scholarly journals Effect of Sintering on In Vivo Biological Performance of Chemically Deproteinized Bovine Hydroxyapatite

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3946 ◽  
Author(s):  
Bruno De Carvalho ◽  
Eric Rompen ◽  
Geoffrey Lecloux ◽  
Peter Schupbach ◽  
Emilie Dory ◽  
...  
Keyword(s):  
Surface Area ◽  
Alveolar Bone ◽  
Structural Characteristics ◽  
Morphological Properties ◽  
Critical Conditions ◽  
Lower Percentage ◽  
Material Contact ◽  
Bovine Hydroxyapatite ◽  
Biological Performance

The influence of the manufacturing process on physicochemical properties and biological performance of xenogenic biomaterials has been extensively studied, but its quantification on bone-to-material contact remains poorly investigated. The aim of this study was to investigate the effect of different heat treatments of an experimental chemically-deproteinized bovine hydroxyapatite in vivo in terms of new bone formation and osteoconductivity. Protein-free hydroxyapatite from bovine origin was produced under sub-critical conditions and then either sintered at 820 °C or 1200 °C. Structural and morphological properties were assessed by scanning electron microscopy (SEM), measurement of surface area and X-ray diffractometry (XRD). The materials were then implanted in standardized alveolar bone defects in minipigs and histomorphometric evaluations were performed using non-decalcified sections. Marked topographical differences were observed by SEM analysis. As the sintering temperature of the experimental material increased, the surface area significantly decreased while crystallite size increased. In vivo samples showed that the highly sintered BHA presented a significantly lower percentage of newly formed bone than the unheated one (p = 0.009). In addition, the percentage of bone-to-material contact (BMC) was significantly lowered in the highly sintered group when compared to the unsintered (p = 0.01) and 820 °C sintered (p = 0.02) groups. Non-sintered or sintered at 820 °C BHA seems to maintain a certain surface roughness allowing better bone regeneration and BMC. On the contrary, sintering of BHA at 1200 °C has an effect on its morphological and structural characteristics and significantly modify its biological performance (osteoconductivity) and crystallinity.

Biocompatibility and biodegradation properties of polycaprolactone/polydioxanone composite scaffolds prepared by blend or co-electrospinning

2019 ◽  
Vol 34 (2) ◽  
pp. 115-130 ◽  
Author(s):  
Xin Zhou ◽  
Yiwa Pan ◽  
Ruihua Liu ◽  
Xin Luo ◽  
Xianyan Zeng ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Mechanical Strength ◽  
Structural Characteristics ◽  
Tissue Engineering Scaffold ◽  
Morphological Properties ◽  
Composite Scaffolds ◽  
Electrospun Scaffolds ◽  
Hybrid Scaffolds

Electrospun polymer scaffolds are regarded as an ideal tissue engineering scaffold due to similar morphological properties with the native extracellular matrix. Among these, polycaprolactone is widely used to fabricate electrospun fibrous scaffolds due to its excellent biocompatibility, good mechanical properties, and ease of manufacture. However, its low biodegradation rate has a negative influence on its application in tissue engineering scaffold. To address this issue, this study prepared hybrid scaffolds composed of polycaprolactone and polydioxanone (a fast-degrading polyether-ester) via either the blend or co-electrospinning. Subsequently, the structural characteristics, mechanical strength, in vitro/vivo degradation, cellularization, and vascularization of two kinds of hybrid scaffolds were evaluated to decide which method is more suitable for producing tissue engineering scaffolds. The incorporation of polydioxanone increased the mechanical strength of both composite scaffolds. Moreover, co-electrospun scaffolds exhibited improved hydrophilicity compared to blend scaffolds. The results of in vitro and in vivo degradation studies showed that the degradation rate of both composite scaffolds was faster than that of neat polycaprolactone scaffolds due to the incorporated polydioxanone component. Especially in co-electrospun scaffolds, the fast degradation of polydioxanone fiber gave rise to larger pore size, thus leading to faster cellularization and better vascularization compared to blend scaffolds. Therefore, co-electrospinning was demonstrated to be superior to blend electrospinning for the preparation of composite scaffolds. Co-electrospun polycaprolactone–polydioxanone scaffolds may be promising candidates for tissue engineering.

