scholarly journals Bioapplications of Bacterial Cellulose Polymers Conjugated with Resveratrol for Epithelial Defect Regeneration

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1048 ◽  
Author(s):  
En Meng ◽  
Chin-Li Chen ◽  
Chuan-Chieh Liu ◽  
Cheng-Che Liu ◽  
Shu-Jen Chang ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Bacterial Cellulose ◽  
Wound Repair ◽  
Cell Attachment ◽  
Skin Irritation ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Skin Substitutes ◽  
Epithelial Regeneration

Excellent wound dressing is essential for effective wound repair and regeneration. However, natural polymeric skin substitutes often lack mechanical strength and hydrophilicity. One way to overcome this limitation is to use biodegradable polymers with high mechanical strength and low skin-irritation induction in wet environments. Bacterial cellulose (BC) is an attractive polymer for medical applications; unlike synthetic polymers, it is biodegradable and renewable and has a strong affinity for materials containing hydroxyl groups. Therefore, we conjugated it with resveratrol (RSV), which has a 4′-hydroxyl group and exhibits good biocompatibility and no cytotoxicity. We synthesized BC scaffolds with immobilized RSV and characterized the resulting BC/RSV scaffold with scanning electron microscopy and Fourier-transform infrared spectroscopy. We found that RSV was released from the BC in vitro after ~10 min, and immunofluorescence staining showed that BC was highly biocompatible and regenerated epithelia. Additionally, Masson’s trichrome staining showed that the scaffolds preserved the normal collagen-bundling pattern and induced re-epithelialization in defective rat epidermis. These results indicated that RSV-conjugated BC created a biocompatible environment for stem cell attachment and growth and promoted epithelial regeneration during wound healing.

scholarly journals Enhancement of Antioxidant and Hydrophobic Properties of Alginate via Aromatic Derivatization: Preparation, Characterization, and Evaluation

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2575
Author(s):  
Smaher M. Elbayomi ◽  
Haili Wang ◽  
Tamer M. Tamer ◽  
Yezi You
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Benzoyl Group ◽  
Antioxidant Evaluation ◽  
Thermo Stability

The preparation of bioactive polymeric molecules requires the attention of scientists as it has a potential function in biomedical applications. In the current study, functional substitution of alginate with a benzoyl group was prepared via coupling its hydroxyl group with benzoyl chloride. Fourier transform infrared spectroscopy indicated the characteristic peaks of aromatic C=C in alginate derivative at 1431 cm−1. HNMR analysis demonstrated the aromatic protons at 7.5 ppm assigned to benzoyl groups attached to alginate hydroxyl groups. Wetting analysis showed a decrease in hydrophilicity in the new alginate derivative. Differential scanning calorimetry and thermal gravimetric analysis showed that the designed aromatic alginate derivative demonstrated higher thermo-stability than alginates. The aromatic alginate derivative displayed high anti-inflammatory properties compared to alginate. Finally, the in vitro antioxidant evaluation of the aromatic alginate derivative showed a significant increase in free radical scavenging activity compared to neat alginate against DPPH (2,2-diphenyll-picrylhydrazyl) and ABTS free radicals. The obtained results proposed that the new alginate derivative could be employed for gene and drug delivery applications.

scholarly journals Synthesis and biotical activity of bacterial cellulose 6-(2-phthalimidoethanesulfonate)

2020 ◽  
Vol 61 (2) ◽  
pp. 29-36
Author(s):  
Zoya P. Belousova ◽  
Keyword(s):  
Bacterial Cellulose ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Cellulose Derivatives ◽  
Wound Surface ◽  
Reaction Products ◽  
Absorption Bands ◽  
Hydroxymethyl Group ◽  
Antibacterial And Antifungal

