Experimental study of the liposomal form of fenoterol after improving the method of obtaining it

The effect of different concentrations of cryoprotector (sucrose) on the efficiency of fenoterol inclusion in the lipid matrix during lyophilization has been studied. It has been shown that the liposomal form with the content of cryoprotector in the internal environment of liposomes 2.5 % and in the external environment equal to 2 % provides long-term preservation of the drug in the liposome cavity. Under these conditions, it is possible to achieve a monodisperse distribution of particles with an average diameter of 4.281.62 m. The assumed quantitative composition of the cryoprotector ensures the manufacturability of the liposome production process, increases the stability of the lyophilizate structure and prevents the particles from sticking together, ensuring their uniformity. The profile of two-stage release of fenoterol from the liposomal form has been shown in vitro. The first stage of rapid release was characterized by a transition to free form within 15 minutes to 42 % of the encapsulated fenoterol. At the second stage, the active principle was released more slowly for 480 minutes. The model of bronchospasm induced by 1% histamine has shown the advantage of the liposomal form of fenoterol in comparison with its free form in the form of an aqueous solution. Intra-tracheal administration of the liposomal form of fenoterol at a dose of 17 ukg/kg provided for 360 minutes the preservation of external respiratory function at the level of initial values, despite histamine inhalation, while the duration of action of fenoterol did not exceed 120 minutes.

Download Full-text

Entrapment of the Fastest Known Carbonic Anhydrase with Biomimetic Silica and Its Application for CO2 Sequestration

Polymers ◽

10.3390/polym13152452 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2452

Author(s):

Chia-Jung Hsieh ◽

Ju-Chuan Cheng ◽

Chia-Jung Hu ◽

Chi-Yang Yu

Keyword(s):

Carbonic Anhydrase ◽

High Activity ◽

Co2 Sequestration ◽

Residual Activity ◽

Entrapment Efficiency ◽

Free Form ◽

Uncatalyzed Reaction ◽

The Stability ◽

Time Required

Capturing and storing CO2 is of prime importance. The rate of CO2 sequestration is often limited by the hydration of CO2, which can be greatly accelerated by using carbonic anhydrase (CA, EC 4.2.1.1) as a catalyst. In order to improve the stability and reusability of CA, a silica-condensing peptide (R5) was fused with the fastest known CA from Sulfurihydrogenibium azorense (SazCA) to form R5-SazCA; the fusion protein successfully performed in vitro silicification. The entrapment efficiency reached 100% and the silicified form (R5-SazCA-SP) showed a high activity recovery of 91%. The residual activity of R5-SazCA-SP was two-fold higher than that of the free form when stored at 25 °C for 35 days; R5-SazCA-SP still retained 86% of its activity after 10 cycles of reuse. Comparing with an uncatalyzed reaction, the time required for the onset of CaCO3 formation was shortened by 43% and 33% with the addition of R5-SazCA and R5-SazCA-SP, respectively. R5-SazCA-SP shows great potential as a robust and efficient biocatalyst for CO2 sequestration because of its high activity, high stability, and reusability.

Download Full-text

Photodynamic Treatment of Colorectal Cancer Using Chlorin e6-Loaded Poly(lactide-co-glycolide)- Based Nanoparticles

Journal of Biomedical Nanotechnology ◽

10.1166/jbn.2021.3170 ◽

2021 ◽

Vol 17 (10) ◽

pp. 1939-1950

Author(s):

Beibei Lin ◽

Xuegu Xu ◽

Xiaobi Zhang ◽

Yinfei Yu ◽

Xiaoling Wang

Keyword(s):

Colorectal Cancer ◽

Drug Loading ◽

Average Diameter ◽

Plga Nanoparticles ◽

Chlorin E6 ◽

Photodynamic Treatment ◽

Hct 116 ◽

Hct 116 Cells ◽

The Stability

We prepared poly(lactide-co-glycolide) (PLGA) encapsulated with chlorin e6 (Ce6) in an effort to increase the stability and efficiency of photosensitizers for photodynamic therapy (PDT). We determined that Ce6-loaded PLGA nanoparticles (PLGA-Ce6 NPs) had drug-loading efficiency of 5%. The efficiency of encapsulation was 82%, the zeta potential was- 25 mV, and the average diameter was 130 nm. The encapsulation of Ce6 in PLGA nanoparticles showed excellent stability. The nanoparticles exhibited sustained Ce6 release profiles with 50% released at the end of 3 days, whereas free Ce6 showed rapid release within 1 day. Ce6 release patterns were controlled by encapsulation into PLGA. The uptake of PLGA-Ce6 NPs was significantly enhanced by endocytosis in the first 8 hours in the HCT-116 cell line. An intracellular reactive oxygen species assay revealed the enhanced uptake of the nanoparticles. An in vitro anti-tumor activity assay showed that the PLGA-Ce6 NPs exhibited enhanced phototoxicity toward HCT-116 cells and a slightly lower IC50 value in HCT-116 cells than Ce6 solution alone. Exposure of HCT-116 cell spheroids to PLGA-Ce6 NPs penetrated more profoundly and had better phototoxicity than pure drugs. These findings suggest that PLGA-Ce6 NPs might serve as PDT for colorectal cancer.

