Bioresorbable Mg-Based Metastable Nano-Alloys for Orthopedic Fixation Devices

This research has been accomplished using the advanced selective laser melting (SLM) technique as well as HIP post-treatment in order to improve mechanical properties and biocompatibility of Mg– Ca–Sr alloy. Through this research it becomes clearly noticeable that the Mg–1.5Ca–xSr (x = 0.6, 2.1, 2.5) alloys with Sr exhibited better mechanical properties and corrosion potentials. This is more particular with the Mg–1.5Ca–2.5Sr alloy after HIP post-treatment allowing it to provide a desired combination of degradation and mechanical behavior for orthopedic fracture fixation during a desired treatment period. In vivo trials, there was a clear indication and exhibition that this Mg–1.5Ca–2.5Sr alloy screw can completely dissolve in miniature pig’s body which leads to an acceleration in growth of bone tissues. Mg–Ca–Sr alloy proved potential candidate for use in orthopedic fixation devices through Our results concluded that Mg–Ca–Sr alloy are potential candidate for use in orthopedic fixation devices through mechanical strength and biocompatibility evaluations (in vitro or In vivo).

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Improved Bioactivity of 3D Printed Porous Titanium Alloy Scaffold with Chitosan/Magnesium-Calcium Silicate Composite for Orthopaedic Applications

Materials ◽

10.3390/ma12020203 ◽

2019 ◽

Vol 12 (2) ◽

pp. 203 ◽

Cited By ~ 18

Author(s):

Chun-Hao Tsai ◽

Chih-Hung Hung ◽

Che-Nan Kuo ◽

Cheng-Yu Chen ◽

Yu-Ning Peng ◽

...

Keyword(s):

Mechanical Properties ◽

Calcium Silicate ◽

Cell Attachment ◽

Three Dimensional ◽

Bone Defects ◽

Metal Alloys ◽

Potential Candidate ◽

Natural Bone

Recently, cases of bone defects have been increasing incrementally. Thus, repair or replacement of bone defects is gradually becoming a huge problem for orthopaedic surgeons. Three-dimensional (3D) scaffolds have since emerged as a potential candidate for bone replacement, of which titanium (Ti) alloys are one of the most promising candidates among the metal alloys due to their low cytotoxicity and mechanical properties. However, bioactivity remains a problem for metal alloys, which can be enhanced using simple immersion techniques to coat bioactive compounds onto the surface of Ti–6Al–4V scaffolds. In our study, we fabricated magnesium-calcium silicate (Mg–CS) and chitosan (CH) compounds onto Ti–6Al–4V scaffolds. Characterization of these surface-modified scaffolds involved an assessment of physicochemical properties as well as mechanical testing. Adhesion, proliferation, and growth of human Wharton’s Jelly mesenchymal stem cells (WJMSCs) were assessed in vitro. In addition, the cell attachment morphology was examined using scanning electron microscopy to assess adhesion qualities. Osteogenic and mineralization assays were conducted to assess osteogenic expression. In conclusion, the Mg–CS/CH coated Ti–6Al–4V scaffolds were able to exhibit and retain pore sizes and their original morphologies and architectures, which significantly affected subsequent hard tissue regeneration. In addition, the surface was shown to be hydrophilic after modification and showed mechanical strength comparable to natural bone. Not only were our modified scaffolds able to match the mechanical properties of natural bone, it was also found that such modifications enhanced cellular behavior such as adhesion, proliferation, and differentiation, which led to enhanced osteogenesis and mineralization downstream. In vivo results indicated that Mg–CS/CH coated Ti–6Al–4V enhances the bone regeneration and ingrowth at the critical size bone defects of rabbits. These results indicated that the proposed Mg–CS/CH coated Ti–6Al–4V scaffolds exhibited a favorable, inducive micro-environment that could serve as a promising modification for future bone tissue engineering scaffolds.

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

Polymers ◽

10.3390/polym13091441 ◽

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.