Bacterial cellulose obtained by culturing Gluconacetobacter sucrofermentans in HS environment was converted to sulfonate derivatives using methane-, toluene- and 2-phthalimidoethanesulfonic acids in pyridine. When the ratio of the starting reagents is 1 : 1, the modification of bacterial cellulose according to the primary hydroxyl group of glucopyranose fragments is most likely. The formation of 6-substituted bacterial cellulose derivatives was observed in the reaction mixture. The IR spectra of the reaction products contain absorption bands, which are specific for (O–SO2) group in the region 1377-1338 cm−1 (as), 1178-1154 cm−1 (s), fragments of the corresponding sulfonic acids, as well as free hydroxyl groups of glucopyranose in the region 3495-3382 cm−1. Bacterial cellulose 2-phthalimidoethanesulfonate was dissolved in pyridine. After drying with a desiccant in a desiccator, it turned into a dense transparent film of brown color. The increased molecular film allows to explain the side reaction occurring between the oxo group and fragments of one of the chains of modified cellulose and the non-substituted hydroxymethyl group. The IR spectrum of bacterial cellulose 6-(2-phthalimidoethanesulfonate) contains absorption bands in the region 1711 cm−1, which are specific for (Ar–CO–O) group, and absorption bands in the region 1618 cm−1, which prove the presence of (CO–NH) group. In order to impart antibiotic properties to the bacterial cellulose 6-(2-phthalimido-ethanesulfonate) film, it was physically modified with clotrimazole. The obtained experimental data showed that the films subjected to treatment with a 1% solution of clotrimazole have antibacterial and antifungal effects and prevent the growth of pathogenic microbiota on the wound surface. The exit rates of clotrimazole from the bacterial cellulose 6-(2-phthalimidoethanesulfonate) film and from the pure bacterial cellulose film differed, but only slightly. 2-Phthalimidoethanesulfonate bacterial cellulose films can be used to form composites of effective wound covering, since in addition to the unique properties of bacterial cellulose itself (low allergenicity and adhesion to the wound surface, high hygroscopicity) they will have a regenerating effect.

scholarly journals Chemical and biochemical studies on 18-hydroxyoestrone

1974 ◽  
Vol 137 (2) ◽  
pp. 263-272 ◽  
Author(s):  
John K. Findlay ◽  
Lothar Siekmann ◽  
Heinz Breuer
Keyword(s):  
Mass Spectra ◽  
Strong Acid ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
No Formation ◽  
Polar Metabolites ◽  
Characteristic Fragmentation ◽  
Liquid Chromatographic

1. 18-Hydroxyoestrone was reduced by NaBH4 in methanol, giving 18-hydroxyoestradiol-17α and 18-hydroxyoestradiol-17β in the ratio 3:7. 2. Treatment of 18-hydroxyoestrone with a strong alkali yielded 18-noroestrone; however, the 18-hydroxyoestradiols did not undergo transformation to their respective 18-nor derivatives. 3. All the 18-hydroxylated oestrogens were stable under acid conditions. They formed Kober chromogens: the chromogenicity of 18-hydroxyoestrone was only one-third that of the 18-hydroxyoestradiols and oestriol. 4. Paper-, thin-layer- and gas–liquid-chromatographic systems for the characterization of these compounds are described. 5. An examination of the mass spectra revealed peaks characteristic of the substituted carbon atoms. Definite assignment of the 17α- and 17β-hydroxyl groups of the epimeric 18-hydroxyoestrogens was possible by characteristic fragmentation of the free steroids. Further, the configuration of 18-hydroxyoestradiol-17β was confirmed by the formation of the dimethylsildioxy derivative of the 3-methylether of the steroid. 6. Both rat and rabbit liver slices reduced 18-hydroxyoestrone to 18-hydroxyoestradiol-17β and some other labile, polar metabolites with properties similar to 2-hydroxylated oestrogens. No formation of 18-hydroxyoestradiol-17α in vitro was observed. 7. The results are discussed with respect to the possible influence of the 18-hydroxyl group on reactions at C-17, as well as the reactions of 18-hydroxylated oestrogens with strong acid (Kober reactions) and alkali.

scholarly journals Platelet-Rich Plasma-Derived Exosomal USP15 Promotes Cutaneous Wound Healing via Deubiquitinating EIF4A1

