Influence of Natural Polysaccharides on Properties of the Biomicroconcrete-Type Bioceramics

In this paper, novel hybrid biomicroconcrete-type composites were developed and investigated. The solid phase of materials consisted of a highly reactive α -tricalcium phosphate (α-TCP) powder, hybrid hydroxyapatite-chitosan (Hap-CTS) material in the form of powder and granules (as aggregates), and the polysaccharides sodium alginate (SA) or hydroxypropyl methylcellulose (HPMC). The liquid/gel phase in the studied materials constituted a citrus pectin gel. The influence of SA or HPMC on the setting reaction, microstructure, mechanical as well as biological properties of biomicroconcretes was investigated. Studies revealed that manufactured cement pastes were characterized by high plasticity and cohesion. The dual setting system of developed biomicroconcretes, achieved through α-TCP setting reaction and polymer crosslinking, resulted in a higher compressive strength. Material with the highest content of sodium alginate possessed the highest mechanical strength (~17 MPa), whereas the addition of hydroxypropyl methylcellulose led to a subtle compressive strength decrease. The obtained biomicroconcretes were chemically stable and characterized by a high bioactive potential. The novel biomaterials with favorable physicochemical and biological properties can be prosperous materials for filling bone tissue defects of any shape and size.

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Brushite cement containing gelatin: evaluation of mechanical strength and in vitro degradation

Cerâmica ◽

10.1590/0366-69132019653742585 ◽

2019 ◽

Vol 65 (374) ◽

pp. 261-266 ◽

Cited By ~ 1

Author(s):

L. P. Silva ◽

M. D. P. Ribeiro ◽

E. S. Trichês ◽

M. Motisuke

Keyword(s):

Mechanical Properties ◽

Weight Loss ◽

Compressive Strength ◽

Solid Phase ◽

Setting Time ◽

Biological Properties ◽

Solubility In Water ◽

Ringer’S Solution ◽

Weight Loss Data

Abstract Calcium phosphate cements (CPCs) are potential materials for repairing bone defects, mainly due to their excellent biocompatibility and osteoconductivity. Nevertheless, their low mechanical properties limit their usage in clinical applications. The gelatin addition may improve the mechanical and biological properties of CPCs, but their solubility in water may increase the porosity of the cement during degradation. Thus, the aim of this work was to investigate the influence of gelatin on the setting time, compressive strength and degradation rate of a brushite cement. CPCs were prepared with the addition of 0, 5, 10 and 20 wt% of gelatin powder in the solid phase of the cement. The results indicated that the setting time increased with gelatin. Furthermore, cement with 20 wt% of gelatin had an initial compressive strength of 14.1±1.8 MPa while cement without gelatin had 4.5±1.2 MPa. The weight loss, morphology and compressive strength were evaluated after degradation in Ringer’s solution. According to the weight loss data, gelatin was eliminated of samples during degradation. It was concluded that the presence of gelatin improved CPCs mechanical properties; however, as degradation in Ringer’s solution evolved, cement compressive strength decreased due to gelatin dissolution and, consequently, an increase in sample porosity.

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Physical and Biological Properties of a High-Plasticity Tricalcium Silicate Cement

BioMed Research International ◽

10.1155/2018/8063262 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Arthur Dias Galarça ◽

Wellington Luiz de Oliveira Da Rosa ◽

Tiago Machado Da Silva ◽

Giana da Silveira Lima ◽

Neftalí Lenin Villarreal Carreño ◽

...

