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Bone tissue formation with human mesenchymal stem cells and biphasic calcium phosphate ceramics: The local implication of osteoclasts and macrophages

Bone tissue formation with human mesenchymal stem cells and biphasic calcium phosphate ceramics: The local implication of osteoclasts and macrophages

Human mesenchymal stem cells (hMSC) have immunomodulative properties and, associated with cal- cium phosphate (CaP) ceramics, induce bone tissue repair. However, the mechanisms of osteoinduction by hMSC with CaP are not clearly established, in particular the role of osteoclasts and macrophages. Biphasic calcium phosphate (BCP) particles were implanted with or without hMSC in the paratibial muscles of nude mice. hMSC increased osteoblastic gene expression at 1 week, the presence of macro- phages at 2 and 4 weeks, osteoclastogenesis at 4 and 8 weeks, and osteogenesis at 4 and 8 weeks. hMSC disappeared from the implantation site after 2 weeks, indicating that hMSC were inducers rather than effectors of bone formation. Induced blockage of osteoclastogenesis by anti-Rankl treatment significantly impaired bone formation, revealing the pivotal role of osteoclasts in bone formation. In summary, hMSC positively influence the body foreign reaction by attracting circulating haematopoietic stem cells and inducing their differentiation into macrophages M1 and osteoclasts, thus favouring bone formation.
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In vitro characterization of an osteoinductive biphasic calcium phosphate in combination with recombinant BMP2

In vitro characterization of an osteoinductive biphasic calcium phosphate in combination with recombinant BMP2

Currently, one area of research that has been highly investigated in recent years is the field of osteoinductive biomaterials [7]. Originally, osteoinduction was de- scribed as the ability for an undifferentiated progenitor cell to auto-induce down the osteoblast lineage [14]. Much of the original findings were developed by Urist and Strates who extracted a complex of bone morpho- genetic proteins (BMPs) from demineralized bone matrix [15]. Since the mid 1970s, the only FDA approved com- mercially available biomaterials with ‘ osteoinductive potential’ are limited to demineralized freeze-dried bone allograft (DFDBA) and BMP2 [7]. More recently how- ever, it has been shown that synthetically fabricated bone grafts made from biphasic calcium phosphate (BCP) materials sintered at low temperatures have shown the potential for osteoinduction by demonstrating ectopic bone formation when materials were implanted in extra- skeletal sites (either muscle or epithelial tissues) [16, 17]. As the ability for these materials to guide mesenchymal progenitor cells down the osteoblast lineage without the use of inductive growth factors such as BMP2, our la- boratory has become increasingly interested in their po- tential as future regenerative materials. One of the main thoughts contributing to their osteoinductive potential has been proposed to be highly regulated from cells derived from the monocyte lineage including either macrophages or osteoclasts [18]. Currently, an array of recent research has been carried out investigating these materials and their ability to induce ectopic bone formation [19 – 23].
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Effect of nano hydroxyapatite coating on the osteoinductivity of porous biphasic calcium phosphate ceramics

Effect of nano hydroxyapatite coating on the osteoinductivity of porous biphasic calcium phosphate ceramics

treatment of more than 3,000 pediatric patients with bone cancer cost more than $70 million [2]. Autogenous bone grafting is the gold standard for treating bone defects, but sources of donor tissue are limited. Furthermore, autolo- gous bone grafts have shown considerable bone resorption before bone healing [3,4]. Bone allografts are not exten- sively applied in clinical practice due to the associated risks of infection and immune rejection [5,6]. Therefore, synthetic materials have been studied extensively as po- tential bone substitutes, including calcium phosphate (CaP) ceramics [7-9]. One CaP ceramic material, biphasic calcium phosphate (BCP), is composed of hydroxyapatite
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Comparative evaluation of alloplast (biphasic calcium phosphate) and demineralized freeze-dried bone allograft (dfdba) in the treatment of periodontal intrabony defects-a clinical and radiographic study

Comparative evaluation of alloplast (biphasic calcium phosphate) and demineralized freeze-dried bone allograft (dfdba) in the treatment of periodontal intrabony defects-a clinical and radiographic study

