Scaffolds For Bone Tissue Regeneration Research Articles

Smart biomaterials: Surfaces functionalized with proteolytically stable osteoblast-adhesive peptides

Engineered scaffolds for bone tissue regeneration are designed to promote cell adhesion, growth, proliferation and differentiation. Recently, covalent and selective functionalization of glass and titanium surfaces with an adhesive peptide (HVP) mapped on [351–359] sequence of human Vitronectin allowed to selectively increase osteoblast attachment and adhesion strength in in vitro assays, and to promote osseointegration in in vivo studies. For the first time to our knowledge, in this study we investigated the resistance of adhesion sequences to proteolytic digestion: HVP was completely cleaved after 5 h. In order to overcome the enzymatic degradation of the native peptide under physiological conditions we synthetized three analogues of HVP sequence. A retro-inverted peptide D-2HVP, composed of D amino acids, was completely stable in serum-containing medium. In addition, glass surfaces functionalized with D-2HVP increased human osteoblast adhesion as compared to the native peptide and maintained deposition of calcium. Interestingly, D-2HVP increased expression of IBSP, VTN and SPP1 genes as compared to HVP functionalized surfaces. Total internal reflection fluorescence microscope analysis showed cells with numerous filopodia spread on D-2HVP-functionalized surfaces. Therefore, the D-2HVP sequence is proposed as new osteoblast adhesive peptide with increased bioactivity and high proteolytic resistance.

Ribose mediated crosslinking of collagen-hydroxyapatite hybrid scaffolds for bone tissue regeneration using biomimetic strategies

This study explores for the first time the application of ribose as a highly biocompatible agent for the crosslinking of hybrid mineralized constructs, obtained by bio-inspired mineralization of self-assembling Type I collagen matrix with magnesium-doped-hydroxyapatite nanophase, towards a biomimetic mineralized 3D scaffolds (MgHA/Coll) with excellent compositional and structural mimicry of bone tissue. To this aim, two different crosslinking mechanisms in terms of pre-ribose glycation (before freeze drying) and post-ribose glycation (after freeze drying) were investigated. The obtained results explicate that with controlled freeze-drying, highly anisotropic porous structures with opportune macro-micro porosity are obtained. The physical-chemical features of the scaffolds characterized by XRD, FTIR, ICP and TGA demonstrated structural mimicry analogous to the native bone. The influence of ribose greatly assisted in decreasing solubility and increased enzymatic resistivity of the scaffolds. In addition, enhanced mechanical behaviour in response to compressive forces was achieved. Preliminary cell culture experiments reported good cytocompatibility with extensive cell adhesion, proliferation and colonization. Overall, scaffolds developed by pre-ribose glycation process are preferred, as the related crosslinking technique is more facile and robust to obtain functional scaffolds. As a proof of concept, we have demonstrated that ribose crosslinking is cost-effective, safe and functionally effective. This study also offers new insights and opportunities in developing promising scaffolds for bone tissue engineering.

Electrophoretic deposition of spray-dried Sr-containing mesoporous bioactive glass spheres on glass–ceramic scaffolds for bone tissue regeneration

The development of strong and bioactive scaffolds with a trabecular architecture mimicking that of cancellous bone is one of the major and still partially unmet challenges of modern biomaterials science and regenerative medicine. In this work, we exploited the electrophoretic process to deposit highly bioactive particles of mesoporous glass on the struts of a mechanically strong but almost inert glass–ceramic scaffold produced by the sponge replica method. A SiO2–CaO–SrO mesoporous glass was innovatively synthesized by aerosol-assisted spray drying in order to obtain spherical particles with high control over shape and morphology. The glass microspheres underwent morphological, chemical and textural characterizations, and the release kinetics of strontium—known for its ability to stimulate new bone formation in osteoporotic bone—were assessed upon immersion in simulated body fluid. Sr-containing mesoporous glass particles electrophoretically deposited on the scaffold walls retained a fast apatite-forming ability and formed a highly bioactive coating on the macroporous substrate without occluding the pores. The meso-macroporous hierarchical constructs produced in this research could be proposed as bioactive and mechanically strong implants for potential applications in bone tissue engineering.

