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Macrograph and micrograph of the degraded S-Ⅱ scaffolds after immersion tests, (a) macrograph of the scaffolds, (b, c) SEM images at 2 w, (d, e) SEM images at 4 w, (f, g) SEM images at 6 w, the inserted SEM image of (f) shows the magnified view of degradation layer at 6 w, and EDS analysis results of strut surface are shown in the inserted chart of (b), (d) and (f), respectively.
Source publication
Interconnectivity is the key characteristic of bone tissue engineering scaffold modulating cell migration, blood vessels invasion and transport of nutrient and waste. However, efforts and understanding of the interconnectivity of porous Mg is limited due to the diverse architectures of pore struts and pore size distribution of Mg scaffold systems....
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Context 1
... and similar specific surface area of S-Ⅰ , S-Ⅱ and S-Ⅲ . Collectively, the effect of interconnectivity as well as pore size distribution on the change of the microenvironment in extract functioned in the manner of the specific surface area. The macrograph of the degraded S-Ⅱ Mg scaffolds after long-term semi-static immersion tests is shown in Fig. 5 a. Visible degradation deposit and volume loss were observed after 6 weeks. Nevertheless, the presented Mg scaffolds provided sufficient structural integrity within 4 weeks, which could be attributed to the formation of a MgF 2 coating on the pore strut during the removal of Ti template in hydrofluoric acid. The MgF 2 layer on Mg ...
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... Nevertheless, the presented Mg scaffolds provided sufficient structural integrity within 4 weeks, which could be attributed to the formation of a MgF 2 coating on the pore strut during the removal of Ti template in hydrofluoric acid. The MgF 2 layer on Mg alloys has been reported with enhanced degradation resistance due to its insolubility [47] . Fig. 5 b-g displays the SEM images of the degraded S-Ⅱ scaffolds, the inserted images are the EDS results of elemental composition on the pore strut. The micromorphology of the degraded scaffolds confirmed that few deposit particles were found on pore strut after 4 weeks, the hierarchical porous structure maintained within 6 weeks, but a ...
Citations
... The human bone cancellous part has a complex, porous structure with non-homogeneous anisotropic properties and porosity ranging from 50% to 90% [42]. The porosity and interconnectivity of the bone scaffold are critical for cell growth and migration, nutrition and waste delivery, and blood vessel invasion [45], [46]. Tissue engineering studies have shown that the average pore size of bone scaffolds ranges from 50 µm to 1500 µm [47], [48]. ...
Biodegradable scaffolds are needed to repair bone defects. To promote the resorption of scaffolds, a large surface area is required to encourage neo-osteogenesis. Herein, we describe the synthesis and freeze-drying methodologies of ferric-ion (Fe3+) doped Dicalcium Phosphate Dihydrate mineral (DCPD), also known as brushite, which has been known to favour the in situ condition for osteogenesis. In this investigation, the role of chitosan during the synthesis of DCPD was explored to enhance the antimicrobial, scaffold pore distribution, and mechanical properties post freeze-drying. During the synthesis of DCPD, the calcium nitrate solution was hydrolysed with a predetermined stoichiometric concentration of ammonium phosphate. During the hydrolysis reaction, 10 (mol)% iron (Fe3+) nitrate (Fe(NO3)3) was incorporated, and the DCPD minerals were precipitated (Fe3+-DCPD). Chitosan stir-mixed with Fe3+-DCPD minerals was freeze-dried to create scaffolds. The structural, microstructural, and mechanical properties of freeze-dried materials were characterized.
... Among the structural clues provided by biomaterials, porosity is one of the main factors regulating the mechanical properties of the scaffold [69] . For example, our group developed a type of Haversian bonemimicking scaffold with a layered Haversian bone structure through DLP-based 3D printing [70] . By changing the parameters of the Haversian bone simulation structure, the porosity of the scaffold could be well controlled, thereby affecting the compressive strength of the scaffold [ Figure 4]. ...
... The design of this heterogeneous structure would enable the scaffold to exhibit coordinated dynamic mechanical stimulation characteristics, promoting endochondral ossification and leading to effective subchondral bone regeneration. [70] . Copyright 2020, American Association for the Advancement of Science. ...
