Bioactivity and Physico-Chemical Properties of Composites on Basis of Hydroxyapatite with Lactic and Glycolic Acids Oligomers

2015 ◽  
Vol 1085 ◽  
pp. 394-399 ◽  
Author(s):  
Lyudmila A. Rasskazova ◽  
Darya Lytkina ◽  
Yelena Shapovalova ◽  
Vladimir V. Botvin ◽  
Maksim A. Pozdnyakov ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Chemical Properties ◽  
Biological Properties ◽  
Phosphate Layer ◽  
Physical Chemical ◽  
Physico Chemical ◽  
Soxhlet Apparatus ◽  
Calcium Phosphate Layer ◽  
Properties Of Composites

A new methodin situfor producing of biocompatible composites based on hydroxyapatite and oligomers of lactic and glycolic acid is described. Their thermo-mechanical, physical-chemical and biological properties are studied as well. The formation of bonds between hydroxyapatite with lactic and glycolic oligomers in composites are confirmed by IR spectroscopy of the samples, including those obtained in the Soxhlet apparatus. The formation of calcium-phosphate layer on the composite's surface containing hydroxyapatite was shown by SBF-investigation. The scaffolds based on lactic acid oligomer do not stimulate formation of a calcium-phosphate layer and they are subjected to destruction by the way of hydrolysis.

Calcium Phosphate Materials in Restorative Dentistry: a Review

1988 ◽  
Vol 2 (1) ◽  
pp. 164-180 ◽  
Author(s):  
R.Z. Legeros
Keyword(s):  
Calcium Phosphate ◽  
Polymer Composites ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
Current Status ◽  
Medical Applications ◽  
Restorative Dentistry ◽  
Calcium Phosphate Cements ◽  
Physico Chemical

This report deals with some of the calcium phosphate materials which are currently used in preventive and restorative dentistry and other calcium phosphate materials which have potential for dental and medical applications. Such materials include those which form calcium phosphate in situ (e.g., Bioglass ceramics and calcium phosphate cements) and those originating from natural materials (such as corals and bones). The reports on the development and current status of the calcium phosphate ceramics and glass ceramics presented here were based on recent reviews and recent evaluations of clinical studies for the period 1975 to 1986 (Table 3) with humans and with animals when reports on human studies were not yet available. Methods of preparation and relevant physico-chemical properties of some of the calcium phosphate materials were based on data reported in the literature and on other studies by the author. New calcium phosphate materials, e.g., calcium phosphate cements, calcium phosphate-coated implants, calcium phosphate/polymer composites, have also been briefly covered in this report. Based on the information summarized in Tables 1 to 6 and on solicited comments from clinicians and researchers involved with calcium phosphate materials, several areas of basic and clinical research are recommended (Table 7).

Chitosan-Nanocellulose Composites for Regenerative Medicine Applications

2020 ◽  
Vol 27 (28) ◽  
pp. 4584-4592 ◽  
Author(s):  
Avik Khan ◽  
Baobin Wang ◽  
Yonghao Ni
Keyword(s):  
Regenerative Medicine ◽  
Preparation Method ◽  
Chemical Properties ◽  
Biological Properties ◽  
Next Generation ◽  
Structure Property ◽  
Physico Chemical ◽  
Structure Property Relationship ◽  
Attractive Candidate ◽  
Fundamental Understanding

Regenerative medicine represents an emerging multidisciplinary field that brings together engineering methods and complexity of life sciences into a unified fundamental understanding of structure-property relationship in micro/nano environment to develop the next generation of scaffolds and hydrogels to restore or improve tissue functions. Chitosan has several unique physico-chemical properties that make it a highly desirable polysaccharide for various applications such as, biomedical, food, nutraceutical, agriculture, packaging, coating, etc. However, the utilization of chitosan in regenerative medicine is often limited due to its inadequate mechanical, barrier and thermal properties. Cellulosic nanomaterials (CNs), owing to their exceptional mechanical strength, ease of chemical modification, biocompatibility and favorable interaction with chitosan, represent an attractive candidate for the fabrication of chitosan/ CNs scaffolds and hydrogels. The unique mechanical and biological properties of the chitosan/CNs bio-nanocomposite make them a material of choice for the development of next generation bio-scaffolds and hydrogels for regenerative medicine applications. In this review, we have summarized the preparation method, mechanical properties, morphology, cytotoxicity/ biocompatibility of chitosan/CNs nanocomposites for regenerative medicine applications, which comprises tissue engineering and wound dressing applications.

