scholarly journals The Potential of Magnesium Based Materials in Mandibular Reconstruction

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 302 ◽  
Author(s):  
Somasundaram Prasadh ◽  
Vaishnavi Ratheesh ◽  
Vyasaraj Manakari ◽  
Gururaj Parande ◽  
Manoj Gupta ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metal Ion ◽  
Degradation Products ◽  
Stress Shielding ◽  
The Body ◽  
Mandibular Reconstruction ◽  
Anatomic Site ◽  
Metallic Biomaterials ◽  
Anti Cancer

The future of biomaterial design will rely on development of bioresorbable implant materials that completely and safely degrade in vivo after the tissues grow, without generating harmful degradation products at the targeted anatomic site. Permanent biomaterials such as Ti6Al4V alloy, 316L stainless steel, and Co-based alloys currently used in mandibular reconstruction often result in stress shielding effects due to mismatch in the Young’s modulus values between the bone and the implant, resulting in implant loosening. Also, allergic responses due to metal ion releases necessitates revision surgery to prevent long term exposure of the body to toxic implant contents. Bioresorbable metals are perceived as revolutionary biomaterials that have transformed the nature of metallic biomaterials from bioinert to bioactive and multi-bio functional (anti-bacterial, anti-proliferation, and anti-cancer). In this aspect, magnesium (Mg)-based materials have recently been explored by the biomedical community as potential materials for mandibular reconstruction, as they exhibit favorable mechanical properties, adequate biocompatibility, and degradability. This article reviews the recent progress that has led to advances in developing Mg-based materials for mandibular reconstruction; correlating with the biomechanics of mandible and types of mandibular defects. Mg-based materials are discussed regarding their mechanical properties, corrosion characteristics, and in vivo performance. Finally, the paper summarizes findings from this review, together with a proposed scope for advancing the knowledge in Mg-based materials for mandibular reconstruction.

scholarly journals Injectable non-leaching tissue-mimetic bottlebrush elastomers as an advanced platform for reconstructive surgery

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Erfan Dashtimoghadam ◽  
Farahnaz Fahimipour ◽  
Andrew N. Keith ◽  
Foad Vashahi ◽  
Pavel Popryadukhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reconstructive Surgery ◽  
Biomedical Applications ◽  
The Body ◽  
Surrounding Tissue ◽  
Curing Time ◽  
Materials Used ◽  
Significant Health

AbstractCurrent materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage the brush-like polymer architecture to design and administer minimally invasive injectable elastomers that cure in vivo into leachable-free implants with mechanical properties matching the surrounding tissue. This strategy allows tuning curing time from minutes to hours, which empowers a broad range of biomedical applications from rapid wound sealing to time-intensive reconstructive surgery. These injectable elastomers support in vitro cell proliferation, while also demonstrating in vivo implant integrity with a mild inflammatory response and minimal fibrotic encapsulation.

scholarly journals Injectable Non-leaching Tissue-mimetic Bottlebrush Elastomers: A New Platform for Advancing Reconstructive Surgery

2020 ◽  
Author(s):  
Erfan Dashtimoghadam ◽  
Farahnaz Fahimipour ◽  
Andrew Keith ◽  
Foad Vashahi ◽  
Pavel Popryadukhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reconstructive Surgery ◽  
Biomedical Applications ◽  
The Body ◽  
Surrounding Tissue ◽  
Curing Time ◽  
Materials Used ◽  
Significant Health

Abstract Current materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage the brush-like polymer architecture to design and administer minimally invasive injectable elastomers that cure in vivo into leachable-free implants with mechanical properties matching the surrounding tissue. This strategy allows tuning curing time from minutes to hours, which empowers a broad range of biomedical applications from rapid wound sealing to time-intensive reconstructive surgery. These injectable elastomers support in vitro cell proliferation, while also demonstrating in vivo implant integrity with a mild inflammatory response and minimal fibrotic encapsulation.

scholarly journals Radiopaque Chitosan Ducts Fabricated by Extrusion-Based 3D Printing to Promote Healing After Pancreaticoenterostomy

