Molecules

Editorial

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3 pages, 105 KiB

Open AccessEditorial

Macromolecules Applied to Pharmaceutical Chemistry

by Claudio J. Salomon

Molecules 2005, 10(1), 3-5; https://doi.org/10.3390/10010003 - 31 Jan 2005

Viewed by 5863

Abstract

Macromolecular and polymer science have evolved significantly over the past few years, with remarkable advances in many areas such as polymeric drugs, self-assembly systems, implant materials, drug delivery systems and controlled drug release.[...] Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

Research

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20 pages, 952 KiB

Open AccessArticle

Bioadhesive Properties of Gantrez Nanoparticles

by Juan M. Irache, María Huici, Monica Konecny, Socorro Espuelas, Miguel Angel Campanero and Pau Arbos

Molecules 2005, 10(1), 126-145; https://doi.org/10.3390/10010126 - 31 Jan 2005

Cited by 71 | Viewed by 17137

Abstract

Bioadhesive nanoparticles have been proposed as carriers for the oral delivery of poorly available drugs and facilitate the use of this route. This work summarises some experiments describing the bioadhesive potential of Gantrez nanoparticles fluorescently labeled with rhodamine B isothiocyanate. The adhesive potential [...] Read more.

Bioadhesive nanoparticles have been proposed as carriers for the oral delivery of poorly available drugs and facilitate the use of this route. This work summarises some experiments describing the bioadhesive potential of Gantrez nanoparticles fluorescently labeled with rhodamine B isothiocyanate. The adhesive potential of Gantrez was found to be stronger when folded as nanoparticles than in the solubilised form. Conventional nanoparticles displayed a tropism for the upper areas of the gastrointestinal tract, with a maximum of adhesion 30 min post-administration and a decrease in the adhered fraction along the time depending on the given dose. The cross-linkage of nanoparticles with increasing amounts of 1,3-diaminopropane stabilised the resulting carriers and prolonged their half-life in an aqueous environment; although, the adhesive capacity of nanoparticles, the intensity and the relative duration of the adhesive interactions within the gut as a function of the cross-linking degree. Finally, nanoparticles were coated with either gelatin or albumin. In the first case, the presence of gelatin dramatically decreased the initial capacity of these carriers to interact with the gut mucosa and the intensity of these phenomenons. In the latter, bovine serum albumin coated nanoparticles (BSA-NP) showed an important tropism for the stomach mucosa without further significant distribution to other parts of the gut mucosa. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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9 pages, 300 KiB

Open AccessArticle

AFM study of a New Carrier Based on PLA and Salen Copolymers for Gene Therapy

by V. Nadeau and P. Hildgen

Molecules 2005, 10(1), 105-113; https://doi.org/10.3390/10010105 - 31 Jan 2005

Cited by 7 | Viewed by 10754

Abstract

The aim of this study was to synthesize novel biodegradable charged polymers to be used in DNA complexation for genetic delivery in different diseases. A new copolymer of PLA and complexed Schiff bases was synthesized in a several steps. This copolymer will be [...] Read more.

The aim of this study was to synthesize novel biodegradable charged polymers to be used in DNA complexation for genetic delivery in different diseases. A new copolymer of PLA and complexed Schiff bases was synthesized in a several steps. This copolymer will be used as a nanocarrier. Also, AFM comparative studies in tapping mode were performed; on cationic copolymer and on PLA-Schiff base copolymer, on non-oriented and oriented film and on the DNA-cationic complex. The results indicated a difference in the topology and on phase picture of AFM film with or without cationic charge. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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7 pages, 166 KiB

Open AccessArticle

Synthesis of PLA-b-PEG Multiblock Copolymers for Stealth Drug Carrier Preparation

by R. Quesnel and P. Hildgen

Molecules 2005, 10(1), 98-104; https://doi.org/10.3390/10010098 - 31 Jan 2005

Cited by 33 | Viewed by 9619

Abstract

An efficient method of preparing biodegradable and biocompatible multiblock copolymers from lactic acid and polyethylene glycol is proposed. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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17 pages, 341 KiB

Open AccessArticle

Fragrance Release from the Surface of Branched Poly (Amide) S

by F. Aulenta, M. Drew, A. Foster, W. Hayes, S. Rannard, D. Thornthwaite and T. Youngs

Molecules 2005, 10(1), 81-97; https://doi.org/10.3390/10010081 - 31 Jan 2005

Cited by 14 | Viewed by 15388

Abstract

Enzymes are powerful tools in organic synthesis that are able to catalyse a wide variety of selective chemical transformations under mild and environmentally friendly conditions. Enzymes such as the lipases have also found applications in the synthesis and degradation of polymeric materials. However, [...] Read more.