... Bone repair is a complex process that involves the reconstruction of biological functions and the restoration of mechanical properties. Recently, the strategy for repairing bone defects is to design bioactive scaffolds [70] . Copyright 2020, American Association for the Advancement of Science. ...
Repairing tissue defects caused by diseases and traumas presents significant challenges in the clinic. Recent advancements in biomaterials have offered promising strategies for promoting tissue regeneration. In particular, the exploration of 3D macro and microstructures of biomaterials has proven crucial in this process. The integration of macro, micro, and nanostructures facilitates the performance of biomaterials in terms of their mechanical properties, degradation rate, and distinctive impacts on cellular activities. In this review, we summarize the recent progress in biomaterials with hierarchical structures for tissue regeneration. We explore the various methods and strategies employed in designing biomaterials with hierarchical structures of different dimensions. The improvement of physicochemical properties and bioactivities by hierarchically structured biomaterials, including the regulation of mechanical properties, degradability, and the specific functions of cell behaviors, has been highlighted. Furthermore, the current applications of hierarchically structured biomaterials for tissue regeneration are discussed. Finally, we conclude by summarizing the developments of hierarchically structured biomaterials for tissue regeneration and provide future perspectives.
... This facilitates the loading of cells into the scaffold while the inside of the pore wall acts as a vessel for cell attachment and also exchange of nutrient and waste. 46,47 Our study found that GelCL24 and GelCL12 exhibits a significantly higher range of 6,12-12,22 μm and 5,57-12,31 μm. GelUCL had narrower interconnectivity with range from 1,9-2,33 μm. ...
The development of biomaterial as substitution to connective tissue graft for treating gingival recession is growing nowadays. Hydrogels received attention as potential scaffold to be used in gingival tissue engineering since their capability to mimic soft tissue characteristic as they can hold amount of water. Gelatin is a natural polymer that widely used in hydrogel preparation with good biological properties, but it has poor physical stability for the used as scaffold. Chemical crosslinking strategy using EDC/NHS was performed in this study to overcome its limitation. One uncrosslinked gelatin and two crosslinked gelatin hydrogels different concentration of EDC/NHS were prepared in this study. This study investigated the difference of physical characterization from the prepared gelatin hydrogels. Our findings suggest the crosslinking strategy using EDC/NHS increase physical properties of the gelatin hydrogels without interfering the chemical structure of the gelatin. The higher crosslinker concentration will result in better morphology and more resilient to biodegradation. As a result, the crosslinked gelatin hydrogel with gelatin:EDC:NHS mass ratio of 12:1:1 met the physical characteristic for future use as scaffold for gingival tissue regeneration.
... For example, Jia et al. fabricated porous magnesium (Mg) scaffolds for bone TE by modulating pores size and distribution. Although mechanical strength decreases with the increase of pores' size and interconnectivity, degradation rates was not affected and cell migration as well as cell viability and proliferation were enhanced [92]. The porosity of a scaffold can be tailored based on the specific TE application and desired outcomes. ...
The advancements achieved in Tissue Engineering are based on a careful and in-depth study of cell-tissue interaction. The choice of a certain biomaterial in Tissue Engineering is fundamental as it represents an interface for adherent cells in the creation of a microenvironment suitable for cell growth and differentiation. The knowledge of the biochemical and biophysical properties of the extracellular matrix is a useful tool for the optimization of polymeric scaffolds. The aim of this re-view is to analyse the chemical, physical and biological parameters on which it is possible to act in Tissue Engineering for the optimization of polymeric scaffolds. Understanding the scaffold impact on cell fate is of paramount importance for the successful advancement of Tissue Engineering.
... sensory fibers. Conversely, increasing porosity and pore diameter has the negative effect of reducing compressive strength and elastic modulus [97][98][99]. Another crucial property of a scaffold is biodegradability with minimal cytotoxic byproducts [100]. ...
... In addition, even more space may be required for the ideal passage of waste, nutrients, and other important axons with larger diameters such as pyramidal tract axons, purkinje cell axons, Aα sensory fibers, and Aβ sensory fibers. Conversely, increasing porosity and pore diameter has the negative effect of reducing compressive strength and elastic modulus [97][98][99]. Another crucial property of a scaffold is biodegradability with minimal cytotoxic byproducts [100]. ...
