Theoretical model for diffusion-reaction based drug delivery from a multilayer spherical capsule

Nanomedicine poses a new frontier in medical technology with the advantages of targeted delivery and patient specific design. In applications of nanoparticle targeted drug delivery, the delivery efficiency is controlled by the physical properties of the nanoparticle such as its size, shape, ligand density, as well as external environmental conditions such as flow rate and blood vessel diameter. Proper drug dosage choice relies on determination of the attachment and detachment rates of the nanoparticles at the active region and the understanding of the complex process of targeted drug delivery. A few particulate models have been proposed to study the adhesion individual spherical or non-spherical nanoparticles on receptor coated wall. Meanwhile, continuum convection-diffusion-reaction models have been widely used to calculate the drug concentration under various conditions, which usually assumes specific binding and de-binding constants. In reality, these binding and de-binding rates largely vary with physical properties of the particles and local flow conditions. However, there has not been any study that links the particulate level nanoparticle size and shape information to the system level bounded particle concentration. A hybrid particle binding dynamics and continuum convection-diffusion-reaction model is presented to study the effect of shear flow rate and particle size on binding efficiency. The simulated concentration of bounded nanoparticles agrees well with experimental results in flow chamber studies.

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Poly(vinyl alcohol boric acid)-Diclofenac Sodium Salt Drug Delivery Systems: Experimental and Theoretical Studies

Journal of Immunology Research ◽

10.1155/2020/3124304 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Daniela Ailincai ◽

Alexandra Maria Dorobanțu ◽

Bogdan Dima ◽

Ștefan Andrei Irimiciuc ◽

Cristian Lupașcu ◽

...

Keyword(s):

Drug Delivery ◽

Theoretical Model ◽

Drug Release ◽

Mathematical Models ◽

Boric Acid ◽

Sodium Salt ◽

Vinyl Alcohol ◽

Drug Delivery Systems ◽

Diclofenac Sodium ◽

Poly Vinyl Alcohol

The main aim of the paper was to simulate the drug release by a multifractal theoretical model, as a valuable method to assess the drug release mechanism. To do this, drug delivery films were prepared by mixing poly(vinyl alcohol boric acid) (PVAB) and diclofenac (DCF) sodium salt drug in different mass ratios from 90/10 to 70/30, in order to obtain drug delivery systems with different releasing rates. The different drug content of the three systems was confirmed by energy-dispersive spectroscopy (EDAX) analysis, and the encapsulation particularities were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and polarized optical microscopy (POM) techniques. The ability of the PVAB matrix to anchor the DCF was assessed by Fourier transform infrared (FTIR) spectroscopy. The in vitro release of the diclofenac sodium salt from the formulations was investigated in biomimetic conditions (pH=7.4 and 37°C) by UV-Vis spectroscopy, measuring the absorbance of the drug at 275 nm and fitting the results on a previously drawn calibration curve. An estimation of the drug release kinetics was performed by fitting three traditional mathematical models on experimental release data. Further, the drug delivery was simulated by the fractal theory of motion, in which the release dynamics of the polymer-drug complex system is described through various Riccati-type “regimes.” To explain such dynamics involved multifractal self-modulation in the form of period doubling, quasiperiodicity, intermittency, etc., as well as multifractal self-modulation of network type. Standard release dynamics were explained by multifractal behaviors of temporary kink type. The good correlation between the traditional mathematical models and the new proposed theoretical model demonstrated the validity of the multifractal model for the investigation of the drug release.

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Theoretical Model of the Influence of Irreversibly Electroporated Cells on Post Pulse Drug Delivery to Reversibly Electroporated Cells

International Journal for Numerical Methods in Biomedical Engineering ◽

10.1002/cnm.3564 ◽

2021 ◽

Author(s):

Sid M. Becker

Keyword(s):

Drug Delivery ◽

Theoretical Model

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Novel pKa/DFT-Based Theoretical Model for Predicting the Drug Loading and Release of a pH-Responsive Drug Delivery System

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.8b02794 ◽

2018 ◽

Vol 122 (23) ◽

pp. 12279-12290 ◽

Cited By ~ 2

Author(s):

Shaukatali N. Inamdar ◽

Khalid Ahmed ◽

Nashiour Rohman ◽

Adam A. Skelton

Keyword(s):

Drug Delivery ◽

Theoretical Model ◽

Drug Delivery System ◽

Delivery System ◽

Drug Loading ◽

Ph Responsive

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Trajectory Simulation of Magnetic Nanoparticles in the Blood Vessel for the Magnetic Targeted-Drug Delivery

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.753-755.988 ◽

2013 ◽

Vol 753-755 ◽

pp. 988-994 ◽

Cited By ~ 1

Author(s):

Jie Feng ◽

Rui Lin Zhang ◽

Ya Nan Qu ◽

Ping Geng ◽

Shou Liang Qi

Keyword(s):

Magnetic Field ◽

Drug Delivery ◽

Magnetic Nanoparticles ◽

Theoretical Model ◽

Blood Vessel ◽

Targeted Drug Delivery ◽

Magnetic Circuit ◽

Critical Parameters ◽

Retention Ratio ◽

Targeted Drug

Magnetic nanoparticles (MNPs) have been considered as potential therapeutic agent carrier for the magnetic targeted-drug delivery in the fight against cancer. Trajectories of MNPs in the blood vessel determine the capture and retention ratio, and the final effectiveness of the treatment. In the present study, a theoretical model of MNPs trajectory is deduced at first. Then two kinds of magnets are proposed, and their magnetic field distributions are calculated through the finite element method software of ANSYS. Using the model and magnetic field inputs, the MNPs trajectories are determined, and the influences of the MNP diameter (Rp), the blood flow velocity (vf) and magnetic field intensity (H) on the trajectories are clarified finally. It is found that the proposed method combining the theoretical model and numerical simulation is feasible. The closed magnetic circuit with concave-convex poles has better MNPs retention ratio than that of the open magnetic circuit because it has higher H and Grad (H). LargeRp, lowvf, and high H are good to capture the MNPs. Especiallyvfand H are critical parameters for the retention ratio of MNPs, and highvfand low H may let MNPs escape the magnetic field region.

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Observation by HVEM of the martensite transformation and the superconducting transition in Nb3Sn

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106004 ◽

1988 ◽

Vol 46 ◽

pp. 788-789

Author(s):

M. A. Kirk ◽

M. C. Baker ◽

B. J. Kestel ◽

H. W. Weber

Keyword(s):

Thin Films ◽

Low Temperature ◽

Superconducting State ◽

Martensite Transformation ◽

Sputter Deposition ◽

Diffusion Reaction ◽

Solute Diffusion ◽

Superconducting Transition ◽

Twin Boundaries ◽

Martensite Structure

It is well known that a number of compound superconductors with the A15 structure undergo a martensite transformation when cooled to the superconducting state. Nb3Sn is one of those compounds that transforms, at least partially, from a cubic to tetragonal structure near 43 K. To our knowledge this transformation in Nb3Sn has not been studied by TEM. In fact, the only low temperature TEM study of an A15 material, V3Si, was performed by Goringe and Valdre over 20 years ago. They found the martensite structure in some foil areas at temperatures between 11 and 29 K, accompanied by faults that consisted of coherent twin boundaries on {110} planes. In pursuing our studies of irradiation defects in superconductors, we are the first to observe by TEM a similar martensite structure in Nb3Sn.Samples of Nb3Sn suitable for TEM studies have been produced by both a liquid solute diffusion reaction and by sputter deposition of thin films.

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