scholarly journals Characterization and Mathematical Modeling of Alginate/Chitosan-Based Nanoparticles Releasing the Chemokine CXCL12 to Attract Glioblastoma Cells

Pharmaceutics ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 356 ◽  
Author(s):  
Suzanne Gascon ◽  
Angéla Giraldo Solano ◽  
Wiam El Kheir ◽  
Hélène Therriault ◽  
Pierre Berthelin ◽  
...  

Chitosan (Chit) currently used to prepare nanoparticles (NPs) for brain application can be complexed with negatively charged polymers such as alginate (Alg) to better entrap positively charged molecules such as CXCL12. A sustained CXCL12 gradient created by a delivery system can be used, as a therapeutic approach, to control the migration of cancerous cells infiltrated in peri-tumoral tissues similar to those of glioblastoma multiforme (GBM). For this purpose, we prepared Alg/Chit NPs entrapping CXCL12 and characterized them. We demonstrated that Alg/Chit NPs, with an average size of ~250 nm, entrapped CXCL12 with ~98% efficiency for initial mass loadings varying from 0.372 to 1.490 µg/mg NPs. The release kinetic profiles of CXCL12 were dependent on the initial mass loading, and the released chemokine from NPs after seven days reached 12.6%, 32.3%, and 59.9% of cumulative release for initial contents of 0.372, 0.744, and 1.490 µg CXCL12/mg NPs, respectively. Mathematical modeling of released kinetics showed a predominant diffusive process with strong interactions between Alg and CXCL12. The CXCL12-NPs were not toxic and did not promote F98 GBM cell proliferation, while the released CXCL12 kept its chemotaxis effect. Thus, we developed an efficient and tunable CXCL12 delivery system as a promising therapeutic strategy that aims to be injected into a hydrogel used to fill the cavity after surgical tumor resection. This system will be used to attract infiltrated GBM cells prior to their elimination by conventional treatment without affecting a large zone of healthy brain tissue.

TAPPI Journal ◽  
2011 ◽  
Vol 10 (9) ◽  
pp. 17-23 ◽  
Author(s):  
ANNE RUTANEN ◽  
MARTTI TOIVAKKA

Coating color stability, as defined by changes in its solid particle fraction, is important for runnability, quality, and costs of a paper coating operation. This study sought to determine whether the size or density of particles is important in size segregation in a pigment coating process. We used a laboratory coater to study changes in coating color composition during coating operations. The results suggest that size segregation occurs for high and low density particles. Regardless of the particle density, the fine particle size fraction (<0.2 μm) was the most prone for depletion, causing an increase in the average size of the particles. Strong interactions between the fine particles and other components also were associated with a low depletion tendency of fine particles. A stable process and improved efficiency of fine particles and binders can be achieved by controlling the depletion of fine particles.


2017 ◽  
Vol 110 ◽  
pp. 100-114 ◽  
Author(s):  
Tiancheng Ouyang ◽  
Pan Wang ◽  
Haozhong Huang ◽  
Ning Zhang ◽  
Nan Chen

2004 ◽  
Vol 91 (01) ◽  
pp. 43-51 ◽  
Author(s):  
Matti Ben-Moshe ◽  
Sholomo Magdassi ◽  
Raphael Gorodetsky ◽  
Gerard Marx

SummaryWe previously described synthetic peptides of 19-21 amino acid residues, homologous to the C-termini of fibrinogen Fib340 and Fib420, from the β-chain (Cβ), the extended αE chain (CαE) and near the end of the γ-chain (preCγ) which elicited attachment (haptotactic) responses from mesenchymal cells. We named these haptotactic peptides -Haptides. The effects of Haptides on fibrin clot formation was evaluated and their possible effects on platelet aggregation was examined. The Haptides Cβ, CαE and preCγ, (2-10 μM) increased fibrin clot turbidity and also decreased thrombin-induced clotting time. Higher concentrations (>120 μM of Cβ or preCγ) induced fibrinogen precipitation even without thrombin. These precipitates exhibited different ultrastructure from thrombin-induced fibrin by scanning and transmission microscopy. C-terminal peptides of the other fibrinogen chains exerted no such effects. Sepharose beads covalently coated with either whole fibrinogen or Haptides (SB-Fib or SB-Haptide) highly adsorbed free FITCHaptides. In aqueous solution, Haptides formed nano-particles with average size of ∼150nm in diameter. We suggest that such positively charged aggregates could serve to nucleate and accelerate fibrin gel formation. These results also indicate that Cβ and preCγ sequences within fibrin(ogen) participate in the docking and condensation of fibrin(ogen) during its assembly into a fibrin clot. By contrast, Haptides up to 100µM did not bind to platelets, and had no effect on platelet aggregation. Our findings highlight the roles of the C-terminal sequences of the β and γ chains in fibrin(ogen) polymerization as well as in cell attachment.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Stephanie Da Costa ◽  
Mahiran Basri ◽  
Norashikin Shamsudin ◽  
Hamidon Basri

