Tissue engineering. Part C, Methods最新文献

In tissue engineering and regenerative medicine, biomaterials have transitioned from passive structural supports to dynamic platforms capable of actively modulating regenerative microenvironments. Their tunable physical and chemical properties, combined with the capacity for controlled release of bioactive signals or extrinsic stimuli, allow precise regulation of stem, immune, and tissue-specific cell behaviors. However, single-modality of signal remains insufficient to recapitulate the multifactorial and spatiotemporally coordinated processes underlying complex tissue regeneration. From a biomaterial perspective, we proposed biomaterial-based multimodal tissue engineering strategy, focusing on the synergy of multimodal cell-regulatory signals for enhanced tissue regeneration. These multifunctional biomaterials serve as advanced artificial regenerative niches, capable of delivering coordinated multimodal signals to precisely guide cellular behavior and tissue formation. Inspired by bionic design principles, decoding the compositional, structural, mechanical, and biological parameters of the native extracellular matrix-and elucidating their regulatory effects and molecular mechanisms on cellular activities-has informed the development of multifunctional biomaterials for tissue regeneration. Key material properties-spanning mechanical, topological, biochemical, and dynamic characteristics-can be strategically engineered to function as distinct yet complementary regulatory signals in this multimodal approach.

The development and implementation of novel treatments for temporomandibular joint disorders (TMDs) are limited by the lack of preclinical models that closely mimic in vivo conditions. Specifically, models that support three-dimensional (3D) cell culture and mechanical stimulation are needed, as both factors significantly influence cell behavior and, consequently, the success of TMDs treatments. We designed a novel 3D in vitro model using cells subjected to dynamic moderate loading (simulating chewing) or constant excessive loading (simulating clenching) applicable as an in vivo-mimetic system for TMDs research. In this study, cylindrical constructs (diameter: 6 mm, height: 3 mm), composed of 3% agarose containing mouse bone marrow mesenchymal stem cells (BMSCs), were cultured in chondrogenic medium. Cells in these constructs exhibited a 3.0-fold increase in Sox9 RNA expression compared to cells inside agarose constructs cultured in proliferation medium and a 2.5-fold increase compared to micromass cultures (golden standard). After confirming the chondrogenic potential, we subjected the cell-agarose constructs to dynamic and constant mechanical loading using a custom-designed bioreactor. The constructs were divided into five groups: unloaded controls, dynamic loading (5% compression at 1 Hz), and constant loading at 10%, 20%, and 30% compression for 20 min per day. Finite element modeling analysis revealed that by increasing the strain compression level, the uniformity of displacement and von Mises stress distribution within the hydrogel will be reduced. Moreover, 30% constant loading compromised the structural integrity of the agarose constructs. Nitric oxide production by BMSCs was significantly elevated in response to 5% dynamic loading (2.8-fold), 20% constant loading (2.7-fold), and 30% constant loading (2.4-fold) after 20 min of stimulation compared to controls. Furthermore, 5% dynamic loading significantly upregulated c-Fos (2.0-fold) and c-Jun (1.5-fold) gene expression relative to controls, while 10% and 20% constant loading also significantly increased c-Jun expression (1.5-fold and 1.6-fold, respectively). Interestingly, 20% constant strain reduced the number of live cells compared with 10% constant loading. These findings demonstrate that a novel 3D preclinical model allowing to investigate cartilage regeneration under in vivo-like physiological and pathological mechanical stimuli has been established, providing a promising platform for future studies on chondroinductive agents and mechanical loading treatments for the TMDs.

Regenerative therapy involving transplanted bone marrow mononuclear cells (BM-MNCs) and hematopoietic stem cells (HSCs) is markedly effective against many diseases. However, manual MNC separation requires skilled labor and cell-processing centers. Thus, efforts have been targeted toward fractionating MNCs using cell separators. A double-blind, placebo-controlled study of myocardial infarction using BM-MNCs separated by an existing device was conducted, and no therapeutic effects were found. The development of a cell separator to replace manual techniques would significantly contribute to the widespread application of BM-MNC therapy. Therefore, we developed a BM-MNC separation device that can reproduce manual separation. We changed the shape of the injection port on the centrifuge container and determined its circuit to improve the performance of HSC separation and remove degenerative red blood cells (RBCs). We assessed HSC recovery and degenerative RBC removal rates using fluorescence-activated cell sorting. Additionally, we evaluated the therapeutic effects of cells separated using our device in mouse models of stroke. The HSC recovery and degenerative RBC removal rates using the device were comparable to those obtained using manual separation. We also confirmed the therapeutic effects of BM-MNCs separated by the device in the models. The new automated device could replace manual cell separation and render cell-based therapy using BM-MNC feasible without laborious manual tasks at dedicated cell-processing centers.