Novel calcified gum Arabic porous nano-composite scaffold for bone tissue regeneration

The aim of this study was to investigate the biomechanical and biological properties of a nanocomposite scaffold containing both mineral and polysaccharide constituents. Hydroxyapatite nanoparticles (n-HA) was synthesized from dead abra ovata shells using wet chemical methods and was used in different ratios in concert with gum Arabic, a branched plant polysaccharide. N-HA/gum nanocomposite was fabricated with freeze-drying process and characterized by FTIR and SEM for chemical structure and morphology. Porosity was estimated using liquid substitution method. The scaffold mechanical properties were evaluated by compressive test measurement. Osteogenic differentiation was assessed using alkaline phosphatase production and biomineralization was evaluated using Alizarin red assay. Results demonstrated that the hydroxyapatite/gum Arabic nanocomposite had favorable biocompatibility and a similar structure to natural bone matrix. Porous nanocomposite possessed macropore networks with a porosity 87–93% and mean pore size ranging between 164 and 230 μm. The gum/HA with a ratio of 50% w/w HA had the highest compressive modulus of ∼75.3 MPa Pa (MPa) and the ultimate compressive stress of ∼16.6 MPa. C2C12 cells cultured on a scaffold with higher percentage (40 and 50 w/w) of HA demonstrated increased ALP levels and calcium deposition. The data from the present study demonstrated significant changes to the biomechanical properties and osteoconductivity of the nanocomposite scaffold by modulating its mineral content. Nanocomposite scaffolds containing gum and n-HA of 40–50% exhibited highest mechanical properties, as well as supported increased biomineralization.

Influence of strontium for calcium substitution on the glass–ceramic network and biomimetic behavior in the ternary system SiO2–CaO–MgO

Strontium (Sr) enhances bone formation both in vitro and in vivo, while it reduces bone resorption. Thus, Sr incorporation in bioactive glass–ceramic scaffolds for bone tissue regeneration could further enhance osteogenesis. The aim of this work was the synthesis, characterization and investigation of the apatite-forming ability in inorganic environment of two sol–gel-derived bioactive Sr-containing glass–ceramic materials with 5 and 10% of SrO. The thermal properties of the synthesized materials were studied using differential thermal analysis (TG–DTA). The apatite-forming ability test was conducted in SBF for various immersion times for both thermally treated and untreated samples. The characterization of the samples before and after immersion in SBF was performed with Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and scanning electron microscopy with associated energy-dispersive spectroscopy. FTIR spectra revealed that all synthesized glass–ceramic materials presented the characteristic bands of silicate glasses, while XRD identified various crystalline phases, mostly calcium silicates. Strontium is present in the form of strontium silicate in both as-received and thermally treated specimens, and Sr-diopside in the thermally treated specimens. The apatite-forming ability of the glass–ceramic materials was confirmed by the formation of a hydroxyapatite layer after 3 and 5 days of immersion in SBF on the surface of the untreated and thermally treated samples, respectively. The apatite layer, also, became thicker as the immersion time increased.

MECHANICAL PROPERTIES OF 3D SCAFFOLDS FOR BONE REGENERATION / 3D KARKASŲ, SKIRTŲ KAULŲ REGENERACIJAI, MECHANINIŲ SAVYBIŲ TYRIMAS