This paper emphasizes the formation of a positively charged nanoemulsion system for steroid drugs (hydrocortisone). It is believed that positively charged nanoemulsion provides more effective penetration of the skin. Therefore in our study we focused on the incorporation of phytosphingosine which serves as a positively charged cosurfactant in the nanoemulsion system. Negatively charged nanoemulsions were formulated mainly for comparison. Freshly prepared formulations were formed with particle size less than 300 nm and showed good stability over time. The oil-in-water nanoemulsion also showed good viscosity, conductivity, and pH values. From TEM micrograph, particle size showed consistent results with the measurement using photon correlation spectroscopy. It was concluded that both positively and negatively charged nanoemulsions showed good stability and have great potential in transdermal delivery system. Though, further investigation of the drug release and drug penetration of both positively and negatively charged nanoemulsions will be studied to further prove the efficacy of nanoemulsion with hydrocortisone as a delivery system for dermal application.


Author(s):  
A. Habbal ◽  
P.-E. Jabin

International audience This paper contains two short presentations related to the mathematical modeling of Cancer. The first part intends to introduce a tumour-immune system interaction, which describes the early dynamics of cancerous cells, competing with the immune system, potentially leading to either the elimination of tumoral cells or to the viability of a solid tumor. The second part of the paper addresses the case where a solid tumor has grown enough to initiate angiogenesis, a process which equips the tumor with its own blood network. Nash game theory is used to model the interaction between activators and inhibitors of the angiogenesis process.


Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 553 ◽  
Author(s):  
A. Katharina Kolonko ◽  
Nadine Bangel-Ruland ◽  
Francisco M. Goycoolea ◽  
Wolf-Michael Weber

Nanoscale drug delivery systems exhibit a broad range of applications and promising treatment possibilities for various medical conditions. Nanomedicine is of great interest, particularly for rare diseases still lacking a curative treatment such as cystic fibrosis (CF). CF is defined by a lack of Cl− secretion through the cystic fibrosis transmembrane conductance regulator (CFTR) and an increased Na+ absorption mediated by the epithelial sodium channel (ENaC). The imbalanced ion and water transport leads to pathological changes in many organs, particularly in the lung. We developed a non-viral delivery system based on the natural aminopolysaccharide chitosan (CS) for the transport of antisense oligonucleotides (ASO) against ENaC to specifically address Na+ hyperabsorption. CS–ASO electrostatic self-assembled nanocomplexes were formed at varying positive/negative (P/N) charge ratios and characterized for their physicochemical properties. Most promising nanocomplexes (P/N 90) displayed an average size of ~150 nm and a zeta potential of ~+30 mV. Successful uptake of the nanocomplexes by the human airway epithelial cell line NCI-H441 was confirmed by fluorescence microscopy. Functional Ussing chamber measurements of transfected NCI-H441 cells showed significantly decreased Na+ currents, indicating successful downregulation of ENaC. The results obtained confirm the promising characteristics of CS as a non-viral and non-toxic delivery system and demonstrate the encouraging possibility to target ENaC with ASOs to treat abnormal ion transport in CF.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Rania Ibrahim Shebl ◽  
Faten Farouk ◽  
Hassan Mohamed El-Said Azzazy

Unmodified magnetic nanoparticles (MNPs) lack antibacterial potential. We investigated MNPs surface modifications that can impart antibacterial activity. Six MNPs species were prepared and characterized. Their antibacterial and antibiofilm potentials, surface affinity, and cytotoxicity were evaluated. Prepared MNPs were functionalized with citric acid, amine group, amino-propyl trimethoxy silane (APTMS), arginine, or oleic acid (OA) to give hydrophilic and hydrophobic MNPs with surface charge ranging from −30 to +30 mV. Prepared MNPs were spherical in shape with an average size of 6–15 nm. Hydrophobic (OA-MNPs) and positively charged MNPs (APTMS-MNPs) had significant concentration dependent antibacterial effect. OA-MNPs showed higher inhibitory potential againstS. aureusandE. coli(80%) than APTMS-MNPs (70%). Both particles exhibited surface affinity toS. aureusandE. coli.Different concentrations of OA-MNPs decreasedS. aureusandE. colibiofilm formation by 50–90%, while APTMS-MNPs reduced it by 30–90%, respectively. Up to 90% of preformed biofilms ofS. aureusandE. coliwere destroyed by OA-MNPs and APTMS-MNPs. In conclusion, surface positivity and hydrophobicity enhance antibacterial and antibiofilm properties of MNPs.


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