In situ dual crosslinking strategy to improve the physico-chemical properties of thermoplastic starch

2021 ◽  
pp. 118250
Author(s):  
Hamed Peidayesh ◽  
Abolfazl Heydari ◽  
Katarína Mosnáčková ◽  
Ivan Chodák
Keyword(s):  
Chemical Properties ◽  
Thermoplastic Starch ◽  
Physico Chemical

scholarly journals Soil physico-chemical characterization in the different soil layers of National Maize Research Program, Rampur, Chitwan, Nepal

2018 ◽  
Vol 3 (1) ◽  
pp. 28-44
Author(s):  
Dinesh Khadka ◽  
Sushil Lamichhane ◽  
Amit P Timilsina ◽  
Bandhu R Baral ◽  
Kamal Sah ◽  
...  
Keyword(s):  
Research Program ◽  
Soil Structure ◽  
Sandy Loam ◽  
Chemical Properties ◽  
Single Layer ◽  
Chemical Characterization ◽  
Bottom Layer ◽  
Soil Parameters ◽  
Physico Chemical

Soil pit digging and their precise study is a decision making tool to assess history and future of soil management of a particular area. Thus, the present study was carried out to differentiate soil physico-chemical properties in the different layers of excavated pit of the National Maize Research Program, Rampur, Chitwan, Nepal. Eight pits were dug randomly from three blocks at a depth of 0 to 100 cm. The soil parameters were determined in-situ, and in laboratory for texture, pH, OM, N, P (as P2O5), K (as K2O), Ca, Mg, S, B, Fe, Zn, Cu and Mn of collected soils samples of different layers following standard analytical methods at Soil Science Division, Khumaltar. The result revealed that soil structure was sub-angular in majority of the layers, whereas bottom layer was single grained. The value and chrome of colour was increasing in order from surface to bottom in the majority pits. Similarly, the texture was sandy loam in majority layers of the pits. Moreover, four types of consistence (loose to firm) were observed. Furthermore, mottles and gravels were absent in the majority layers. Likewise, soil was very to moderately acidic in observed layers of majority pits, except bottom layer of agronomy block was slightly acidic. Regarding fertility parameters (OM, macro and micronutrients), some were increasing and vice-versa, while others were intermittent also. Therefore, a single layer is not dominant for particular soil physico-chemical parameters in the farm. In overall, surface layer is more fertile than rest of the layers in all the pits.     

scholarly journals In situ sol-gel synthesis of hyaluronan derivatives bio-nanocomposite hydrogels

2019 ◽  
Vol 6 (5) ◽  
pp. 249-258 ◽  
Author(s):  
U D’Amora ◽  
A Ronca ◽  
M G Raucci ◽  
S M Dozio ◽  
H Lin ◽  
...  
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Filler Concentration ◽  
Similar Degree ◽  
Nanocomposite Hydrogels ◽  
Physico Chemical ◽  
Inorganic Fillers ◽  
Sol Gel Synthesis ◽  
Physical Blending

Abstract The main driving idea of the present study was the comparison between two different chemical modifications of hyaluronic acid (HA) followed by the development of nanocomposite hydrogels directly in situ by biomineralization of photocrosslinkable HA polymers through sol-gel synthesis. In this way, it has been possible to overcome some limitations due to classical approaches based on the physical blending of inorganic fillers into polymer matrix. To this aim, methacrylated and maleated HA, synthesized with similar degree of substitution (DS) were compared in terms of mechanical and physico-chemical properties. The success of in situ biomineralization was highlighted by reflect Fourier transform infrared spectroscopy and thermogravimetric analysis. Furthermore, mechanical characterization demonstrated the reinforcing effect of inorganic fillers evidencing a strong correlation with DS. The swelling behavior resulted to be correlated with filler concentration. Finally, the cytotoxicity tests revealed the absence of toxic components and an increase of cell proliferation over culture time was observed, highlighting these bio-nanocomposite hyaluronan derivatives as biocompatible hydrogel with tunable properties.

scholarly journals Exploring the difference in xerogels and organogels through in situ observation

2018 ◽  
Vol 5 (1) ◽  
pp. 170492
Author(s):  
Binglian Bai ◽  
Zhiming Li ◽  
Haitao Wang ◽  
Min Li ◽  
Yukihiro Ozaki ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Fluorescence Spectra ◽  
Chemical Properties ◽  
Columnar Structure ◽  
In Situ Observation ◽  
Physico Chemical ◽  
Aggregation Structure ◽  
Ft Ir ◽  
The Difference

Solvent–gelator interactions play a key role in mediating organogel formation and ultimately determine the physico-chemical properties of the organogels and xerogels. The ethanol organogels of 1,4-bis[(3,4,5-trihexyloxy phenyl)hydrazide]phenylene (TC6) were investigated in situ by FT-IR, Raman and fluorescence spectra, and XRD, and it was confirmed that the intermolecular interaction and aggregation structure of TC6 ethanol organogels were quite different from those of xerogels. Simultaneously, unprecedented phase transition from organogel to suspension upon heating was observed in ethanol organogel, and the suspension phase exhibited lytropic liquid crystalline behaviour with a rectangular columnar structure. This study may open the possibility to design new gelators with a new dimension of versatility.

Assessment of elemental fractionation and matrix effects during in situ Rb–Sr dating of phlogopite by LA-ICP-MS/MS: implications for the accuracy and precision of mineral ages

2021 ◽  
Author(s):  
Ahmad Redaa ◽  
Juraj Farkaš ◽  
Sarah Gilbert ◽  
Alan S. Collins ◽  
Ben Wade ◽  
...  
Keyword(s):  
Matrix Effects ◽  
Chemical Properties ◽  
Elemental Fractionation ◽  
Physical Chemical ◽  
Accuracy And Precision ◽  
Icp Ms

The effect of physical/chemical properties and Rb/Sr elemental fractionation on the accuracy of in situ Rb–Sr dating via LA-ICP-MS/MS.

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