One of the biggest challenges in modern tissue engineering is a creation 3D scaffolds for bone tissue regeneration. Until now, in order to restore bone defects are used various bone substitutes (autologous and allogeneic), however, their usage is limited because is required additional surgery, possible complications, also limited their use is associated with ethical point of view. In this work we aim to determine the mechanical properties of 3D printed PLA objects having various orientation woodpile microarchitectures. In this work we chose three different 3D microarchitectures: woodpile BCC (each layer consists of parallel logs which are rotated 90 deg every next layer), woodpile FCC (every layer is additionally shifted half of the period in respect to the previous parallel log layer) and a rotating woodpile 60 deg (each layer is rotated 60 deg in respect to the previous one). Compressive and bending tests were carried out with TIRAtest2300 universal testing machine. We found that 60 deg rotating woodpile geometry had the highest mechanical values which were approximately about 3 times higher than the BCC or FCC microstructures. Vienas didžiausių šiuolaikinės audinių inžinerijos iššūkių yra 3D karkasų, skirtų kaulinio audinio regeneracijai, sukūrimas. Iki šiol, norint atstatyti kaulo defektus, naudojami įvairūs kaulo pakaitalai (autogeniniai ir alogeniniai), kurių naudojimo galimybės jau nebeatitinka poreikių, nes reikalinga papildoma operacija, galimos komplikacijos, taip pat ribotas jų naudojimas, susijęs su etinėmis pažiūromis. Šiame darbe lyginamos 3D spausdintuvu suformuotų mikrodarinių, skirtų kaulinio audinio defektui atkurti, mechaninės savybės. Darbe pasirinktos trys skirtingos 3D karkasų mikrostruktūros: woodpile BCC (kiekvienas sluoksnis susideda iš lygiagrečių rąstų, kurie keičiami 90 laipsnių kampu prieš tai esančio sluoksnio atžvilgiu), woodpile FCC (kiekvienas sluoksnis papildomai keičiasi per pusę periodo sluoksnio, esančio prieš tai, atžvilgiu) ir woodpile 60 deg (besisukanti rąstų rietuvė, kiekvienas tokios gardelės sluoksnis yra pasuktas 60 laipsnių prieš tai esančios atžvilgiu). Gniuždymo ir lenkimo bandymai buvo atlikti TIRAtest 2300 universalia bandymų mašina. Buvo nustatyta, kad, taikant 60 laipsnių kampu besikeičiančią woodpile geometriją, galima pasiekti didžiausias mechanines vertes, kurios buvo maždaug tris kartus didesnės nei woodfile BCC arba woodfile FCCmikrostruktūros.

Template-Mediated Biomineralization for Bone Tissue Engineering.

Template-mediated mineralization describes a research field of materials chemistry that deals with templates influencing product formation of foremost inorganic functional materials and composites. These templates are usually organic compounds - as far as molecules with natural origin are involved, the terminology "biomineralization" or "biomimetic mineralization: is used. The present review gives insight into recent developments in the research area of bone-tissue engineering with focus on chemical templates and cell-based approaches. The review is structured as follows: (1) a brief general overview about the principle of templating and recently used template materials, (2) important analytical methods, (3) examples of template-guided mineralization of various bone-related materials, (4) natural bone mineralization, (5) scaffolds for bone-tissue regeneration and (6) cell-based therapeutic approaches. For this purpose, a literature screening with emphasis on promising potential practical applications was performed. In particular, macromolecular structures and polymer composites with relation to naturally occurring compounds were favored. Priority was given to publications of the last five years. Although the present review does not cover the whole topic to full extent, it should provide information about current trends and the most promising approaches in the research area of bone-tissue engineering based on applications of organic templates/scaffolds as well as cell-based strategies.

Indirect casting of patient-specific tricalcium phosphate zirconia scaffolds for bone tissue regeneration using rapid prototyping methodology

Bio-composite scaffolds were fabricated by impregnating 10, 20, 30, 40 and 50% ZrO2 content with the β-TCP matrix to heal load bearing large size bone defects. The composite scaffolds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and mechanical testing. The in vitro degradation of scaffolds was calculated by immersing the samples in phosphate buffer saline for a period of 21 days. Biocompatibility was evaluated by XTT assay using human Osteosarcoma cell line (MG-63). Results include scaffold surface morphology, overall porosity, phase transformation, bonding, compressive strength, biodegradability and cytotoxicity with an increase in ZrO2 percentages. The conclusions proved that β-TCP scaffold with 30% ZrO2 content exhibits the best-required properties for the application in the field of bone tissue regeneration.

Microwave-induced porosity and bioactivation of chitosan-PEGDA scaffolds: morphology, mechanical properties and osteogenic differentiation.

