Journal of Tissue Engineering and Regenerative Medicine最新文献

Background: The induced membrane (IM) preclinical models have been described in small animals, but few studies have looked at bone regeneration achievement. The optimisation and validation of such a preclinical model, considering the results obtained after the use of biomaterials as a substitute for bone grafting, could lead to simplifying the surgical procedure and enhance the clinical results.

Methods: An in vivo model of the IM technique was developed on the femur of Lewis rats after a 4-mm critical bone defect stabilised with an osteosynthesis plate. A first optimisation phase was performed by evaluating different osteotomy methods and two different osteosynthesis plate sizes. The efficiency of the model was evaluated by the failure rate obtained 6 weeks after the first operative time. Thereafter, bone regeneration was evaluated histologically and radiologically at 24 weeks to confirm the critical nature of the bone defect (negative control), the effectiveness of the IM with a syngeneic bone graft (positive control) and the possibility of using a biomaterial (GlassBone Noraker) in this model.

Results: Sixty-three rats were included and underwent the first surgical step. Nineteen rats subsequently underwent the second surgical step. The results obtained led to select piezotomy as the best osteotomy technique and 1-mm-thick plates with 2.0-mm-diameter screws as osteosynthesis material. Twenty-four weeks after the second surgical step, solely the group with both surgical steps and a syngeneic bone graft showed complete ossification of the bone defect. In contrast, the group without a graft did not present a suitable ossification, which confirms the critical nature of the defect. IM produced an incomplete bone regeneration using GlassBone alone.

Conclusions: A piezotome osteotomy with an osteosynthesis plate of sufficient stiffness is required for this two-stage bone regeneration model in rats. The 4-mm bone defect is critical for this model and suitable for biomaterial evaluation.

Bone marrow–derived mesenchymal stem cells (BM-MSCs) are well established for their osteogenic potential but are prone to senescence with aging or in vitro expansion. Drug treatments that reduce cellular senescence may enhance the regenerative capacity of BM-MSCs. This study investigates the effects of losartan and fisetin, both separately and in combination, on cellular senescence and osteogenesis. Human BM-MSCs were exposed to low and high concentrations of each drug for 24 h. Our findings showed that high-dose losartan exhibited cytotoxicity, focusing subsequent analyses on the low doses. Both low-dose losartan and fisetin effectively mitigated cellular senescence, with combined treatment showing synergistic effects in reducing senescence markers. From these initial findings, subsequent experiments utilized low doses of both compounds to evaluate their effect on differentiation capacity. Our multimodal approach, incorporating flow cytometry, senescence-associated heterochromatin foci (SAHF) immunohistochemistry, senescence-associated secretory phenotype (SASP) quantification, and differentiation potential assays, revealed that the combination of 23.6 μM of losartan and 50 μM of fisetin was optimal for reducing cellular senescence and enhancing osteogenesis in BM-MSCs. These results support potential therapeutic strategies to counteract age-related declines in bone health and improve healing. By targeting cellular senescence while promoting osteogenesis, losartan and fisetin offer promising avenues for future research aimed at enhancing the regenerative capacity of BM-MSCs in the context of musculoskeletal regenerative medicine.

Background: Tendon injuries are increasingly common and heal by fibrosis rather than scar-less regeneration. Tissue engineering seeks to improve repair using synthetic polymer scaffolds with biomimetic factors to enhance the regenerative potential.

Methods: In this study, we compared three groups, namely, poly(lactic acid) (PLA) meltblown scaffolds, PLA meltblown scaffolds coated with tendon-derived matrix (TDM), and PLA meltblown scaffolds with carbodiimide crosslinked TDM (2.5:1:1 EDC:NHS:COOH ratio) (EDC-TDM) and determined their potential for engineered tendon development. We cultured human adipose stem cells (hASCs) for 28 days on meltblown scaffolds (n = 4–6/group) and measured tensile mechanical function, matrix synthesis, and matrix composition using biochemical assays and proteomics.

Results: Coating PLA meltblown scaffolds with TDM improved yield stretch and stress at 28 days compared with PLA. Matrix synthesis rates for TDM or EDC-TDM were similar to PLA. Proteomic analysis revealed that hASCs produced a collagen-rich extracellular matrix, with many tendon-related matrix proteins. Coating scaffolds with TDM led to an increase in collagen type I whereas EDC-TDM scaffolds had an increase in glycoproteins and ECM regulators compared with other groups, consistent with increased maturity of the newly deposited matrix.

Conclusions: TDM coating and crosslinking of meltblown scaffolds demonstrated matricellular benefits for the proteome of engineered tendon development but provided fewer clear benefits toward mechanical, biochemical, and rate of matrix accumulation than expected, and that previous work with electrospun scaffolds would suggest. However, electrospun scaffolds have different fiber structure and microarchitecture than meltblown, suggesting that further consideration of these differences and refinement of TDM application methods to meltblown scaffolds is required.

