Drug Release from Hydrogel: A New Understanding of Transport Phenomena

Perale, Giuseppe; Rossi, Filippo; Santoro, Marco; Marchetti, Patrizia; Mele, Andrea; Castiglione, Francesca; Raffa, E.; Masi, Maurizio

doi:10.1166/jbn.2011.1302

Cited by 24 publications

(28 citation statements)

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“…The issue of SF self-aggregationi na queous solutions has already been addressed in previous work. [30] For the sake of clarity,wesummarize the main concepts here. The self-aggregation of SF in D 2 Os olutionsw as assessedb yt he inspection of linewidths in the 1 HNMR spectra.H igh resolution NMR bands were detectable up to aS Fc oncentration of 100 mg mL À1 , showingt he threshold for the formation of aggregates.…”

Section: Discussionmentioning

confidence: 99%

“…[21,30,32] In brief, the 1 HNMR spectra of the hydrogel systems were recorded on aB ruker Avances pectrometer operating at 500 MHz proton frequency,e quipped with ad ual 1 H/ 13 CH R-MAS probe head for semisolid samples. Self-diffusion coefficients were measured by diffusion ordered correlation spectroscopy (DOSY) experiments, based on ap ulsed field gradient spin-echo (PGSE) approach.…”

Section: Hr-mas Nmr Spectroscopymentioning

confidence: 99%

“…SF self-diffusion coefficients were measured in water andi ng el by means of pulsed magnetic field gradients spin-echo (PGSE) nuclear magnetic resonance (NMR) spectroscopyu sing the high-resolution magic angle spinning (HR-MAS) technique. [28][29][30] Then, to understand the differences in terms of drug transport through water solutiona nd hydrogel environment, we propose am athematical model based on adsorptionm echanismsf irstly applied by Carta and Schirmer on polysaccharide-based hydrogels for chromatography [31] and then optimized by our research group for hydrogel-based drug-delivery systems. [32] In addition, we considered the aggregation contribution, which takes place in ad ifferent manner between the two environments and is common in several commonly-used drugs.…”

Section: Introductionmentioning

confidence: 99%

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The Role of Drug–Drug Interactions in Hydrogel Delivery Systems: Experimental and Model Study

et al. 2016

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To address the increasing need for improved tissue substitutes, tissue engineering seeks to create synthetic, three-dimensional scaffolds made from polymeric materials able to incorporate cells and drugs. The interpretation of transport phenomena is a key step, but comprehensive theoretical data is still missing and many issues related to these systems are still unsolved. In particular, the contribution of solute-solute interactions is not yet completely understood. Here, we investigate a promising agar-carbomer (AC) hydrogel loaded with sodium fluorescein (SF), a commonly used drug mimetic. The self-diffusion coefficient of SF in AC formulations was measured by using high resolution magic angle spinning NMR spectroscopy (HR-MAS NMR). Starting from experimental data, a complete overview on SF transport properties is provided, in particular a mathematical model that describes and rationalizes the differences between gel and water environments is developed and presented. The hydrogel molecular environment is able to prevent SF aggregation, owing to the adsorption mechanism that reduces the number of monomers available for oligomer formation at low solute concentration. Then, when all adsorption sites are saturated free SF molecules are able to aggregate and form oligomers. The model predictions satisfactorily match with experimental data obtained in water and the gel environment, thus indicating that the model presented here, despite its simplicity, is able to describe the key phenomena governing device behavior and could be used to rationalize experimental activity.

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Section: Discussionmentioning

confidence: 99%

Section: Hr-mas Nmr Spectroscopymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Role of Drug–Drug Interactions in Hydrogel Delivery Systems: Experimental and Model Study

et al. 2016

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“…The chosen hydrogel, specifically developed for central nervous system repair strategies, was obtained by synthesis from statistical block polycondensation between agarose and carbomer 974P (briefly termed as AC, acronymic of their main components), together with cross-linkers 36,37 . IP self-diffusion coefficients were measured in water and in gel by means of pulsed magnetic field gradients spin-echo (PGSE) nuclear magnetic resonance (NMR) spectroscopy using the high resolution magic angle spinning (HR-MAS) technique [38][39][40] . In addition we considered here also the aggregation contribution (drug-drug interaction) that takes place in water and in hydrogel and it is very common in several commonlyused drugs 41,42 .…”

Section: Introductionmentioning

confidence: 99%

On the parallelism between the mechanisms behind chromatography and drug delivery: the role of interactions with a stationary phase

Rossi

Castiglione

Salvalaglio

et al. 2017

Phys. Chem. Chem. Phys.