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

Nature Communications ◽

10.1038/s41467-021-23962-8 ◽

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.

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Zn-Containing Membranes for Guided Bone Regeneration in Dentistry

Polymers ◽

10.3390/polym13111797 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1797

Author(s):

Manuel Toledano ◽

Marta Vallecillo-Rivas ◽

María T. Osorio ◽

Esther Muñoz-Soto ◽

Manuel Toledano-Osorio ◽

...

Keyword(s):

Mechanical Properties ◽

Bone Regeneration ◽

Bone Healing ◽

Bone Repair ◽

Complex Modulus ◽

Bacterial Colonization ◽

Guided Bone Regeneration ◽

M2 Macrophage

Barrier membranes are employed in guided bone regeneration (GBR) to facilitate bone in-growth. A bioactive and biomimetic Zn-doped membrane with the ability to participate in bone healing and regeneration is necessary. The aim of the present study is to state the effect of doping the membranes for GBR with zinc compounds in the improvement of bone regeneration. A literature search was conducted using electronic databases, such as PubMed, MEDLINE, DIMDI, Embase, Scopus and Web of Science. A narrative exploratory review was undertaken, focusing on the antibacterial effects, physicochemical and biological properties of Zn-loaded membranes. Bioactivity, bone formation and cytotoxicity were analyzed. Microstructure and mechanical properties of these membranes were also determined. Zn-doped membranes have inhibited in vivo and in vitro bacterial colonization. Zn-alloy and Zn-doped membranes attained good biocompatibility and were found to be non-toxic to cells. The Zn-doped matrices showed feasible mechanical properties, such as flexibility, strength, complex modulus and tan delta. Zn incorporation in polymeric membranes provided the highest regenerative efficiency for bone healing in experimental animals, potentiating osteogenesis, angiogenesis, biological activity and a balanced remodeling. Zn-loaded membranes doped with SiO2 nanoparticles have performed as bioactive modulators provoking an M2 macrophage increase and are a potential biomaterial for promoting bone repair. Zn-doped membranes have promoted pro-healing phenotypes.

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Fibronectin Adsorption on Electrospun Synthetic Vascular Grafts Attracts Endothelial Progenitor Cells and Promotes Endothelialization in Dynamic In Vitro Culture

Cells ◽

10.3390/cells9030778 ◽

2020 ◽

Vol 9 (3) ◽

pp. 778 ◽

Cited By ~ 4

Author(s):

Ruben Daum ◽

Dmitri Visser ◽

Constanze Wild ◽

Larysa Kutuzova ◽

Maria Schneider ◽

...

Keyword(s):

Mechanical Properties ◽

Cell Activation ◽

Vascular Endothelial Cells ◽

Endothelial Progenitor ◽

Advanced Therapy Medicinal Product ◽

Endothelial Colony Forming Cells ◽

Advanced Therapy ◽

Custom Made

Appropriate mechanical properties and fast endothelialization of synthetic grafts are key to ensure long-term functionality of implants. We used a newly developed biostable polyurethane elastomer (TPCU) to engineer electrospun vascular scaffolds with promising mechanical properties (E-modulus: 4.8 ± 0.6 MPa, burst pressure: 3326 ± 78 mmHg), which were biofunctionalized with fibronectin (FN) and decorin (DCN). Neither uncoated nor biofunctionalized TPCU scaffolds induced major adverse immune responses except for minor signs of polymorph nuclear cell activation. The in vivo endothelial progenitor cell homing potential of the biofunctionalized scaffolds was simulated in vitro by attracting endothelial colony-forming cells (ECFCs). Although DCN coating did attract ECFCs in combination with FN (FN + DCN), DCN-coated TPCU scaffolds showed a cell-repellent effect in the absence of FN. In a tissue-engineering approach, the electrospun and biofunctionalized tubular grafts were cultured with primary-isolated vascular endothelial cells in a custom-made bioreactor under dynamic conditions with the aim to engineer an advanced therapy medicinal product. Both FN and FN + DCN functionalization supported the formation of a confluent and functional endothelial layer.