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yan Xu ◽  
Ze Lin ◽  
Lei He ◽  
Yanzhen Qu ◽  
Liu Ouyang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Wound Repair ◽  
Platelet Rich Plasma ◽  
Healing Process ◽  
Cell Counting ◽  
Wound Healing Process ◽  
Hacat Cells ◽  
Epithelial Regeneration

Epithelial regeneration is an essential wound healing process, and recent work suggests that different types of exosomes (Exos) can improve wound repair outcomes by promoting such epithelial regeneration. Platelet-rich plasma (PRP) is known to facilitate enhanced wound healing, yet the mechanisms underlying its activity are poorly understood. To explore these mechanisms, we first isolated PRP-derived Exos (PRP-Exos). Using immortalized keratinocytes (HaCaT cells) treated with PBS, PRP, or PRP-Exos, we conducted a series of in vitro Cell Counting Kit-8 (CCK-8), EdU, scratch wound, and transwell assays. We then established a wound defect model in vivo in mice and assessed differences in the mRNA expression within these wounds to better understand the basis for PRP-mediated wound healing. The functions of PRP-Exos and USP15 in the context of wound healing were then confirmed through additional in vitro and in vivo experiments. We found that PRP-Exos effectively promoted the in vitro proliferation, migration, and wound healing activity of HaCaT cells. USP15 was further identified as a key mediator through which these PRP-Exos were able to promote tissue repair both in vitro and in vivo. At a mechanistic level, USP15 enhanced the functional properties of HaCaT cells by promoting EIF4A1 deubiquitination. Thus, PRP-Exos and USP15 represent promising tools that can promote wound healing via enhancing epithelial regeneration.

scholarly journals Production of High Silicon-Doped Hydroxyapatite Thin Film Coatings via Magnetron Sputtering: Deposition, Characterisation, and In Vitro Biocompatibility

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 190 ◽  
Author(s):  
Samuel C. Coe ◽  
Matthew D. Wadge ◽  
Reda M. Felfel ◽  
Ifty Ahmed ◽  
Gavin S. Walker ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Silicon Content ◽  
Cellular Response ◽  
Cell Attachment ◽  
Initial Response ◽  
Weight Percent ◽  
Hydroxyl Groups

In recent years, it has been found that small weight percent additions of silicon to HA can be used to enhance the initial response between bone tissue and HA. A large amount of research has been concerned with bulk materials, however, only recently has the attention moved to the use of these doped materials as coatings. This paper focusses on the development of a co-RF and pulsed DC magnetron sputtering methodology to produce a high percentage Si containing HA (SiHA) thin films (from 1.8 to 13.4 wt.%; one of the highest recorded in the literature to date). As deposited thin films were found to be amorphous, but crystallised at different annealing temperatures employed, dependent on silicon content, which also lowered surface energy profiles destabilising the films. X-ray photoelectron spectroscopy (XPS) was used to explore the structure of silicon within the films which were found to be in a polymeric (SiO2; Q4) state. However, after annealing, the films transformed to a SiO44−, Q0, state, indicating that silicon had substituted into the HA lattice at higher concentrations than previously reported. A loss of hydroxyl groups and the maintenance of a single-phase HA crystal structure further provided evidence for silicon substitution. Furthermore, a human osteoblast cell (HOB) model was used to explore the in vitro cellular response. The cells appeared to prefer the HA surfaces compared to SiHA surfaces, which was thought to be due to the higher solubility of SiHA surfaces inhibiting protein mediated cell attachment. The extent of this effect was found to be dependent on film crystallinity and silicon content.

scholarly journals Metabolism of apigenin and related compounds in the rat. Metabolite formation in vivo and by the intestinal microflora in vitro

1972 ◽  
Vol 128 (4) ◽  
pp. 901-911 ◽  
Author(s):  
L. A. Griffiths ◽  
G. E. Smith
Keyword(s):  
Oral Administration ◽  
Intestinal Microflora ◽  
Biochanin A ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Flavonoid Compounds ◽  
Ring Fission ◽  
Micro Organisms

