scholarly journals Polymeric materials for drug carriers

2008 ◽  
Vol 23 (6) ◽  
pp. 610-617
Author(s):  
Masayuki Yokoyama
Author(s):  
Ana Aguiar-Ricardo ◽  
Vasco D. B. Bonifácio ◽  
Teresa Casimiro ◽  
Vanessa G. Correia

The integrated use of supercritical carbon dioxide (scCO 2 ) and micro- and nanotechnologies has enabled new sustainable strategies for the manufacturing of new medications. ‘Green’ scCO 2 -based methodologies are well suited to improve either the synthesis or materials processing leading to the assembly of three-dimensional multifunctional constructs. By using scCO 2 either as C1 feedstock or as solvent, simple, economic, efficient and clean routes can be designed to synthesize materials with unique properties such as polyurea dendrimers and oxazoline-based polymers/oligomers. These new biocompatible, biodegradable and water-soluble polymeric materials can be engineered into multifunctional constructs with antimicrobial activity, targeting moieties, labelling units and/or efficiently loaded with therapeutics. This mini-review highlights the particular features exhibited by these materials resulting directly from the followed supercritical routes.


Nanoscale ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 2970-2982 ◽  
Author(s):  
Gracia Mendoza ◽  
Isabel Ortiz de Solorzano ◽  
Inmaculada Pintre ◽  
Sara Garcia-Salinas ◽  
Victor Sebastian ◽  
...  

NIR labelling of polymeric materials by chemical modification has been achieved to obtain biocompatible drug carriers for preclinical imaging.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1770 ◽  
Author(s):  
Mohammad Sadegh Amiri ◽  
Vahideh Mohammadzadeh ◽  
Mohammad Ehsan Taghavizadeh Yazdi ◽  
Mahmood Barani ◽  
Abbas Rahdar ◽  
...  

Gums are carbohydrate biomolecules that have the potential to bind water and form gels. Gums are regularly linked with proteins and minerals in their construction. Gums have several forms, such as mucilage gums, seed gums, exudate gums, etc. Plant gums are one of the most important gums because of their bioavailability. Plant-derived gums have been used by humans since ancient times for numerous applications. The main features that make them appropriate for use in different applications are high stabilization, viscosity, adhesive property, emulsification action, and surface-active activity. In many pharmaceutical formulations, plant-based gums and mucilages are the key ingredients due to their bioavailability, widespread accessibility, non-toxicity, and reasonable prices. These compete with many polymeric materials for use as different pharmaceuticals in today’s time and have created a significant achievement from being an excipient to innovative drug carriers. In particular, scientists and pharmacy industries around the world have been drawn to uncover the secret potential of plant-based gums and mucilages through a deeper understanding of their physicochemical characteristics and the development of safety profile information. This innovative unique class of drug products, useful in advanced drug delivery applications, gene therapy, and biosynthesis, has been developed by modification of plant-based gums and mucilages. In this review, both fundamental and novel medicinal aspects of plant-based gums and mucilages, along with their capacity for pharmacology and nanomedicine, were demonstrated.


2013 ◽  
Vol 24 ◽  
pp. 107-122
Author(s):  
Nimish Shah ◽  
R.K. Mewada ◽  
Tejal Mehta

Chitosan is a modified form of Chitin. It is a modified carbohydrate polymer derived by hydrolyzing the aminoacetyl groups of chitin. Chitosan is a biodegradable natural polymer which is, biocompatible, non-toxic. It also shows anti-bacterial properties. This polysaccharide is available in different forms such as nanoparticles, solution, powder, flake, fiber, film, etc. Due to its wide range of physical forms and good reactivity with other compounds, chitosan can produce various blends. Nanoparticles of various natural biopolymers have emerged as potential carrier for drugs in oral controlled drug delivery. Nanostructured drug carriers allow the delivery of not only small-molecule drugs but also of nucleic acids and proteins. Chemical modification of nanoparticles of chitosan is useful for the association of bioactive molecules to polymer and controlling the drug release profile. In recent years focus on chitosan is shifted to its derivatives. This versatile material has broad applications in many different fields. Various physical forms of chitosan and its blends together with other derivatives such as composites and graft copolymers have been developed to overcome limitations of different polymeric materials such as poor mechanical properties and to improve its functionality towards specific applications. Nanoparticles of chitosan and it derivatives are extensively exploited in the field of oral drug delivery. The progress made in converting chitosan and its blends into nanoparticles forms as well as the preparation methods are studied. For preparation of these blends and nanoparticles of chitosan need to be dissolved in for reactions. We also studied its dissolution behavior with different acids. It shows quite interesting results.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Anupama Shrivastav ◽  
Hae-Yeong Kim ◽  
Young-Rok Kim

