somatosensory evoked potentials were superior in the latter compared to nerves treated with the polymer.

Potentially commercializable nerve guidance conduits for peripheral nerve injury: Past, present, and future

Peripheral nerve injuries are a prevalent global issue that has garnered great concern. Although autografts remain the preferred clinical approach to repair, their efficacy is hampered by factors like donor scarcity. The emergence of nerve guidance conduits as novel tissue engineering tools offers a promising alternative strategy. This review aims to interpret nerve guidance conduits and their commercialization from both clinical and laboratory perspectives. To enhance comprehension of clinical situations, this article provides a comprehensive analysis of the clinical efficacy of nerve conduits approved by the United States Food and Drug Administration. It proposes that the initial six months post-transplantation is a critical window period for evaluating their efficacy. Additionally, this study conducts a systematic discussion on the research progress of laboratory conduits, focusing on biomaterials and add-on strategies as pivotal factors for nerve regeneration, as supported by the literature analysis. The clinical conduit materials and prospective optimal materials are thoroughly discussed. The add-on strategies, together with their distinct obstacles and potentials are deeply analyzed. Based on the above evaluations, the development path and manufacturing strategy for the commercialization of nerve guidance conduits are envisioned. The critical conclusion promoting commercialization is summarized as follows: 1) The optimization of biomaterials is the fundamental means; 2) The phased application of additional strategies is the emphasized direction; 3) The additive manufacturing techniques are the necessary tools. As a result, the findings of this research provide academic and clinical practitioners with valuable insights that may facilitate future commercialization endeavors of nerve guidance conduits.

Advances in biomaterial-based tissue engineering for peripheral nerve injury repair

Peripheral nerve injury is a common clinical disease. Effective post-injury nerve repair remains a challenge in neurosurgery, and clinical outcomes are often unsatisfactory, resulting in social and economic burden. Particularly, the repair of long-distance nerve defects remains a challenge. The existing nerve transplantation strategies show limitations, including donor site morbidity and immune rejection issues. The multiple studies have revealed the potential of tissue engineering strategies based on biomaterials in the repair of peripheral nerve injuries. We review the events of regeneration after peripheral nerve injury, evaluates the efficacy of existing nerve grafting strategies, and delves into the progress in the construction and application strategies of different nerve guidance conduits. A spotlight is cast on the materials, technologies, seed cells, and microenvironment within these conduits to facilitate optimal nerve regeneration. Further discussion was conducted on the approve of nerve guidance conduits and potential future research directions. This study anticipates and proposes potential avenues for future research, aiming to refine existing strategies and uncover innovative approaches in biomaterial-based nerve repair. This study endeavors to synthesize the collective insights from the fields of neuroscience, materials science, and regenerative medicine, offering a multifaceted perspective on the role of biomaterials in advancing the frontiers of peripheral nerve injury treatment.

Biomimetic ECM nerve guidance conduit with dynamic 3D interconnected porous network and sustained IGF-1 delivery for enhanced peripheral nerve regeneration and immune modulation

Recent advancements in tissue engineering have promoted the development of nerve guidance conduits (NGCs) that significantly enhance peripheral nerve injury treatment, improving outcomes and recovery rates. However, utilising tailored biomimetic three-dimensional (3D) topological porous structures combined with multiple bio-effect neurotrophic factors to create environments similar to neural tissues, regulate local immune responses, and develop a supportive microenvironment to promote peripheral nerve regeneration and repair poses significant challenges. Herein, a biomimetic extracellular matrix (ECM) NGC featuring an interconnected 3D porous network and sustained delivery of insulin-like growth factor-1 (IGF-1) is designed using multi-functional gelatine microcapsules (GMs). Nerve conduits made by blending chitosan (CS) with GMs demonstrate suitable degradation rates, reduced swelling rates, increased suture tensile strength, improved elongation at break, and 50 % radial compression performance that meet clinical application requirements. In vitro cytological studies indicate that biomimetic ECM NGCs exhibit good biocompatibility, promote early survival, proliferation, and remyelination potential of Schwann cells (SCs), and support neurite outgrowth. The biomimetic ECM NGCs comprising a 3D interconnected porous network in a 10-mm sciatic nerve defect rat model sustain IGF-1 delivery, promoting early infiltration of macrophages and polarisation towards M2-type macrophages. Furthermore, observations at 12 weeks post-implantation revealed improvements in electrophysiological performance, alleviation of gastrocnemius muscle atrophy, increased peripheral nerve regeneration, and motor function restoration. Thus, biomimetic ECM NGCs offer a therapeutic strategy for peripheral nerve regeneration with promising clinical applications and transformation prospects to regulate immune microenvironments, promoting SC proliferation and differentiation with nerve axon growth.

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.

Hybrid construction of tissue-engineered nerve graft using skin derived precursors induced neurons and Schwann cells to enhance peripheral neuroregeneration

Peripheral nerve injury is a major challenge in clinical treatment due to the limited intrinsic capacity for nerve regeneration. Tissue engineering approaches offer promising solutions by providing biomimetic scaffolds and cell sources to promote nerve regeneration. In the present work, we investigated the potential role of skin-derived progenitors (SKPs), which are induced into neurons and Schwann cells (SCs), and their extracellular matrix in tissue-engineered nerve grafts (TENGs) to enhance peripheral neuroregeneration. SKPs were induced to differentiate into neurons and SCs in vitro and incorporated into nerve grafts composed of a biocompatible scaffold including chitosan neural conduit and silk fibroin filaments. In vivo experiments using a rat model of peripheral nerve injury showed that TENGs significantly enhanced nerve regeneration compared to the scaffold control group, catching up with the autograft group. Histological analysis showed improved axonal regrowth, myelination and functional recovery in animals treated with these TENGs. In addition, immunohistochemical staining confirmed the presence of induced neurons and SCs within the regenerated nerve tissue. Our results suggest that SKP-induced neurons and SCs in tissue-engineered nerve grafts have great potential for promoting peripheral nerve regeneration and represent a promising approach for clinical translation in the treatment of peripheral nerve injury. Further optimization and characterization of these engineered constructs is warranted to improve their clinical applicability and efficacy.

Graphene/ chitosan tubes inoculated with dental pulp stem cells promotes repair of facial nerve injury

Introduction: Facial nerve injury significantly impacts both the physical and psychological] wellbeing of patients. Despite advancements, there are still limitations associated with autografts transplantation. Consequently, there is an urgent need for effective artificial grafts to address these limitations and repair injuries. Recent years have witnessed the recognition of the beneficial effects of chitosan (CS) and graphene in the realm of nerve repair. Dental pulp stem cells (DPSCs) hold great promise due to their high proliferative and multi-directional differentiation capabilities. Methods: In this study, Graphene/CS (G/CST) composite tubes were synthesized and their physical, chemical and biological properties were evaluated, then DPSCs were employed as seed cells and G/CST as a scaffold to investigate their combined effect on promoting facial nerve injury repair. Results and Disscussion: The experimental results indicate that G/CST possesses favorable physical and chemical properties, along with good cyto-compatibility. making it suitable for repairing facial nerve transection injuries. Furthermore, the synergistic application of G/CST and DPSCs significantly enhanced the repair process for a 10 mm facial nerve defect in rabbits, highlighting the efficacy of graphene as a reinforcement material and DPSCs as a functional material in facial nerve injury repair. This approach offers an effective treatment strategy and introduces a novel concept for clinically managing facial nerve injuries.