During development and regeneration, bone is formed by endochondral ossification (EO) through the remodeling of a cartilage template. This complex process involves multiple cell types and interactions that cannot currently be modeled in vitro. This study aimed to develop a novel tissue-engineered human in vitro model of certain aspects of the early stages of EO by integrating cartilage which undergoes mineralization, self-assembled vascular networks, and osteoclasts into a single system. We first studied the dynamics of osteoclastogenesis and vascularization in an in vivo model of stromal cell-mediated EO, to inform our in vitro system. Next, we aimed to develop a fully human cell-based three-dimensional model of EO by combining pediatric bone marrow stromal cells differentiating into chondrocytes, osteoclasts derived from human CD14+ monocytes, and human umbilical vein endothelial cells and adipose-derived stromal cells as vessel-forming cells. We investigated how mineralizing cartilage affects osteoclast and vessel formation in vitro through separate cartilage-osteoclasts and cartilage-vessels cocultures. Finally, we combined these elements and established a complex in vitro model that supports the functionality of all these cell types and recapitulates chondrogenesis, cartilage mineralization, vessel formation and osteoclastogenesis. This integrated approach reaches unprecedented complexity and will enable new tissue engineering strategies to model skeletal diseases or cancer metastasis to the bone.

The unique advantages and broad applicability of nanocomposite hydrogels in wound care have become an indispensable driving force for innovative therapeutic strategies. However, comprehensive reviews of their latest research progress, application trends, and strategies remain insufficient. To address this, the present study employs bibliometric methods to systematically analyze the literature on nanocomposite hydrogels in wound care, covering various dimensions, including publication years, major contributing countries and institutions, core authors, publication distribution, and keyword co-occurrence networks. The analysis reveals a significant upward trend in academic attention to this field, with a steady increase in publications. Subsequently, we delve into four research hotspots, including the intelligent responsiveness of nanocomposite hydrogels, their adjustable drug release performance, their ability to promote cell proliferation and differentiation, and their innovative integration with stem cell therapy. Then, we explore the application features of nanocomposite hydrogels in wound healing, focusing on their roles in anti-inflammatory and infection control, promoting cell proliferation and angiogenesis, and providing moisturization and mechanical support. Finally, we discuss the challenges and emerging development trends in wound care using nanocomposite hydrogels, including deep integration with sensor technology, advancements toward artificial intelligence and multifunctionality, and optimization of biosafety. This study provides valuable insights and new perspectives for the future development of nanocomposite hydrogels in wound care.

Orofacial bone tissue engineering addresses bone loss caused by trauma, malformations, or tumors, enabling restoration and implant rehabilitation. Angiogenesis plays a crucial role in osteogenesis by ensuring nutrient and oxygen transport essential for bone regeneration. Preclinical large animal models are vital for translational research and require noninvasive, nondestructive methods aligned with 3Rs principles (Replacement, Reduction, and Refinement) to assess angiogenesis. This study proposes high-resolution cone-beam computed tomography subtraction angiography (HR-CBCT-SA) adapted for the orofacial region as an innovative method for monitoring angiogenesis during jawbone regeneration. Three Yucatan minipigs with a surgically created buccal wall jawbone defect per hemimandible were followed for 90 days by CBCT-SA to assess vascular remodeling. Morphometric parameters, including vessel number, node count, radius, and length, were analyzed and validated against histological morphometry. CBCT-SA revealed vascular dynamics during healing. By day 10, increased vessel and node counts along with reduced vessel radius and length indicated neoangiogenesis. At day 30, vessel maturation was aligned with transition of fibrous tissue to osteoid matrix deposition. By day 90, vascular metrics stabilized, reflecting bone remodeling phases characterized by replacement of lamellar and medullary bone replacement. Extrabony vascular networks underwent more pronounced changes than intrabony vessels, underscoring the leading role of periosteum in regeneration. Histology validated CBCT-SA findings, although resolution limitations prevented detection of vessels smaller than 500 µm. Nevertheless, CBCT-SA captured angiogenic changes over time and supported nondestructive monitoring without compromising tissue integrity. This study establishes HR-CBCT-SA as a reliable, nondestructive imaging technique for assessing vascular changes during jawbone regeneration in preclinical models. It demonstrates significant translational potential because of the clinically validated use of CBCT-angiography. Advances in artificial intelligence (AI)-driven image analysis are expected to enhance sensitivity and accuracy, improving vascular assessment. Moreover, this approach can be extended for investigating vascular-related oral pathologies (e.g., radiochemical osteonecrosis of the jaws), offering valuable tool to advance research in jawbone regeneration.