In this study, a new foaming method, based on physical foaming combined with microwave-induced curing, is proposed in combination with a surface bioactivation to develop scaffold for bone tissue regeneration. In the first step of the process, a stable physical foaming was induced using a surfactant (Pluronic) as blowing agent of a homogeneous blend of Chitosan and polyethylene glycol diacrylate (PEGDA700) solutions. In the second step, the porous structure of the foaming was chemically stabilized by radical polymerization induced by homogeneous heating of the sample in a microwave reactor. In this step, 2,2-azobis[2-(2-imidazolin-2yl)propane]dihydrochloride was used as thermoinitiator (TI). Chitosan and PEGDA were mixed in different blends to investigate the influence of the composition on the final properties of the material. The chemical properties of each sample were evaluated by infrared attenuated total reflectance analysis, before and after curing in order to maximize reaction yield and optimize kinetic parameters (i.e. time curing, microwave power). Absorption capacity, elastic modulus, porosity and morphology of the porous structure were measured for each sample. The stability of materials was evaluated in vitro by degradation test in phosphate-buffered saline. To improve the bioactivity and biological properties of chitosan scaffold, a biomineralization process was used. Biological characterization was carried out with the aim to prove the effect of biomineralization scaffold on human mesenchymal stem cells behaviour. Copyright © 2016 John Wiley & Sons, Ltd.

Electrically active and 3D porous TiO2-x ceramic scaffolds for bone tissue regeneration

Bone healing can be significantly improved by applying electrical stimuli in the injured region. Thus, electrically active scaffolds with 3D structure are of interest as bone graft substitute materials. Such materials can locally deliver electrical current to the cells in the bone defects and in the same time ensure space for new bone formation. Present study is focused on preparation of novel highly porous and electrically active TiO2-x ceramic scaffolds via polymer replica method. Scaffolds showed fully open and interconnected pore structure with porosity above 95%. Thermal treatment of the scaffolds under high vacuum conditions was realized to obtain nonstoichiometric TiO2-x scaffolds and as a result electrical conductivity significantly increased from ∼10−9mS/m to ∼40mS/m. In vitro studies confirmed that scaffolds are cytocompatible and enhances cell spreading. Thus, TiO2-x scaffolds holds a potential to be used in bone tissue regeneration as an electrical stimuli supplier enhancing bone healing process.

Effect of the biodegradation rate controlled by pore structures in magnesium phosphate ceramic scaffolds on bone tissue regeneration in vivo.

Similar to calcium phosphates, magnesium phosphate (MgP) ceramics have been shown to be biocompatible and support favorable conditions for bone cells. Micropores below 25μm (MgP25), between 25 and 53μm (MgP53), or no micropores (MgP0) were introduced into MgP scaffolds using different sizes of an NaCl template. The porosities of MgP25 and MgP53 were found to be higher than that of MgP0 because of their micro-sized pores. Both in vitro and in vivo analysis showed that MgP scaffolds with high porosity promoted rapid biodegradation. Implantation of the MgP0, MgP25, and MgP53 scaffolds into rabbit calvarial defects (with 4- and 6-mm diameters) was assessed at two times points (4 and 8weeks), followed by analysis of bone regeneration. The micro-CT and histologic analyses of the 4-mm defect showed that the MgP25 and MgP53 scaffolds were degraded completely at 4weeks with simultaneous bone and marrow-like structure regeneration. For the 6-mm defect, a similar pattern of regeneration was observed. These results indicate that the rate of degradation is associated with bone regeneration. The MgP25 and MgP53 scaffold-implanted bone showed a better lamellar structure and enhanced calcification compared to the MgP0 scaffold because of their porosity and degradation rate. Tartrate-resistant acid phosphatase (TRAP) staining indicated that the newly formed bone was undergoing maturation and remodeling. Overall, these data suggest that the pore architecture of MgP ceramic scaffolds greatly influence bone formation and remodeling activities and thus should be considered in the design of new scaffolds for long-term bone tissue regeneration. The pore structural conditions of scaffold, including porosity, pore size, pore morphology, and pore interconnectivity affect cell ingrowth, mechanical properties and biodegradabilities, which are key components of scaffold in bone tissue regeneration. In this study, we designed hierarchical pore structure of the magnesium phosphate (MgP) scaffold by combination of the 3D printing process, self-setting reaction and salt-leaching technique, and first studied the effect of pore structures of bioceramic scaffolds on bone tissue regeneration through both in vitro and in vivo studies (rabbit calvarial model). The MgP scaffolds with higher porosity promoted more rapid biodegradation and enhanced new bone formation and remodeling activities at the same time.