Several studies demonstrated that the use of graft material has better clinical results for the treatment of intrabony defects. The purpose of this study is to compare the clinical and radiographic efficacy of alloplast (Biphasic calcium phosphate) and demineralized freeze-dried bone allograft (DFDBA) in treatment of periodontal intraosseous defects. A split mouth study was conducted in 20 subjects diagnosed with chronic periodontitis presenting atleast two intrabony defects in either arch. One quadrant (Site A) received alloplast (Biphasic calcium phosphate) and the contralateral defect (Site B) received DFDBA. The results of study showed that clinically Site B (DFDBA) showed greater reduction in pocket depth and gain in clinical attachment level than site A (Biphasic calcium phosphate), however it was not statistically significant. Site A (Biphasic calcium phosphate) showed slightly more gingival marginal recession than Site B (DFDBA). Radiographically Site B (DFDBA) showed greater bone fill compared to Site A (Biphasic calcium phosphate) which was statistically significant.
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The Formation and Characterization of Nanocrystalline Phases by Mechanical Milling of Biphasic Calcium Phosphate/Poly L Lactide Biocomposite

The Formation and Characterization of Nanocrystalline Phases by Mechanical Milling of Biphasic Calcium Phosphate/Poly L Lactide Biocomposite

successful application of this composite as bone substitute material. However, the work on achieving a better compat- ibility in mechanical properties is still in progress. Besides biocompatibility, a response from the living organism to an applied implant depends on various factors such as porosity, surface microstructure, elastic modules, compressive strength, etc. 6–8) Addition of biphasic calcium phosphate (BCP) to polymers can significantly improve the polymer bioactivity, 9) while BCP itself can be an exceptional carrier

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Sol-gel Derived Biphasic Calcium Phosphate Ceramics on Nitinol for Medical Applications

Sol-gel Derived Biphasic Calcium Phosphate Ceramics on Nitinol for Medical Applications

Nitinol and Ti-based alloys are classified as bioinert materials as they do not induce bone formation on their surface [11]. An achieved integrity and structural continuity of implant material with surrounding bone are of extreme importance for in vivo behavior and a longer life-time of implants [12]. Hence, the formation of calcium phosphates (CaPs) coating serves as a good barrier to Nitinol degradation and combines good mechanical properties of the metallic substrate with a good bio-behavior of coatings [1,13-16]. It is necessary to stress that the bioactive concept, developed for biphasic calcium phosphate ceramics, is based on an optimum balance of the more stable phase of hydroxyapatite (HAp) and more soluble tricalcium phosphate (TCP), depending on the application aspect. Thus, the presence of TCP in the bioceramic material is not necessarily detrimental as was considered earlier, since its rate of dissolution is greater than that of HAp in physiological environments [17]. TCP gradually dissolves in the body and a biological calcium phosphate layer precipitates and leads to a more effective bone regeneration ability [18]. Hence, low content of TCP in bioceramic material is helpful for the enhanced osseointegration [19].
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Efficacy of platelet rich fibrin in combination with biphasic calcium phosphate in fracture healing

Efficacy of platelet rich fibrin in combination with biphasic calcium phosphate in fracture healing

I Hereby declare that this dissertation entitled “EFFICACY OF PLATELET RICH FIBRIN IN COMBINATION WITH BIPHASIC CALCIUM PHOSPHATE IN FRACTURE HEALING” is a bonafide and genuine research work carried out by me under the guidance of Dr.B.K.Dinakar Rai , D.Ortho.,M.S. Ortho , Professor & HOD, Department of Orthopaedics, PSG IMS&R, Coimbatore, dissertation is submitted to the Tamilnadu Dr.M.G.R. Medical University in fulfillment of the university regulations for the award of degree of Master of Surgery in Orthopaedics. This dissertation has not been submitted for award of any other degree or diploma.
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Surface mineralized biphasic calcium phosphate ceramics loaded with urine-derived stem cells are effective in bone regeneration

Surface mineralized biphasic calcium phosphate ceramics loaded with urine-derived stem cells are effective in bone regeneration

