Are structurally modified galactomannan derivatives biologically active?

Galactomannans are versatile macromolecules with broad industrial potential. The influence of changes in the chemical structures and respective bioactivities of these polysaccharides have been extensively studied. The derivatives obtained by sulfation, complexation, and phosphorylation are the most studied biological properties in galactomannans. The derivatives obtained have shown several pharmacological activities such as antiviral, antimicrobial, anticoagulant, fibrinolytic, chemopreventive, anticancer, antioxidant, chondroprotective, analgesic, immunomodulatory, and antileishmanial. Considering the relevance of these studies, we aim to provide an overview of studies that apply galactomannan modification or derivatization strategies to improve their properties for applications in the biomedical area. We identified the success of most modified galactomannans for pharmacological purposes. However, some studies found loss of bioactivity of the original polysaccharide after chemical changes to its original structures.info:eu-repo/semantics/publishedVersio

Supporting the Photocatalysts on ZrO2 : An Effective Way to Enhance the Photocatalytic Activity of SrSnO3

This work was supported by Paraíba State Research Foundation /FAPESQ (grant number 0012/2019), PROINFRA/FINEP/MCTIC and in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001. The authors acknowledge Professor Graeme Paton from the School of Biological Sciences – University of Aberdeen, for the use of the spectrofluorimeter and Ana Rita Ferreira Alves Teixeira for kindly giving in the photocatalytic results with P25 for comparison. CRediT authorship contribution statement Luzia Maria Castro Honorio: Conceptualization, Investigation, Writing - original draft. André Luiz Menezes Oliveira: Formal analysis, Writing - original draft. Edson Cavalcanti Silva Filho: . Josy Anteveli Osajima: . Amer Hakki: . Donald E. Macphee: Writing - review & editing. Iêda Maria Garcia Santos: Investigation, Writing - review & editing, Supervision.Peer reviewedPostprin

Cytotoxic and antibacterial activity of chichá gum hydrogel associated with nerolidol

Chichá gum is a polysaccharide from the Sterculia striata plant, with a chemical structure composed of hydroxyl groups, which favor the formation of hydrogels, enabling the association with other materials to improve their biological properties and as drug delivery systems. Hydrogels were produced from chichá gum associated with nerolidol in concentrations of 1 and 2%, cytotoxicity was evaluated against Artemia salina. The hydrogels were tested against the strains Staphylococcus aureus and Escherichia coli, by the direct contact test. the material showed no toxic activity and an antibacterial effect was observed with 83.6% growth inhibition with the use of the hydrogel with 2% nerolidol. It concludes that the materials produced have the potential to be used in the future as products with good antibacterial properties.info:eu-repo/semantics/publishedVersio

The effect of natural and organophilic palygorskite on skin wound healing in rats

In view of growing interest in natural treatments, clays would appear to be a good alternative for speeding up the healing process during the treatment of wounds. Of the various clays, palygorskite, a clay from the Brazilian State of Piauí, composed of silicon and aluminum, has shown itself to be pharmaceutically useful as a healing agent. The aim of this article is to evaluate the effect on the healing of wounds of Piauí palygorskite, both in its natural state and when organophilic, by way of comparative analysis of macroscopic and histological tests on skin wounds in adult male and female two-month-old Wistar rats. To this end, a circular trichotomy of the dorsal cornus of the rats was carried out to confirm the effects of treatments involving 0.9% saline solution, collagenase, natural palygorskite, organophilic palygorskite with cetyltrimethylammonium chloride, and organophilic palygorskite with alkyldimethylbenzylammonium chloride. The testing of all the clays involved microbiological evaluation using the depth of plaque and surface striation methods, along with post-treatment macroscopic analysis of skin wounds by way of organoleptics, pachymetry and histological analysis. Microbiological evaluation revealed the need for sterilization of the clay prior to incorporation in the pharmaceutical form. Macroscopic analysis suggests that healing of the wounded area occurred, and histological analysis showed the beneficial effect of the topical use of clay material. Our data suggest that palygorskite may be more powerful than other healing agents, although, on completing treatment, all the animals studied showed the same degree of tissue repair.Devido ao crescente interesse da população pelos tratamentos naturais, as argilas representam uma boa alternativa para a aceleração da cicatrização durante o tratamento de feridas. Dentre as argilas, a paligorsquita, uma argila piauiense, devido à sua composição com silício e alumínio, demonstra certa aplicabilidade farmacêutica como agente cicatrizante. O objetivo deste artigo é avaliar a ação cicatrizante da paligorsquita piauiense em sua forma natural e organofilizadas por meio da análise comparativa da macroscopia e dos exames histológicos em feridas cutâneas de ratos machos e fêmeas Wistar adultos com 2 meses de idade. Para tanto, foram realizadas tricotomia circular no corno dorsal dos ratos para verificar os efeitos dos tratamentos realizados com solução salina 0,9%, colagenase, paligorsquita natural, paligorsquita organofilizada por cloreto de cetiltrimetilamônio e paligorsquita organofilizada por cloreto de alquildimetilbenzilamônio. Para todas as argilas testadas foi feita a avaliação microbiológica pelo método de plaqueamento em profundidade e do método de estrias em superfície, bem como foi realizada após tratamento, a análise macroscópica das feridas cutâneas por meio organoléptico, medição em paquímetro e análise histológica. Por meio da avaliação microbiológica foi detectada a necessidade de esterilização da argila para posterior incorporação na forma farmacêutica. A análise macroscópica sugere que houve cicatrização da área lesionada, bem como a análise histológica demonstrou efeito benéfico após o uso tópico do material argiloso. Nossos dados sugerem que a paligorsquita pode exercer um maior efeito cicatrizante em relação aos demais tratamentos, embora após o término deste tratamento, todos os animais analisados apresentaram a mesma reparação tecidual