Strontium eluting nanofibers augment stem cell osteogenesis for bone tissue regeneration

Strontium is known to offer a therapeutic benefit to osteoporotic patients by promoting bone formation. Thus, toward engineering scaffolds for bone tissue regeneration we have prepared polymer nanocomposite scaffolds by electrospinning. Strontium carbonate nanoparticles (nSrCO3) were added to poly(ε-caprolactone) (PCL) at 10 and 20wt% to develop nanocomposite fibrous scaffolds (PCL/SrC10 and PCL/SrC20) with fiber diameter in the range of 300⿿500nm. Incorporation of nSrCO3 decreased crystallinity and the elastic modulus of PCL. The composite scaffolds released Sr2+ ions with up to 65ppm in 4days from the PCL/SrC20 scaffolds. Cell studies confirmed that the composite scaffold with 20% nSrCO3 enhanced proliferation of human mesenchymal stem cells in vitro. There was marked increase in mineral deposition up to four folds in PCL/SrC20 suggesting enhanced osteogenesis. This was corroborated by increased mRNA and protein expression of various osteogenic markers such as BMP-2, Osterix and Runx2 in the PCL/SrC20 fibers. Thus, incorporation of nSrCO3 in polymer scaffolds is a promising strategy for bone tissue engineering as an alternative to the use of labile growth factors to impart bioactivity to polymer scaffolds.

Surface Chemistry of Nanoscale Mineralized Collagen Regulates Periodontal Ligament Stem Cell Fate.

The interplay between stem cells and their extracellular microenvironment is of critical importance to the stem cell-based therapeutics in regenerative medicine. Mineralized collagen is the main component of bone extracellular matrix, but the effect of interfacial properties of mineralized collagen on subsequent cellular behaviors is unclear. This study examined the role of surface chemistry of nanoscale mineralized collagen on human periodontal ligament stem cell (hPDLSC) fate decisions. The intrafibrillarly mineralized collagen (IMC), fabricated by a biomimetic bottom-up approach, showed a bonelike hierarchy with nanohydroxyapatites (HAs) periodically embedded within fibrils. The infrared spectrum of the IMC showed the presence of phosphate, carbonate, amide I and II bands; and infrared mapping displayed uniform and higher spatial distribution of mineralization in the IMC. However, the distribution of the phosphate group differed far from that of the amide I group in the extrafibrillarly mineralized collagen (EMC), in which flowerlike HA clusters randomly depositing around the surface of the fibrils. Moreover, a large quantity of extrafibrillar HAs covered up the C═O stretch and N-H in-plane bend, resulting in substantial reduction of amide I and II bands. Cell experiments demonstrated that the hPDLSCs seeded on the IMC exhibited a highly branched, osteoblast-like polygonal shape with extended pseudopodia and thick stress fiber formation; while cells on the EMC displayed a spindle shape with less branch points and thin actin fibril formation. Furthermore, the biocompatibility of EMC was much lower than that of IMC. Interestingly, even without osteogenic induction, mRNA levels of major osteogenic differentiation genes were highly expressed in the IMC during cultivation time. These data suggest that the IMC with a similar nanotopography and surface chemistry to natural mineralized collagen directs hPDLSCs toward osteoblast differentiation, providing a promising scaffold in bone tissue regeneration.

Fabrication and in vivo evaluation of an osteoblast-conditioned nano-hydroxyapatite/gelatin composite scaffold for bone tissue regeneration.

In this study, the effects of osteoblast-conditioning on mechanical behavior, biocompatibility, biodegradation and osteoinductive properties of a nano-hydroxyapatite/gelatin (HA/GEL) nanocomposite scaffold was investigated. The scaffold was fabricated using the layer solvent casting combined with the freeze-drying and lamination techniques. The scaffolds were conditioned by culture of osteoblasts on their surface and their elimination by a repeated freeze-thawing process. The potential of the osteoblast-conditioned HA/GEL (HA/GEL/OC) scaffold to support cell adhesion and growth and its cytotoxicity was assessed in vitro using rat mesenchymal stem cells. For in vivo studies, the HA/GEL/OC nanocomposite was implanted in the critical size bone defect created on rat calvarium and studied after 7, 30 and 90 days. The results showed that mechanical and in vitro biological properties of the scaffold were not affected by the process of conditioning. However, in vivo studies demonstrated that osteoblast-conditioning enhanced biocompatibility and osteoinductivity and of the nanocomposite scaffold. The osteoblast conditioning also accelerated collagen content during the bone healing. In the experimental group that received the HA/GEL/OC and MSCs, the newly formed bone occupied almost the entire defect (93.4 ± 3.3%) within 3 months. In conclusion, this study indicates that osteoblast-conditioning is a viable strategy for the development of bone tissue engineering scaffolds. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2001-2010, 2016.

