Adsorption characteristics of a cationic porphyrin on nanoclay at various pH

Rice, Zachary; Bergkvist, Magnus

doi:10.1016/j.jcis.2009.02.070

Cited by 11 publications

(3 citation statements)

References 26 publications

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“…Two different pH-dependent adsorption responses may be observed after interaction between clay and blood meal compound (see Figure , IV): large adsorption rate at basic pH’s and either linear or low adsorption rate at acid or neutral pH’s. Rice and Bergkvist found a linear absorption response at acidic and basic pH’s and a slight deviation, probably due to a gradual transition between protonated and deprotonated states, at intermediate pH’s. They reported that porphyrin adsorption on clay occurs in a monolayer formation at low/high pH, while at slightly acidic/neutral pH, they possibly rearrange on the surface and/or form aggregates.…”

Section: Resultsmentioning

confidence: 94%

Blood Meal-Based Compound. Good Choice as Iron Fertilizer for Organic Farming

Yunta

Foggia

Bellido-Díaz

et al. 2013

J. Agric. Food Chem.

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Prevention of iron chlorosis with Fe synthetic chelates is a widespread agronomical practice but implies high costs and environmental risks. Blood meal is one of the main fertilizers allowed to be used in organic farming. Through this work a novel blood meal fertilizer was audited. Measurements such as FTIR, Raman, electron paramagnetic resonance, and Mössbauer spectroscopy, UV-visible properties, stability against pH, and batch experiments were performed to characterize and assess the reactivity on soil constituents and agronomic soils. The spectroscopy findings give clear indications that Fe is in the ferric oxidation state, is hexacoordinated, and has a low-spin form suggesting a similar structure to hemin and hematin. A spectrophotometric method at 400 nm was validated to quantify blood meal concentration at low electrolyte concentrations. Batch experiments demonstrated high reactivity of blood meal fertilizer with soil constituents, mainly in the presence of calcium, where aggregation processes are predominant, and its ability to take Fe from synthetic Fe (hydr)oxides. The beneficial profile of blood meal by a providing nitrogen source together with the capability to keep the Fe bound to porphyrin organic compounds makes it a good candidate to be used as Fe fertilizer in organic farming.

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Section: Resultsmentioning

confidence: 94%

Blood Meal-Based Compound. Good Choice as Iron Fertilizer for Organic Farming

Yunta

Foggia

Bellido-Díaz

et al. 2013

J. Agric. Food Chem.

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“…A redshift (bathochromic shift) in the Soret band was observed, similar to that observed for TPPS J-aggregates (edge-by-edge or side-to-side stacks) formed at lower pH [36]. It is possible that the shift seen in cESG-TPPS is due to a similar mechanism, where the orientation of the exterior aromatic rings were rotated upon binding, leading to delocalization of π-electrons in the porphyrin core [37]. The increase in the fluorescence intensity of cESG-TPPS complexes over free TPPS indicated that binding did not lead to self-quenching.…”

Section: Discussionmentioning

confidence: 66%

Cationic dendritic starch as a vehicle for photodynamic therapy and siRNA co-delivery

Engelberth

Hempel

Bergkvist

2017

Journal of Photochemistry and Photobiology B: Biology

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Cationic enzymatically synthesized glycogen (cESG) is a naturally-derived, nano-scale carbohydrate dendrite that has shown promise as a cellular delivery vehicle owing to its flexibility in chemical modifications, biocompatibility and relative low cost. In the present work, cESG was modified and evaluated as a vehicle for tetraphenylporphinesulfonate (TPPS) in order to improve cellular delivery of this photosensitizer and investigate the feasibility of co-delivery with short interfering ribonucleic acid (siRNA). TPPS was electrostatically condensed with cESG, resulting in a sub-50 nm particle with a positive zeta potential of approximately 5 mV. When tested in normal ovarian surface epithelial and ovarian clear cell carcinoma cell culture models, encapsulation of TPPS in cESG significantly improved cell death in response to light treatment compared to free drug alone. Dosages as low as 0.16 μM TPPS resulted in cellular death upon illumination with a 4.8 J/cm2 light dosage, decreasing viability by 96%. cESG-TPPS was then further evaluated as a co-delivery system with siRNA for potential combination therapy, by charge-based condensation of an siRNA directed at reducing expression of manganese superoxide dismutase (Sod2) as a proof of principle target. Simultaneous delivery of TPPS and siRNA was achieved, reducing Sod2 protein expression to 48%, while maintaining the photodynamic properties of TPPS under light exposure and maintaining low dark toxicity. This study demonstrates the versatility of cESG as a platform for dual delivery of small molecules and oligonucleotides, and the potential for further development of this system in combination therapy applications.

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“…Lin gave evidence that nature vermiculite has excellent adsorptive performance on CV dye [10]. A tremendous amount of the following scientific work [11][12][13][14][15][16][17][18][19] from different aspects suggest: clay is a kind of promising absorbent.…”

Section: Introductionmentioning

confidence: 99%

Adsorption Properties of the Macro/Nano-Clay in Crystal Violet Solution

Bai

Jin

Zhang

et al. 2015

MSF

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In this study, different appearances, structures and morphologies of macro-clay G105-Polymer grade montmorillonite (PMMT) and nanoclay Lithium magnesium silicate (LMSH) were compared and analyzed, which were used in different conditions of non-adsorption and adsorption of crystal violent (CV). Adsorption kinetics and properties of the macro/nanoclay in CV solution were studied, and adsorption time, dye concentration and environmental pH were the main factors on the inspection in this work. The adsorption mechanisms of the macro-/nanoclay on CV were investigated. The results showed that adsorption actions of PMMT and LMSH on CV were some similar, such as time-dependent, linear growth of adsorbed CV amount with increasing CV concentration, adsorption capacity of macro-/nanoclay declined firstly and then increased in 10mg/L CV solution along with increasing pH value. But the adsorption differences in two systems of PMMT-CV and LMSH-CV were obvious. Adsorption behavior of LMSH-CV system showed two adsorption phenomena. Under neutral conditions, adsorbed CV amount in 0.5g LMSH was 1.69 times that of PMMT. Adsorption amount of LMSH was more significant to be affected by dye concentration and pH conditions. The research achievements further showed that adsorption mechanism was the root cause of the following difference. The adsorption of PMMT-CV relied mainly on iron-exchange effect of layers replaceable cations and surface adsorbed ions with CV cations, while the significant adsorption of LMSH-CV was mainly due to the electrostatic interaction from layers negative charge distribution and CV cationic properties in the solution, partly surface ions exchanges also existed in the adsorption process of LMSH-CV.

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Adsorption characteristics of a cationic porphyrin on nanoclay at various pH

Cited by 11 publications

References 26 publications

Blood Meal-Based Compound. Good Choice as Iron Fertilizer for Organic Farming

Blood Meal-Based Compound. Good Choice as Iron Fertilizer for Organic Farming

Cationic dendritic starch as a vehicle for photodynamic therapy and siRNA co-delivery

Adsorption Properties of the Macro/Nano-Clay in Crystal Violet Solution

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