Use of light microscopy in the qualitative and quantitative study of liquid crystalline order

1992 ◽  
Vol 50 (1) ◽  
pp. 264-265
Author(s):  
Christopher Viney
Keyword(s):  
Light Microscopy ◽  
Liquid Crystalline ◽  
Structural Characteristics ◽  
Molecular Order ◽  
Liquid Crystalline Phases ◽  
Convenient Technique ◽  
Liquid Crystalline Materials ◽  
Transparent Windows

Light microscopy is a convenient technique for characterizing molecular order in fluid liquid crystalline materials. Microstructures can usually be observed under the actual conditions that promote the formation of liquid crystalline phases, whether or not a solvent is required, and at temperatures that can range from the boiling point of nitrogen to 600°C. It is relatively easy to produce specimens that are sufficiently thin and flat, simply by confining a droplet between glass cover slides. Specimens do not need to be conducting, and they do not have to be maintained in a vacuum. Drybox or other controlled environmental conditions can be maintained in a sealed chamber equipped with transparent windows; some heating/ freezing stages can be used for this purpose. It is relatively easy to construct a modified stage so that the generation and relaxation of global molecular order can be observed while specimens are being sheared, simulating flow conditions that exist during processing. Also, light only rarely affects the chemical composition or molecular weight distribution of the sample. Because little or no processing is required after collecting the sample, one can be confident that biologically derived materials will reveal many of their in vivo structural characteristics, even though microscopy is performed in vitro.

The role of aromatic microbial metabolites

2018 ◽  
pp. 97-108
Author(s):  
Н.В. Белобородова ◽  
В.В. Мороз ◽  
А.Ю. Бедова
Keyword(s):  
Process Integration ◽  
Biological Effects ◽  
Clinical Findings ◽  
Multiple Organ ◽  
Critical Conditions ◽  
Clear Understanding ◽  
Microbial Metabolites ◽  
Blood Concentrations

Интеграция метаболизма макроорганизма и его микробиоты, обеспечивающая в норме симбиоз и саногенез, нарушается при заболеваниях, травме, критическом состоянии, и вектор взаимодействия может изменяться в пользу прокариотов по принципу «метаболиты бактерий - против хозяина». Анализ литературы показал, что, с одной стороны, имеется живой интерес к ароматическим микробным метаболитам, с другой - отсутствует четкое представление об их роли в организме человека. Публикации, касающиеся ряда ароматических микробных метаболитов (фенилкарбоновых кислот, ФКК), как правило, не связаны между собой по тематике и направлены на решение тех или иных прикладных задач в разных областях биологии и медицины. Цель обзора - анализ информации о происхождении, биологических эффектах ФКК в экспериментах in vitro и in vivo , и клинических наблюдениях. Обобщая результаты приведенных в обзоре исследований на клеточном, субклеточном и молекулярном уровнях, логично предположить участие ароматических микробных метаболитов в патогенезе полиорганной недостаточности при сепсисе. Наиболее перспективным для раскрытия роли ароматических микробных метаболитов представляется изучение механизмов вторичной почечной недостаточности и септической энцефалопатии. Важным направлением для будущих исследований является изучение влияния продуктов микробной биодеградации ароматических соединений на развитие диссеминированного внутрисосудистого свертывания крови, артериальной гипотензии и септического шока. Результаты дальнейших исследований будут иметь не только фундаментальное значение, но и обогатят практическую медицину новыми диагностическими и лечебными технологиями. Significant increases in blood concentrations of some aromatic metabolites (phenylcarboxylic acids, PhCAs) in patients with sepsis have been previously shown. Enhanced bacterial biodegradation of aromatic compounds has been demonstrated to considerably contribute to this process. Integration of macroorganism metabolism and its microbiota, which provides normal symbiosis and sanogenesis, is disturbed in diseases, trauma, and critical conditions. Direction of this interaction may change in favor of prokaryotes according to the principle, “bacterial metabolites are against the host”. Analysis of literature showed a particular interest of many investigators to aromatic microbial metabolites. However, there is no clear understanding of their role in the human body. Publications on PhCAs are generally not thematically interrelated and usually focus on solving applied tasks in different fields of biology and medicine. The aim of this work was to consolidate existing information about origin and biological effects of PhCAs in in vitro / in vivo experiments and some clinical findings. The presented summary of reported data from studies performed at cellular, sub-cellular, and molecular levels suggests participation of aromatic microbial metabolites in the pathogenesis of multiple organ failure in sepsis. Studying mechanisms of secondary renal failure and septic encephalopathy is most promising for discovering the function of aromatic microbial metabolites. Effects of microbial biodegradation products of aromatic substances on development of disseminated intravascular coagulation, hypotension, and septic shock are an important challenge for future studies. Results of further investigations will be not only fundamental, but will also enrich medical practice with new diagnostic and therapeutic technologies.