Characterization and synthesis of hardystonite (HT) as a novel nanobioceramic powder

Objective(s):Hardystonite (HT) has been successfully prepared by a modified sol-gel method. We hypothesized that nano-sized (HT) would mimic more efficiently the nanocrystal structure and function of natural bone apatite, owing to the higher surface area, compare to conventional micron-size (HT). Materials and Methods: The hardystonite nanopowder was prepared via a modified sol-gel method.Optimization in calcination temperature and mechanicalball milling resulted in a pure and nano-sized powder which was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FTIR). Results:Pure (HT) powders were successfully obtained via a simple sol-gel method followed by calcination at1150 ∞C. Mechanical grinding in a ceramic ball mill for 6 hours resulted in (HT) nanoparticles in the range of about 32-55nm. Conclusion:Our study suggested that nanohardystonite (NHT) might be a potential candidate by itself as a nanobioceramic filling powder or in combination with other biomaterials as a composite scaffold in bone tissue regeneration.

Investigating processing techniques for bovine gelatin electrospun scaffolds for bone tissue regeneration.

Tissue engineering has emerged as a promising solution to tissue regeneration in the case of significant bone loss due to disease or injury. The ability to promote cellular attachment, migration, and differentiation into tissue is dependent on the scaffold's surface properties and composition. Bovine gelatin is a natural polymer commonly used as a scaffolding material for tissue engineering applications. Nonetheless, due to the hydrophilic behavior of gelatin, cross-linking and additives are necessary to maintain the scaffold's structure and overall strength in vivo. In this article, we discuss various processing techniques to determine the optimal electrospinning, cross-linking, sintering, and mineralization parameters necessary to yield a porous, mechanically enhanced scaffold. The scaffolds were evaluated quantitatively using compressive mechanical testing, and qualitatively using scanning electron microscopy (SEM). Mechanical data concluded the use of biocompatible microbial transglutaminase (mTG) as a cross-linking agent, led to increased compressive strength. SEM images confirmed the presence of individual gelatin and polymeric nanofibers woven into one scaffold. Sintering before leaching the scaffold yielded structured pores throughout the three-dimensional scaffold when compared to the scaffolds that were leached prior to sintering. The results presented in this article will provide novel information about processing techniques that can be utilized to develop a hybrid synthetic and biological based biomimetic mineralized scaffold for trabecular bone tissue regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1131-1140, 2017.

In vitro apatite forming ability and ketoprofen release of radiation synthesized (gelatin‐polyvinyl alcohol)/bioglass composite scaffolds for bone tissue regeneration

A series of bioglass (BG) reinforced composite scaffolds based on polyvinyl alcohol and Gelatin were prepared using γ‐radiation as clean source of initiation and crosslinking. To evaluate the potential applicability of the obtained reinforced BG composites as a scaffold for bone tissue regeneration, the in vitro apatite‐forming ability was assessed in simulated body fluid. The formation of apatite layer was confirmed using different techniques including Fourier transform spectroscopy technique, X‐ray diffraction, and scanning electron microscopy. In addition, gel fraction, swelling behavior, and thermal properties using thermogravimetric analysis technique of the composite scaffolds were investigated. The obtained data revealed that the presence of the BG particles entrapped within the scaffold matrix promotes hydroxyapatite formation, as a function of immersion time. The degradation of the reinforced composites in phosphate buffer was studied by measuring their weight loss as well as changes in the pH of the incubating medium as a function of time and BG content. In vitro release of ketoprofen as anti‐inflammatory and analgesic drug was investigated to evaluate the composite scaffolds potential as drug carrier. The obtained results showed that the ketoprofen loaded scaffolds were able to deliver the loaded drug in a sustainable manner that last for about 144 h. POLYM. COMPOS., 39:606–615, 2018. © 2016 Society of Plastics Engineers