As a kind of calcium phosphate (CaP), biphasic calcium phosphate ceramics (BCPs) have been widely used in the biomedical field because of its excellent biocompatibility and bioactivity [7]. BCPs consist of hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP), which are similar to the inorganic minerals of bone tissue [8]. The biological effects of BCPs, including protein adsorption, regulation of the osteogenic gene expression, biological degradation, biological risk, and anticancer activity, make it a preferred candidate for bone repair [9, 10]. Calcium ion released from BCPs can increase expression of growth factor, activate Ca sensing receptors in osteoblast cells, and enhance cell proliferation, differentiation, and mineralization [11]. In addition, compared to other kinds of biomaterials, BCPs are more beneficial to biomineralization in hard tissue re- generation [12]. The key to bone formation is bone calcifi- cation, also known as mineralization. The mineralization of biomaterials in vivo mainly refers to the formation of bone- like HAp, a biologically active apatite interface layer, on the surface of materials [13]. However, following the implant- ation of materials into bone defects, the process of surface mineralization takes a few weeks [14]. Therefore, we hypothesize that mineralization of materials in vitro, and combination with stem cells could promote and accelerate the process of bone repair. In addition, there is no research that has figured out whether apatite interface layer en- hances osteoinductivity of BCPs on stem cells, especially USCs. Therefore, the first aim of our study is to investigate biological characteristics and multilineage differentiation potential of USCs. The second aim of our study is to evalu- ate the effect of surface mineralization of apatite interface layer on osteogenic potential of USCs in vitro and in vivo.
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Comparative evaluation of biphasic calcium phosphate and biphasic calcium phosphate collagen composite on osteoconductive potency in rabbit calvarial defect

Comparative evaluation of biphasic calcium phosphate and biphasic calcium phosphate collagen composite on osteoconductive potency in rabbit calvarial defect

because their chemical and structural characters are simi- lar to those of human bone [1]. Indeed, they have shown favorable biocompatibility and osteoconductivity when used as bone graft materials [3]. Among Ca-Ps, HA, which is very stable, can maintain the space effectively but has low osteoconductivity [4,5]. In contrast, β-TCP is more biodegradable and rapidly replaced by newly formed bone but has low capacity of space maintaining [6]. Therefore biphasic calcium phosphate (BCP), which is composed of HA and β-TCP, was introduced to overcome limitations of each material and several studies have been demon- strated that BCPs can be used as bone substitutes suc- cessfully [5,7,8].
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Cuttlefish bone-derived biphasic calcium phosphate scaffolds coated with sol-gel derived bioactive glass

Cuttlefish bone-derived biphasic calcium phosphate scaffolds coated with sol-gel derived bioactive glass

Bone is the second most transplanted tissue after blood. Autologous bone grafts are still considered the gold standard procedure, but unfortunately, their availability is limited and they are intimately associated with donor site morbidity [1]. Thus, bone tissue engineering represents an important challenge in order to overcome the shortcomings of bone grafts, where porous scaffolds can be combined with cells and bioactive growth factors, providing a suitable environment for tissue development [2]. Bioceramic-based scaffolds have been successfully used for bone repair and replacement. Among the different bioceramics, calcium phosphate materials (CaP) like hydroxyapatite (HA) and -tricalcium phosphate (-TCP) are the most commonly used ones due to their close chemical similarity to the inorganic part of the bone. HA is stable under physiological conditions and has a slow resorption rate and; on the other hand, -TCP is a more soluble phase with a lower mechanical stability. Mixtures of HA and -TCP phases originate biphasic calcium phosphate (BCP) materials and enable to control the bioactivity and the balance between resorption and solubilisation rates [3]. Bioactive glasses (BGs) have been used as an alternative to CaP materials. They have the capacity to strongly bond to the living tissues, through the growth of a bone-like HA layer on the glass surface [4,5]. Moreover, BGs release critical concentrations of ions like Si, P or Ca, which act as chemical stimuli for the activation of osteoprogenitor cells and, consequently, enhance bone formation. The release of these ions is also known to stimulate neovascularisation and angiogenesis and, thereby, promoting bone healing [6,7]. BGs were firstly synthesized by melt- quenching technique. Nevertheless, the sol-gel approach has been gaining more relevance in the last decades [8–10]. When compared to melt-quenching, the sol-gel derived BGs are prepared at significantly lower temperatures and they have a higher specific surface area, which, consequently, enhances their bioactive response [11]. Apart from that, the sol-gel derived BGs can be prepared with amounts of SiO 2 up to 90 wt.%, whilst SiO 2 contents higher than 60 wt.% are hardly achievable by
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Effect of Magnesium on the Mechanical and Bioactive Properties of Biphasic Calcium Phosphate