INFLUENCE OF GROWTH REGULATORS AND LED IRRADIATORS ON PINE STRAWBERRY ADAPTATION

1970 ◽  
pp. 12-15
Author(s):  
M. G. Markova ◽  
E. N. Somova
Keyword(s):  
Surface Area ◽  
Growth Regulators ◽  
Leaf Surface ◽  
Combined Treatment ◽  
Fragaria X Ananassa ◽  
Leaf Surface Area ◽  
External Conditions ◽  
Light Effects ◽  
Control Version

Work on going through the adaptation stage of rooted micro-stalks comes down to searching for new growth regulators and studying the influence of external conditions, which include, among other things, light effects. The data of 2018-2019 on the effect of growth regulators Siliplant, EcoFus and experimental LED phytoradiators on the adaptation of rooted micro-stalks of garden strawberries (Fragaria x ananassa duch) in vivo are presented. The object of research is rooted micro-stalks of garden strawberries of the Korona variety. It was revealed that, at the adaptation stage of rooted micro-stalks of strawberries, the most effective was the treatment of plants by spraying with Siliplant at a concentration of 1.0 ml/l and the combined treatment with Siliplant and EcoFus at concentrations of 0.5 ml/l: regardless of lighting, the survival rate averaged 99.4 - 99.7%, the leaf surface area increased significantly from 291.85 mm2 to 334.4 mm2. The number of normally developed leaves of strawberry microplants increased significantly after treatment with all preparations from 3.5 to 6.0, 5.8 and 6.5 pcs/plant, and a significant increase in the height of strawberry rosettes was facilitated by treatment with Siliplant and Siliplant together with EcoFus. Regardless of growth regulators, the most effective was the experimental LED phyto-irradiator with a changing spectrum, which contributed to an increase in leaf surface area, height of rosettes and the number of normally developed leaves in strawberry microplants. When illuminated with a flashing phytoradiator, these indicators are lower than in the control version, but not significantly. By the end of the rooting stage, all microplants of garden strawberries corresponded to GOST R 54051-2010.

scholarly journals In Vivo Study for Clinical Application of Dental Stem Cell Therapy Incorporated with Dental Titanium Implants

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 381
Author(s):  
Hyunmin Choi ◽  
Kyu-Hyung Park ◽  
Narae Jung ◽  
June-Sung Shim ◽  
Hong-Seok Moon ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Formation ◽  
Alveolar Bone ◽  
Human Mesenchymal Stem Cells ◽  
Titanium Implants ◽  
Osteogenic Potential ◽  
Induction Medium ◽  
Radiographic Analysis ◽  
New Bone Formation

The aim of this study was to investigate the behavior of dental-derived human mesenchymal stem cells (d-hMSCs) in response to differently surface-treated implants and to evaluate the effect of d-hMSCs on local osteogenesis around an implant in vivo. d-hMSCs derived from alveolar bone were established and cultured on machined, sandblasted and acid-etched (SLA)-treated titanium discs with and without osteogenic induction medium. Their morphological and osteogenic potential was assessed by scanning electron microscopy (SEM) and real-time polymerase chain reaction (RT-PCR) via mixing of 5 × 106 of d-hMSCs with 1 mL of Metrigel and 20 μL of gel-cell mixture, which was dispensed into the defect followed by the placement of customized mini-implants (machined, SLA-treated implants) in New Zealand white rabbits. Following healing periods of 2 weeks and 12 weeks, the obtained samples in each group were analyzed radiographically, histomorphometrically and immunohistochemically. The quantitative change in osteogenic differentiation of d-hMSCs was identified according to the type of surface treatment. Radiographic analysis revealed that an increase in new bone formation was statistically significant in the d-hMSCs group. Histomorphometric analysis was in accordance with radiographic analysis, showing the significantly increased new bone formation in the d-hMSCs group regardless of time of sacrifice. Human nuclei A was identified near the area where d-hMSCs were implanted but the level of expression was found to be decreased as time passed. Within the limitations of the present study, in this animal model, the transplantation of d-hMSCs enhanced the new bone formation around an implant and the survival and function of the stem cells was experimentally proven up to 12 weeks post-sacrifice.