Rapid prototyping assisted fabrication of patient specific β-tricalciumphosphate scaffolds for bone tissue regeneration

Beta Tri calcium phosphate scaffolds were produced by inverse casting methodology using rapid prototyping technology. Β-TCP scaffold sintered at different temperatures were analyzed by using Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, uniaxial compression test and cytotoxicity test. Results incorporate scaffold pore size, bonding, phase chance, porosity, mechanical strength, and cytotoxic profile with an increase in the sintering temperatures. Together, these properties are required for scaffold fabrication in the field of bone tissue regeneration.

Production of new 3D scaffolds for bone tissue regeneration by rapid prototyping.

The incidence of bone disorders, whether due to trauma or pathology, has been trending upward with the aging of the worldwide population. The currently available treatments for bone injuries are rather limited, involving mainly bone grafts and implants. A particularly promising approach for bone regeneration uses rapid prototyping (RP) technologies to produce 3D scaffolds with highly controlled structure and orientation, based on computer-aided design models or medical data. Herein, tricalcium phosphate (TCP)/alginate scaffolds were produced using RP and subsequently their physicochemical, mechanical and biological properties were characterized. The results showed that 60/40 of TCP and alginate formulation was able to match the compression and present a similar Young modulus to that of trabecular bone while presenting an adequate biocompatibility. Moreover, the biomineralization ability, roughness and macro and microporosity of scaffolds allowed cell anchoring and proliferation at their surface, as well as cell migration to its interior, processes that are fundamental for osteointegration and bone regeneration.

A new approach for bioceramic additive manufacturing

Event Abstract Back to Event A new approach for bioceramic additive manufacturing Hui-Suk Yun1 1 Korea Institute of Materials Science (KIMS), Powder and Ceramics Division, Korea Additive manufacturing (AM), or so-called 3D printing, is a fabrication process in which objects are made from various materials (e.g., polymers, metals, ceramics, and composites) in 2D layers that are stacked to produce a 3D object. AM is a computer-aided system that can produce customized and predefined internal pore structures and external shapes with high reproducibility, and is consequently viewed as an ideal process for the fabrication of scaffolds for bone tissue regeneration. Several AM processes are available for fabrication of bioceramic scaffolds, including selective laser sintering, powder printing, stereo-lithography, and material extruding. Almost all the ceramics processes include a sintering step at high temperature, both to remove binder and to achieve the desired mechanical properties. However, the sintering process often leads to shortcomings in biofunctional performance of ceramic scaffolds because biofunctional materials, such as drugs, proteins and cells, are easily denatured by heat and therefore cannot simultaneously print with ceramics. Our group is the first to suggest a novel process for creation of bioceramic scaffolds without sintering, to enhance the biofunctionality of ceramic scaffolds. Mechanical stability of the bioceramic scaffold was achieved by adapting a bone cement reaction rather than using a sintering process. A two-step process was used to prepare 3D porous bioceramic scaffolds. The first step was fabrication of the 3D porous scaffold green body using an AM process without the cement reaction. The second step was cementation, carried out by immersing the scaffold green body into the reactant solution for hardening; this replaced the typical sintering step. Separation of the AM process and cement reaction was important to secure enough time to fabricate 3D structural scaffolds of various sizes and architectures under homogeneous printing conditions. This original process was highly effective in producing bioceramic scaffolds with good biofunctionality and performance. This process could be applied to fabricate various types of bioceramic scaffolds with biofunctional materials, such as osteoblast cells, drugs, and proteins, thereby providing highly biofunctional scaffolds for effective bone tissue regeneration. Korea Ministry of Education, Science, and Technology (MEST) (2011-0017572) Keywords: Bone Regeneration, Calcium phosphate, Bioprinting, 3D scaffold Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: New Frontier Oral Topic: Biomaterials in printing Citation: Yun H (2016). A new approach for bioceramic additive manufacturing. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.00374 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Hui-Suk Yun Google Hui-Suk Yun Google Scholar Hui-Suk Yun PubMed Hui-Suk Yun Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.