scholarly journals Chemical grafting of cholesterol on monomer and PDMMLA polymers, a step towards the development of new polymers for biomedical applications

RSC Advances ◽  
2020 ◽  
Vol 10 (54) ◽  
pp. 32602-32608
Author(s):  
Elnaz Gholizadeh ◽  
Rima Belibel ◽  
Thomas Bachelart ◽  
Chérifa Bounadji ◽  
Christel Barbaud
Keyword(s):  
Biomedical Applications ◽  
Hydroxyl Groups ◽  
Steglich Esterification ◽  
Chemical Grafting

PDMMLAs are synthetic biopolyesters synthesized from tri-substituted β-lactones with available hydroxyl groups. We grafted cholesterol on both monomer and polymers following the Steglich esterification protocol.

Study on lignin-free lignocellulosic biomass and PSF-PEG membrane compatibility

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 1063-1075
Author(s):  
Abiodun A. Amusa ◽  
Abdul L. Ahmad ◽  
Jimoh K. Adewole
Keyword(s):  
Contact Angle ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Lignocellulosic Biomass ◽  
Biomedical Applications ◽  
Composite Membranes ◽  
Hydroxyl Groups ◽  
Chemical Pretreatment ◽  
Physical And Chemical ◽  
Porosity Measurements

Lignocellulosic biomass was delignified by combining physical and chemical pretreatment techniques. Then, a polysulfone-polyethylene glycol blend, which was compatible with the lignin-free biomass (0 wt% to 3.0 wt%), was used to fabricate composite membranes. The presence of hydroxyl groups after the pretreatment was evaluated via Fourier transform infrared spectroscopy. The rheology of the polymer solutions was assessed via the viscometric method. Also, the hydrophobicity of the fabricated membranes was determined using contact angle and porosity measurements. The fabricated membranes with near superhydrophobic properties (a contact angle of approximately 140°) based on this study revealed that contactor systems and biomedical applications would benefit from this modification.

scholarly journals Design of Cyclodextrin-Based Functional Systems for Biomedical Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Wanjia Xu ◽  
Xiumei Li ◽  
Liang Wang ◽  
Siyuan Li ◽  
Shengnan Chu ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Enzymatic Catalysis ◽  
Functional Materials ◽  
Hydroxyl Groups ◽  
Guest Molecules ◽  
Functional Systems ◽  
Starting Point ◽  
Recognition Ability ◽  
Biomedical Diagnosis ◽  
Metal Organic

Cyclodextrins (CDs) are a family of α-1,4-linked cyclic oligosaccharides that possess a hydrophobic cavity and a hydrophilic outer surface with abundant hydroxyl groups. This unique structural characteristic allows CDs to form inclusion complexes with various guest molecules and to functionalize with different substituents for the construction of novel sophisticated systems, ranging from derivatives to polymers, metal-organic frameworks, hydrogels, and other supramolecular assemblies. The excellent biocompatibility, selective recognition ability, and unique bioactive properties also make these CD-based functional systems especially attractive for biomedical applications. In this review, we highlight the characteristics and advantages of CDs as a starting point to design different functional materials and summarize the recent advances in the use of these materials for bioseparation, enzymatic catalysis, biochemical sensing, biomedical diagnosis and therapy.

Catechins as Model Bioactive Compounds for Biomedical Applications

2020 ◽  
Vol 26 (33) ◽  
pp. 4032-4047
Author(s):  
Adriana N. dos Santos ◽  
Tatiana R. de L. Nascimento ◽  
Brenna L. C. Gondim ◽  
Marilia M. A. C. Velo ◽  
Renaly I. de A. Rêgo ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Inflammatory Responses ◽  
Hydroxyl Groups ◽  
Protective Mechanisms ◽  
Bioactive Properties ◽  
Living Organisms ◽  
The Stability ◽  
Antioxidant Effects ◽  
Novel Delivery Systems ◽  
Health Applications