Development of composite scaffolds based on cerium doped-hydroxyapatite and natural gums-biological and mechanical properties

Hydroxyapatite (HAp) is a ceramic material composing the inorganic portion of bones. Ionic substitutions enhance characteristics of HAp, for example, calcium ions (Ca2+) by cerium ions (Ce3+). The use of HAp is potentialized through biopolymers, cashew gum (CG), and gellan gum (GG), since CG/GG is structuring agents in the modeling of structured biocomposites, scaffolds. Ce-HApCG biocomposite was synthesized using a chemical precipitation method. The obtained material was frozen (–20 °C for 24 h), and then vacuum dried for 24 h. The Ce-HApCG was characterized by X-Ray diffractograms (XRD), X-ray photoemission spectra (XPS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS). XRD and FTIR showed that Ce-HApCG was successfully synthesized. XRD showed characteristic peaks at 2θ = 25.87 and 32.05, corresponding to the crystalline planes (0 0 2) and (2 1 1), respectively, while phosphate bands were present at 1050 cm−1 and 1098 cm−1, indicating the success of composite synthesis. FESEM showed pores and incorporated nanostructured granules of Ce-HApCG. The mechanical test identified that Ce-HApCG has a compressive strength similar to the cancellous bone’s strength and some allografts used in surgical procedures. In vitro tests (MTT assay and hemolysis) showed that scaffold was non-toxic and exhibited low hemolytic activity. Thus, the Ce-HApCG has potential for application in bone tissue engineering.info:eu-repo/semantics/publishedVersio

Tuned Hydroxyapatite Materials for Biomedical Applications

Hydroxyapatite stands out between biomaterials due to its properties of osteoconduction and osteoinduction, being adequate to be used in bone grafts. The high stability and flexibility of the structure allows for several biomedical applications, for example, the use as polysaccharide based on the scaffold formulations and the cationic substitutions occurring through the doping of the material using metals, which may enhance biological characteristics, such as improving the action of combating bacterial infections in situ. This study was a research of articles and patents, without and with time restriction (2007–2017), which contain information about hydroxyapatite in the tissue engineering, biomedical, doped with cerium and its properties of antibacterial activity. There were also searches of products and companies that commercialize these types of materials aimed at tissue engineering area. Scopus was used for searched of articles and were EPO, USPTO, and INPI used for patents, and to search for products and companies were used search engines. Few papers were found to associate all the keywords, but the ones found are recent works, thus showing a new area with potential to be investigated

Study of the effect of solvent on acetylate cashew gum-based nanoparticles properties and antimicrobial activity

The aim of this work was to investigate the influence of acetone and dimethyl sulfoxide (DMSO) on acetylated cashew gun (ACG) nanoparticles parameters and to assess their antimicrobial activity. C1 nanoparticles presented smaller size (81.3 nm) than compared to C2 (115.7 nm). Although, acetone formed particles with lower PDI value. Both C1 and C2 presented negative zeta potential (-39.8 and -31.7 respectively). Particle tracking analysis showed that C1 was slightly more concentrated than C2. No statistical differences (p 0.05) between the same samples after 5 months were found. Both samples did not exert inhibitory effect on E. coli, on the contrary S. aureus, in which both C1 (36.9%) and C2 (19.9%) provided important inhibitory effect. C1 presented a more pronounced antifungal effect (81.2%), compared to C2 (18.8%), indicating a promising platform to be used in several biomedical application. Keywords: polysaccharide, nanoparticles, biopolymers, modification, biological applications of polymers.

Nanostructured polymeric system based of cashew gum for oral admnistration of insulin

The subcutaneous administration of insulin has been the treatment of millions of diabetics in the world.However, for such via insulin is invasive and not mimics the physiological action causing side effects. Theoral route would be the most physiological and comfortable option, but the oral bioavailability of insulin islow by proteolytic activity and reduced permeability of the gastrointestinal tract. The aim of the study was todevelop a nanostructured system integrating biomaterials for oral insulin delivery. Cashew gum (CG) is apolysaccharide extracted from the exudate of the plant Anacardium occidentale. It is a biopolymer composedof simple sugars and glucuronic acid and it can be used in nanostructured systems for the incorporation ofmolecules. The exudate was isolated, dissolved in water, filtered, precipitated in ethanol and purified. TheCG was characterized by infrared spectroscopy and molecular weight by size exclusion chromatography.Nanoparticles were prepared through ionotropic gelation integrating cashew gum, dextran sulfate and poloxamercontaining insulin stabilized with chitosan, poly(ethyleneglycol) and coated with albumin. The particleswere analyzed for particle size, zeta potential and insulin entrapment efficiency. The FTIR spectrum for CGshowed a band at 3395 cm-1 due to the stretching vibration of O-H, a band at 2926 cm-1 of C-H vibrations;absorption at 1639 cm-1 of O-H type from bound water molecules and bands at 1143, 1073 and 1024 cm-1 duevibrations of the C-O-C from glycosidic bonds and O-H of alcohols. The peak molar mass of GC was 2.35 ×104 g/mol. The particles had a size of 156 nm and after coating, size of 5387 nm with 92% insulin entrapmentefficiency and zeta potential of -51 mV indicating electrostatic stabilization. The results suggest an innovativecashew gum base system for oral insulin administration.Keywords: Nanostructures, biomaterials, cashew gum, insulin, oral delivery