Investigation of the regularities of physical interactions by means of bonding energy

Background: Micelles as drug carriers are characterized by their inherent instability due to the weak physical interactions that facilitate the self-assembly of amphiphilic block copolymers. As one of the strong physical interactions, the stereocomplexation between the equal molar of enantiomeric polylactides, i.e., the poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA), may be harnessed to obtain micelles with enhanced stability and drug loading capacity and consequent sustained release. </P><P> Aims/Methods: In this paper, stereocomplexed micelles gama-PGA-g-PLA micelles) were fabricated from the stereocomplexation between poly(gama-glutamic acid)-graft-PLLA gama-PGA-g-PLA) and poly(gamaglutamic acid)-graft-PDLA gama-PGA-g-PLA). These stereocomplexed micelles exhibited a lower CMC than the corresponding enantiomeric micelles. Result: Furthermore, they showed higher drug loading content and drug loading efficiency in addition to more sustained drug release profile in vitro. In vivo imaging confirmed that the DiR-encapsulated stereocomplexed gama-PGA-g-PLA micelles can deliver anti-cancer drug to tumors with enhanced tissue penetration. Overall, gama-PGA-g-PLA micelles exhibited greater anti-cancer effects as compared with the free drug and the stereocomplexation may be a promising strategy for fabrication of anti-cancer drug carriers with significantly enhanced efficacy.

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Roles of pRB in the Regulation of Nucleosome and Chromatin Structures

BioMed Research International ◽

10.1155/2016/5959721 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 10

Author(s):

Chiharu Uchida

Keyword(s):

Target Genes ◽

Chromosome Instability ◽

Cancer Therapies ◽

Induce Cell Cycle Arrest ◽

Cellular Events ◽

Cycle Arrest ◽

Histone Modifiers ◽

Physical Interactions ◽

Functional Inactivation

Retinoblastoma protein (pRB) interacts with E2F and other protein factors to play a pivotal role in regulating the expression of target genes that induce cell cycle arrest, apoptosis, and differentiation. pRB controls the local promoter activity and has the ability to change the structure of nucleosomes and/or chromosomes via histone modification, epigenetic changes, chromatin remodeling, and chromosome organization. Functional inactivation of pRB perturbs these cellular events and causes dysregulated cell growth and chromosome instability, which are hallmarks of cancer cells. The role of pRB in regulation of nucleosome/chromatin structures has been shown to link to tumor suppression. This review focuses on the ability of pRB to control nucleosome/chromatin structures via physical interactions with histone modifiers and chromatin factors and describes cancer therapies based on targeting these protein factors.

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Synthesis of Nanogels: Current Trends and Future Outlook

Gels ◽

10.3390/gels7020036 ◽

2021 ◽

Vol 7 (2) ◽

pp. 36

Author(s):

Emanuele Mauri ◽

Sara Maria Giannitelli ◽

Marcella Trombetta ◽

Alberto Rainer

Keyword(s):

3D Printing ◽

Ad Hoc ◽

Sol Gel ◽

Controlled Polymerization ◽

Current Trends ◽

Chip Technology ◽

Physico Chemical ◽

Physical Interactions ◽

Sol Gel Transition ◽

Gel Transition

Nanogels represent an innovative platform for tunable drug release and targeted therapy in several biomedical applications, ranging from cancer to neurological disorders. The design of these nanocarriers is a pivotal topic investigated by the researchers over the years, with the aim to optimize the procedures and provide advanced nanomaterials. Chemical reactions, physical interactions and the developments of engineered devices are the three main areas explored to overcome the shortcomings of the traditional nanofabrication approaches. This review proposes a focus on the current techniques used in nanogel design, highlighting the upgrades in physico-chemical methodologies, microfluidics and 3D printing. Polymers and biomolecules can be combined to produce ad hoc nanonetworks according to the final curative aims, preserving the criteria of biocompatibility and biodegradability. Controlled polymerization, interfacial reactions, sol-gel transition, manipulation of the fluids at the nanoscale, lab-on-a-chip technology and 3D printing are the leading strategies to lean on in the next future and offer new solutions to the critical healthcare scenarios.

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Graph neural networks for an accurate and interpretable prediction of the properties of polycrystalline materials

npj Computational Materials ◽

10.1038/s41524-021-00574-w ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Minyi Dai ◽

Mehmet F. Demirel ◽

Yingyu Liang ◽

Jia-Mian Hu

Keyword(s):

Neural Network ◽

Network Architecture ◽

Polycrystalline Materials ◽

Feed Forward Neural Network ◽

Microscopic Interactions ◽

Physical Interactions ◽

Graph Neural Networks ◽

Individual Grains ◽

Physical Features ◽

Machine Learning Models

AbstractVarious machine learning models have been used to predict the properties of polycrystalline materials, but none of them directly consider the physical interactions among neighboring grains despite such microscopic interactions critically determining macroscopic material properties. Here, we develop a graph neural network (GNN) model for obtaining an embedding of polycrystalline microstructure which incorporates not only the physical features of individual grains but also their interactions. The embedding is then linked to the target property using a feed-forward neural network. Using the magnetostriction of polycrystalline Tb0.3Dy0.7Fe2 alloys as an example, we show that a single GNN model with fixed network architecture and hyperparameters allows for a low prediction error of ~10% over a group of remarkably different microstructures as well as quantifying the importance of each feature in each grain of a microstructure to its magnetostriction. Such a microstructure-graph-based GNN model, therefore, enables an accurate and interpretable prediction of the properties of polycrystalline materials.

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Constant curvature coefficients and exact solutions in fractional gravity and geometric mechanics

Open Physics ◽

10.2478/s11534-011-0040-5 ◽

2011 ◽

Vol 9 (5) ◽

Cited By ~ 4

Author(s):

Dumitru Baleanu ◽

Sergiu Vacaru

Keyword(s):

Fractional Derivative ◽

Fractional Derivatives ◽

Geometric Mechanics ◽

Fractional Dynamics ◽

Constant Matrix ◽

Curve Flows ◽

Physical Interactions ◽

Nonholonomic Manifolds ◽

Lagrange Mechanics ◽

Fractional Gravity

AbstractWe present a study of fractional configurations in gravity theories and Lagrange mechanics. The approach is based on a Caputo fractional derivative which gives zero for actions on constants. We elaborate fractional geometric models of physical interactions and we formulate a method of nonholonomic deformations to other types of fractional derivatives. The main result of this paper consists of a proof that, for corresponding classes of nonholonomic distributions, a large class of physical theories are modelled as nonholonomic manifolds with constant matrix curvature. This allows us to encode the fractional dynamics of interactions and constraints into the geometry of curve flows and solitonic hierarchies.

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