Multiscale mechanical models of DNA nanotubes: A theoretical basis for the design and tuning of DNA nanocarriers

Mapping Intimacies ◽

10.1101/2021.12.12.472306 ◽

2021 ◽

Author(s):

Han-Lin Liu ◽

Neng-Hui Zhang ◽

Wei Lu

Keyword(s):

Mechanical Properties ◽

Theoretical Basis ◽

Beam Theory ◽

Drug Carriers ◽

Potential Control ◽

Mechanics Model ◽

Artificial Dna ◽

Dna Nanotubes ◽

Interchain Interactions

DNA nanostructures are one of potential candidates for drug carriers due to their good biocompatibility and non-specificity in vivo. A reliable prediction about mechanical properties of artificial DNA structures is desirable to improve the efficiency of DNA drug carriers, however there is only a handful of information on mechanical functionalities of DNA nanotubes (DNTs). This paper focuses on quantifying the multiscale correlations among DNT deformation, packaging conditions and surrounding factors to tune mechanical properties of DNTs. By combining WLC statistical mechanics model, Parsegian's mesoscopic liquid crystal model and Euler's continuum beam theory, we developed a multiscale DNA-frame model; then theoretically characterize the initial packed states of DNTs for the first time, and reveal the diversity mechanism in mechanical properties of DNTs induced by interchain interactions and initial packed states. Moreover, the study of parameters, such as packaging conditions and environmental factors, provides a potential control strategy for tuning mechanical properties of DNTs. These conclusions provide a theoretical basis for accurately controlling the property and deformation of DNT in various DNT dynamic devices, such as DNA nanocarriers.

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Beam Theory of Thermal–Electro-Mechanical Coupling for Single-Wall Carbon Nanotubes

Nanomaterials ◽

10.3390/nano11040923 ◽

2021 ◽

Vol 11 (4) ◽

pp. 923

Author(s):

Kun Huang ◽

Ji Yao

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Beam Theory ◽

Bending Stiffness ◽

Single Wall Carbon Nanotubes ◽

Beam Model ◽

Euler Beam ◽

New Model ◽

Mechanical Coupling ◽

Electrostatic Fields

The potential application field of single-walled carbon nanotubes (SWCNTs) is immense, due to their remarkable mechanical and electrical properties. However, their mechanical properties under combined physical fields have not attracted researchers’ attention. For the first time, the present paper proposes beam theory to model SWCNTs’ mechanical properties under combined temperature and electrostatic fields. Unlike the classical Bernoulli–Euler beam model, this new model has independent extensional stiffness and bending stiffness. Static bending, buckling, and nonlinear vibrations are investigated through the classical beam model and the new model. The results show that the classical beam model significantly underestimates the influence of temperature and electrostatic fields on the mechanical properties of SWCNTs because the model overestimates the bending stiffness. The results also suggest that it may be necessary to re-examine the accuracy of the classical beam model of SWCNTs.

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In vivo measurement of the anisotropic mechanical properties of human skin by indentation test

Mechanics of Materials ◽

10.1016/j.mechmat.2021.103851 ◽

2021 ◽

pp. 103851

Author(s):

Lei Zhou ◽

Shibin Wang ◽

Jian Zhang ◽

Jialin Wang ◽

Chuanwei Li

Keyword(s):

Mechanical Properties ◽

Human Skin ◽

Indentation Test ◽

In Vivo Measurement ◽

Anisotropic Mechanical Properties

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Concomitant control of mechanical properties and degradation in resorbable elastomer-like materials using stereochemistry and stoichiometry for soft tissue engineering

Nature Communications ◽

10.1038/s41467-020-20610-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Mary Beth Wandel ◽

Craig A. Bell ◽

Jiayi Yu ◽

Maria C. Arno ◽

Nathan Z. Dreger ◽

...

Keyword(s):

Mechanical Properties ◽

Drug Delivery ◽

Soft Tissue ◽

Tissue Regeneration ◽

Biological Tissues ◽

Soft Tissue Regeneration ◽

Soft Tissue Engineering ◽

Degradation Properties ◽

Enhance Cell Adhesion

AbstractComplex biological tissues are highly viscoelastic and dynamic. Efforts to repair or replace cartilage, tendon, muscle, and vasculature using materials that facilitate repair and regeneration have been ongoing for decades. However, materials that possess the mechanical, chemical, and resorption characteristics necessary to recapitulate these tissues have been difficult to mimic using synthetic resorbable biomaterials. Herein, we report a series of resorbable elastomer-like materials that are compositionally identical and possess varying ratios of cis:trans double bonds in the backbone. These features afford concomitant control over the mechanical and surface eroding degradation properties of these materials. We show the materials can be functionalized post-polymerization with bioactive species and enhance cell adhesion. Furthermore, an in vivo rat model demonstrates that degradation and resorption are dependent on succinate stoichiometry in the elastomers and the results show limited inflammation highlighting their potential for use in soft tissue regeneration and drug delivery.