Drug delivery technology is emerging as an interdisciplinary science aimed at improving human health. The controlled delivery of pharmacologically active agents to the specific site of action at the therapeutically optimal rate and dose regimen has been a major goal in designing drug delivery systems. Over the past few decades, there has been considerable interest in developing biodegradable drug carriers as effective drug delivery systems. Polymeric materials from natural sources play an important role in controlled release of drug at a particular site. Polyhydroxyalkanoates, due to their origin from natural sources, are given attention as candidates for drug delivery materials. Biodegradable and biocompatible polyhydroxyalkanoates are linear polyesters produced by microorganisms under unbalanced growth conditions, which have emerged as potential polymers for use as biomedical materials for drug delivery due to their unique physiochemical and mechanical properties. This review summarizes many of the key findings in the applications of polyhydroxyalkanoates and polyhydroxyalkanoate nanoparticles for drug delivery system.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2623
Author(s):  
Shubham Sharma ◽  
P. Sudhakara ◽  
Jujhar Singh ◽  
R. A. Ilyas ◽  
M. R. M. Asyraf ◽  
...  

In the determination of the bioavailability of drugs administered orally, the drugs’ solubility and permeability play a crucial role. For absorption of drug molecules and production of a pharmacological response, solubility is an important parameter that defines the concentration of the drug in systemic circulation. It is a challenging task to improve the oral bioavailability of drugs that have poor water solubility. Most drug molecules are either poorly soluble or insoluble in aqueous environments. Polymer nanocomposites are combinations of two or more different materials that possess unique characteristics and are fused together with sufficient energy in such a manner that the resultant material will have the best properties of both materials. These polymeric materials (biodegradable and other naturally bioactive polymers) are comprised of nanosized particles in a composition of other materials. A systematic search was carried out on Web of Science and SCOPUS using different keywords, and 485 records were found. After the screening and eligibility process, 88 journal articles were found to be eligible, and hence selected to be reviewed and analyzed. Biocompatible and biodegradable materials have emerged in the manufacture of therapeutic and pharmacologic devices, such as impermanent implantation and 3D scaffolds for tissue regeneration and biomedical applications. Substantial effort has been made in the usage of bio-based polymers for potential pharmacologic and biomedical purposes, including targeted deliveries and drug carriers for regulated drug release. These implementations necessitate unique physicochemical and pharmacokinetic, microbiological, metabolic, and degradation characteristics of the materials in order to provide prolific therapeutic treatments. As a result, a broadly diverse spectrum of natural or artificially synthesized polymers capable of enzymatic hydrolysis, hydrolyzing, or enzyme decomposition are being explored for biomedical purposes. This summary examines the contemporary status of biodegradable naturally and synthetically derived polymers for biomedical fields, such as tissue engineering, regenerative medicine, bioengineering, targeted drug discovery and delivery, implantation, and wound repair and healing. This review presents an insight into a number of the commonly used tissue engineering applications, including drug delivery carrier systems, demonstrated in the recent findings. Due to the inherent remarkable properties of biodegradable and bioactive polymers, such as their antimicrobial, antitumor, anti-inflammatory, and anticancer activities, certain materials have gained significant interest in recent years. These systems are also actively being researched to improve therapeutic activity and mitigate adverse consequences. In this article, we also present the main drug delivery systems reported in the literature and the main methods available to impregnate the polymeric scaffolds with drugs, their properties, and their respective benefits for tissue engineering.


2019 ◽  
Vol 20 (2) ◽  
pp. 278 ◽  
Author(s):  
Minghan Chi ◽  
Manlin Qi ◽  
Lan A ◽  
Ping Wang ◽  
Michael Weir ◽  
...  