Bone defects are becoming a true challenge in global health care due to the aging population and higher prevalence of musculoskeletal disorders. The interest in using plant-origin compounds and plant-derived biomaterials in bone tissue engineering (BTE) has been increased due to their availability (abundance), safety, biocompatibility, biodegradability, and low cost. Plant-origin compounds have supportive effects on bone tissue healing, and cell-laden plant-derived biomaterials can be applied in formulating bioinks for three-dimensional (3D) bioprinting to facilitate the preparation of native bone tissue–mimicking structures and customized bone scaffolds. Such plant-derived materials also have the capacity to improve cell viability and support osteoconductive and osteoinductive properties of a bone construct. In this article, we review the ethnomedical aspects related to the use of medicinal plants and plant-origin bioactive compounds in bone healing and the recent developments in the 3D bioprinting of bone constructs with plant-derived biomaterials for advancing BTE. The commonly used 3D-bioprinting techniques, the properties of plant-origin compounds and biomaterials (for bone 3D bioprinting), and the selective examples of bone scaffolds fabricated using plant-derived biomaterials are discussed with a special reference set on applicability, performance, advantages, limitations, and challenges. Plant-origin compounds, biomaterials, and biomimetic 3D-bioprinted constructs could be the basis for a next-generation BTE.

Peripheral neuropathy is painful and can cause a considerable decline in quality of life. Surgery and autograft are the current approaches and clinical standards for restoring function after nerve damage. However, they usually result in unacceptable clinical results, so we need modern peripheral nerve defect treatment approaches. Tissue engineering techniques have been developed as a promising approach, but there are some considerations for translational application. Clinical application of novel tissue engineering methods is related to combining the appropriate cell and scaffold type to introduce safe and efficient bioscaffolds. Efficient nerve regeneration occurs by mimicking the extracellular matrix and combining topographical, biochemical, mechanical, and conductive signs via different cells, biomolecules, and polymers. In brief, ideal engineered biomaterial scaffolds will have to cover all characteristics of nerve tissue, such as nerve number, myelin, and axon thickness. Nerve regeneration has a highly sensitive response to its surrounding microenvironment. For designing a suitable construct, matching the regenerative potential of the autograft as the golden standard is essential. This review article examines the newest advancements in peripheral nerve tissue engineering. Specifically, the discussion will focus on incorporating innovative cues, biological modification, biomaterials, techniques, and concepts in this area of research.

Wound healing is an intricate process involving multiple cells and distinct phases, presenting challenges for comprehensive investigations. Currently available treatments for wounds have limited capacity to fully restore tissue and often require significant investments of time in the form of repetitive dressing changes and/or reapplications. This article presents a novel study that aims to enhance wound healing by developing biomaterial scaffolds using Medpor®, a porous polyethylene implant, as a model scaffold. The study incorporates electrospun poly(e-caprolactone) (PCL) fibers and a protein mixture (PM) containing collagen IV and laminin onto the Medpor® scaffolds. To evaluate the impact of these implants on wound healing, a unique splinted wound model in mice is employed. The wounds were evaluated for closure, inflammation, collagen deposition, angiogenesis, epithelialization, and proliferation. The results show that wounds treated with Medpor® + PCL + PM implants demonstrate accelerated closure rates, improved epithelialization, and enhanced angiogenesis compared to other implant groups. However, there were no significant differences observed in collagen deposition and inflammatory response among the implant groups. This study provides valuable insights into the potential benefits of incorporating PCL fibers and a PM onto scaffolds to enhance wound healing. Furthermore, the developed splinted wound model with integrated implants offers a promising platform for future studies on implant efficacy and the advancement of innovative wound healing strategies.

The challenge in developing tissue-engineered bones (TEBs) for clinical applications lies in the constraints associated with the source and availability of autologous mesenchymal stem cells (MSCs) derived from the bone marrow, which creates a bottleneck. While allogeneic MSCs have shown promise in TEB applications, their ability to promote bone growth is notably diminished because of the inflammatory reaction at the transplant site and the inherent immune response triggered by allogeneic MSCs. Hence, there is a pressing need to develop methods that enhance the osteogenic differentiation of allogeneic MSCs during transplantation. Previous studies have found that IL-17 is a key proinflammatory factor in initiating inflammation and cascade amplification in the early stages of an inflammatory response, and proinflammatory cytokines such as TNF-α and IL-17 can inhibit the osteogenic differentiation of MSCs in an immune environment. In this study, MSCs expressing HVEM were successfully constructed by viral transfection and further reconfirmed that IL-17 can inhibit the in vivo and in vitro osteogenesis of allogeneic MSCs through in vitro experiments and mouse calvarial bone defect (diameter about 3 mm) model, while MSCs that express herpesvirus-entry mediator (HVEM) exhibit the capacity to suppress immune responses and sustain strong osteogenic potential. We further pointed out that the mechanism by which HVEM promotes the osteogenesis of allogeneic MSCs is related to its inhibition of the IκB kinase (IKK)-NF-κB signaling pathway activated by IL-17 in the immune environment, which can significantly inhibit the ubiquitination and degradation of β-catenin in MSCs induced by the IKK-NF-κB pathway, upregulate the expression of β-catenin, and promote bone formation. Hence, this research provides an initial connection between the Wnt/β-catenin signaling pathway and the IKK-NF-κB pathway during allogeneic MSC transplantation, offering new avenues for investigation and establishing a theoretical foundation for the potential use of HVEM-expressing MSCs in clinical treatments for bone defects.