scholarly journals Simple Equations Pertaining to the Particle Number and Surface Area of Metallic, Polymeric, Lipidic and Vesicular Nanocarriers

2021 ◽  
Vol 89 (2) ◽  
pp. 15
Author(s):  
M. R. Mozafari ◽  
E. Mazaheri ◽  
K. Dormiani
Keyword(s):  
Drug Delivery ◽  
Surface Area ◽  
Particle Number ◽  
Analytical Techniques ◽  
Metallic Particles ◽  
Nutraceutical Compounds ◽  
Mathematical Formulas ◽  
Simple Equations

Introduction: Bioactive encapsulation and drug delivery systems have already found their way to the market as efficient therapeutics to combat infections, viral diseases and different types of cancer. The fields of food fortification, nutraceutical supplementation and cosmeceuticals have also been getting the benefit of encapsulation technologies. Aim: Successful formulation of such therapeutic and nutraceutical compounds requires thorough analysis and assessment of certain characteristics including particle number and surface area without the need to employ sophisticated analytical techniques. Solution: Here we present simple mathematical formulas and equations used in the research and development of drug delivery and controlled release systems employed for bioactive encapsulation and targeting the sites of infection and cancer in vitro and in vivo. Systems covered in this entry include lipidic vesicles, polymeric capsules, metallic particles as well as surfactant- and tocopherol-based micro- and nanocarriers.

scholarly journals Newly Emerging Airborne Pollutants: Current Knowledge of Health Impact of Micro and Nanoplastics

2021 ◽  
Vol 18 (6) ◽  
pp. 2997
Author(s):  
Alessio Facciolà ◽  
Giuseppa Visalli ◽  
Marianna Pruiti Ciarello ◽  
Angela Di Pietro
Keyword(s):  
Surface Area ◽  
Current Knowledge ◽  
Oxidative Degradation ◽  
Health Impact ◽  
Outdoor Exposure ◽  
Environmental Matrices ◽  
Potential Health ◽  
Bodily Fluids

Plastics are ubiquitous persistent pollutants, forming the most representative material of the Anthropocene. In the environment, they undergo wear and tear (i.e., mechanical fragmentation, and slow photo and thermo-oxidative degradation) forming secondary microplastics (MPs). Further fragmentation of primary and secondary MPs results in nanoplastics (NPs). To assess potential health damage due to human exposure to airborne MPs and NPs, we summarize the evidence collected to date that, however, has almost completely focused on monitoring and the effects of airborne MPs. Only in vivo and in vitro studies have assessed the toxicity of NPs, and a standardized method for their analysis in environmental matrices is still missing. The main sources of indoor and outdoor exposure to these pollutants include synthetic textile fibers, rubber tires, upholstery and household furniture, and landfills. Although both MPs and NPs can reach the alveolar surface, the latter can pass into the bloodstream, overcoming the pulmonary epithelial barrier. Despite the low reactivity, the number of surface area atoms per unit mass is high in MPs and NPs, greatly enhancing the surface area for chemical reactions with bodily fluids and tissue in direct contact. This is proven in polyvinyl chloride (PVC) and flock workers, who are prone to persistent inflammatory stimulation, leading to pulmonary fibrosis or even carcinogenesis.

scholarly journals Recent Developments in Inonotus obliquus (Chaga mushroom) Polysaccharides: Isolation, Structural Characteristics, Biological Activities and Application