Keyword(s):

Compressive Strength ◽

Film Thickness ◽

Cell Viability ◽

Water Solubility ◽

Setting Time ◽

Mineral Trioxide Aggregate ◽

Biological Properties ◽

High Plasticity ◽

Silicate Matrix ◽

Time Flow

Introduction. Mineral Trioxide Aggregate (MTA) is a tricalcium-based silicate, dicalcium silicate matrix. Despite its good biologic properties, some clinicians still claim to have difficulties in handling MTA after its preparation due to its sandy consistency. The aim of the present study was to evaluate the physicochemical properties and cytotoxicity of MTA Repair HP (Angelus, Londrina, PR, Brazil) compared with MTA Angelus (Angelus, Londrina, PR, Brazil). Materials and Method. The properties assessed were particle size, setting time, flow, film thickness, radiopacity, water solubility, compressive strength, and cytotoxicity. Statistical analysis was performed considering p < 0.05 as statistically significant. Results. For radiopacity, water absorption and solubility MTA Repair HP were statistically similar to MTA Angelus. The MTA Angelus had statistically different film thickness values, higher than MTA Repair HP (p < 0.05). Besides, MTA Angelus showed a lower and statistically different compressive strength after 28 days than MTA Repair HP (p<0.05). Additionally, MTA Repair HP set more slowly (p < 0.05). Relative to cell viability, MTA Repair HP was statistically similar to MTA Angelus after 24 and 48 h in cell viability. Conclusions. The MTA Repair HP presented similar cell viability, lower film thickness, higher flow, setting time, and compressive strength values after 28 days than MTA Angelus. In general, the MTA Repair HP presented physicochemical and biological properties similar to the MTA Angelus.

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Ytterbium Oxide as Radiopacifier of Calcium Silicate-Based Cements. Physicochemical and Biological Properties

Brazilian Dental Journal ◽

10.1590/0103-6440201802033 ◽

2018 ◽

Vol 29 (5) ◽

pp. 452-458 ◽

Cited By ~ 2

Author(s):

Bernardo Cesar Costa ◽

Juliane Maria Guerreiro-Tanomaru ◽

Roberta Bosso-Martelo ◽

Elisandra Márcia Rodrigues ◽

Idomeo Bonetti-Filho ◽

...

Keyword(s):

Compressive Strength ◽

Cell Viability ◽

Calcium Silicate ◽

Setting Time ◽

Neutral Red ◽

Biological Properties ◽

Alizarin Red ◽

Ytterbium Oxide ◽

Physicochemical And Biological Properties ◽

Bioactive Potential

Abstract This study evaluated physicochemical properties, cytotoxicity and bioactivity of MTA Angelus (MTA), calcium silicate-based cement (CSC) and CSC with 30% Ytterbium oxide (CSC/Yb2O3). Setting time was evaluated using Gilmore needles. Compressive strength was evaluated in a mechanical machine. Radiopacity was evaluated using radiographs of materials and an aluminum scale. Solubility was evaluated after immersion in water. Cell viability was evaluated by means of MTT assay and neutral red staining, and the mineralization activity by using alkaline phosphatase activity and Alizarin Red staining. The data were submitted to ANOVA, Tukey and Bonferroni tests (5% significance). The bioactive potential was evaluated by scanning electron microscopy. The materials presented similar setting time. MTA showed the lowest compressive strength. MTA and CSC/Yb2O3 presented similar radiopacity. CSC/Yb2O3 showed low solubility. Saos-2 cell viability tests showed no cytotoxic effect, except to 1:1 dilution in NR assay which had lower cell viability when compared to the control. ALP at 1 and 7 days was similar to the control. MTA and CSC had greater ALP activity at 3 days when compared to control. All the materials present higher mineralized nodules when compared with the control. SEM analysis showed structures suggesting the presence of calcium phosphate on the surface of materials demonstrating bioactivity. Ytterbium oxide proved to be a properly radiopacifying agent for calcium silicate-based cement since it did not affected the physicochemical and biological properties besides preserving the bioactive potential of this material.