2021 ◽  
Vol 9 ◽  
Author(s):  
Maoen Pan ◽  
Chaoqian Zhao ◽  
Zeya Xu ◽  
Yuanyuan Yang ◽  
Tianhong Teng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Pancreatic Duct ◽  
Silicone Rubber ◽  
The Body ◽  
Molecular Weights ◽  
Pancreatic Duct Stent ◽  
3D Printed

Long-term placement of non-degradable silicone rubber pancreatic duct stents in the body is likely to cause inflammation and injury. Therefore, it is necessary to develop degradable and biocompatible stents to replace silicone rubber tubes as pancreatic duct stents. The purpose of our research was to verify the feasibility and biological safety of extrusion-based 3D printed radiopaque chitosan (CS) ducts for pancreaticojejunostomy. Chitosan-barium sulfate (CS-Ba) ducts with different molecular weights (low-, medium-, and high-molecular weight CS-Ba: LCS-Ba, MCS-Ba, and HCS-Ba, respectively) were soaked in vitro in simulated pancreatic juice (SPJ) (pH 8.0) with or without pancreatin for 16 weeks. Changes in their weight, water absorption rate and mechanical properties were tested regularly. The biocompatibility, degradation and radiopaque performance were verified by in vivo and in vitro experiments. The results showed that CS-Ba ducts prepared by this method had regular compact structures and good molding effects. In addition, the lower the molecular weight of the CS-Ba ducts was, the faster the degradation rate was. Extrusion-based 3D-printed CS-Ba ducts have mechanical properties that match those of soft tissue, good biocompatibility and radioopacity. In vitro studies have also shown that CS-Ba ducts can promote the growth of fibroblasts. These stents have great potential for use in pancreatic duct stent applications in the future.

scholarly journals Biodegradable and Biocompatible Polyhydroxyalkanoates (PHA): Auspicious Microbial Macromolecules for Pharmaceutical and Therapeutic Applications

2018 ◽  
Author(s):  
Martin Koller
Keyword(s):  
Tissue Engineering ◽  
Melt Spinning ◽  
Degradation Products ◽  
Nerve Repair ◽  
Polymer Processing ◽  
Anti Cancer ◽  
Negative Effect ◽  
Processing Techniques

Polyhydroxyalkanotes (PHA) are bio-based microbial biopolyesters with stiffness, elasticity, crystallinity and degradability tunable by the monomeric composition, bio-production strategy and post-synthetic processing; they display biological alternatives for diverse technomers of petrochemical origin. This, together with the fact that their monomeric and oligomeric in vivo degradation products do not exert any toxic or elsewhere negative effect to living cells or tissue of humans or animals, makes them highly stimulating for various applications in the medical field. The article provides an overview of PHA application in the therapeutic, surgical and tissue engineering area, and reviews strategies to produce PHA at purity levels high enough to be used in vivo. Tested applications of differently composed PHA and advanced follow-up products as carrier materials for controlled in vivo release of anti-cancer drugs or antibiotics, as scaffolds for tissue engineering, as guidance conduits for nerve repair or as enhanced sutures, implants or meshes are discussed from both a biotechnological and a material-scientific perspective. Particular attention is devoted to the adaptation of traditional polymer processing techniques for production of medicine-related devices based on PHA, such as melt-spinning, melt extrusion, or solvent evaporation, and to emerging processing techniques like 3D-printing, computer-aided wet-spinning, laser perforation, or electrospinning.

scholarly journals Mechanical properties of red and white swimming muscles as a function of the position along the body of the eelAnguilla anguilla

2001 ◽  
Vol 204 (13) ◽  
pp. 2221-2230 ◽  
Author(s):  
K. D’Août ◽  
N. A. Curtin ◽  
T. L. Williams ◽  
P. Aerts
Keyword(s):  
Mechanical Properties ◽  
Body Length ◽  
Isometric Force ◽  
The Body ◽  
In Vivo Studies ◽  
Muscle Fibres ◽  
Entire Body ◽  
Work Output ◽  
Longitudinal Position

