Silica encapsulated hemoglobin and myoglobin powders prepared by an aqueous fast-freezing technique

McCool, Benjamin A.; Cashon, Robert E.; Karles, G.; DeSisto, William J.

doi:10.1016/j.jnoncrysol.2003.09.061

Cited by 11 publications

(7 citation statements)

References 13 publications

(14 reference statements)

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“…After the addition of peroxynitrite, the shift of the maximum of the absorption band from 415 to 408 nm indicates the final conversion to metHb (Figure 6). The slight shift of the maximum of the absorption band of metHb from 405 to 408 nm was already observed when metHb was encapsulated in a silica matrix 64 or immobilized on a glass surface. 65 Although the local Hb concentration within the vesicles was close to 30 μM, the overall protein concentration in solution (∼100 nM) was far below the Raman detection limit (∼10 μM).…”

Section: ■ Results and Discussionmentioning

confidence: 75%

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Polymer Nanoreactors with Dual Functionality: Simultaneous Detoxification of Peroxynitrite and Oxygen Transport

et al. 2012

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The design of multifunctional systems is in focus today as a key strategy for coping with complex challenges in various domains that include chemistry, medicine, environmental sciences, and technology. Herein, we introduce protein-containing polymer nanoreactors with dual functionality: peroxynitrite degradation and oxygen transport. Vesicles made of poly-(2-methyloxazoline)-poly(dimethylsiloxane)-poly(2-methyloxazoline) successfully encapsulated hemoglobin (Hb), which serves as a model protein because of its dual function in oxygen transport and peroxynitrite degradation. By inserting channel proteins, the polymer membranes of vesicles permitted passage of various compounds that served for the assessment of in situ Hb activity. The requisite conformational changes in the protein structure and the change in oxidation states that took place within the confined space of the vesicle cavity demonstrated that Hb preserved its dual functionality: peroxynitrite degradation and oxygen transport. The functionality of our nanoreactor, combined with its simple procedure of production and extensive stability over several months, supports it as a promising system for further medical applications.

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Section: ■ Results and Discussionmentioning

confidence: 75%

“…After the addition of peroxynitrite, the shift of the maximum of the absorption band from 415 to 408 nm indicates the final conversion to metHb (Figure ). The slight shift of the maximum of the absorption band of metHb from 405 to 408 nm was already observed when metHb was encapsulated in a silica matrix or immobilized on a glass surface…”

Section: Resultsmentioning

confidence: 76%

Polymer Nanoreactors with Dual Functionality: Simultaneous Detoxification of Peroxynitrite and Oxygen Transport

et al. 2012

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“…The liquid nitrogen freezing technique is believed to preserve the open polymeric structure of the gel leading to high surface area powders. 27,28 A surface area of 286.7 m 2 /g and a mean pore volume of 0.37 mL/g were then recorded for the as prepared sample. For the insulin containing freeze-dried sample, the drastic decrease in surface area (from 286.7 m 2 /g to 2.9 m 2 /g) and pore volume (from 0.37 mL/g to 0.05 mL/g) is the consequence of insulin incorporation in silica-based matrix, the silica shell being formed around the insulin molecules.…”

Section: Discussionmentioning

confidence: 99%

Freeze-dried and spray-dried zinc-containing silica microparticles entrapping insulin

et al. 2013

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New approaches for oral administration of insulin are strongly related to novel insulin carriers. The aim of this study was the insulin microencapsulation in a new zinc-silica matrix for drug protection and controlled release. Zinc-silica microparticles loaded with insulin were obtained by sol-gel process via spray drying and freeze drying methods. Inorganic silica matrix isolates and constrains the movement of the biomolecules preventing their aggregation and denaturation, while the zinc oxide improves the system stability. Moreover, formation of insulin hexamers in the presence of zinc ions leads to an increased stability of the insulin three-dimensional structure during preparation, storage and release. The particles were characterized with respect to average size, specific surface area, porosity and morphology. In vitro behavior of insulin-loaded particles together with protein structural conformation was also evaluated. The release profile can be adapted by synthesis route of microparticles.

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“…These optical characteristics have been investigated for the development of optical biosensors to detect dissolved oxygen (DO), nitric oxide (NO), and carbon monoxide (CO) 11, 12. In optical applications, sol–gels have been widely investigated as immobilization substrates 13. The entrapment of hemoproteins in sol–gel matrices has resulted in the retention of the spectroscopic properties and chemical functions of these proteins 10.…”

Section: Introductionmentioning

confidence: 99%

Immobilization of myoglobin from horse skeletal muscle in hydrophilic polymer networks

Castro-Forero

Jimenez

López‐Garriga

et al. 2007

J of Applied Polymer Sci

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This work examines the immobilization of myoglobin from horse skeletal muscle in hydrophilic polymer networks. Due to specific changes in the spectroscopic properties of hemoproteins during ligand binding, they could be employed in optical sensing devices. Two immobilization techniques were considered: imbibition and entrapment. Anionic hydrogels composed of methacrylic acid (MAA), cationic hydrogels composed of dimethylamino ethyl methacrylate (DMAEM), and neutral hydrogels composed of poly(ethylene glycol) monomethyl ether monomethacrylate (PEGMA; molecular weight = 200, 400, or 1000), all crosslinked with poly(ethylene glycol) dimethacrylate (PEGDMA) (molecular weight = 200, 600, or 1000), were synthesized by free-radical solution polymerization. By the imbibition method, MAA-based hydrogels incorporated the highest amount of myoglobin in comparison with PEGMA or DMAEM polymers. The evaluation of the correlation length of the networks revealed that MAA hydrogels had the highest correlation length in comparison with PEGMA-containing matrices or DMAEM hydrogels. Release experiments from MAA hydrogels at pHs 5.8 and 7.0 showed that the solute-transport mechanism was a combination of Fickian and chain relaxation diffusion. Myoglobin-loaded MAA hydrogels retained their heme reactivity after the immobilization process. The release of myoglobin incorporated by entrapment in MAA-PEGDMA hydrogels was highly influenced by the chain relaxation process. The diffusion coefficients of myoglobin incorporated by entrapment into anionic hydrogels were 2 orders of magnitude smaller (~10-13) than those for myoglobin incorporated by imbibition (10-11), both evaluated at pH 7.0. Substrate binding studies indicated that the protein biological activity was not compromised in those hydrogels loaded by the imbibition method, whereas prepolymeric solutions showed detrimental effects on protein stability.

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Silica encapsulated hemoglobin and myoglobin powders prepared by an aqueous fast-freezing technique

Cited by 11 publications

References 13 publications

Polymer Nanoreactors with Dual Functionality: Simultaneous Detoxification of Peroxynitrite and Oxygen Transport

Polymer Nanoreactors with Dual Functionality: Simultaneous Detoxification of Peroxynitrite and Oxygen Transport

Freeze-dried and spray-dried zinc-containing silica microparticles entrapping insulin

Immobilization of myoglobin from horse skeletal muscle in hydrophilic polymer networks

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