1. The metabolism of a group of flavonoid compounds related in structure to apigenin (4′,5,7-trihydroxyflavone) and including apigenin, apiin, naringin, phlorrhizin, acacetin, kaempferol, robinin, chrysin, tectochrysin and 4′,7-dihydroxyflavone, was studied both in vivo after oral administration to the rat, and in vitro in cultures of micro-organisms derived from the intestine of the rat. 2. The rat intestinal microflora is capable of effecting degradation of flavonoid compounds to metabolites observed in the urine after oral administration of the specific flavonoid. 3. All compounds possessing free 5- and 7-hydroxyl groups in the A ring and a free 4′-hydroxyl group in the B ring gave rise to ring-fission products, which included 4′-hydroxyphenylacyl derivatives. 4. On anaerobic incubation in a thioglycollate medium, intestinal micro-organisms can effect flavonoid-ring fission, cleavage of glycosidic bonds and the reduction of double bonds in the side chains of certain metabolites. 5. Two flavonoids (chrysin and tectochrysin) undergo hydroxylation in the 4′-position in vivo but not during incubation with the intestinal microflora in vitro. 6. Observations on the metabolism of other compounds substituted in the 4′-position, e.g. epiafzelechin, pelargonin and the isoflavones, genistein, biochanin A, daidzein and formononetin, by the intestinal microflora of the rat are also reported.

scholarly journals Phenolic Hydroxyl Groups in the Lignin Polymer Affect the Formation of Lignin Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1790
Author(s):  
Jae Hoon Lee ◽  
Tae Min Kim ◽  
In-Gyu Choi ◽  
Joon Weon Choi
Keyword(s):  
Solvent Extraction ◽  
Colloidal Stability ◽  
Molecular Size ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Nanoprecipitation Method ◽  
Phenolic Hydroxyl Groups ◽  
Soda Lignin

Alkaline soda lignin (AL) was sequentially fractionated into six fractions of different molecular size by means of solvent extraction and their phenolic hydroxyl groups were chemoselectively methylated to determine their effect on nanoparticle formation of lignin polymers. The effect of the lignin structure on the physical properties of nanoparticles was also clarified in this study. Nanoparticles were obtained from neat alkaline soda lignin (ALNP), solvent-extracted fractions (FALNPs, i.d. 414–1214 nm), and methylated lignins (MALNPs, i.d. 516–721 nm) via the nanoprecipitation method. Specifically, the size properties of MALNPs showed a high negative correlation (R2 = 0.95) with the phenolic hydroxyl group amount. This indicates that the phenolic hydroxyl groups in lignin could be influenced on the nucleation or condensation during the nanoprecipitation process. Lignin nanoparticles exhibited high colloidal stability, and most of them also showed good in vitro cell viability. This study presents a possible way to control nanoparticle size by blocking specific functional groups and decreasing the interaction between hydroxyl groups of lignin.

scholarly journals Adrenomedullin Receptor Expression in Human Lung and in Pulmonary Tumors

1997 ◽  
Vol 45 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Alfredo Martínez ◽  
Mae Jean Miller ◽  
Kevin J. Catt ◽  
Frank Cuttitta
Keyword(s):  
Wound Repair ◽  
Regulatory System ◽  
Receptor Expression ◽  
Respiratory Physiology ◽  
Basal Cells ◽  
Lung Carcinogenesis ◽  
Autocrine Loop ◽  
Epithelial Regeneration

Adrenomedullin (AM) is a multifunctional regulatory peptide that stimulates cyclic AMP production in many target tissues and is highly expressed in the lung. Analysis of the distribution of the recently cloned AM receptor (AM-R) by non-radioactive in situ hybridization revealed abundant expression in the basal cells of the airway epithelium and Type II pneumocytes. The expression of AM-R in the two cell types involved in epithelial regeneration of the lung suggests that AM may be relevant in such functions as organ development, wound repair, and epithelial turnover. AM-Rs are also synthesized in vivo and in vitro by a variety of tumor cells that also express the ligand, suggesting the existence of an autocrine loop that may be involved in tumor growth stimulation. The present findings suggest that the AM/AM-R regulatory system plays a major role in respiratory physiology and lung carcinogenesis and that new functions for AM remain to be identified.