SUMMARYThe way in which muscles power steady swimming depends on a number of factors, including fibre type and recruitment, muscle strain, stimulation pattern and intensity, and the intrinsic mechanical properties of the muscle fibres. For a number of undulatory swimming fish species, in vivo studies have shown that muscles at different positions along the body are stimulated during different phases of the strain cycle. Moreover, some intrinsic contractile properties of the muscles have been found to vary according to their position along the body.We report the first results on the mechanical properties of the red and white muscles of an anguilliform swimmer, Anguilla anguilla. Small preparations (0.147–1.335mg dry mass) were dissected from positions at fractions of 0.2, 0.4, 0.6 and 0.8 of total body length (BL). We determined the time to 50% and 100% peak force and from the last stimulus to 50% relaxation for isometric contractions; we measured the sarcomere lengths that coincided with in situ resting length. None of these quantities varied significantly with the longitudinal position from which the fibres were taken. We also measured power and work output during contractions under conditions approximating those used in vivo (cycle frequency, 1Hz; strain amplitude, ±10%L0, where L0 is the length giving maximum isometric force). During these experiments, work output was affected by stimulation phase, but did not depend on the longitudinal position in the body from which the muscles were taken.Our results indicate that red and white eel muscles have uniform properties along the body. In this respect, they differ from the muscle of most non-anguilliforms, in which muscle kinetics varies in a systematic way along the body. Uniform properties may be beneficial for anguilliform swimmers, in which the amplitude of the travelling wave can be pronounced over the entire body length.

The Metabolism and Pharmacokinetics of Rhein and Aurantio-Obtusin

2020 ◽  
Vol 21 (12) ◽  
pp. 960-968
Author(s):  
Shun-Li Xiao ◽  
Liang-Jun Guan ◽  
Ren-Feng Jiang ◽  
Xiang-Gen Wang ◽  
Xing Li ◽  
...  
Keyword(s):  
Chinese Literature ◽  
Liver Microsomes ◽  
The Body ◽  
Plant Family ◽  
Pharmacological Activities ◽  
Pharmacological Mechanism ◽  
Comprehensive Information ◽  
Anti Cancer ◽  
First Time

Background: Anthraquinones, rhein and aurantio-obtusin were isolated from the herb Duhaldea nervosa for the first time by our group, which were also found in plants that belong to the plant family Compositae. Anthraquinone compounds have a range of pharmacological activities such as anti-inflammatory, anti-cancer, antioxidation, anti-diabetes, etc. and can be used as a laxative, for liver protection, treatment of chronic renal failure, etc. However, in recent years, anthraquinones have been reported to be cytotoxic to the liver and kidneys. Therefore, it is very important to study the pharmacokinetics and metabolism of rhein and aurantio-obtusin, which are common ingredients in many traditional Chinese medicines (TCM). According to our research, the pharmacokinetics and metabolism of rhein and aurantio-obtusin are comprehensively summarized in the paper for the first time. Objective: The study provides comprehensive information on pharmacokinetics and metabolism of rhein and aurantio- obtusin in different Species; meanwhile, the aim of this review is also to provide a reference for a reasonable application of TCM enriched with these two ingredients. Methods: The metabolism and pharmacokinetics of rhein and aurantio-obtusin were searched by the Web of Science, PubMed, Google scholar and some Chinese literature databases. Results: Rhein and aurantio-obtusin exist mainly in the form of metabolites in the body. Rhein and aurantio-obtusin and its metabolites might be responsible for pharmacological effects in the body. Therefore, the significance of studying the in vivo metabolites of rhein and aurantio-obtusin is not only essential to clarify their pharmacological mechanism, but also to find new active compound ingredients. The metabolism of rhein is different in different species, so the toxicity effects of rhein may also be different after oral administration in different species; however, the metabolic profiles of aurantio-obtusin in the liver microsomes of different species are similar. Conclusion: This paper not only provides detail regarding the pharmacokinetics of rhein and aurantio-obtusin, but it is anticipated that it will also facilitate further study on the metabolism of rhein and aurantio-obtusin.