Persistent air leaks caused by thoracic surgery, physical trauma, or spontaneous pneumothoraces are a cause of patient morbidity with need for extended chest tube durations and surgical interventions. Current treatment measures involve mechanical closure of air leaks in the compromised pleura. Organ and membrane decellularisation offers a broad range of biomimetic scaffolds of allogeneic and xenogeneic origins, exhibiting innate tissue-specific characteristics. We explored a physicochemical method for decellularising porcine pleural membranes (PPM) as potential tissue-engineered surrogates for lung tissue repair. Decellularised PPM (dPPM) was characterised with histology, quantitative assays, mechanical testing, and sterility evaluation. Cytotoxicity and recellularisation assays assessed biocompatibility of decellularised PPM (dPPM). Haematoxylin and Eosin (H&E) staining showed an evident reduction in stained nuclei in the dPPM, confirmed with nuclear staining and analysis ( ^∗∗∗∗p < 0.0001). Sulphated glycosaminoglycans (sGAG) and collagen histology demonstrated minimal disruption to the gross structural assembly of core extracellular matrix (ECM) in dPPM. Confocal imaging demonstrated realignment of ECM fibres in dPPM against native control. Quantitative analysis defined a significant change in the angular distribution ( ^∗∗∗∗p < 0.0001) and coherence ( ^∗∗∗p < 0.001) of fibre orientations in dPPM versus native ECM. DNA quantification indicated ≥85% reduction in native nuclear dsDNA in dPPM ( ^∗∗p < 0.01). Collagen and sGAG quantification indicated reductions of both ( ^∗∗p < 0.01). dPPM displayed increased membrane thickness ( ^∗∗∗p < 0.001). However, Young’s modulus (459.67 ± 10.36 kPa) and ultimate tensile strength (4036.22 ± 155.1 kPa) of dPPM were comparable with those of native controls at (465.82 ± 10.51 kPa) and (3912.9 ± 247.42 kPa), respectively. In vitro cytotoxicity and scaffold biocompatibility assays demonstrated robust human mesothelial cell line (MeT-5A) attachment and viability. DNA quantification in reseeded dPPM with MeT-5A cells exhibited significant increase in DNA content at day 7 ( ^∗∗p < 0.01) and day 15 ( ^∗∗∗∗p < 0.0001) against unseeded dPPM. Here, we define a decellularisation protocol for porcine pleura that represents a step forward in their potential tissue engineering applications as bioscaffolds.

Tissue engineering is a promising approach for the production of small-diameter vascular grafts; however, there are limited data directly comparing the suitability of applicable cell types for vessel biofabrication. Here, we investigated the potential of adult smooth muscle cells (SMCs), placental mesenchymal stem cells (MSCs), placental endothelial colony-forming cells (ECFCs), and a combination of MSCs and ECFCs on highly porous biocompatible poly(ɛ-caprolactone) (PCL) scaffolds produced via melt electrowriting (MEW) for the biofabrication of tissue-engineered vascular grafts (TEVGs). Cellular attachment, proliferation, and deposition of essential extracellular matrix (ECM) components were analysed in vitro over four weeks. TEVGs cultured with MSCs accumulated the highest levels of collagenous components within a dense ECM, while SMCs and the coculture were more sparsely populated, ascertained via histological and immunofluorescence imaging, and biochemical assessment. Scanning electron microscopy (SEM) enabled visualisation of morphological differences in cell attachment and growth, with MSCs and SMCs infiltrating and covering scaffolds completely within the 28-day culture period. Coverage and matrix deposition by ECFCs was limited. However, ECFCs lined the ECM formed by MSCs in coculture, visualised via immunostaining. Thus, of cells investigated, placental MSCs were identified as the preferred cell source for the fabrication of tissue-engineered constructs, exhibiting extensive population of porous polymer scaffolds and production of ECM components; with the inclusion of ECFCs for luminal endothelialisation, an encouraging outcome warranting further consideration in future studies. In combination, these findings represent a substantial step toward the development of the next generation of small-diameter vascular grafts in the management of cardiovascular disease.