Effect of Magnesium on the Mechanical and Bioactive Properties of Biphasic Calcium Phosphate

Incorporation of trace elements into calcium phosphate structure is of great interest for the development of artificial bone implants. Biphasic calcium phosphate (BCP) composed of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) have been synthesized in the presence of magnesium (5 M% - 20 M%) by gel method under physiological conditions. Crystallization of Mg-BCP in the gel medium mimics the Mg intake in the human body. Powder X-ray dif- fraction and Fourier transform infrared analyses confirmed that the Mg doping leads to the enrichment of β-TCP phase and suppresses the HA content in BCP. Nanoindentation studies indicate a significant decrease in hardness and elastic modulus values of BCP due to Mg doping. In vitro bioactivity study has confirmed the formation of apatite layer on the Mg doped samples making it suitable for bone replacement. The results suggest that the optimum Mg doping promotes the bioactivity which is perquisite for biomedical applications.
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Benefits of biphasic calcium phosphate hybrid scaffold-driven osteogenic differentiation of mesenchymal stem cells through upregulated leptin receptor expression

Benefits of biphasic calcium phosphate hybrid scaffold-driven osteogenic differentiation of mesenchymal stem cells through upregulated leptin receptor expression

proved that the osteoinductive calcium phosphates, both HA and BCP, could upregulate the gene expression of BMPs, in addition to even upregulating the expression of intracellular signal transduction molecules in the Smad pathway during osteogenesis in MSCs [35]. Leptin exerts its effect by binding to leptin-R and activating the JAK/STAT pathway, which is highly expressed in human osteoblasts [36, 37]. In the present study, the BCP hybrid scaffold culture resulted in higher upregulation of mRNA (Fig. 2) and protein (Fig. 3) expression of leptin- R in MSCs than did the coralline HA hybrid scaffold. Leptin [19] and leptin-R [20] are expressed in MSCs and might act as a local (autocrine) factor in the osteogenesis of MSCs and bone remodeling. Enhancement of the ex- pression of transforming growth factor (TGF)-β [38] and ALP [39] by leptin has previously been reported, and the stimulatory effect of leptin on the osteogenesis of MSCs was also confirmed by the ALP activity measured in this study (Fig. 4).
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Pre-clinical studies of bone regeneration with human bone marrow stromal cells and biphasic calcium phosphate

Pre-clinical studies of bone regeneration with human bone marrow stromal cells and biphasic calcium phosphate

Bone marrow aspirates were obtained from the iliac crest, by standard puncture and aspiration, of healthy human donors (21 to 26 years old) after receiving informed consent according to the Declaration of Helsinki. The project was approved by the Ethical Committee of Ulm University. A maximum of 37 ml bone marrow was aspi- rated using up to four 20 ml Omnifix syringes (B. Braun, Melsungen, Germany) and transplant aspiration needles (Somatex, Teltow, Germany). Each syringe was prefilled with 1,000 IU heparin in 2 ml NaCl (B. Braun). BMSCs used in this study are of GMP grade and were expanded according to previously published protocols [6]. In brief, BMSCs were isolated from heparinized bone marrow aspirates by seeding 50,000 white blood cells/cm 2 on two-chamber CellStacks (Corning/VWR, Ulm, Germany) in alpha minimum essential medium (Lonza, Basel, Switzerland) supplemented with 5% GMP-grade human platelet lysate (IKT, Ulm, Germany) in order to avoid animal products [5]. Cells were cultured for 10 or 14 days with medium exchange twice per week. Cells were detached and reseeded at a density of 4,000 BMSCs/cm 2 on two-chamber CellStacks in alpha minimum essential medium supple- mented with 8% PL for a further 5 or 7 days. A production license for this protocol has been granted from the regional government (Regierungspräsidium Tübingen, Germany; production and import license: DE_BW_01_ MIA_2013_0040/DE_BW_01_IKT Ulm). To assess the quality of the aspirates, measures such as colony-forming units (CFUs-F), BM-MNC content and doubling times were measured. For phenotypic characterization, flow cytometry was performed as described previously [5,6]. Fluorescent intensities of 50,000 to 100,000 BMSCs were acquired. Briefly, BMSCs were stained for 15 minutes in 100 μl phosphate-buffered saline using the following com- binations of antibodies: IgG-FITC (clone X40), IgG-PE (clone X40), IgG-PerCP (clone X40); CD90-FITC (clone 5E10), CD34-PE (clone 8G12), CD45-PerCP (clone 2D1); CD105-FITC (clone SN6), CD73-PE (clone AD2), CD3- PerCP (clone SK7); and HLA-DR,DQ,DP-FITC (clone Tü39), HLA-A,B,C-PE (clone G46-2.6). All antibodies were sourced from Becton Dickinson (Heidelberg, Germany), except CD105 that was from AbDSerotec (Puchheim, Germany). After washing with phosphate- buffered saline, cells were analyzed using a BD FACScan (BD Biosciences, Heidelberg, Germany).
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The use of a biphasic calcium phosphate in a maxillary sinus floor elevation procedure: a clinical, radiological, histological, and histomorphometric evaluation with 9- and 12-month healing times