In vivo Anti-Cancer Activity of Korean Angelica Gigas and its Major Pyranocoumarin Decursin

2009 ◽  
Vol 37 (01) ◽  
pp. 127-142 ◽  
Author(s):  
Hyo Jeong Lee ◽  
Hyo Jung Lee ◽  
Eun Ok Lee ◽  
Jae Ho Lee ◽  
Kuen Sung Lee ◽  
...  
Keyword(s):  
Ethanol Extract ◽  
The Body ◽  
Lewis Lung ◽  
Lewis Lung Cancer ◽  
Angelica Gigas ◽  
Immunodeficient Mice ◽  
Decursinol Angelate ◽  
Anti Cancer ◽  
Cancer Activity

We have reported that a 10-herbal traditional formula containing Korean Angelica gigas Nakai (AGN) exerts potent anti-cancer efficacy and identified decursin and decursinol angelate (DA) from AGN as novel anti-androgens. Here, we determined whether AGN would exert in vivo anti-cancer activity and whether decursin or DA could account for its efficacy. The AGN ethanol extract was tested against the growth of mouse Lewis lung cancer (LLC) allograft in syngenic mice or human PC-3 and DU145 prostate cancer xenograft in immunodeficient mice. The pharmacokinetics of decursin and DA were determined. The AGN extract significantly inhibited LLC allograft growth (30 mg/kg) and PC-3 and DU145 xenograft growth (100 mg/kg) without affecting the body weight of the host mice. Biomarker analyses revealed decreased cell proliferation (Ki67, PCNA), decreased angiogenesis (VEGF, microvessel density) and increased apoptosis (TUNEL, cPARP) in treated tumors. Decursin and DA injected intraperitoneally were rapidly hydrolyzed to decursinol. Decursinol and decursin at 50 mg/kg inhibited LLC allograft growth to the same extent, comparable to 30 mg AGN/kg. Therefore the AGN extract possessed significant in vivo anti-cancer activity, but decursin and DA only contributed moderately to that activity, most likely through decursinol.

Engineered Fibrillar Microenvironments With Controllable Architecture and Mechanics for Studying Cellular Stiffness Sensing

2013 ◽  
Author(s):  
Brendon M. Baker ◽  
Britta Trappmann ◽  
Iris L. Kim ◽  
Jason A. Burdick ◽  
Christopher S. Chen
Keyword(s):  
Mechanical Properties ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Human Mesenchymal Stem Cells ◽  
The Body ◽  
Material System ◽  
Current Effort ◽  
Precise Control

The mechanical properties of the extracellular matrix (ECM) have emerged as fundamental players in numerous basic cellular functions such as spreading, migration, proliferation and differentiation, thus impacting many biological processes including embryonic development, adult tissue homeostasis, and disease pathogenesis such as fibrosis and cancer [1,2,3]. Synthetic matrices have been crucial to studying the effect of mechanics on cell behavior, as they allow for precise control of mechanical properties over a wide stiffness range, unachievable in vivo or in many naturally derived material systems. Seminal work employing polyacrylamide hydrogels of varying stiffness to direct the differentiation of human mesenchymal stem cells concluded that the bulk modulus, a measure of the material’s resistance to uniform deformation, is a defining parameter influencing cell function [4]. While much current effort aims to shed light on the molecular mechanisms governing stiffness sensing, existing knowledge is limited by the dissimilarity between the simple hydrogel surfaces employed in these studies and the topographically and mechanically more complex ECM cells routinely reside within in vivo. In contrast to the flat expanse of cell adhesive ligand and linear elastic, continuum behavior of typical gel systems, within the body, cell-scale mechanics and ligand availability are entwined, as both are defined by the presence and organization of the proteins that compose the surrounding ECM. The structure of native ECMs vary but largely are fibrillar, given that collagen comprises approximately 25% of the human body by mass. Thus, there remains a significant need for engineered fibrillar materials that afford precise and independent control of architectural features and resulting mechanical properties for application in cell biology. In this work, we establish a novel material system towards this end.