scholarly journals New Nystatin-Related Antifungal Polyene Macrolides with Altered Polyol Region Generated via Biosynthetic Engineering of Streptomyces noursei

2011 ◽  
Vol 77 (18) ◽  
pp. 6636-6643 ◽  
Author(s):  
Trygve Brautaset ◽  
Håvard Sletta ◽  
Kristin F. Degnes ◽  
Olga N. Sekurova ◽  
Ingrid Bakke ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Fungal Infections ◽  
Therapeutic Index ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Marginal Effect ◽  
P450 Monooxygenase ◽  
Polyene Macrolides ◽  
Biosynthetic Engineering

ABSTRACTPolyene macrolide antibiotics, including nystatin and amphotericin B, possess fungicidal activity and are being used as antifungal agents to treat both superficial and invasive fungal infections. Due to their toxicity, however, their clinical applications are relatively limited, and new-generation polyene macrolides with an improved therapeutic index are highly desirable. We subjected the polyol region of the heptaene nystatin analogue S44HP to biosynthetic engineering designed to remove and introduce hydroxyl groups in the C-9-C-10 region. This modification strategy involved inactivation of the P450 monooxygenase NysL and the dehydratase domain in module 15 (DH15) of the nystatin polyketide synthase. Subsequently, these modifications were combined with replacement of the exocyclic C-16 carboxyl with the methyl group through inactivation of the P450 monooxygenase NysN. Four new polyene macrolides with up to three chemical modifications were generated, produced at relatively high yields (up to 0.51 g/liter), purified, structurally characterized, and subjected toin vitroassays for antifungal and hemolytic activities. Introduction of a C-9 hydroxyl by DH15 inactivation also blocked NysL-catalyzed C-10 hydroxylation, and these modifications caused a drastic decrease in both antifungal and hemolytic activities of the resulting analogues. In contrast, single removal of the C-10 hydroxyl group by NysL inactivation had only a marginal effect on these activities. Results from the extended antifungal assays strongly suggested that the 9-hydroxy-10-deoxy S44HP analogues became fungistatic rather than fungicidal antibiotics.

A review of functionalised bacterial cellulose for targeted biomedical fields

2021 ◽  
pp. 088532822199803
Author(s):  
Yunus Emre Oz ◽  
Zalike Keskin-Erdogan ◽  
Neriman Safa ◽  
E Esin Hames Tuna
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Mechanical Strength ◽  
Bacterial Cellulose ◽  
Cell Attachment ◽  
Inorganic Compounds ◽  
High Water ◽  
Ex Situ ◽  
Proliferation And Differentiation ◽  
Natural Tissue

Bacterial cellulose (BC), which can be produced by microorganisms, is an ideal biomaterial especially for tissue engineering and drug delivery systems thanks to its properties of high purity, biocompatibility, high mechanical strength, high crystallinity, 3 D nanofiber structure, porosity and high-water holding capacity. Therefore, wide ranges of researches have been done on the BC production process and its structural and physical modifications to make it more suitable for certain targeted biomedical applications thoroughly. BC’s properties such as mechanical strength, pore diameter and porosity can be tuned in situ or ex situ processes by using various polymer and compounds. Besides, different organic or inorganic compounds that support cell attachment, proliferation and differentiation or provide functions such as antimicrobial effectiveness can be gained to its structure for targeted application. These processes not only increase the usage options of BC but also provide success for mimicking the natural tissue microenvironment, especially in tissue engineering applications. In this review article, the studies on optimisation of BC production in the last decade and the BC modification and functionalisation studies conducted for the three main perspectives as tissue engineering, drug delivery and wound dressing with diverse approaches are summarized.

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