The use of a biphasic calcium phosphate in a maxillary sinus floor elevation procedure: a clinical, radiological, histological, and histomorphometric evaluation with 9- and 12-month healing times

Bone biopsies were obtained during implant surgery as previously described [37]. Trephines were split and opened in order to secure the orientation of the biopsies. The biopsies were fixed overnight in 4% phosphate- buffered formaldehyde and transferred to alcohol 70% [38]. After dehydration, the bone specimens were embed- ded without prior decalcification in methylmethacrylate supplemented with 20% dibuthylphtalaat and 0.008 g/ml Lucidol. The biopsies were cut into 5-μm longitudinal sec- tions (Polycut S., Leica microtome type sm2500s, Leica, Wetzlar, Germany). Bone mass indices and osteoid surface were measured in Goldner’s trichrome stained sections [39]. Tartrate-resistant acid phosphate (TRAP) staining was performed to visualize osteoclasts. Measurements were performed semi-automatically using a digitizer and image analysis software (Osteomeasure, Atlanta, GA, USA). In this study, the Von Kossa staining was used to verify remnant particles of BCP (Straumann® Bone Cer- amic). BCP particles were detected semi-quantitatively by three independent observers and classified into quartiles (<25% of BCP, >25% and <50% of BCP, >50 <75% of BCP, >75% of BCP). Nomenclature was used according to the American Society for Bone and Mineral Research (ASBMR) nomenclature committee [40].
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Ridge preservation using an in situ hardening biphasic calcium phosphate (β-TCP/HA) bone graft substitute—a clinical, radiological, and histological study

Ridge preservation using an in situ hardening biphasic calcium phosphate (β-TCP/HA) bone graft substitute—a clinical, radiological, and histological study

Background: Post-Extraction ridge preservation using bone graft substitutes is a conservative technique to maintain the width of the alveolar ridge. The objective of the present study was to evaluate an in situ hardening biphasic (HA/ β -TCP) bone graft substitutes for ridge preservation without primary wound closure or a dental membrane. Methods: A total of 15 patients reported for tooth extraction were enrolled in this study. Implants were placed in average 5.2 ± 2 months after socket grafting. At this visit, Cone Beam CT (CBCT) images and core biopsies were taken. Implant stability (ISQ) was assessed at the insertion as well as at the day of final restoration.
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The Influences of Different Ratios of Biphasic Calcium Phosphate and Collagen Augmentation on Posterior Lumbar Spinal Fusion in Rat Model

The Influences of Different Ratios of Biphasic Calcium Phosphate and Collagen Augmentation on Posterior Lumbar Spinal Fusion in Rat Model