Exploiting Cancer Metal Metabolism using Anti-Cancer Metal- Binding Agents

2019 ◽  
Vol 26 (2) ◽  
pp. 302-322 ◽  
Author(s):  
Angelica M. Merlot ◽  
Danuta S. Kalinowski ◽  
Zaklina Kovacevic ◽  
Patric J. Jansson ◽  
Sumit Sahni ◽  
...  
Keyword(s):  
Metal Ion ◽  
Antitumor Agents ◽  
Metal Ion Binding ◽  
Toxicological Assessment ◽  
Metal Metabolism ◽  
Metal Levels ◽  
Anti Cancer ◽  
Binding Agents

Metals are vital cellular elements necessary for multiple indispensable biological processes of living organisms, including energy transduction and cell proliferation. Interestingly, alterations in metal levels and also changes in the expression of proteins involved in metal metabolism have been demonstrated in a variety of cancers. Considering this and the important role of metals for cell growth, the development of drugs that sequester metals has become an attractive target for the development of novel anti-cancer agents. Interest in this field has surged with the design and development of new generations of chelators of the thiosemicarbazone class. These ligands have shown potent anticancer and anti-metastatic activity in vitro and in vivo. Due to their efficacy and safe toxicological assessment, some of these agents have recently entered multi-center clinical trials as therapeutics for advanced and resistant tumors. This review highlights the role and changes in homeostasis of metals in cancer and emphasizes the pre-clinical development and clinical assessment of metal ion-binding agents, namely, thiosemicarbazones, as antitumor agents.

scholarly journals Effect of Dehydrothermal Treatment on the Mechanical Properties and Biocompatibility of Plaster of Paris–CaCO3 Hydrogel Loaded With Cinnamaldehyde for Biomedical Purposes

2021 ◽  
Vol 16 (1) ◽  
pp. 1934578X2098460
Author(s):  
Anne Handrini Dewi ◽  
Dedy Kusuma Yulianto ◽  
Widowati Siswomihardjo ◽  
Rochmadi Rochmadi ◽  
Ika Dewi Ana
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Inflammatory Cells ◽  
The Body ◽  
Chemical Agent ◽  
3 Dimensional ◽  
Plaster Of Paris ◽  
Inflammatory Agent ◽  
Anti Inflammatory

CaCO3 hydrogel incorporation into Plaster of Paris (POP) formulations decreased the resorption rate of the POP after implantation in the body. Although an inflammatory process is required as part of wound healing, the accumulation and activation of inflammatory cells in the POP–hydrogel CaCO3 implant area needs to be controlled. Therefore, cinnamaldehyde, as an anti-inflammatory agent with a unique α, β-unsaturated aldehyde, was incorporated into the CaCO3 hydrogel. During the incorporation, both the lipophilic and hydrophilic sides of the cinnamaldehyde molecule can influence the physical and mechanical properties of the CaCO3 hydrogel, in which mechanical properties of a tissue engineering scaffold are important to fine tune cellular activity during implantation. On the other hand, as a 3-dimensional polymeric structure, crosslinking is needed for the CaCO3 hydrogel to stabilize and increase its molecular weight for better mechanical strength, and more resistance to heat, wear, and solvent attack. For that purpose, dehydrothermal treatment (DHT) was applied to the crosslink hydrogel system as a favorable crosslinking method to avoid the use of a chemical agent. In this study, 3 groups of hydrogels of CaCO3, namely DHT crosslinked, loaded with cinnamaldehyde, and loaded with cinnamaldehyde followed by DHT crosslinking were developed before being combined with POP in 50 wt%. To evaluate the effect of DHT to the final POP-cinnamaldehyde-loaded CaCO3 hydrogel properties and biocompatibility, scanning electron microscopy, contact angle, surface roughness, hardness, diametral tensile strength, and in vivo biocompatibility studies were conducted. It was observed that cinnamaldehyde with DHT treatment improved the POP–hydrogel CaCO3 properties and had good biocompatibility. Thus, POP-cinnamaldehyde-loaded CaCO3 hydrogel can be a promising bone substitute containing an anti-inflammatory agent.

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