Effect of sintering on physicochemical characteristics and biological performance of bovine HA

Self-assembled supramolecular structures based on polyion complex (PIC) formation between oppositely charged polymers are attracting much attention for developing drug delivery systems able to endure harsh in vivo environments. As controlling polymer complexation provides an opportunity for engineering the assemblies, an improved understanding of the PIC formation will allow constructing assemblies with enhanced structural and functional capabilities. Here, we focused on the influence of the mixing charge ratio between block aniomers and catiomers on the physicochemical characteristics and in vivo biological performance of the resulting PIC micelles (PIC/m). Our results showed that by changing the mixing charge ratio, the structural state of the core was altered despite the sizes of PIC/m remaining almost the same. These structural variations greatly affected the stability of the PIC/m in the bloodstream after intravenous injection and determined their biodistribution.

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PR572: Effect of sintering on physicochemical characteristics and biological performance of bovine HA

Journal Of Clinical Periodontology ◽

10.1111/jcpe.574_12915 ◽

2018 ◽

Vol 45 ◽

pp. 315-315

Keyword(s):

Physicochemical Characteristics ◽

Biological Performance

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Advanced polymeric nanotechnology to augment therapeutic delivery and disease diagnosis

Nanomedicine ◽

10.2217/nnm-2020-0145 ◽

2020 ◽

Vol 15 (23) ◽

pp. 2287-2309

Author(s):

Cláudia Martins ◽

Veeren M Chauhan ◽

Marco Araújo ◽

Amjad Abouselo ◽

Cristina C Barrias ◽

...

Keyword(s):

Aqueous Solubility ◽

Science Research ◽

Physicochemical Characteristics ◽

Disease Diagnosis ◽

Polymer Science ◽

Natural Polymers ◽

Disease Treatment ◽

Biological Performance ◽

Treatment And Diagnosis ◽

Synthetic And Natural Polymers

Therapeutic and diagnostic payloads are usually associated with properties that compromise their efficacy, such as poor aqueous solubility, short half-life, low bioavailability, nonspecific accumulation and diverse side effects. Nanotechnological solutions have emerged to circumvent some of these drawbacks, augmenting therapeutic and/or diagnostic outcomes. Nanotechnology has benefited from the rise in polymer science research for the development of novel nanosystems for therapeutic and diagnostic purposes. Polymers are a widely used class of biomaterials, with a considerable number of regulatory approvals for application in clinics. In addition to their versatility in production and functionalization, several synthetic and natural polymers demonstrate biocompatible properties that dictate their successful biological performance. This article highlights the physicochemical characteristics of a variety of natural and synthetic biocompatible polymers, as well as their role in the manufacture of nanotechnology-based systems, state-of-art applications in disease treatment and diagnosis, and current challenges in finding a way to clinics.

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Evaluation of Alginate-Based Bioinks for 3D Bioprinting, Mesenchymal Stromal Cell Osteogenesis, and Application for Patient-Specific Bone Grafts

10.1101/2020.08.09.242131 ◽

2020 ◽

Author(s):

Tomas Gonzalez-Fernandez ◽

Alejandro J. Tenorio ◽

Kevin T. Campbell ◽

Eduardo A. Silva ◽

J. Kent Leach

Keyword(s):