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Nanostructured Ethosomal Gel Loaded with Arctostaphylos uva-ursi extract; In-vitro/In-vivo Evaluation as a Cosmeceutical Product

Current Drug Delivery ◽

10.2174/1567201818666210729111026 ◽

2021 ◽

Vol 18 ◽

Author(s):

Nayla Javed ◽

Shakeel Ijaz ◽

Naveed Akhtar ◽

Haji Muhammad Shoaib Khan

Keyword(s):

Zeta Potential ◽

Biological Activities ◽

Skin Permeation ◽

Radical Scavenging ◽

Reducing Power ◽

Potential Candidate ◽

Skin Rejuvenation ◽

In Vivo Evaluation

Background: Arctostaphylos uva-ursi (AUU) being rich in polyphenols and arbutin is known to have promising biological activities and can be a potential candidate as a cosmaceutical. Ethosomes encourage the formation of lamellar-shaped vesicles with improved solubility and entrapment of many drugs including plant extracts. Objective: The objective of this work was to develop an optimized nanostructured ethosomal gel formulation loaded with AUU extract and evaluated for skin rejuvenation and depigmentation. Methods: AUU extract was tested for phenolic and flavonoid content, radical scavenging potential, reducing power activity, and in-vitro SPF (sun protection factor) estimation. AUU loaded 12 formulations were prepared and characterized by SEM (scanning electron microscopy), vesicular size, zeta potential, and entrapment efficiency (%EE). The optimized formulation was subjected to non-invasive in-vivo investigations after incorporating it into the gel system and ensuring its stability and skin permeation. Results: Ethosomal vesicles were spherical in shape and Zeta size, zeta potential, PDI (polydispersity index), % EE and in-vitro skin permeation of optimized formulation (F3) were found to be 114.7nm, -18.9mV, 0.492, 97.51±0.023%, and 79.88±0.013% respectively. AUU loaded ethosomal gel formulation was stable physicochemically and exhibited non-Newtonian behavior rheologically. Moreover, it significantly reduced skin erythema, melanin as well as sebum level and improved skin hydration and elasticity. Conclusion: A stable AUU based ethosomal gel formulation could be a better vehicle for phytoextracts than conventional formulations for cosmeceutical applications such as for skin rejuvenation and depigmentation etc.

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In Vitro and In Vivo Degradation, Mechanical Properties, and Histocompatibility of Weft-Knitted Silk Mesh-Like Grafts

Journal of Biomaterials and Tissue Engineering ◽

10.1166/jbt.2022.2911 ◽

2022 ◽

Vol 12 (2) ◽

pp. 411-416

Author(s):

Liang Tang ◽

Si-Yu Zhao ◽

Ya-Dong Yang ◽

Geng Yang ◽

Wen-Yuan Zhang ◽

...

Keyword(s):

Mechanical Properties ◽

Simulated Body Fluid ◽

Body Fluid ◽

Degradation Rate ◽

Maximum Load ◽

Artificial Ligament ◽

In Vivo Degradation

To investigate the degradation, mechanical properties, and histocompatibility of weft-knitted silk mesh-like grafts, we carried out the In Vitro and In Vivo silk grafts degradation assay. The In Vitro degradation experiment was performed by immersing the silk grafts in simulated body fluid for 1 year, and the results showed that the degradation rate of the silk mesh-like grafts was very slow, and there were few changes in the mechanical properties and quality of the silk mesh-like graft. In Vivo degradation assay was taken by implantation of the silk mesh-like grafts into the subcutaneous muscles of rabbits. At 3, 6, and 12 months postoperation, the rate of mass loss was 19.36%, 31.84%, and 58.77%, respectively, and the maximum load was 63.85%, 34.63%, and 10.76%, respectively of that prior to degradation. The results showed that the degradation rate of the silk graft and the loss of mechanical properties In Vivo were faster than the results obtained in the In Vitro experiments. In addition, there were no significant differences in secretion of serum IL-6 and TNF-α between the experimental and normal rabbits (P >0.05), suggesting no obvious inflammatory reaction. The findings suggest that the weft-knitted silk mesh-like grafts have good mechanical properties, histocompatibility, and In Vivo degradation rate, and therefore represent a candidate material for artificial ligament