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A huge number of studies and works in drug delivery literature are focused on understanding and modeling transport phenomena, the pivotal point for a good device design. The rationalization of all phenomena involved is fundamental, but several concerns arise leaving many issues unsolved. In order to change point of view we decided to focus our attention on parallelisms between two fields that seem to be very far each other: chromatography and drug release. Taking advantages on the studies conducted by many researchers with chromatographic columns we decided to explain all the phenomena involved in drug delivery considering sodium ibuprofen molecules (IP) as analytes and hydrogel as stationary phase. In particular we considered not only diffusion, but also drug-polymer interactions as adsorption on the stationary phase and drug-drug interactions as analytes aggregation. Hydrogel investigated is a promising formulation made of agarose and carbomer 974p (AC) loaded with IP, a non-steroidal common anti-inflammatory drugs. The self-diffusion coefficient of IP in AC formulations was measured by using an innovative method based on Magic Angle Spinning NMR spectroscopic technique to produce High Resolution (liquid-like) spectra.This method (HR-MAS NMR) is used in combination with pulsed field gradient spin echo (PGSE) liquid-state techniques. The model predictions satisfactorily match with experimental data obtained in water and the gel environment, indicating that the model presented here, despite its simplicity, is able to describe the key phenomena governing the device behavior and could be used to rationalize the experimental activity.!

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“…For the reasons mentioned above, we performed intravitreal and suprachoroidal injections to assess the possibility of utilizing a novel peptide hydrogel for drug delivery to the posterior segment. Although hydrogels have been widely used for drug delivery, few studies have evaluated the utility of hydrogels in the delivery of drugs to the posterior segment [7,8,25]. However, because of their transparency, hydrogels have been widely used in ophthalmology, especially for refractive media substitutes and refractive correction, to form materials such as intraocular lenses, vitreous substitutes, contact lenses, and even keratoprostheses [10][11][12].…”

Section: Discussionmentioning

confidence: 99%

Evaluation of RGD peptide hydrogel in the posterior segment of the rabbit eye

Wang

Liang

et al. 2012

Journal of Biomaterials Science, Polymer Edition

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The aim of this study was to evaluate the biocompatibility and biodegradability of RGD peptide hydrogel in the posterior segment of the eye as a biomaterial potentially useful for sustained drug delivery systems. RGD peptide hydrogel was injected into the vitreous cavity and suprachoroidal space of rabbit eyes. Clinical follow-up and histological observation were performed up to four weeks. The biodegradability was also evaluated by the lifetime of the hydrogel which was defined by ophthalmoscopic observation or ultrasonography. The results showed that RGD peptide hydrogel was well tolerated in the vitreous cavity and suprachoroidal space, and disappeared from the injection sites progressively. As for suprachoroidal injection, the hydrogel was clearly identified by ultrasound echography and was confirmed innoxious to the retinal vessels by fluorescein angiography. Histological observations showed that the structures of retina, choroid and other tissues around the injection site remained normal after the injection. The lifetime of the hydrogel was 25.7 ± 2.65 days and 14.3 ± 3.3 days in the vitreous cavity and suprachoroidal space, respectively. The results obtained demonstrated that RGD peptide hydrogel, which showed excellent biocompatibility and favorable biodegradability in the posterior segment of rabbit eyes, appears to be a promising biomaterial to deliver drugs focally to the choroid and the retina.

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Drug Release from Hydrogel: A New Understanding of Transport Phenomena

Cited by 24 publications

References 0 publications

The Role of Drug–Drug Interactions in Hydrogel Delivery Systems: Experimental and Model Study

The Role of Drug–Drug Interactions in Hydrogel Delivery Systems: Experimental and Model Study

On the parallelism between the mechanisms behind chromatography and drug delivery: the role of interactions with a stationary phase

Evaluation of RGD peptide hydrogel in the posterior segment of the rabbit eye

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