Enzymes are powerful tools in organic synthesis that are able to catalyse a wide variety of selective chemical transformations under mild and environmentally friendly conditions. Enzymes such as the lipases have also found applications in the synthesis and degradation of polymeric materials. However, the use of these natural catalysts in the synthesis and the post-synthetic modification of dendrimers and hyperbranched molecules is an application of chemistry yet to be explored extensively. In this study the use of two hydrolytic enzymes, a lipase from Candida cylindracea and a cutinase from Fusarium solani pisii, were investigated in the selective cleavage of ester groups situated on the peripheral layer of two families of branched polyamides. These branched polyamides were conjugated to simple fragrances citronellol and L-menthol via ester linkages. Hydrolysis of the ester linkage between the fragrances and the branched polyamide support was carried out in aqueous buffered systems at slightly basic pH values under the optimum operative conditions for the enzymes used. These preliminary qualitative investigations revealed that partial cleavage of the ester functionalities from the branched polyamide support had occurred. However, the ability of the enzymes to interact with the substrates decreased considerably as the branching density, the rigidity of the structure and the bulkiness of the polyamide-fragrance conjugates increased. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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28 pages, 2081 KiB

Open AccessArticle

Scleroglucan: A Versatile Polysaccharide for Modified Drug Delivery

by Tommasina Coviello, Antonio Palleschi, Mario Grassi, Pietro Matricardi, Gianfranco Bocchinfuso and Franco Alhaique

Molecules 2005, 10(1), 6-33; https://doi.org/10.3390/10010006 - 31 Jan 2005

Cited by 114 | Viewed by 20628

Abstract

Scleroglucan is a natural polysaccharide, produced by fungi of the genus Sclerotium, that has been extensively studied for various commercial applications (secondary oil recovery, ceramic glazes, food, paints, etc.) and also shows several interesting pharmacological properties. This review focuses its attention on the [...] Read more.

Scleroglucan is a natural polysaccharide, produced by fungi of the genus Sclerotium, that has been extensively studied for various commercial applications (secondary oil recovery, ceramic glazes, food, paints, etc.) and also shows several interesting pharmacological properties. This review focuses its attention on the use of scleroglucan, and some derivatives, in the field of pharmaceutics and in particular for the formulation of modified-release dosage forms. The reported investigations refer mainly to the following topics: natural scleroglucan suitable for the preparation of sustained release tablets and ocular formulations; oxidized and crosslinked scleroglucan used as a matrix for dosage forms sensitive to environmental conditions; co-crosslinked scleroglucan/gellan whose delivery rate can be affected by calcium ions. Furthermore, a novel hydrogel obtained with this polysaccharide and borate ions is described, and the particular structure of this hydrogel network has been interpreted in terms of conformational analysis and molecular dynamics. Profound attention is devoted to the mechanisms involved in drug release from the tested dosage forms that depend, according to the specific preparation, on swelling and/or diffusion. Experimental data are also discussed on the basis of a mathematical approach that allows a better understanding of the behavior of the tested polymeric materials. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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Review

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19 pages, 319 KiB

Open AccessReview

Optimization of Protein Therapies by Polymer-Conjugation as an Effective DDS

by Hiroko Shibata, Shinsaku Nakagawa and Yasuo Tsutsumi

Molecules 2005, 10(1), 162-180; https://doi.org/10.3390/10010162 - 31 Jan 2005

Cited by 14 | Viewed by 12111

Abstract

Due to recent advances in disease proteomics, many disease-related proteins have been found. It is expected that there will be therapeutically useful proteins among them. However, it is clinically difficult to use most proteins as effective and safe drugs because of their very [...] Read more.

Due to recent advances in disease proteomics, many disease-related proteins have been found. It is expected that there will be therapeutically useful proteins among them. However, it is clinically difficult to use most proteins as effective and safe drugs because of their very low stability and pleiotropic actions in vivo. To promote disease proteomic based drug development for protein therapies, we have attempted to develop an optimal polymer-conjugation system for improving the therapeutic potency of proteins. In this review, we introduce this innovative protein-drug system. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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16 pages, 229 KiB

Open AccessReview

Biodegradable Polymers for Microencapsulation of Drugs

by J. Park, M. Ye and K. Park

Molecules 2005, 10(1), 146-161; https://doi.org/10.3390/10010146 - 31 Jan 2005

Cited by 284 | Viewed by 28461

Abstract

Drug delivery has become increasingly important mainly due to the awareness of the difficulties associated with a variety of old and new drugs. Of the many polymeric drug delivery systems, biodegradable polymers have been used widely as drug delivery systems because of their [...] Read more.

