The regeneration of tissues and organs poses an immense challenge due to the extreme complexity in the research work involved. Despite the tissue engineering approach being considered as a promising ...strategy for more than two decades, a key issue impeding its progress is the lack of ideal scaffold materials. Nature-inspired synthetic peptide hydrogels are inherently biocompatible, and its high resemblance to extracellular matrix makes peptide hydrogels suitable 3D scaffold materials. This review covers the important aspects of peptide hydrogels as 3D scaffolds, including mechanical properties, biodegradability and bioactivity, and the current approaches in creating matrices with optimized features. Many of these scaffolds contain peptide sequences that are widely reported for tissue repair and regeneration and these peptide sequences will also be discussed. Furthermore, 3D biofabrication strategies of synthetic peptide hydrogels and the recent advances of peptide hydrogels in tissue engineering will also be described to reflect the current trend in the field. In the final section, we will present the future outlook in the design and development of peptide-based hydrogels for translational tissue engineering applications.
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The application of scaffolding materials is believed to hold enormous potential for tissue regeneration. Despite the widespread application and rapid advance of several tissue-engineered scaffolds ...such as natural and synthetic polymer-based scaffolds, they have limited repair capacity due to the difficulties in overcoming the immunogenicity, simulating in-vivo microenvironment, and performing mechanical or biochemical properties similar to native organs/tissues. Fortunately, the emergence of decellularized extracellular matrix (dECM) scaffolds provides an attractive way to overcome these hurdles, which mimic an optimal non-immune environment with native three-dimensional structures and various bioactive components. The consequent cell-seeded construct based on dECM scaffolds, especially stem cell-recellularized construct, is considered an ideal choice for regenerating functional organs/tissues. Herein, we review recent developments in dECM scaffolds and put forward perspectives accordingly, with particular focus on the concept and fabrication of decellularized scaffolds, as well as the application of decellularized scaffolds and their combinations with stem cells (recellularized scaffolds) in tissue engineering, including skin, bone, nerve, heart, along with lung, liver and kidney.
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•dECM scaffolds for tissue regeneration are primarily introduced according to the development and fabrication of decellularized scaffolds, as well as the application of dECM scaffolds and their constructs combined with stem cells in various tissue engineering.•Limitations, challenges, and perspectives of dECM for accelerating development of tissue regeneration are discussed, respectively.
A 3D mechanically stable scaffold is shown to accommodate the volume change of a high‐specific‐capacity nickel–tin nanocomposite during operation as a Li‐ion battery anode. The nickel–tin anode is ...supported by an electrochemically inactive conductive scaffold with an engineered free volume and controlled characteristic dimensions, which engender the electrode with significantly improved cyclability.
Bioprinting is an emerging field in regenerative medicine. Producing cell-laden, three-dimensional structures to mimic bodily tissues has an important role not only in tissue engineering, but also in ...drug delivery and cancer studies. Bioprinting can provide patient-specific spatial geometry, controlled microstructures and the positioning of different cell types for the fabrication of tissue engineering scaffolds. In this brief review, the different fabrication techniques: laser-based, extrusion-based and inkjet-based bioprinting, are defined, elaborated and compared. Advantages and challenges of each technique are addressed as well as the current research status of each technique towards various tissue types. Nozzle-based techniques, like inkjet and extrusion printing, and laser-based techniques, like stereolithography and laser-assisted bioprinting, are all capable of producing successful bioprinted scaffolds. These four techniques were found to have diverse effects on cell viability, resolution and print fidelity. Additionally, the choice of materials and their concentrations were also found to impact the printing characteristics. Each technique has demonstrated individual advantages and disadvantages with more recent research conduct involving multiple techniques to combine the advantages of each technique.
Successful regeneration of weight‐bearing bone defects and critical‐sized cartilage defects remains a major challenge in clinical orthopedics. In the past decades, biodegradable polymer materials ...with biomimetic chemical and physical properties have been rapidly developed as ideal candidates for bone and cartilage tissue engineering scaffolds. Due to their unique advantages over other materials of high specific‐surface areas, suitable mechanical strength, and tailorable characteristics, scaffolds made of polymer fibers have been increasingly used for the repair of bone and cartilage defects. This Review summarizes the preparation and compositions of polymer fibers, as well as their characteristics. More importantly, the applications of polymer fiber scaffolds with well‐designed structures or unique properties in bone, cartilage, and osteochondral tissue engineering have been comprehensively highlighted. On the whole, such a comprehensive summary affords constructive suggestions for the development of polymer fiber scaffolds in bone and cartilage tissue engineering.
The rapid development of polymer fiber scaffolds has attracted increasing attention in tissue engineering recently due to their tailorable, comparable mechanical and biomimetic properties with human tissues. This Review summarizes the preparation, components, and characteristics of polymer fiber scaffolds with well‐designed structures for their applications as bone and cartilage tissue engineering scaffolds and predicts future development.
