Tissue Engineering. Part B, Reviews最新文献

Pelvic organ prolapse (POP) is a common yet complex condition affecting women, characterized by the descent of pelvic organs due to weakened pelvic floor structures. While several treatment strategies exist, their efficacy is often limited, and complications such as surgical failure or recurrence can hinder long-term success. Hydrogels, due to their unique properties such as high-water content, biocompatibility, and flexibility, offer promising potential in the management of POP. This review summarizes various animal models of POP including abdominal wall weakness model, sustained pressure method (vaginal ball stretching), ovariectomy (OVX) model, and gene knockout model. This review further provides a comprehensive overview of the role of hydrogels in POP, highlighting their applications in tissue engineering, drug delivery, and as coatings or injectable materials for prolapsed organs. Furthermore, the challenges in their development were discussed, including material selection, degradability, mechanical properties, and long-term biocompatibility. The strategies to optimize hydrogel performance to better meet clinical needs, with an emphasis on personalization and multifunctionality, were outlined. In conclusion, while hydrogels offer significant promise, further research into their design, application methods, and clinical outcomes is crucial to fully realize their potential in the treatment of POP. Impact Statement This review highlights the transformative potential of hydrogels in treating pelvic organ prolapse, a condition with limited long-term therapeutic success. By systematically analyzing animal models and exploring hydrogel applications in tissue repair and drug delivery, it identifies critical challenges and future directions. The insights offered lay the groundwork for personalized, multifunctional hydrogel systems, guiding future research and accelerating clinical translation.

The poor prognosis constitutes a significant difficulty for spinal cord injury (SCI) individuals. Although mesenchymal stem cells (MSCs) hold promises as advanced therapy medicinal products (ATMPs) for SCI patients, challenges such as Good Manufacturing Practice-compliant manufacturing, cellular senescence, and limited therapeutic efficacy continue to hinder their clinical translation. Recent advances have identified botanical nanovesicles (BNs) as potent bioactive mediators capable of "priming" MSCs to self-rejuvenate, augment paracrine effect, and establish inflammatory tolerance. In this review, we introduce the physicochemical properties of BNs and systematically explore their synergistic relationship with MSCs in regenerative medicine. By integrating BNs with MSC, BNs-empowered MSCs (Be-MSCs) represent next-generation ATMPs. This innovative strategy addresses the limitations of conventional MSC therapies and offers a scalable, nonimmunogenic solution with significant potential for clinical application in SCI.

The reconstruction of critical-sized bone defects remains a challenging clinical problem. At present, the implantation of autogenous and allogeneic grafts is the main clinical treatment strategy but faces some drawbacks, such as inadequate source, donor site-related complications, and immune rejection, driving researchers to develop artificial bone substitutes based on distinct materials and fabrication technologies. Among the bone substitutes, bioceramic-based substitutes exhibit a remarkable biocompatibility, which can also be designed to degrade concomitantly with the formation of new bone. In addition, three-dimensional (3D) printing technologies are frequently used for fabricating personalized 3D bioceramic scaffolds, which can achieve accurate imitation of native bone structures. Especially, bioprinting can produce organoids by integrating cells into scaffolds, which achieves the simultaneous imitation of organ structure and biological function. This review summarizes recent progresses of bioceramic-based materials, including hydroxyapatite, tricalcium phosphate, bioactive glass, calcium silicate, alumina, and zirconia. In addition, the application of 3D printing technologies and bioprinting is also elaborated in this text, offering important reference for future research of 3D-printed bioceramics.

Breast cancer remains the most commonly diagnosed malignancy among women worldwide. Standard treatment often involves mastectomy, followed by chemotherapy and/or radiation. Approximately 40% of patients undergo breast reconstruction to address the physical and psychological effects of tissue loss. Since the first autologous breast reconstruction described in 1887, both autologous and alloplastic techniques have evolved significantly to improve patient outcomes. However, current approaches are limited by issues such as the inability to restore biological breast function, suboptimal tissue integration, and concerns over long-term implant viability. Tissue engineering has emerged as a promising field capable of overcoming these limitations. Since the 1990s, advances in biomaterials, stem cell research, and regenerative strategies have enabled the development of vascularized, patient-specific constructs with potential applications in both structural and functional breast reconstruction. This review provides a comprehensive overview of the evolution of breast reconstruction techniques and the integration of tissue engineering into the field. Particular emphasis is placed on tissue engineering's role in enhancing breast cancer treatment and diagnosis while also exploring future directions toward functional restoration, including lactation.

Peripheral nerve injuries, though rarely fatal, can lead to sensory and motor deficits and neuropathic pain, significantly lowering patients' quality of life. Thus, it is crucial to explore potential treatments that can promote the regeneration of injured sciatic nerves. Currently, nerve anastomosis is performed between the two ends for short-gap nerve defects, while long-gap nerve defects require the use of nerve conduits, scaffolds, and nerve grafts. In terms of neural tissue engineering, identifying suitable biomaterials remains a key challenge. Polylactic acid (PLA) is a synthetic, biodegradable polymer with excellent processability, allowing it to be manufactured into various structures. Its mechanical properties, biodegradability, biomineralization capacity, and antibacterial properties make it a promising material for neural tissue engineering applications. In this work, we first introduce the physical and chemical properties, as well as the synthesis routes, of PLA and further elucidate the effect of various additives on its mechanical properties. Finally, we critically evaluate PLA-based strategies-including scaffolds, nerve conduits, drug delivery carriers, films, and microspheres-for promoting peripheral nerve regeneration. Taken together, PLA and its derivatives have a promising future in neural tissue engineering, with application methods and scenarios set to become more diverse.