Spinal cord injury (SCI) is a profoundly debilitating yet common central nervous system condition resulting in significant morbidity and mortality rates. Major causes of SCI encompass traumatic incidences such as motor vehicle accidents, falls, and sports injuries. Present treatment strategies for SCI aim to improve and enhance neurologic functionality. The ability for neural stem cells (NSCs) to differentiate into diverse neural and glial cell precursors has stimulated the investigation of stem cell scaffolds as potential therapeutics for SCI. Various scaffolding modalities including composite materials, natural polymers, synthetic polymers, and hydrogels have been explored. However, most trials remain largely in the preclinical stage, emphasizing the need to further develop and refine these treatment strategies before clinical implementation. In this review, we delve into the physiological processes that underpin NSC differentiation, including substrates and signaling pathways required for axonal regrowth post-injury, and provide an overview of current and emerging stem cell scaffolding platforms for SCI.
... However, high porosity and large pore size are found to improve osteoconductivity but delineate the strength of the scaffold [51]. Interconnectivity of the pores is pivotal for cell migration, exchange of nutrients and waste, and blood vessel invasion into the scaffold [52]. Biomaterials with interconnected pores are preferred over dead-end pores for promoting ingrowth of new bone [49], resorption of the materials (in a rabbit femur defect), and even reduce hospitalization rates [53]. ...
Limitations associated with conventional bone substitutes such as autografts, increasing demand for bone grafts, and growing elderly population worldwide necessitate development of unique materials as bone graft substitutes. Bone tissue engineering (BTE) would ensure therapy advancement, efficiency, and cost-effective treatment modalities of bone defects. One way of engineering bone tissue scaffolds by mimicking natural bone tissue composed of organic and inorganic phases is to utilize polysaccharide-bioceramic hybrid composites. Polysaccharides are abundant in nature, and present in human body. Biominerals, like hydroxyapatite are present in natural bone and some of them possess osteoconductive and osteoinductive properties. Ion doped bioceramics could substitute protein-based biosignal molecules to achieve osteogenesis, vasculogenesis, angiogenesis, and stress shielding. This review is a systemic summary on properties, advantages, and limitations of polysaccharide-bioceramic/ion doped bioceramic composites along with their recent advancements in BTE.
... 83 The porosity can facilitate the betterinterconnected pore structure and promote cell migration to induce the biological mechanism in bone. 84,85 Therefore, the design of the bone scaffold must consider enabling the natural function of the bone, such as biocompatibility, suitable mechanical properties, and an excellent response to external or internal stimuli to facilitate tissue regeneration. 86 As a natural polymer, chitosan has received great interest in medical fields due to its biocompatibility, noncytotoxicity, biodegradability, low immunogenicity, antibacterial, and good cell adhesion properties. ...
Over the past decade, smart and functional biomaterials have escalated as one of the most rapidly emerging fields in the life sciences because the performance of biomaterials could be improved by careful consideration of their interaction and response with the living systems. Thus, chitosan could play a crucial role in this frontier field because it possesses many beneficial properties, especially in the biomedical field such as excellent biodegradability, hemostatic properties, antibacterial activity, antioxidant properties, biocompatibility, and low toxicity. Furthermore, chitosan is a smart and versatile biopolymer due to its polycationic nature with reactive functional groups that allow the polymer to form many interesting structures or to be modified in various ways to suit the targeted applications. In this review, we provide an up-to-date development of the versatile structures of chitosan-based smart biomaterials such as nanoparticles, hydrogels, nanofibers, and films, as well as their application in the biomedical field. This review also highlights several strategies to enhance biomaterial performance for fast growing fields in biomedical applications such as drug delivery systems, bone scaffolds, wound healing, and dentistry.
... The porous architecture of the electrospun nanofiber scaffolds is critical in cell survival, proliferation, and secretion of ESM [32]. Good pore connectivity allows the effective transport of nutrients, oxygen, and metabolic waste products to and from cells [33,34]. The biocompatibility and biodegradability pro- vide a good environment for cell adherence, differentiation, and proliferation, thereby widening the applications of electrospun nanofibers in biomedical fields such as wound dressing [30,35], tissue scaffolds [36], drug delivery [13], cosmetics [37], implants [38], biosensor [39,40], antibacterial agent [16,41], etc. ...
