Examination of aqueous oxidized cellulose dispersions as a potential drug carrier. I. Preparation and characterization of oxidized cellulose-phenylpropanolamine complexes

Zhu, Lihua; Kumar, Vijay; Banker, Gilbert S.

doi:10.1208/pt050469

Cited by 9 publications

(7 citation statements)

References 11 publications

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“… 314 Among them, the most common TEMPO-mediated oxidation is able to achieve complete surface oxidation ( Figure 8 d). 236 , 239 The introduced carboxyl groups (p K a = 3–4) 315 , 316 can be deprotonated to introduce repulsive negative charges on cellulose, weakening interfibrillar interactions and strongly enhancing fibrillation. TEMPO-oxidized cellulose can be dispersed by mild disintegration in a high-speed blender to obtain coarse TO–CNFs.…”

Section: Deconstruction and Modification Of Biopolymers And Biocolloidsmentioning

confidence: 99%

“…Chemical pretreatments in the nanofiber production are mostly based on the introduction of charged functional groups through modification of chemically accessible surface hydroxyl groups . Among them, the most common TEMPO-mediated oxidation is able to achieve complete surface oxidation (Figure d). , The introduced carboxyl groups (p K a = 3–4) , can be deprotonated to introduce repulsive negative charges on cellulose, weakening interfibrillar interactions and strongly enhancing fibrillation. TEMPO-oxidized cellulose can be dispersed by mild disintegration in a high-speed blender to obtain coarse TO–CNFs .…”

Section: Deconstruction and Modification Of Biopolymers And Biocolloidsmentioning

confidence: 99%

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Deconstruction and Reassembly of Renewable Polymers and Biocolloids into Next Generation Structured Materials

et al. 2021

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This review considers the most recent developments in supramolecular and supraparticle structures obtained from natural, renewable biopolymers as well as their disassembly and reassembly into engineered materials. We introduce the main interactions that control bottom-up synthesis and top-down design at different length scales, highlighting the promise of natural biopolymers and associated building blocks. The latter have become main actors in the recent surge of the scientific and patent literature related to the subject. Such developments make prominent use of multicomponent and hierarchical polymeric assemblies and structures that contain polysaccharides (cellulose, chitin, and others), polyphenols (lignins, tannins), and proteins (soy, whey, silk, and other proteins). We offer a comprehensive discussion about the interactions that exist in their native architectures (including multicomponent and composite forms), the chemical modification of polysaccharides and their deconstruction into high axial aspect nanofibers and nanorods. We reflect on the availability and suitability of the latter types of building blocks to enable superstructures and colloidal associations. As far as processing, we describe the most relevant transitions, from the solution to the gel state and the routes that can be used to arrive to consolidated materials with prescribed properties. We highlight the implementation of supramolecular and superstructures in different technological fields that exploit the synergies exhibited by renewable polymers and biocolloids integrated in structured materials.

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Section: Deconstruction and Modification Of Biopolymers And Biocolloidsmentioning

confidence: 99%

Section: Deconstruction and Modification Of Biopolymers And Biocolloidsmentioning

confidence: 99%

Deconstruction and Reassembly of Renewable Polymers and Biocolloids into Next Generation Structured Materials

et al. 2021

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“…These products have shown either enhanced activities, lower toxicity, and/or sustained drug release. 75,77,78 In addition to OC, periodate oxidized DAC is also being tested as a potential biocompatible matrix, which could be useful as a scaffold in tissue engineering. In the powdered form, it has been extensively investigated as a carrier for a variety of drugs and biomacromolecules ( p-aminosalicylic acid, chymotrypsin, insulin etc.).…”

Section: Drug Carriersmentioning

confidence: 99%

Oxycellulose: Significant characteristics in relation to its pharmaceutical and medical applications

Bajerová¹,

Krejčová²,

Rabišková³

et al. 2009

Adv Polym Technol

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As a biomaterial, cellulose can be converted into a wide range of derivatives with desired properties for a variety of medical, biomedical, and pharmaceutical applications. The oxidation of cellulose yields oxidized cellulose (OC, oxycellulose, 6-carboxycellulose). OC represents an important class of biocompatible and bioresorbable polymers. In vivo bioabsorption of OC occurs via chemical depolymerization and enzymatic hydrolysis. Despite the fact OC is well established as a hemostatic agent and is widely used in a clinical practice, it still attracts a great interest and its new applications, especially pharmaceutical, are investigated. The present review is focused on characterization of OC's physical and chemical properties. Its synthesis and mechanisms involved in its in vivo and in vitro biodegradation are discussed. Medical and biomedical applications of OC are summarized, and especially its hemostatic, enterosorbent, and wound-healing properties are described. In addition to these applications, OC could be used as a pharmaceutical excipient in solid (e.g.

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“…1a) is a semi-synthetic derivative of naturally occurring cellulose which undergoes chemical depolymerization and enzymatic hydrolysis under in vivo conditions (3,4). Being a non-toxic, biodegradable, biocompatible and bioresorbable polymer (5,6), OC is a well-established surgical material commercially available as a knitted fabric or staple fibre used in humans to stop bleeding and prevent the undesirable tissue adhesion occurring during post-operative healing processes (7,8). OC is practically insoluble in water and common organic solvents (9) and can form different salts, which differ in their physicochemical properties.…”

Section: Introductionmentioning

confidence: 99%

Oxycellulose Beads with Drug Exhibiting pH-Dependent Solubility

Bajerová

Krejčová²,

Rabišková

et al. 2011

AAPS PharmSciTech

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Abstract. The aim of this study was to develop novel hydrogel-based beads and characterize their potential to deliver and release a drug exhibiting pH-dependent solubility into distal parts of gastrointestinal (GI) tract. Oxycellulose beads containing diclofenac sodium as a model drug were prepared by the ionotropic external gelation technique using calcium chloride solution as the crosslinking medium. Resulting beads were characterized in terms of particle shape and size, encapsulation efficacy, swelling ability and in vitro drug release. Also, potential drug-polymer interactions were evaluated using Fourier transform infrared spectroscopy. The particle size was found to be 0.92-0.96 mm for inactive (oxycellulose only) and 1.47-1.60 mm for active (oxycellulose-diclofenac sodium) beads, respectively. In all cases, the sphericity factor was between 0.70 and 0.81 with higher values observed for samples containing higher polymer and drug concentrations. The swelling of inactive beads was found to be strongly influenced by the pH and composition (i.e. Na + concentration) of the selected media (simulated gastric fluid vs. phosphate buffer pH 6.8). The encapsulation efficiency of the prepared particles ranged from 58% to 65%. Results of dissolution tests showed that the drug loading inside of the particles influenced the rate of its release. In general, prepared particles were able to release the drug within 12-16 h after a lag time of 4 h. Fickian diffusion was found as the predominant drug release mechanism. Thus, this novel particulate system showed a good potential to deliver drugs specifically to the distal parts of the human GI tract.

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Examination of aqueous oxidized cellulose dispersions as a potential drug carrier. I. Preparation and characterization of oxidized cellulose-phenylpropanolamine complexes

Cited by 9 publications

References 11 publications

Deconstruction and Reassembly of Renewable Polymers and Biocolloids into Next Generation Structured Materials

Deconstruction and Reassembly of Renewable Polymers and Biocolloids into Next Generation Structured Materials

Oxycellulose: Significant characteristics in relation to its pharmaceutical and medical applications

Oxycellulose Beads with Drug Exhibiting pH-Dependent Solubility

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