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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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Anticancer Compounds Derived from Marine Diatoms

Marine Drugs ◽

10.3390/md18070356 ◽

2020 ◽

Vol 18 (7) ◽

pp. 356 ◽

Cited By ~ 2

Author(s):

Hanaa Ali Hussein ◽

Mohd Azmuddin Abdullah

Keyword(s):

Unsaturated Fatty Acids ◽

High Surface ◽

High Surface Area ◽

Drug Carriers ◽

Growth Cycle ◽

In Vivo Studies ◽

High Yield ◽

Anti Cancer ◽

Nano Medicine

Cancer is the main cause of death worldwide, so the discovery of new and effective therapeutic agents must be urgently addressed. Diatoms are rich in minerals and secondary metabolites such as saturated and unsaturated fatty acids, esters, acyl lipids, sterols, proteins, and flavonoids. These bioactive compounds have been reported as potent anti-cancer, anti-oxidant and anti-bacterial agents. Diatoms are unicellular photosynthetic organisms, which are important in the biogeochemical circulation of silica, nitrogen, and carbon, attributable to their short growth-cycle and high yield. The biosilica of diatoms is potentially effective as a carrier for targeted drug delivery in cancer therapy due to its high surface area, nano-porosity, bio-compatibility, and bio-degradability. In vivo studies have shown no significant symptoms of tissue damage in animal models, suggesting the suitability of a diatoms-based system as a safe nanocarrier in nano-medicine applications. This review presents an overview of diatoms’ microalgae possessing anti-cancer activities and the potential role of the diatoms and biosilica in the delivery of anticancer drugs. Diatoms-based antibodies and vitamin B12 as drug carriers are also elaborated.

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Rheology of hydrocarbon gels

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1950.0008 ◽

1950 ◽

Vol 200 (1061) ◽

pp. 183-188 ◽

Cited By ~ 21

Keyword(s):

Mechanical Properties ◽

Experimental Measurement ◽

Theoretical Basis ◽

Continuous Media ◽

Point Of View ◽

Coarse Grained ◽

Testing Instrument ◽

Fine Grained ◽

Mineral Oils ◽

Space And Time

Hydrocarbon gels contain a number of materials, such as rubber, greases, saponified mineral oils, etc., of great interest for various engineering purposes. Specific requirements in mechanical properties have been met by producing gels in appropriately chosen patterns of constituent components of visible, colloidal, molecular and atomic sizes, ranging from coarse-grained aggregates, represented by sponges, foams, emulsions, etc.; to fine-grained and apparently homogeneous ones, represented by optically clear compounds. The engineer who has to deal with the whole range of such materials will adopt a macroscopic point of view, based on an apparent continuity of all the material structures and of the distributions in space and time of the displacements and forces occurring under mechanical actions. It has been possible to determine these distributions in the framework of a comprehensive scheme in which the fundamental principles of the mechanics of continuous media provide the theoretical basis, and a testing instrument of new design, termed Rheogoniometer, the means of experimental measurement (Weissenberg 1931, 1934, 1946, 1947, 1948).

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Near-infrared persistent luminescence hollow mesoporous nanospheres for drug delivery and in vivo renewable imaging

Journal of Materials Chemistry B ◽

10.1039/c6tb02674e ◽

2016 ◽

Vol 4 (48) ◽

pp. 7845-7851 ◽

Cited By ~ 18

Author(s):

Junpeng Shi ◽

Meng Sun ◽

Xia Sun ◽

Hongwu Zhang

Keyword(s):

Drug Delivery ◽

Near Infrared ◽

High Sensitivity ◽

Drug Carriers ◽

Template Method ◽

Persistent Luminescence ◽

Deep Tissue ◽

Large Capacity

Near-infrared persistent luminescence hollow mesoporous nanospheres have been synthesized via a template method. These nanospheres can be used as large capacity drug carriers and realize super long-term and high sensitivity tracking of drug delivery in deep tissue.

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