Understanding and recreating biomechanical forces in in vitro cultures is integral to regenerating cardiac tissue and finding novel therapies for cardiovascular disease. Mechanical forces influence cardiac physiology from a microscopic cellular scale to the global function of the heart. Here, we will review the mechanical forces within the heart as understood clinically and evaluate in vitro device designs that mimic these mechanical forces at a cellular and tissue level. We will further follow the evolution of bioreactors toward recapitulating multiaxial mechanical forces as they are experienced in vivo and understand the current limitations associated with in vitro systems in the context of recreating in vivo cardiac physiology.

Myocardial infarction (MI), a prevalent critical cardiovascular disease (CVD), poses a severe threat to patients' lives. Despite the availability of pharmacological, interventional, and surgical treatments in clinical practice, these conventional therapies encounter the bottleneck of difficulty in repairing and reconstructing damaged myocardial tissue. Additionally, novel cardiac repair approaches based on stem cell and cardiomyocyte injections are restricted by the harsh microenvironment of infarcted areas. However, biomaterial hydrogels emerge as promising candidates for MI treatment due to their strong mechanical properties, good biocompatibility, high water absorption capacity, and excellent anti-inflammatory and antioxidant properties. These features enable them to enhance the microenvironment, promote myocardial regeneration, and restore myocardial function. This article delves into the therapeutic effects of sodium alginate (SA) and its composite hydrogel materials in repairing and regenerating myocardial injuries caused by MI. Furthermore, it offers insights into the future research directions of SA and its composite hydrogel materials. It also explores their potential applications in the field of CVDs. Impact Statement This review article highlights the significance and potential impact of sodium alginate (SA)-based hydrogels in myocardial infarction (MI) treatment. It effectively communicates the importance of the research, the gap in the current treatments for MI, and how the reviewed SA hydrogels offer a promising solution with their unique properties. It also clearly states the intended contribution to the field and the potential benefits for researchers and clinicians.

Three-dimensional (3D) (bio)printing has emerged as a relevant approach in bone tissue regeneration, enabling the precise fabrication of biomimetic scaffolds. The incorporation of extracellular vesicles (EVs) into 3D-(bio)printed constructs represents a promising cell-free strategy to enhance bone regeneration. EVs, as natural mediators of intercellular communication, contribute to osteogenesis, angiogenesis, and immune modulation. This review aims to evaluate current evidence on the use of EVs-enhanced 3D (bio)printing for bone regeneration. The literature search was conducted across different databases. In vitro and in vivo studies using EVs-containing (bio)printed constructs to assess osteogenic differentiation and/or bone regeneration were included. Out of 552 articles, 35 met the inclusion criteria. Most EVs were derived from bone marrow mesenchymal stem cells and were incorporated into scaffolds either before or after printing. Extrusion-based bioprinting was the most commonly used method. Nearly all studies reported enhanced osteogenic differentiation and bone formation in EV-treated groups, underscoring their therapeutic potential. EVs-based bioinks retain the regenerative benefits of stem cells while avoiding challenges associated to cell-based therapies. Despite encouraging results, standardization in EV isolation, storage, and delivery remains crucial for clinical translation. This review highlights the growing significance of EVs in regenerative medicine and identifies key areas for future research and development.

Human vocal folds (VFs), a pair of small, soft tissues in the larynx, have a layered mucosal structure with unique mechanical strength to support high-level tissue deformation by phonation. Severe pathological changes to VF have causes including surgery, trauma, age-related atrophy, and radiation, and lead to partial or complete communication loss and difficulty in breathing and swallowing. VF glottal insufficiency requires injectable VF biomaterials such as hyaluronan, calcium hydroxyapatite, and autologous fat to augment VF functions. Although these biomaterials provide an effective short-term solution, significant variations in patient response and requirements of repeat reinjection remain notable challenges in clinical practice. Tissue engineering strategies have been actively explored in the search of an injectable biomaterial that possesses the capacity to match native tissue's material properties while promoting permanent tissue regeneration. This review aims to assess the current status of biomaterial development in VF tissue engineering. The focus will be on examining state-of-the-art techniques including modification with bioactive molecules, cell encapsulation, composite materials, and in situ crosslinking with click chemistry. We will discuss potential opportunities that can further leverage these engineering techniques in the advancement of VF injectable biomaterials. Impact Statement Injectable vocal fold (VF) biomaterials augment tissue function through minimally invasive procedures, yet there remains a need for long-term VF reparation. This article reviews cutting-edge research in VF biomaterial development to propose safe and effective tissue engineering strategies for improving regenerative outcomes. Special focus is paid to methods to enhance bioactivity and achieve tissue-mimicking mechanical properties, longer in situ stability, and inherent biomaterial bioactivity.