Drug delivery has become increasingly important mainly due to the awareness of the difficulties associated with a variety of old and new drugs. Of the many polymeric drug delivery systems, biodegradable polymers have been used widely as drug delivery systems because of their biocompatibility and biodegradability. The majority of biodegradable polymers have been used in the form of microparticles, from which the incorporated drug is released to the environment in a controlled manner. The factors responsible for controlling the drug release rate are physicochemical properties of drugs, degradation rate of polymers, and the morphology and size of microparticles. This review discusses the conventional and recent technologies for microencapsulation of the drugs using biodegradable polymers. In addition, this review presents characteristics and degradation behaviors of biodegradable polymers which are currently used in drug delivery. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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12 pages, 253 KiB

Open AccessReview

Covalent Polymer-Drug Conjugates

by C. Elvira, A. Gallardo, J. Roman and A. Cifuentes

Molecules 2005, 10(1), 114-125; https://doi.org/10.3390/10010114 - 31 Jan 2005

Cited by 112 | Viewed by 15332

Abstract

In this work, polymer-drugs conjugates used as drug delivery systems (DDS) are revised attending to their chemical conjugation. Namely, the classification of this type of DDS is based on the conjugation sites of the reactive groups (i.e., via end groups or pendant polymer [...] Read more.

In this work, polymer-drugs conjugates used as drug delivery systems (DDS) are revised attending to their chemical conjugation. Namely, the classification of this type of DDS is based on the conjugation sites of the reactive groups (i.e., via end groups or pendant polymer groups). Advantages and limitations of these types of DDS are discussed through representative examples of polymer-drugs and polymer-proteins conjugates recently developed. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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16 pages, 2588 KiB

Open AccessReview

Polymeric Particulates to Improve Oral Bioavailability of Peptide Drugs

by Florence Delie and María José Blanco-Príeto

Molecules 2005, 10(1), 65-80; https://doi.org/10.3390/10010065 - 31 Jan 2005

Cited by 125 | Viewed by 18954

Abstract

Oral administration remains the most convenient way of delivering drugs. Recent advances in biotechnology have produced highly potent new molecules such as peptides, proteins and nucleic acids. Due to their sensitivity to chemical and enzymatic hydrolysis as well as a poor cellular uptake, [...] Read more.

Oral administration remains the most convenient way of delivering drugs. Recent advances in biotechnology have produced highly potent new molecules such as peptides, proteins and nucleic acids. Due to their sensitivity to chemical and enzymatic hydrolysis as well as a poor cellular uptake, their oral bioavailability remains very low. Despite sophisticated new delivery systems, the development of a satisfactory oral formulation remains a challenge. Among the possible strategies to improve the absorption of drugs, micro- and nanoparticles represent an exciting approach to enhance the uptake and transport of orally administered molecules. Increasing attention has been paid to their potential use as carriers for peptide drugs for oral administration. This article reviews the most common manufacturing methods for polymeric particles and the physiology of particle absorption from the gastrointestinal (GI) tract. In a second part, the use of polymeric particulate systems to improve the oral absorption of insulin is discussed. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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31 pages, 477 KiB

Open AccessReview

Polymers for DNA Delivery

by H. Eliyahu, Y. Barenholz and A. J. Domb

Molecules 2005, 10(1), 34-64; https://doi.org/10.3390/10010034 - 31 Jan 2005

Cited by 191 | Viewed by 17430

Abstract

Nucleic acid delivery has many applications in basic science, biotechnology, agriculture, and medicine. One of the main applications is DNA or RNA delivery for gene therapy purposes. Gene therapy, an approach for treatment or prevention of diseases associated with defective gene expression, involves [...] Read more.

Nucleic acid delivery has many applications in basic science, biotechnology, agriculture, and medicine. One of the main applications is DNA or RNA delivery for gene therapy purposes. Gene therapy, an approach for treatment or prevention of diseases associated with defective gene expression, involves the insertion of a therapeutic gene into cells, followed by expression and production of the required proteins. This approach enables replacement of damaged genes or expression inhibition of undesired genes. Following two decades of research, there are two major methods for delivery of genes. The first method, considered the dominant approach, utilizes viral vectors and is generally an efficient tool of transfection. Attempts, however, to resolve drawbacks related with viral vectors (e.g., high risk of mutagenicity, immunogenicity, low production yield, limited gene size, etc.), led to the development of an alternative method, which makes use of non-viral vectors. This review describes non-viral gene delivery vectors, termed "self-assembled" systems, and are based on cationic molecules, which form spontaneous complexes with negatively charged nucleic acids. It introduces the most important cationic polymers used for gene delivery. A transition from in vitro to in vivo gene delivery is also presented, with an emphasis on the obstacles to achieve successful transfection in vivo. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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