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1441
Author(s):  
Yangpeng Lu ◽  
Yanan Jia ◽  
Zihan Xue ◽  
Nannan Li ◽  
Junyu Liu ◽  
...  
Keyword(s):  
Biological Activities ◽  
Structural Characteristics ◽  
Potential Candidate ◽  
Health Food ◽  
Inonotus Obliquus ◽  
Recent Developments ◽  
Inonotus Obliquus Polysaccharide ◽  
Future Work

Inonotus obliquus (Chaga mushroom) is a kind of medicine and health food widely used by folk in China, Russia, Korea, and some occidental countries. Among the extracts from Inonotus obliquus, Inonotus obliquus polysaccharide (IOPS) is supposed to be one of the major bioactive components in Inonotus obliquus, which possesses antitumor, antioxidant, anti-virus, hypoglycemic, and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics, and biological activities of IOPS were summarized. This review can provide significant insight into the IOPS bioactivities as their in vitro and in vivo data were summarized, and some possible mechanisms were listed. Furthermore, applications of IOPS were reviewed and discussed; IOPS might be a potential candidate for the treatment of cancers and type 2 diabetes. Besides, new perspectives for the future work of IOPS were also proposed.

scholarly journals Nanocomposite Materials Based on Electrochemically Synthesized Graphene Polymers: Molecular Architecture Strategies for Sensor Applications

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 149
Author(s):  
André Olean-Oliveira ◽  
Gilberto A. Oliveira Brito ◽  
Celso Xavier Cardoso ◽  
Marcos F. S. Teixeira
Keyword(s):  
Conducting Polymers ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Electrochemical Sensors ◽  
Structural Characteristics ◽  
Low Cost ◽  
Large Specific Surface Area ◽  
Molecular Architecture ◽  
Sensor Applications

The use of graphene and its derivatives in the development of electrochemical sensors has been growing in recent decades. Part of this success is due to the excellent characteristics of such materials, such as good electrical and mechanical properties and a large specific surface area. The formation of composites and nanocomposites with these two materials leads to better sensing performance compared to pure graphene and conductive polymers. The increased large specific surface area of the nanocomposites and the synergistic effect between graphene and conducting polymers is responsible for this interesting result. The most widely used methodologies for the synthesis of these materials are still based on chemical routes. However, electrochemical routes have emerged and are gaining space, affording advantages such as low cost and the promising possibility of modulation of the structural characteristics of composites. As a result, application in sensor devices can lead to increased sensitivity and decreased analysis cost. Thus, this review presents the main aspects for the construction of nanomaterials based on graphene oxide and conducting polymers, as well as the recent efforts made to apply this methodology in the development of sensors and biosensors.

scholarly journals Halofuginone functions as a therapeutic drug for chronic periodontitis in a mouse model

2020 ◽  
Vol 34 ◽  
pp. 205873842097489
Author(s):  
Jiang Wang ◽  
Bo Wang ◽  
Xin Lv ◽  
Yingjie Wang
Keyword(s):  
Alveolar Bone ◽  
Immune Cell ◽  
Critical Role ◽  
Therapeutic Drug ◽  
Mice Model ◽  
T Helper 17 ◽  
Th17 Cell Differentiation ◽  
Tnf Α

Periodontitis is an inflammatory disease caused by host immune response, resulting in a loss of periodontium and alveolar bone. Immune cells, such as T cells and macrophages, play a critical role in the periodontitis onset. Halofuginone, a natural quinazolinone alkaloid, has been shown to possess anti-fibrosis, anti-cancer, and immunomodulatory properties. However, the effect of halofuginone on periodontitis has never been reported. In this study, a ligature-induced mice model of periodontitis was applied to investigate the potential beneficial effect of halofuginone on periodontitis. We demonstrated that the administration of halofuginone significantly reduced the expression levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) in vivo, and markedly suppressed immune cell infiltration into the infected sites. Furthermore, we also observed that halofuginone treatment blocked the T-helper 17 (Th17) cell differentiation in vivo and in vitro. We demonstrated for the first time that halofuginone alleviated the onset of periodontitis through reducing immune responses.

Sign in / Sign up

Export Citation Format

Share Document