Fig. 1. Representative microcomputed tomography axial and sagittal view sections of fusion masses from each group. (A) Autobone (group A) showed complete union without graft-bone interface. (B) 7:3 HA: β-TCP (group B) revealed relatively larger fusion mass but less incorporated into recipient lamina. (C) 7:3 HA: β-TCP+collagen (group C) showed little incorporation into lamina but more remaining fusion mass. (D) 3:7 HA: β-TCP (group D) showed re- duced fusion mass but revealed good graft incorporation into recipient lamina. (E) 3:7 HA: β-TCP+collagen (group E) demonstrated excellent graft incor- poration into recipient lamina. HA, hydroxyapatite; β-TCP, beta tricalcium phosphate.
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The effect of local application of low-magnitude high-frequency vibration on the bone healing of rabbit calvarial defects—a pilot study

The effect of local application of low-magnitude high-frequency vibration on the bone healing of rabbit calvarial defects—a pilot study

Methods: Four calvarial defects were created in each of two New Zealand rabbits and filled with the following materials: biphasic calcium phosphate (BCP), deproteinized bovine bone mineral covered with a non-cross-linked collagen membrane (BO/BG), biphasic calcium phosphate covered with a strontium hydroxyapatite-containing collagen membrane (BCP/SR), and non-cross-linked collagen membrane (BG). Four defects in one rabbit served as a control, while the other was additionally subjected to the local LMHFV protocol of 40 Hz, 16 min per day. The rabbits were sacrificed 1 week after surgery. Histomorphometric analysis was performed to determine the percentages of different tissue compartments.
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Lateral alveolar ridge augmentation procedure using subperiosteal tunneling technique: a pilot study

Lateral alveolar ridge augmentation procedure using subperiosteal tunneling technique: a pilot study

GUIDOR easy-graft CRYSTAL (Sunstar Suisse SA, Etoy, Switzerland) is a biphasic synthetic, in situ hardening bone graft substitute composed of 60% HA and 40% β-TCP [9]. The presence of HA causes the material to persist after new bone formation, integrating into the newly formed bone, while facilitating volume maintenance during initial healing. The material is directly applied from an applicator syringe, it is moldable, and, upon contact with blood, i.e. after appli- cation into the bone defect, hardens into a porous, stable scaffold. This in situ hardening property is particularly well suited to subperiosteal augmentation techniques. It allows this material to be readily inserted into the defect through the syringe and further molded and modeled into the de- sired shape through the gingiva during a short period after application before harden. The hardened scaffold remains stable during the early phases of healing [10].
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Incorporation of Carboplatin in Microporous Granular Calcium Phosphate Biphasic Matrix

Incorporation of Carboplatin in Microporous Granular Calcium Phosphate Biphasic Matrix

The 450 mg carboplatin was acquired from Tevacarbo. This drug was incorporated to the microporous bi- phasic granular biomaterial at a concentration of 70 mg/1g of biphasic biomaterial. The high vacuum method was used to incorporate the drug to the biomaterial. This is a physical process which inhibits the modification of the chemical and physical characteristics of the medication and the biomaterial [11].

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Catalytic Conversion of Fructose, Glucose and Industrial Grade Sugar Syrups to 5-Hydroxymethylfurfural, A Platform for Fuels and Chemicals

Catalytic Conversion of Fructose, Glucose and Industrial Grade Sugar Syrups to 5-Hydroxymethylfurfural, A Platform for Fuels and Chemicals

Dehydration of glucose with the combination of Tin-Beta zeolites acid catalysts in water/THF or water/1-butanol biphasic system was investigated by Nikolla et al. They reported higher glucose conversion and HMF selectivity with using biphasic system compared to the single aqueous phase which was attributed to the extraction of HMF from aqueous phase and thus suppressing further degradation of HMF into undesirable by- products. Addition of an inorganic salt such as NaCl to the aqueous phase of the biphasic system increased HMF selectivity and did not affect the activity of the Sn-Beta catalyst even in high salt concentration, suggesting that the inorganic salts contribute to the extraction of HMF from aqueous to the organic phase with minimal involvement in catalyzing the reaction. The activity of Sn-Beta was not also affected by the presence of HCl. HMF selectivity and glucose conversion were found to be 55% and 75%, respectively at 160 o C and 90 min in water/1-butanol biphasic system with Sn-Beta/HCl catalyst. The
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