... The porous architecture of the electrospun nanofiber scaffolds is critical in cell survival, proliferation, and secretion of ESM [32]. Good pore connectivity allows the effective transport of nutrients, oxygen, and metabolic waste products to and from cells [33,34]. The biocompatibility and biodegradability provide a good environment for cell adherence, differentiation, and proliferation, thereby widening the applications of electrospun nanofibers in biomedical fields such as wound dressing [30,35], tissue scaffolds [36], drug delivery [13], cosmetics [37], implants [38], biosensor [39,40], antibacterial agent [16,41], etc. ...
Dural defects are a common problem in neurosurgical procedures and should be repaired to avoid complications such as cerebrospinal fluid leakage, brain swelling, epilepsy, intracranial infection, and so on. Various types of dural substitutes have been prepared and used for the treatment of dural defects. In recent years, electrospun nanofibers have been applied for various biomedical applications, including dural regeneration, due to their interesting properties such as a large surface area to volume ratio, porosity, superior mechanical properties, ease of surface modification, and, most importantly, similarity with the extracellular matrix (ECM). Despite continuous efforts, the development of suitable dura mater substrates has had limited success. This review summarizes the investigation and development of electrospun nanofibers with particular emphasis on dura mater regeneration. The objective of this mini-review article is to give readers a quick overview of the recent advances in electrospinning for dura mater repair.
... The kinetics of the corrosion/degradation is so key for governing the behavior and performance of the scaffolds/implants and bone tissue growth [263][264][265][266][267][268][269] . Concerning ASTM G59-97, the corrosion rate can be estimated by the Eq. ...
Magnesium (Mg)-based materials are a new generation of alloys with the exclusive ability to be biodegradable within the human/animal body. In addition to biodegradability, their inherent biocompatibility and similar-to-bone density make Mg-based alloys good candidates for fabricating surgical bioimplants for use in orthopedic and traumatology treatments. To this end, nowadays additive manufacturing (AM) along with three-dimensional (3D) printing represents a promising manufacturing technique as it allows for the integration of bioimplant design and manufacturing processes specific to given applications. Meanwhile, this technique also faces many new challenges associated with the properties of Mg-based alloys, including high chemical reactivity, potential for combustion, and low vaporization temperature. In this review article, various AM processes to fabricate biomedical implants from Mg-based alloys, along with their metallic microstructure, mechanical properties, biodegradability, biocompatibility, and antibacterial properties, as well as various post-AM treatments were critically reviewed. Also, the challenges and issues involved in AM processes from the perspectives of bioimplant design, properties, and applications were identified; the possibilities and potential scope of the Mg-based scaffolds/implants are discussed and highlighted.
... DLP will be more suitable for Newtonian material, since it does not use pressure or extrusion as its printing mechanism. It can fabricate favourable architecture with high resolution that can support bone regeneration, such as interconnected pores with a 100 to 400 μm diameter, which allow bone ingrowth [12,23]. Bone architectures are also varying in different anatomical structures, e.g., jawbones. ...
As one of the most transplanted tissues of the human body, bone has varying architectures, depending on its anatomical location. Therefore, bone defects ideally require bone substitutes with a similar structure and adequate strength comparable to native bones. Light-based three-dimensional (3D) printing methods allow the fabrication of biomimetic scaffolds with high resolution and mechanical properties that exceed the result of commonly used extrusion-based printing. Digital light processing (DLP) is known for its faster and more accurate printing than other 3D printing approaches. However, the development of biocompatible resins for light-based 3D printing is not as rapid as that of bio-inks for extrusion-based printing. In this study, we developed CSMA-2, a photopolymer based on Isosorbide, a renewable sugar derivative monomer. The CSMA-2 showed suitable rheological properties for DLP printing. Gyroid scaffolds with high resolution were successfully printed. The 3D-printed scaffolds also had a compressive modulus within the range of a human cancellous bone modulus. Human adipose-derived stem cells remained viable for up to 21 days of incubation on the scaffolds. A calcium deposition from the cells was also found on the scaffolds. The stem cells expressed osteogenic markers such as RUNX2, OCN, and OPN. These results indicated that the scaffolds supported the osteogenic differentiation of the progenitor cells. In summary, CSMA-2 is a promising material for 3D printing techniques with high resolution that allow the fabrication of complex biomimetic scaffolds for bone regeneration.
