Tissue Engineering. Part B, Reviews最新文献

Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic tool in stem cell-based therapy due to their immunomodulatory or regenerative characteristics. Nowadays, controlled application of nonpathogenic bacterial cells and their derivatives has shown promise in preconditioning and manipulating MSC behavior. This approach is being explored in various fields, including immunotherapy, tissue engineering, and cell therapy. However, recent discoveries have elucidated the complex interactions between MSCs and microorganisms, especially bacteria and viruses, raising concerns regarding the utility of MSCs in clinical applications. In this review, we discussed the interactions between MSCs and microorganisms and highlighted both positive and negative aspects. We also examined the use of bacterial-derived compounds in MSCs-mediated interventions. The balanced colonization of the microbiome in organs, such as the oral cavity, not only does not hinder therapeutic interventions but also could be crucial for achieving desirable outcomes. On the contrary, disturbances in the microbiome have been found to disturb the biological potential of MSCs, such as migration, osteogenic differentiation, and cell proliferation. Evidence also suggests that commensal bacteria, following certain interventions, can transition to a pathogenic state when interacting with MSCs, leading to acute inflammation. Indeed, the maintenance of homeostasis through various approaches, such as probiotic application, results in an optimal equilibrium during MSCs-based therapies. However, further investigation into this matter is imperative to identify efficacious interventions.

Human decellularized adipose matrix (hDAM) has emerged as a promising, off-the-shelf option for soft tissue augmentation, providing a biocompatible scaffold that supports angiogenesis, adipogenesis, and volume retention with minimal immunogenicity. This systematic review synthesizes preclinical and clinical evidence on hDAM's regenerative potential, focusing on its capacity to integrate with host tissue and enhance volume retention. A comprehensive literature search was performed across multiple databases yielding 21 studies (14 preclinical, 6 clinical, and 1 combined) that met eligibility criteria. Risk of bias (RoB) was evaluated for animal and human studies using the Collaboration for the Assessment of Risks and Benefits of Anticancer Therapies (CAMARADES) and RoB In Nonrandomized Studies of Interventions (ROBINS-I) tools, respectively. Key preclinical findings indicate that hDAM supports progressive angiogenesis and adipogenesis, with significant weekly increases in vessel formation and adipocyte development. Linear mixed models were used to quantify these rates, showing an increase of 0.366% per week (p < 0.001) in the percentage of CD31+ positive area, and a 3.88% rise in perilipin-positive area per week (p < 0.001), representing angiogenesis and adipogenesis, respectively. Variability in regeneration rates underscores the influence of different hDAM preparation methods, such as enzyme-free decellularization and ultrasonication, which have been shown to improve cell compatibility and volume retention. Clinical studies demonstrate that hDAM achieves notable volume retention and patient satisfaction, particularly in facial and body contouring applications, while also improving skin texture, tone, and functionality. Compared with traditional autologous fat transfer and synthetic fillers, hDAM offers advantages in integration, resorption rates, and low complication risks, without donor site morbidity. Limitations of current studies include variability in hDAM preparation techniques, inconsistent outcome measures, and a paucity of long-term follow-up data. This review establishes hDAM as a safe and effective scaffold for soft tissue regeneration and provides a quantitative analysis of its regenerative timeline. Standardizing preparation methods and outcome measures, coupled with more randomized clinical trials, will be essential for optimizing treatment protocols. Future directions include exploring patient-specific factors and combination therapies to enhance hDAM's applicability in reconstructive and aesthetic surgery.

Vascular surgery is facing a critical demand for novel vascular grafts that are biocompatible and thromboresistant. This urgency is particularly applicable to bypass operations involving small caliber vessels. In the realm of tissue engineering, the development of fully vascularized organs is promising as a solution to organ shortage for transplantation. To achieve this, it is essential to (re)construct a biocompatible and nonthrombogenic vascular network within these organs. In this systematic review, we identify, classify, and discuss basic principles and methods used to perform in vitro/ex vivo dynamic thrombogenicity testing of perfusable tissue-engineered organs and tissues. We conducted a preregistered systematic review of studies published in the last 23 years according to PRISMA-P Guidelines. This comprised a systematic data extraction, in-depth analysis, and risk of bias assessment of 116 included studies. We identified shaking (n = 28), flow loop (n = 17), ex vivo (arteriovenous shunt, n = 33), and dynamic in vitro models (n = 38) as the main approaches for thrombogenicity assessment. This comprehensive review reveals a prevalent lack of standardization and provides a valuable guide in the design of standardized experimental setups.