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Nanocement Produced from Borosilicate Bioactive Glass Nanoparticles Composited with Alginate

Australian Journal of Chemistry ◽

10.1071/ch18410 ◽

2019 ◽

Vol 72 (5) ◽

pp. 354 ◽

Cited By ~ 3

Author(s):

Xin Xie ◽

Libin Pang ◽

Aihua Yao ◽

Song Ye ◽

Deping Wang

Keyword(s):

Compressive Strength ◽

Bioactive Glass ◽

Sodium Alginate ◽

Borosilicate Glass ◽

Glass Phase ◽

Solid Phase ◽

Setting Time ◽

Sol Gel ◽

Bone Cements ◽

Composite Bone

A novel injectable bone cement was prepared using sol–gel derived borosilicate bioactive glass nanoparticles as a solid phase and sodium alginate solution as a liquid phase. The gelation reaction of the alginate was modulated by Ca2+ ions released from the borosilicate glass phase, which in turn greatly depended on the boron content of the borosilicate glass phase. Such a gelation reaction not only significantly enhanced the anti-washout property of the bone cements, but also allowed control of the setting, handling properties, and compressive strength of the composite bone cements. Consequently, bone cements with controllable performances can be developed by simply adjusting the B2O3/SiO2 ratio of the borosilicate glass phase. Borosilicate bioactive glass with 20–30 mol-% borate contents exhibit a short setting time, good compressive strength, injectability, and anti-washout properties. With controllable performances and excellent bioactivity, the borosilicate bioactive glass/sodium alginate (BSBG/SA) composite bone cements are highly attractive for bone filling and regeneration applications.

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Synthesis and biological properties of cholecystokinin heptapeptide analogues containing D- and L-forms of tert-leucine or neopentylglycine in position 5

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19912209 ◽

1991 ◽

Vol 56 (10) ◽

pp. 2209-2217 ◽

Cited By ~ 8

Author(s):

Jan Hlaváček ◽

Jana Pírková ◽

Jan Pospíšek ◽

Jiřina Slaninová ◽

Lenka Maletínská

Keyword(s):

Gall Bladder ◽

Solid Phase ◽

Biological Activities ◽

Biological Properties ◽

Phase Synthesis ◽

Structural Modifications ◽

Bladder Contraction ◽

Anorectic Effect ◽

Carboxy Terminal ◽

Anorectic Activity

Using solution or solid-phase synthesis we prepared the cholecystokinin fragment Boc-CCK-7 (Boc-Tyr-(SO3-.Na+)-Met-Gly-Trp-Met-Asp-PheNH2) and its four analogues in which the methionine moiety (Met) in the carboxy-terminal part is replaced by tert-leucine (Tle) or neopentylglycine (Neo) residue or D-enantiomers of these non-coded amino acids. These structural modifications led to reduction of the studied biological activities (gall bladder contraction, anorectic activity, analgetic and sedation activity) of all prepared analogues except Boc[Neo5]-CCK-7 which, being less analgetically active, retains full gall bladder and sedation activity of CCK-8. Moreover, its anorectic activity is substantially higher (400%). This analogue is very interesting particularly for its selectively increased (4x) anorectic effect compared with that of CCK-8.

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Effect of Calcium Nitrate on the Properties of Portland–Limestone Cement-Based Concrete Cured at Low Temperature

Materials ◽

10.3390/ma14071611 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1611

Author(s):

Gintautas Skripkiūnas ◽

Asta Kičaitė ◽

Harald Justnes ◽

Ina Pundienė

Keyword(s):

Compressive Strength ◽

Cement Paste ◽

Setting Time ◽

Calcium Nitrate ◽

Curing Temperature ◽

Hardened Concrete ◽

Cement Pastes ◽

Initial Setting Time ◽

Initial Setting ◽

Early Strength

The effect of calcium nitrate (CN) dosages from 0 to 3% (of cement mass) on the properties of fresh cement paste rheology and hardening processes and on the strength of hardened concrete with two types of limestone-blended composite cements (CEM II A-LL 42.5 R and 42.5 N) at different initial (two-day) curing temperatures (−10 °C to +20 °C) is presented. The rheology results showed that a CN dosage up to 1.5% works as a plasticizing admixture, while higher amounts demonstrate the effect of increasing viscosity. At higher CN content, the viscosity growth in normal early strength (N type) cement pastes is much slower than in high early strength (R type) cement pastes. For both cement-type pastes, shortening the initial and final setting times is more effective when using 3% at +5 °C and 0 °C. At these temperatures, the use of 3% CN reduces the initial setting time for high early strength paste by 7.4 and 5.4 times and for normal early strength cement paste by 3.5 and 3.4 times when compared to a CN-free cement paste. The most efficient use of CN is achieved at −5 °C for compressive strength enlargement; a 1% CN dosage ensures the compressive strength of samples at a −5 °C initial curing temperature, with high early strength cement exceeding 3.5 MPa but being less than the required 3.5 MPa in samples with normal early strength cement.