Mesh Size ◽

Physicochemical Characteristics ◽

Osteogenic Potential ◽

Patient Specific ◽

3D Bioprinting ◽

3D Print ◽

Biological Performance ◽

Cell Matrix Interactions ◽

Thickening Agents

AbstractTo realize the promise of 3D bioprinting, it is imperative to develop bioinks that possess the biological and rheological characteristics needed for the printing of cell-laden tissue grafts. Alginate is widely used as a bioink because its rheological properties can be modified through pre-crosslinking or the addition of thickening agents to increase printing resolution. However, modification of alginate’s physicochemical characteristics using common crosslinking agents can affect its cytocompatibility. Therefore, we evaluated the printability, physicochemical properties, and osteogenic potential of four common alginate bioinks: alginate-CaCl2 (alg-CaCl2), alginate-CaSO4 (alg-CaSO4), alginate-gelatin (alg-gel) and alginate-nanocellulose (alg-ncel) for the 3D bioprinting of patient-specific osteogenic grafts. While all bioinks possessed similar viscosity, printing fidelity was lower in the pre-crosslinked bioinks. When used to print geometrically defined constructs, alg-CaSO4 and alg-ncel exhibited higher mechanical properties and lower mesh size than those printed with alg-CaCl2 or alg-gel. The physical properties of these constructs affected the biological performance of encapsulated bone marrow-derived mesenchymal stromal cells (MSCs). Cell-laden constructs printed using alg-CaSO4 and alg-ncel exhibited greater cell apoptosis and contained fewer living cells 7 days post-printing. In addition, effective cell-matrix interactions were only observed in alg-CaCl2 printed constructs. When cultured in osteogenic media, MSCs in alg-CaCl2 constructs exhibited increased osteogenic differentiation compared to the other three bioinks. This bioink was then used to 3D print anatomically accurate cell-laden scaphoid bones that were capable of partial mineralization after 14 days of in vitro culture. These results highlight the importance of bioink properties to modulate cell behavior and the biofabrication of clinically relevant bone tissues.

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Applications of SEM/EDXA in cement clinker investigation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177489 ◽

1990 ◽

Vol 48 (4) ◽

pp. 870-871

Author(s):

Arezki Tagnit-Hamou ◽

Shondeep L. Sarkar

Keyword(s):

Mineralogical Composition ◽

Physicochemical Characteristics ◽

Cement Clinker ◽

Accurate Information ◽

Phase Identification ◽

History Of ◽

Bulk Chemical ◽

Resolution Imaging ◽

Proven Method ◽

Instantaneous Chemical

All the desired properties of cement primarily depend on the physicochemical characteristics of clinker from which the cement is produced. The mineralogical composition of the clinker forms the most important parameter influencing these properties.Optical microscopy provides reasonably accurate information pertaining to the thermal history of the clinker, while XRDA still remains the proven method of phase identification, and bulk chemical composition of the clinker can be readily obtained from XRFA. Nevertheless, all these microanalytical techniques are somewhat limited in their applications, and SEM/EDXA combination fills this gap uniquely by virtue of its high resolution imaging capability and possibility of instantaneous chemical analysis of individual phases.Inhomogeneities and impurities in the raw meal, influence of kiln conditions such as sintering and cooling rate being directly related to the microstructure can be effectively determined by SEM/EDXA. In addition, several physical characteristics of cement, such as rhcology, grindability and hydraulicity also depend on the clinker microstructure.

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Common modifications of selenocysteine in selenoproteins

Essays in Biochemistry ◽

10.1042/ebc20190051 ◽

2019 ◽

Vol 64 (1) ◽

pp. 45-53 ◽

Cited By ~ 1

Author(s):

Elias S.J. Arnér

Keyword(s):

Amino Acids ◽

Covalent Binding ◽

Physicochemical Characteristics ◽

Redox Active

Abstract Selenocysteine (Sec), the sulfur-to-selenium substituted variant of cysteine (Cys), is the defining entity of selenoproteins. These are naturally expressed in many diverse organisms and constitute a unique class of proteins. As a result of the physicochemical characteristics of selenium when compared with sulfur, Sec is typically more reactive than Cys while participating in similar reactions, and there are also some qualitative differences in the reactivities between the two amino acids. This minireview discusses the types of modifications of Sec in selenoproteins that have thus far been experimentally validated. These modifications include direct covalent binding through the Se atom of Sec to other chalcogen atoms (S, O and Se) as present in redox active molecular motifs, derivatization of Sec via the direct covalent binding to non-chalcogen elements (Ni, Mb, N, Au and C), and the loss of Se from Sec resulting in formation of dehydroalanine. To understand the nature of these Sec modifications is crucial for an understanding of selenoprotein reactivities in biological, physiological and pathophysiological contexts.

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