Tissue engineering, a crucial approach in medical research and clinical applications, aims to regenerate damaged organs. By combining stem cells, biochemical factors, and biomaterials, it encounters challenges in designing complex 3D structures. Artificial intelligence (AI) enhances tissue engineering through computational modeling, biomaterial design, cell culture optimization, and personalized medicine. This review explores AI applications in organ tissue engineering (bone, heart, nerve, skin, cartilage), employing various machine learning (ML) algorithms for data analysis, prediction, and optimization. Each section discusses common ML algorithms and specific applications, emphasizing the potential and challenges in advancing regenerative therapies.

The healing process after tendon injury is often accompanied by the formation of peritendinous adhesion, contributing to limb dysfunction and exerting detrimental effects on the individuals, as well as the development of society and economy. With the continuous development of material science, as well as the augmented understanding of tendon healing and the mechanism of peritendinous adhesion formation, materials used for the fabrication of barrier membranes against peritendinous adhesion emerge endlessly. In this article, based on the analysis of the mechanism of adhesion formation, we first review the commonly used natural and synthetic materials, along with their corresponding fabrication strategies, in order to furnish valuable insights for the future optimization and development of antiperitendinous adhesion barrier membranes. This article also discusses the interaction between antiadhesion materials and cells for ameliorating peritendinous adhesion.

Peri-implant gingival tissue integration (GTI) is pivotal in determining the long-term success and functionality of dental implants. To enhance GTI, researchers have increasingly focused during the past decade on unraveling the response of gingival tissues to implant surfaces. This increased focus on soft instead of hard tissue integration has led to the development of various models, including in vitro cell culture systems and in vivo animal models, designed to predict and assess GTI around dental implants. However, inconsistent study outcomes between the different models have created confusion, highlighting the need for a comprehensive review. Therefore, the main objective of this review is to present a comprehensive overview of existing in vitro models, ranging from 2D to 3D, specifically designed to investigate cellular behavior relevant to peri-implant GTI. To facilitate a better comprehension of the utility of these models, the review initiates an elucidation of the histological characteristics of gingival tissues surrounding natural dentition, offering insights into the healing dynamics and histological adaptation processes occurring in gingival tissues adjacent to dental implants. In addition, through a critical evaluation of the strengths and limitations inherent in each model, our aim is to contribute to a more profound understanding of their applicability and effectiveness in GTI research.

Cartilage tissue engineering (CTE) has revolutionized the field of regenerative medicine, offering significant advancements in surgeries such as autologous chondrocyte transplantation. However, despite these advancements, infections associated with cartilage implants remain a persistent challenge, compromising the success of surgeries and patient recovery. To address these challenges, this review provides a comprehensive foundation for researchers interested in addressing infections in CTE. It begins by briefly outlining the major scaffolds currently used in CTE and distinguishing those with antimicrobial properties. Among the antimicrobial scaffolds identified, chitosan and chondroitin sulfate stand out for their promising compatibility and antibacterial properties. The review then explores additives that meet three essential criteria: compatibility with chondrocytes, suitability for use in CTE scaffolds, and antibacterial efficacy. Chitosan, zinc oxide, silver, and copper emerge as leading candidates due to their compatibility with chondrocytes and proven antibacterial capabilities. Importantly, the criteria used in this review were chosen to provide researchers with a practical and reliable starting point for immediate application. However, it is acknowledged that other promising antibacterial modifications such as fabrication processes and additives such as bioactive glass and graphene oxide, which may not fit these criteria, also hold potential for future research and innovation. This review underscores the need for further research and development to enhance infection control measures and improve patient outcomes.