Research regarding polyphenols has gained prominence over the years because of their potential as pharmacological nutrients. Most polyphenols are flavanols, commonly known as catechins, which are present in high amounts in green tea. Catechins are promising candidates in the field of biomedicine. The health benefits of catechins, notably their antioxidant effects, are related to their chemical structure and the total number of hydroxyl groups. In addition, catechins possess strong activities against several pathogens, including bacteria, viruses, parasites, and fungi. One major limitation of these compounds is low bioavailability. Catechins are poorly absorbed by intestinal barriers. Some protective mechanisms may be required to maintain or even increase the stability and bioavailability of these molecules within living organisms. Moreover, novel delivery systems, such as scaffolds, fibers, sponges, and capsules, have been proposed. This review focuses on the unique structures and bioactive properties of catechins and their role in inflammatory responses as well as provides a perspective on their use in future human health applications.

Chemo-physical Properties and Biomedical Applications of Hyaluronic Acid in Medicine

2017 ◽  
Vol 68 (2) ◽  
pp. 384-386 ◽  
Author(s):  
Danut Vasile ◽  
Raluca Iancu ◽  
Camelia Bogdanici ◽  
Emil Ungureanu ◽  
Dana Ciobotea ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Physical Properties ◽  
Biomedical Applications ◽  
Chemical Properties ◽  
Elastic Behavior ◽  
Current Evidence ◽  
Hydroxyl Groups ◽  
Carboxylate Group ◽  
Medical Problems ◽  
Physico Chemical

Hyaluronic acid is a mucopolysaccharide encountered in most body fluids and extracellular matrix. The aim of our review is to summarize current evidence about chemico-physical properties of hyaluronic acid, highlighting biomedical applications of hyaluronan derivatives. It is a glycosaminoglycan made of repeating disaccharide units containing a carboxylate group, four hydroxyl groups and one carboxylate group, with hydrophilic properties. Its particular structure with multiple coils forming an entangled network results in unique pseudoplastic and viscoelastic characteristics. Its viscous and elastic behavior, depending on the applied strain, makes hyaluronan widely applicable in biomedical field. The large amount of functions and applications is determined by the physico-chemical properties, which allows a polymorphism of the hyaluronic acid structures depending on the molecular weight variations, concentration and ionic status. It is currently used in ophthalmology, orthopedics and rheumatology, in plastic surgery, surgery and otolaryngology as well. Already widely used in clinical practice, hyaluronic acid proves to be often the best solution for difficult medical problems. Future developments in nanomedicine and drug delivery linked to hyaluronic acid are emerging.

Biomedical applications of tannic acid

2022 ◽  
pp. 088532822110580
Author(s):  
Andrew Baldwin ◽  
Brian W Booth
Keyword(s):  
Drug Delivery ◽  
Tannic Acid ◽  
Biomedical Applications ◽  
Crosslinking Agent ◽  
Biochemical Properties ◽  
Hydroxyl Groups ◽  
Severe Burns ◽  
Iron Gall ◽  
Vegetable Tanning ◽  
Antibacterial And Anticancer Activity

Tannic Acid (TA) is a naturally occurring antioxidant polyphenol that has gained popularity over the past decade in the field of biomedical research for its unique biochemical properties. Tannic acid, typically extracted from oak tree galls, has been used in many important historical applications. TA is a key component in vegetable tanning of leather, iron gall ink, red wines, and as a traditional medicine to treat a variety of maladies. The basis of TA utility is derived from its many hydroxyl groups and its affinity for forming hydrogen bonds with proteins and other biomolecules. Today, the study of TA has led to the development of many new pharmaceutical and biomedical applications. TA has been shown to reduce inflammation as an antioxidant, act as an antibiotic in common pathogenic bacterium, and induce apoptosis in several cancer types. TA has also displayed antiviral and antifungal activity. At certain concentrations, TA can be used to treat gastrointestinal disorders such as hemorrhoids and diarrhea, severe burns, and protect against neurodegenerative diseases. TA has also been utilized in biomaterials research as a natural crosslinking agent to improve mechanical properties of natural and synthetic hydrogels and polymers, while also imparting anti-inflammatory, antibacterial, and anticancer activity to the materials. TA has also been used to develop thin film coatings and nanoparticles for drug delivery. In all, TA is fascinating molecule with a wide variety of potential uses in pharmaceuticals, biomaterials applications, and drug delivery strategies.