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There is a vast and rapid increase in the applications of graphene oxide (GO) and reduced graphene oxide (rGO) in the biomedical field, including drug delivery, bio-sensing, and ...diagnostic tools. Among all the applications, the GO and rGO-based scaffolds are a very promising system that have attracted attention because of their great clinical projection in tissue regeneration therapies. Both GO and rGO have shown a strong impact on the proliferation and differentiation of implemented stem cells, but still need to overcome several challenges, such as cytotoxicity, biodistribution, biotransformation or immune response. However, there are still controversial hypothesises regarding the mechanisms involved in these issues that should be clarified in order to improve the applications of these compounds. 3D-scaffolds can help in solving some of those limitations when moving into preclinical studies in regenerative medicine. In this review, we will describe the application of GO and rGO within 3D scaffolds in bone, cardiac and neural regenerative medicine after analyzing the aforementioned challenges.
Injectable Cryogels for Biomedical Applications Eggermont, Loek J.; Rogers, Zachary J.; Colombani, Thibault ...
Trends in biotechnology (Regular ed.),
April 2020, 2020-Apr, 2020-04-00, 20200401, Letnik:
38, Številka:
4
Journal Article
Recenzirano
Odprti dostop
To prevent postoperative complications, there has been a substantial interest in designing syringe-injectable hydrogels. To date, cryogels remain the only viable option for preformed and large-scale ...hydrogels to be delivered through a conventional needle–syringe injection. Cryogels, a type of hydrogel with exceptional features, are fabricated at subzero temperatures. This process typically results in a biomaterial with a unique macroporous network, shape-memory properties, and exceptional flexibility allowing syringe injectability. These advanced biomaterials have been used for a number of biomedical applications, including tissue engineering, drug delivery, and more recently, immunotherapy. This review summarizes the recent progress on the design of injectable cryogels, their current limitations, and strategies to further improve their properties for translatability into the clinic.
Injectable cryogels were disclosed in 2012 as the first preformed large-scale hydrogels to be injected through a conventional hypodermic syringe, obviating the need for invasive surgical implantations.Injectable cryogels have shape-memory properties and are reversibly compactible.When syringe injected, shear-collapsed cryogels flow through conventional needles. Once released, cryogels instantly pop back to their initial shape and size.Cryogels with their inherent interconnected macroporous network can host and/or deliver mammalian cells for tissue regeneration, cell transplantation, and in situ cell manipulation/reprogramming.Biomolecules can be efficiently entrapped within the dense polymer walls of cryogels. Fine-tuning cryogel properties can control the spatiotemporal release of their payloads.Enhancing cryogel properties will expand their potential in the biomedical field.
Potassium metal batteries are considered as attractive alternatives beyond lithium‐ion batteries. However, uncontrollable dendrite growth on the potassium metal anode has restrained their practical ...applications. A high‐performance potassium anode achieved by confining potassium metal into a titanium‐deficient nitrogen‐containing MXene/carbon nanotube freestanding scaffold is reported. The high electronic transport and fast potassium diffusion in this scaffold enable reduced local current density and homogeneous ionic flux during plating/stripping processes. Furthermore, as verified by theoretical calculations and experimental investigations, such “potassium‐philic” MXene sheets can induce the nucleation of potassium, and guide potassium to uniformly distribute in the scaffold upon cycling. Consequently, the as‐developed potassium metal anodes exhibit a dendrite‐free morphology with high Coulombic efficiency and long cycle life during plating/stripping processes. Such anodes also deliver significantly improved electrochemical performances in potassium–sulfur batteries compared with bare potassium metal anodes. This work can provide a new avenue for developing potassium metal‐based batteries.
A high‐performance potassium‐metal anode is developed by confining potassium metal into a titanium‐deficient and nitrogen‐containing MXene/carbon nanotube freestanding scaffold. These potassium‐metal anodes exhibit a dendrite‐free morphology with high Coulombic efficiency and long cycle life during plating/stripping processes.
Bone tissue regeneration strategies have incorporated the use of natural polymers, such as hydroxyapatite (nHA), chitosan (CH), gelatin (GEL), or alginate (ALG). Additionally, platelet concentrates, ...such as platelet-rich fibrin (PRF) have been suggested to improve scaffold biocompatibility. This study aimed to develop scaffolds composed of nHA, GEL, and CH, with or without ALG and lyophilized PRF, to evaluate the scaffold's properties, growth factor release, and dental pulp stem cells (DPSC), and osteoblast (OB) derived from DPSC viability. Four scaffold variations were synthesized and lyophilized. Then, degradation, swelling profiles, and morphological analysis were performed. Furthermore, PDGF-BB and FGF-B growth factors release were quantified by ELISA, and cytotoxicity and cell viability were evaluated. The swelling and degradation profiles were similar in all scaffolds, with pore sizes ranging between 100 and 250 μm. FGF-B and PDGF-BB release was evidenced after 24 h of scaffold immersion in cell culture medium. DPSC and OB-DPSC viability was notably increased in PRF-supplemented scaffolds. The nHA-CH-GEL-PRF scaffold demonstrated optimal physical-biological characteristics for stimulating DPSC and OB-DPSC cell viability. These results suggest lyophilized PRF improves scaffold biocompatibility for bone tissue regeneration purposes.
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