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Bioactive potential of natural biomaterials: identification, retention and assessment of biological properties

Signal Transduction and Targeted Therapy ◽

10.1038/s41392-021-00512-8 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Kieran Joyce ◽

Georgina Targa Fabra ◽

Yagmur Bozkurt ◽

Abhay Pandit

Keyword(s):

Tissue Engineering ◽

Therapeutic Potential ◽

Biological Properties ◽

Biological Assessment ◽

Cross Linking ◽

Natural Polymers ◽

Drug Delivery Device ◽

Biomedical Device ◽

Wide Range ◽

Bioactive Potential

AbstractBiomaterials have had an increasingly important role in recent decades, in biomedical device design and the development of tissue engineering solutions for cell delivery, drug delivery, device integration, tissue replacement, and more. There is an increasing trend in tissue engineering to use natural substrates, such as macromolecules native to plants and animals to improve the biocompatibility and biodegradability of delivered materials. At the same time, these materials have favourable mechanical properties and often considered to be biologically inert. More importantly, these macromolecules possess innate functions and properties due to their unique chemical composition and structure, which increase their bioactivity and therapeutic potential in a wide range of applications. While much focus has been on integrating these materials into these devices via a spectrum of cross-linking mechanisms, little attention is drawn to residual bioactivity that is often hampered during isolation, purification, and production processes. Herein, we discuss methods of initial material characterisation to determine innate bioactivity, means of material processing including cross-linking, decellularisation, and purification techniques and finally, a biological assessment of retained bioactivity of a final product. This review aims to address considerations for biomaterials design from natural polymers, through the optimisation and preservation of bioactive components that maximise the inherent bioactive potency of the substrate to promote tissue regeneration.

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Formulation and Optimization of Sodium Alginate Polymer Film as a Buccal Mucoadhesive Drug Delivery System Containing Cetirizine Dihydrochloride

Pharmaceutics ◽

10.3390/pharmaceutics13050619 ◽

2021 ◽

Vol 13 (5) ◽

pp. 619

Author(s):

Krisztián Pamlényi ◽

Katalin Kristó ◽

Orsolya Jójárt-Laczkovich ◽

Géza Regdon

Keyword(s):

Drug Delivery ◽

Tensile Strength ◽

Sodium Alginate ◽

Drug Delivery System ◽

Delivery System ◽

Polymer Films ◽

Hydroxypropyl Methylcellulose ◽

Chemical Properties ◽

Active Pharmaceutical Ingredient ◽

Swallowing Problems

Currently, pharmaceutical companies are working on innovative methods, processes and products. Oral mucoadhesive systems, such as tablets, gels, and polymer films, are among these possible products. Oral mucoadhesive systems possess many advantages, including the possibility to be applied in swallowing problems. The present study focused on formulating buccal mucoadhesive polymer films and investigating the physical and physical–chemical properties of films. Sodium alginate (SA) and hydroxypropyl methylcellulose (HPMC) were used as film-forming agents, glycerol (GLY) was added as a plasticizer, and cetirizine dihydrochloride (CTZ) was used as an active pharmaceutical ingredient (API). The polymer films were prepared at room temperature with the solvent casting method by mixed two-level and three-level factorial designs. The thickness, tensile strength (hardness), mucoadhesivity, surface free energy (SFE), FTIR, and Raman spectra, as well as the dissolution of the prepared films, were investigated. The investigations showed that GLY can reduce the mucoadhesivity of films, and CTZ can increase the tensile strength of films. The distribution of CTZ proved to be homogeneous in the films. The API could dissolve completely from all the films. We can conclude that polymer films with 1% and 3% GLY concentrations are appropriate to be formulated for application on the buccal mucosa as a drug delivery system.

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