scholarly journals Synthesis and Properties of Bioresorbable Block Copolymers of l-Lactide, Glycolide, Butyl Succinate and Butyl Citrate

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 214 ◽  
Author(s):  
Natalia Śmigiel-Gac ◽  
Elżbieta Pamuła ◽  
Małgorzata Krok-Borkowicz ◽  
Anna Smola-Dmochowska ◽  
Piotr Dobrzyński
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Biomedical Applications ◽  
Chain Growth ◽  
Hydroxyl Groups ◽  
Butylene Succinate ◽  
Branched Copolymers ◽  
Ultrahigh Molecular Weight ◽  
Biological Tests ◽  
Polymerization Mixture

The paper presents the course of synthesis and properties of a series of block copolymers intended for biomedical applications, mainly as a material for forming scaffolds for tissue engineering. These materials were obtained in the polymerization of l-lactide and copolymerization of l-lactide with glycolide carried out using a number of macroinitiators previously obtained in the reaction of polytransesterification of succinic diester, citric triester and 1,4-butanediol. NMR, FTIR and DSC were used to characterize the materials obtained; wettability and surface free energy were assessed too. Moreover, biological tests, i.e., viability and metabolic activity of MG-63 osteoblast-like cells in contact with synthesized polymers were performed. Properties of obtained block copolymers were controlled by the composition of the polymerization mixture and by the composition of the macroinitiator. The copolymers contained active side hydroxyl groups derived from citrate units present in the polymer chain. During the polymerization of l-lactide in the presence of polyesters with butylene citrate units in the chain, obtained products of the reaction held a fraction of highly branched copolymers with ultrahigh molecular weight. The reason for this observed phenomenon was strong intermolecular transesterification directed to lactidyl side chains, formed as a result of chain growth on hydroxyl groups related to the quaternary carbons of the citrate units. Based on the physicochemical properties and results of biological tests it was found that the most promising materials for scaffolds formation were poly(l-lactide–co–glycolide)–block–poly(butylene succinate–co–butylene citrate)s, especially those copolymers containing more than 60 mol % of lactidyl units.

STUDY OF CHITOSAN COATINGS ON NANOPARTICLES FOR BIOMEDICAL APPLICATIONS

2004 ◽  
Vol 03 (04n05) ◽  
pp. 685-689 ◽  
Author(s):  
W. B. TAN ◽  
Y. ZHANG
Keyword(s):  
Biomedical Applications ◽  
Au Nanoparticles ◽  
Biomedical Application ◽  
The Body ◽  
Nanometer Scale ◽  
Hydroxyl Groups ◽  
Coating Process ◽  
Naturally Occurring ◽  
The Relationship

Of late, much work and interest had been generated in the fields involving nanoparticles. Due to their nanometer scale, these particles have been proven to be promising in diverse applications such as electronics and medicine, amongst others. In addition, an emerging and attractive use of nanoparticles as biotherapeutic delivery agents within the body was introduced. However, in order to use these nanoparticles in any biomedical application, they must be rendered biocompatible. In this paper, we attempt to coat chitosan, a naturally-occurring polymer which is biocompatible, biodegradable and nontoxic, onto the surfaces of nanoparticles. 5 nm gold ( Au ) nanoparticles were chosen for our study as they are commercially available. The presence of a chitosan shell not only renders these nanoparticles biocompatible, the amino and hydroxyl groups of chitosan also allow the immobilization of many biotherapeutic agents. The relationship between the concentration of the chitosan used in the coating process and the thickness of the chitosan shell formed is investigated. It is hoped that the results of this study can also be applied to other nanoparticles, in addition to Au , that are intended to be used in bioapplications.

