Nanostructured biomaterials for regenerative medicine: Clinical perspectives
01 Jan 2020-pp 47-80
TL;DR: An overview of innovative platform technologies based on nanostructured biomaterials as a function of their material properties as well as their role in tissue engineering and regenerative medicine is provided.
Abstract: This chapter provides an overview of innovative platform technologies based on nanostructured biomaterials as a function of their material properties as well as their role in tissue engineering and regenerative medicine. Nanostructured ceramics, metals, polymers, and their composites are discussed regarding their applications as bioengineered tissue substitutes in vitro and in vivo and clinical trials. The study also summarizes important parameters related to the use of nanostructured biomaterials (e.g., chemical, mechanical, and structural property) for tissue regeneration and addresses possible directions for future investigation.
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TL;DR: An overview of both discrete and continuous gradient OC tissue scaffolds in terms of cell type, scaffold material, microscale structure, mechanical properties, fabrication methods, and scaffold stimuli is provided.
Abstract: The tissue engineering approach for repairing osteochondral (OC) defects involves the fabrication of a biological tissue scaffold that mimics the physiological properties of natural OC tissue (e.g., the gradient transition between the cartilage surface and the subchondral bone). The OC tissue scaffolds described in many research studies exhibit a discrete gradient (e.g., a biphasic or tri/multiphasic structure) or a continuous gradient to mimic OC tissue attributes such as biochemical composition, structure, and mechanical properties. One advantage of a continuous gradient scaffold over biphasic or tri/multiphasic tissue scaffolds is that it more closely mimics natural OC tissue since there is no distinct interface between each layer. Although research studies to this point have yielded good results related to OC regeneration with tissue scaffolds, differences between engineered scaffolds and natural OC tissue remain; due to these differences, current clinical therapies to repair OC defects with engineered scaffolds have not been successful. This paper provides an overview of both discrete and continuous gradient OC tissue scaffolds in terms of cell type, scaffold material, microscale structure, mechanical properties, fabrication methods, and scaffold stimuli. Fabrication of gradient scaffolds with three-dimensional (3D) printing is given special emphasis due to its ability to accurately control scaffold pore geometry. Moreover, the application of computational modeling in OC tissue engineering is considered; for example, efforts to optimize the scaffold structure, mechanical properties, and physical stimuli generated within the scaffold–bioreactor system to predict tissue regeneration are considered. Finally, challenges associated with the repair of OC defects and recommendations for future directions in OC tissue regeneration are proposed.
74 citations
TL;DR: In this paper, a review of bioactive glass coatings on zirconia as well as surface modification methods (i.e., sol-gel, laser cladding, plasma spraying, etc.) is provided.
Abstract: Nowadays zirconia, due to its interesting properties e.g. biocompatibility, strength, aesthetic, chemical and mechanical properties, has got lots of attention for dental implants. On the other hand, bioactive glasses have been used as coating on tougher substrates such as zirconia. Bioactive glass coatings can decrease the healing time and hence accelerate the formation of the bond between bone and implant. Hence in this study, we introduce the novel zirconia/bioactive glass composites with high mechanical strength and bioactivity to achieve the ideal implant dentistry. Furthermore, a review of bioactive glass coatings (i.e. 45S5 and 58S) on zirconia as well as surface modification methods (i.e. sol-gel, laser cladding, plasma spraying, etc.) is provided.
28 citations
TL;DR: A review of the state of the art regarding the challenges, advantages, and drawbacks of the current strategies for osteochondral regeneration is presented in this paper, where the most promising approaches rely on the principles of additive manufacturing, where technologies are used that allow for the production of complex 3D structures with a high level of control, intended and predefined geometry, size and interconnected pores, in a reproducible way.
Abstract: Due to the extremely high incidence of lesions and diseases in aging population, it is critical to put all efforts into developing a successful implant for osteochondral tissue regeneration. Many of the patients undergoing surgery present osteochondral fissure extending until the subchondral bone (corresponding to a IV grade according to the conventional radiographic classification by Berndt and Harty). Therefore, strategies for functional tissue regeneration should also aim at healing the subchondral bone and joint interface, besides hyaline cartilage. With the ambition of contributing to solving this problem, several research groups have been working intensively on the development of tailored implants that could promote that complex osteochondral regeneration. These implants may be manufactured through a wide variety of processes and use a wide variety of (bio)materials. This review aimed to examine the state of the art regarding the challenges, advantages, and drawbacks of the current strategies for osteochondral regeneration. One of the most promising approaches relies on the principles of additive manufacturing, where technologies are used that allow for the production of complex 3D structures with a high level of control, intended and predefined geometry, size, and interconnected pores, in a reproducible way. However, not all materials are suitable for these processes, and their features should be examined, targeting a successful regeneration.
11 citations
12 Oct 2015
TL;DR: Self assembled peptide (F2S) hydrogels and cellular metabolomics are used to identify a number of innate molecules that are integral to the metabolic processes which drive cellular differentiation and show that simple metabolites provide an alternative means to direct stem cell differentiation.