A stent is a medical device that is inserted into a narrowed or blocked area to normalize the flow when blood or body fluids do not flow smoothly. Covered stents coated with various materials such as silicone and expanded polytetrafluoroethylene (e-PTFE) are mainly used. However, these materials have various disadvantages, such as difficulty adding drugs or applying them to blood vessels. Electrospinning technology offers advantages in multifunctionality, including drug release and biodegradability. However, when coating a stent with an electrospun membrane, there are unresolved problems such as delamination of the membrane during stent surgery due to the weak nature and contraction of the electrospun fiber. Therefore, we studied fabricating by combining the dipping method and the electrospinning method a covered stent composed of a double-layer membrane using polyurethane (PU). It was confirmed that the double-layer membrane developed in this study has high mechanical properties, excellent adhesion to the stent, and can significantly improve the mechanical properties of the stent. This method is expected to overcome the limitations of existing cover stents manufactured using the electrospinning method by increasing the adhesive strength between the stent wire and the membrane.

This bibliometric analysis, conducted on 735 publications from the Web of Science Core Collection database up to April 16, 2025, sheds light on the evolving landscape of nanomaterials in spinal cord injury (SCI) repair. Utilizing tools such as Bibliometrix, VOSviewer, and CiteSpace, the study reveals a significant and exponential growth in literature within this field since 2020, marked by an impressive average annual increase of 13.16%. China has emerged as the global leader in research output, contributing 347 articles, with the United States closely following. Prominent institutions such as Jinzhou Medical University and Zhejiang University have played pivotal roles in advancing this domain. The research has predominantly centered around critical areas including nanoparticles, drug delivery systems, strategies for neural regeneration, and the modulation of inflammation. A notable shift in research focus has been observed in recent years, with keyword trends evolving from foundational cellular investigations toward more applied aspects such as regenerative medicine, the construction of supportive scaffolds, and crucial steps toward clinical translation. This highlights the inherent multidisciplinary potential of nanomaterials in addressing the complex challenges of SCI repair. Despite China's dominant publication volume, the analysis underscores a critical need to deepen fundamental research and foster stronger international collaborations. Looking ahead, future research endeavors should strategically prioritize the development of intelligent nanocarriers, cultivate robust interdisciplinary translational research initiatives, and establish standardized preclinical validation protocols. These targeted efforts are essential to accelerate the crucial transition of promising laboratory findings into effective clinical applications for patients suffering from SCIs.

This study describes the development of a three-dimensional (3D) oral mucosal model (OMM) to investigate how oral tissues respond to masticatory forces. The OMMs replicated key features of human oral mucosa, such as stratified keratinocyte telomerase-immortalized gingival keratinocytes (TIGK) layers and fibroblast-populated collagen matrices. Cyclical mechanical forces (0-10 N) for 2 h applied to the model caused force-dependent changes in the histological structure, including thinning of the epithelium and collagen matrix and cell displacement at higher forces. Lactate dehydrogenase (LDH) cytotoxicity assays revealed that 10 N forces led to significant cell damage (about 50% cell death) in TIGK monolayers, whereas lower forces (1-5 N) caused minimal damage. OMMs showed reduced cell death (∼15% at 10 N), indicating better resilience presumably due to their 3D architecture. Additionally, force-dependent increases in the release of the proinflammatory cytokines IL-6 and IL-8 were observed, with lower responses in OMMs compared with monolayer cultures. This study demonstrates that OMMs can be used to model the effects of masticatory forces on the response of the oral mucosa in denture wearers and has been utilized to investigate the effects of a denture adhesive on the inflammatory response of the OMM to pressure.