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Effects of Cyclic Stress on the Mechanical Properties of Cultured Collagen Fascicles from the Rabbit Patellar Tendon

Journal of Biomechanical Engineering ◽

10.1115/1.1634286 ◽

2003 ◽

Vol 125 (6) ◽

pp. 893-901 ◽

Cited By ~ 21

Author(s):

Ei Yamamoto ◽

Susumu Tokura ◽

Kozaburo Hayashi

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Patellar Tendon ◽

Control Level ◽

Quadratic Function ◽

Peak Stress ◽

Cyclic Stress ◽

Original Strength

Effects of cyclic stress on the mechanical properties of collagen fascicles were studied by in vitro tissue culture experiments. Collagen fascicles (approximately 300 μm in diameter) obtained from the rabbit patellar tendon were applied cyclic load at 4 Hz for one hour per day during culture period for one or two weeks, and then their mechanical properties were determined using a micro-tensile tester. There was a statistically significant correlation between tensile strength and applied peak stress in the range of 0 to 5 MPa, and the relation was expressed by a quadratic function. The maximum strength (19.4 MPa) was obtained at the applied peak stress of 1.8 MPa. The tensile strength of fascicles were within a range of control values, if they were cultured under peak stresses between 1.1 and 2.6 MPa. Similar results were also observed in the tangent modulus, which was maintained at control level under applied peak stresses between 0.9 and 2.8 MPa. The stress of 0.9 to 1.1 MPa is equivalent to approximately 40% of the in vivo peak stress which is developed in the intact rabbit patellar tendon by running, whereas that of 2.6 to 2.8 MPa corresponds to approximately 120% of the in vivo peak stress. Therefore, the fascicles cultured under applied peak stresses of lower than 40% and higher than 120% of the in vivo peak stress do not keep the original strength and modulus. These results indicate that the mechanical properties of cultured collagen fascicles strongly depend upon the magnitude of the stress applied during culture, which are similar to our previous results observed in stress-shielded and overstressed patellar tendons in vivo.

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

10.21203/rs.3.rs-100872/v1 ◽

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.

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An In-Silico Study on Selected Organosulfur Compounds as Potential Drugs for SARS-CoV-2 Infection via Binding Multiple Drug Targets

10.26434/chemrxiv.12505343 ◽

2020 ◽

Author(s):

Liya Thurakkal ◽

Satyam Singh ◽

Sushabhan Sadhukhan ◽

Mintu Porel

Keyword(s):

Drug Targets ◽

Target Prediction ◽

Multiple Drug ◽

Organosulfur Compounds ◽

Potential Candidate ◽

Health Crisis ◽

Drug Molecules ◽

Main Protease

The emerging paradigm shift from ‘one molecule, one target, for one disease’ towards ‘multi-targeted small molecules’ has paved an ingenious pathway in drug discovery in recent years. This idea has been extracted for the investigation of competent drug molecules for the unprecedented COVID-19 pandemic which became the greatest global health crisis now. Perceiving the importance of organosulfur compounds against SARS-CoV-2 from the drugs under clinical trials, a class of organosulfur compounds effective against SARS-CoV were selected and studied the interaction with multiple proteins of the SARS-CoV-2. One compound displayed inhibition against five proteins (both structural and non-structural) of the virus namely, main protease, papain-like protease, spike protein, helicase and RNA dependent RNA polymerase. Consequently, this compound emanates as a potential candidate for treating the virulent disease. The pharmacokinetics, ADMET properties and target prediction studies carried out in this work further inflamed the versatility of the compound and urge to execute in-vitro and in-vivo analysis on SARS-CoV-2 in the future.

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