Characterization of Crystalline Hydroxyapatite Thin Coatings for Biomedical Applications

2007 ◽  
Vol 330-332 ◽  
pp. 525-528 ◽  
Author(s):  
Zhen Hong ◽  
Alexandre Mello ◽  
L. Luan ◽  
Marcos Farina ◽  
L.R. Andrade ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Biomedical Applications ◽  
Rf Magnetron Sputtering ◽  
Xrd Analysis ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
Thin Coatings ◽  
Phosphate Carbonate

Crystalline hydroxyapatite thin coatings have been prepared using a novel opposing RF magnetron sputtering approach at room temperature. X-ray diffraction (XRD) analysis shows that all the principal peaks are attributable to HA, and the as-deposited HA coatings are made up of crystallites in the size range of 50-100nm. Fourier transform infrared spectroscopy (FTIR) studies reveal the existence of phosphate, carbonate and hydroxyl groups, suggesting that HA coatings are carbonated. Finally, in vitro cell culture experiments have demonstrated that murine osteoblast cells attach and grow well on the as-sputtered coatings. These results encourage further studies of hydroxyapatite thin coatings prepared by the opposing RF magnetron sputtering approach as a promising candidate for next-generation bioimplant materials.

scholarly journals Porphyrin Molecules Decorated on Metal–Organic Frameworks for Multi-Functional Biomedical Applications

Biomolecules ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1714
Author(s):  
Navid Rabiee ◽  
Mohammad Rabiee ◽  
Soheil Sojdeh ◽  
Yousef Fatahi ◽  
Rassoul Dinarvand ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Limit Of Detection ◽  
Metal Organic Frameworks ◽  
Protein Structures ◽  
Cellular Protein ◽  
Hydroxyl Groups ◽  
One Pot ◽  
Hydrogen Bond Formation ◽  
Surface Hydroxyl ◽  
Metal Organic

Metal–organic frameworks (MOFs) have been widely used as porous nanomaterials for different applications ranging from industrial to biomedicals. An unpredictable one-pot method is introduced to synthesize NH2-MIL-53 assisted by high-gravity in a greener media for the first time. Then, porphyrins were deployed to adorn the surface of MOF to increase the sensitivity of the prepared nanocomposite to the genetic materials and in-situ cellular protein structures. The hydrogen bond formation between genetic domains and the porphyrin’ nitrogen as well as the surface hydroxyl groups is equally probable and could be considered a milestone in chemical physics and physical chemistry for biomedical applications. In this context, the role of incorporating different forms of porphyrins, their relationship with the final surface morphology, and their drug/gene loading efficiency were investigated to provide a predictable pattern in regard to the previous works. The conceptual phenomenon was optimized to increase the interactions between the biomolecules and the substrate by reaching the limit of detection to 10 pM for the Anti-cas9 protein, 20 pM for the single-stranded DNA (ssDNA), below 10 pM for the single guide RNA (sgRNA) and also around 10 nM for recombinant SARS-CoV-2 spike antigen. Also, the MTT assay showed acceptable relative cell viability of more than 85% in most cases, even by increasing the dose of the prepared nanostructures.

Recent Advances of Chitosan and its Derivatives in Biomedical Applications

2020 ◽  
Vol 27 (18) ◽  
pp. 3023-3045 ◽  
Author(s):  
Fei Ding ◽  
Jiawei Fu ◽  
Chuang Tao ◽  
Yanhua Yu ◽  
Xianran He ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Future Research ◽  
Hydroxyl Groups ◽  
Amine Group ◽  
Research Directions ◽  
The Past ◽  
Free Amine ◽  
Natural Polysaccharide ◽  
Free Amine Group ◽  
Future Research Directions

Chitosan is the second-most abundant natural polysaccharide. It has unique characteristics, such as biodegradability, biocompatibility, and non-toxicity. Due to the existence of its free amine group and hydroxyl groups on its backbone chain, chitosan can undergo further chemical modifications to generate Chitosan Derivatives (CDs) that permit additional biomedical functionality. Chitosan and CDs can be fabricated into various forms, including Nanoparticles (NPs), micelles, hydrogels, nanocomposites and nano-chelates. For these reasons, chitosan and CDs have found a tremendous variety of biomedical applications in recent years. This paper mainly presents the prominent applications of chitosan and CDs for cancer therapy/diagnosis, molecule biosensing, viral infection, and tissue engineering over the past five years. Moreover, future research directions on chitosan are also considered.

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