Abstract: This study reports the use of self assembled peptide (F2S) hydrogels and cellular metabolomics to identify a number of innate molecules that are integral to the metabolic processes which drive cellular differentiation. Current methods for achieving this wholly depend on the use of chemical induction media which generally comprise synthetic molecules or attempting to match the physical environment to that of targeted tissue types. By culturing pericytes on F2S hydrogels with varied mechanical qualities, these cells were induced to undergo neuronal (2 kPa), chondrogenic (15 kPa) and osteogenic (40kPa) differentiation. Because the system relies solely on mechanical tuning of a uniform substrate, alterations in cell behaviour by way of total metabolism could be used to mine for selective compounds of interest by way of patterned depletion. When the selected metabolites (ceramide, lysophosphatidic acid and cholesterol sulphate respectively) were reintroduced into stem cells cultures, they were observed as having the ability to direct differentiation in their own right and with similar efficacy to routinely used induction media. Interestingly, it was also observed that these metabolites, when introduced in vitro, have distinct effects on stem cell behaviour dependent on whether the cells are amenable to them. That is, metabolic functions are innately coupled to the pericytes physical and morphological states. This approach shows that simple metabolites provide an alternative means to direct stem cell differentiation and that materials can be used to identify them simply and quickly which has clear implications for stem cell drug discovery.
5 citations
References
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01 Jan 2008
TL;DR: A review of the current progress in the area of TiO 2 photocatalysis, mainly photocatalytic air purification, sterilization and cancer therapy is discussed in this article.
Abstract: Abstract Scientific studies on photocatalysis started about two and a half decades ago. Titanium dioxide (TiO 2 ), which is one of the most basic materials in our daily life, has emerged as an excellent photocatalyst material for environmental purification. In this review, current progress in the area of TiO 2 photocatalysis, mainly photocatalytic air purification, sterilization and cancer therapy are discussed together with some fundamental aspects. A novel photoinduced superhydrophilic phenomenon involving TiO 2 and its applications are presented.
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TL;DR: The field of photocatalysis can be traced back more than 80 years to early observations of the chalking of titania-based paints and to studies of the darkening of metal oxides in contact with organic compounds in sunlight as discussed by the authors.
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TL;DR: More than 20 polymers, including polyethylene oxide, nylon, polyimide, DNA, polyaramid, and polyaniline, have been electrospun in this paper.
Abstract: Electrospinning uses electrical forces to produce polymer fibres with nanometre-scale diameters. Electrospinning occurs when the electrical forces at the surface of a polymer solution or melt overcome the surface tension and cause an electrically charged jet to be ejected. When the jet dries or solidifies, an electrically charged fibre remains. This charged fibre can be directed or accelerated by electrical forces and then collected in sheets or other useful geometrical forms. More than 20 polymers, including polyethylene oxide, nylon, polyimide, DNA, polyaramid, and polyaniline, have been electrospun in our laboratory. Most were spun from solution, although spinning from the melt in vacuum and air was also demonstrated. Electrospinning from polymer melts in a vacuum is advantageous because higher fields and higher temperatures can be used than in air.
3,431 citations
TL;DR: Two complementary strategies can be used in the fabrication of molecular biomaterials as discussed by the authors : chemical complementarity and structural compatibility, both of which confer the weak and noncovalent interactions that bind building blocks together during self-assembly.
Abstract: Two complementary strategies can be used in the fabrication of molecular biomaterials. In the 'top-down' approach, biomaterials are generated by stripping down a complex entity into its component parts (for example, paring a virus particle down to its capsid to form a viral cage). This contrasts with the 'bottom-up' approach, in which materials are assembled molecule by molecule (and in some cases even atom by atom) to produce novel supramolecular architectures. The latter approach is likely to become an integral part of nanomaterials manufacture and requires a deep understanding of individual molecular building blocks and their structures, assembly properties and dynamic behaviors. Two key elements in molecular fabrication are chemical complementarity and structural compatibility, both of which confer the weak and noncovalent interactions that bind building blocks together during self-assembly. Using natural processes as a guide, substantial advances have been achieved at the interface of nanomaterials and biology, including the fabrication of nanofiber materials for three-dimensional cell culture and tissue engineering, the assembly of peptide or protein nanotubes and helical ribbons, the creation of living microlenses, the synthesis of metal nanowires on DNA templates, the fabrication of peptide, protein and lipid scaffolds, the assembly of electronic materials by bacterial phage selection, and the use of radiofrequency to regulate molecular behaviors.
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TL;DR: Some of the observed new chemical, optical, and thermal properties of metallic nanocrystals when their size is confined to the nanometer length scale and their dynamical processes are observed on the femto- to picosecond time scale are described.
Abstract: The properties of a material depend on the type of motion its electrons can execute, which depends on the space available for them (i.e., on the degree of their spatial confinement). Thus, the properties of each material are characterized by a specific length scale, usually on the nanometer dimension. If the physical size of the material is reduced below this length scale, its properties change and become sensitive to its size and shape. In this Account we describe some of the observed new chemical, optical, and thermal properties of metallic nanocrystals when their size is confined to the nanometer length scale and their dynamical processes are observed on the femto- to picosecond time scale.
2,655 citations