Periodontitis is a common infectious disease characterized by loss of tooth-supporting structures, which eventually leads to tooth loss. The heavy burden of periodontal disease and its negative consequence on the patient’s quality of life indicate a strong need for developing effective therapies. According to the World Health Organization, 10–15% of the global population suffers from severe periodontitis. Advances in understanding the etiology, epidemiology and microbiology of periodontal pocket flora have called for antibacterial therapeutic strategies for periodontitis treatment. Currently, antimicrobial strategies combining with polymer science have attracted tremendous interest in the last decade. This review focuses on the state of the art of antibacterial polymer application against periodontal pathogens and biofilms. The first part focuses on the different polymeric materials serving as antibacterial agents, drug carriers and periodontal barrier membranes to inhibit periodontal pathogens. The second part reviews cutting-edge research on the synthesis and evaluation of a new generation of bioactive dental polymers for Class-V restorations with therapeutic effects. They possess antibacterial, acid-reduction, protein-repellent, and remineralization capabilities. In addition, the antibacterial photodynamic therapy with polymeric materials against periodontal pathogens and biofilms is also briefly described in the third part. These novel bioactive and therapeutic polymeric materials and treatment methods have great potential to inhibit periodontitis and protect tooth structures.


2021 ◽  
Vol 2 (2) ◽  
pp. 1-3
Author(s):  
Priyanka Ray ◽  

Research in the field of polymers and polymeric materials has garnered immense attention in the past few decades due to the versatile functional and structural capabilities of polymers which often can be manipulated for applications in the field of therapy and diagnosis for a host of diseases and disorders. Polymer therapeutics comprises polymer-drug and polymer-protein conjugates as well as supramolecular systems used as drug delivery systems. Although the pharmacological industry invests immensely in the design and discovery of novel drug molecules, small molecular drugs are often inefficient in targeting many diseases like deep seated low vasculature tumours, metastasized cancers and various autoimmune diseases. Coupled with a rapid clearance rate, low solubility, drug resistance and high off target toxicity these small molecular drugs often present modest benefits for a host of common diseases. In order to improve the therapeutic index of pre-existing drugs and shortening the translation from preclinical validation to clinical approval, a vast area of drug delivery research focuses on the improvement of drug carriers by various alterations. The major challenges currently faced by drug delivery systems include a low payload, transition through the desmoplastic barrier for solid tumours and high hepatic and renal clearance. In order to address these issues numerous polymer–protein and polymer-drug conjugates have been engineered and have reported to enhance the stability and pharmacokinetic properties of the active drugs. Highly toxic anticancer drugs like doxorubicin, cis-platin and gemcitabine have successfully been coupled with high molecular weight polymers to formulate targeted drug delivery agents, some of which have undergone successful clinical trials. Apart from PEGylated polymers, dendritic polymers and polyplexes with DNA or RNA moieties have also been considered as candidates for improving the therapeutic index of various drugs. Ongoing efforts in the development of polymer-based therapeutics are promising and open new horizons for personalized medicine for effective cure of various life-threatening diseases.


Author(s):  
D. L. Misell

In the electron microscopy of biological sections the adverse effect of chromatic aberration on image resolution is well known. In this paper calculations are presented for the inelastic and elastic image intensities using a wave-optical formulation. Quantitative estimates of the deterioration in image resolution as a result of chromatic aberration are presented as an alternative to geometric calculations. The predominance of inelastic scattering in the unstained biological and polymeric materials is shown by the inelastic to elastic ratio, I/E, within an objective aperture of 0.005 rad for amorphous carbon of a thickness, t=50nm, typical of biological sections; E=200keV, I/E=16.


Author(s):  
Martin J. Mahon ◽  
Patrick W. Keating ◽  
John T. McLaughlin

Coatings are applied to appliances, instruments and automobiles for a variety of reasons including corrosion protection and enhancement of market value. Automobile finishes are a highly complex blend of polymeric materials which have a definite impact on the eventual ability of a car to sell. Consumers report that the gloss of the finish is one of the major items they look for in an automobile.With the finish being such an important part of the automobile, there is a zero tolerance for paint defects by auto assembly plant management. Owing to the increased complexity of the paint matrix and its inability to be “forgiving” when foreign materials are introduced into a newly applied finish, the analysis of paint defects has taken on unparalleled importance. Scanning electron microscopy with its attendant x-ray analysis capability is the premier method of examining defects and attempting to identify their root cause.Defects are normally examined by cutting out a coupon sized portion of the autobody and viewing in an SEM at various angles.


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