Download Full-text

Morphology, Stability, and Application of Lycopene Microcapsules Produced by Complex Coacervation

Journal of Chemistry ◽

10.1155/2013/982603 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 23

Author(s):

Glaucia A. Rocha-Selmi ◽

Carmen S. Favaro-Trindade ◽

Carlos R. F. Grosso

Keyword(s):

Encapsulation Efficiency ◽

Gum Arabic ◽

Average Diameter ◽

Stability Test ◽

Free Form ◽

Complex Coacervation ◽

The Stability ◽

Processing And Storage ◽

High Degree ◽

And Storage

The interest in lycopene has increased in recent years due to studies that associate it with the reduction in risk of developing cardiovascular diseases and cancer. However, due to its high degree of unsaturation, this carotenoid is inclined to isomerize and oxidize during processing and storage, making it difficult to use in the food industry. Microencapsulation can improve this situation, increasing its stability and making incorporation into food formulations possible. Thus, the aim of this study was to microencapsulate lycopene by complex coacervation using gelatin and gum Arabic as the encapsulating agents. The microcapsules were evaluated based on the encapsulation efficiency and their morphology and then submitted to a stability test and applied in cake making. Most of the systems studied presented spherical microcapsules with defined walls. The encapsulation efficiency values were above 90%, and the average diameter of the capsules ranged from 61 to 144 μm. The stability test showed that microencapsulation offered greater protection to the lycopene as compared to its free form. The application of nonfreeze dried coacervated microcapsules in cake making was satisfactory, but the color transference was low when freezedried coacervated microcapsules were used.

Download Full-text

Protease Responsive Essential Amino-Acid Based Nanocarriers for Near-Infrared Imaging

Scientific Reports ◽

10.1038/s41598-019-56871-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Anshu Kumari ◽

Kalpana Kumari ◽

Sharad Gupta

Keyword(s):

Amino Acid ◽

Self Assembly ◽

Essential Amino Acid ◽

Near Infrared ◽

Infrared Imaging ◽

Average Diameter ◽

The Body ◽

Free Form ◽

Theranostic Agents

AbstractDelivery of the theranostic agents with effective concentration to the desired sites inside the body is a major challenge in disease management. Nanotechnology has gained attention for the delivery of theranostic agents to the targeted location. The use of essential amino-acid based homopolymers for the synthesis of biocompatible and biodegradable nanoparticles (NPs) could serve as a nanocarrier for delivery applications. In this study, poly-l-lysine (PLL) and salts were used to fabricate the NPs for the delivery of exogenous contrast agents. Here, indocyanine green (ICG) was encapsulated within these NPs, and a simple two-step green chemistry-based self-assembly process was used for the fabrication. The morphological and biochemical characterizations confirm the formation of ICG encapsulating spherical PLL NPs with an average diameter of ~225 nm. Further, a detailed study has been carried out to understand the role of constituents in the assembly mechanism of PLL NPs. Our results show a controlled release of the ICG from PLL NPs in the presence of the proteolytic enzyme. In-vitro cellular studies suggest that the PLL NPs were readily taken up by the cells showing their superior delivery efficiency of ICG in comparison to the free-form of the ICG.

Download Full-text

Performance of Polyester-Based Electrospun Scaffolds under In Vitro Hydrolytic Conditions: From Short-Term to Long-Term Applications

Nanomaterials ◽

10.3390/nano9050786 ◽

2019 ◽

Vol 9 (5) ◽

pp. 786 ◽

Cited By ~ 3

Author(s):

Oscar Gil-Castell ◽

José David Badia ◽

Jordi Bou ◽

Amparo Ribes-Greus

Keyword(s):

Molar Mass ◽

Pure Water ◽

Phosphate Buffer Solution ◽

Short Term ◽

Buffer Solution ◽

Electrospun Scaffolds ◽

The Stability ◽

Short Time

The evaluation of the performance of polyesters under in vitro physiologic conditions is essential to design scaffolds with an adequate lifespan for a given application. In this line, the degradation-durability patterns of poly(lactide-co-glycolide) (PLGA), polydioxanone (PDO), polycaprolactone (PCL) and polyhydroxybutyrate (PHB) scaffolds were monitored and compared giving, as a result, a basis for the specific design of scaffolds from short-term to long-term applications. For this purpose, they were immersed in ultra-pure water and phosphate buffer solution (PBS) at 37 °C. The scaffolds for short-time applications were PLGA and PDO, in which the molar mass diminished down to 20% in a 20–30 days lifespan. While PDO developed crystallinity that prevented the geometry of the fibres, those of PLGA coalesced and collapsed. The scaffolds for long-term applications were PCL and PHB, in which the molar mass followed a progressive decrease, reaching values of 10% for PCL and almost 50% for PHB after 650 days of immersion. This resistant pattern was mainly ascribed to the stability of the crystalline domains of the fibres, in which the diameters remained almost unaffected. From the perspective of an adequate balance between the durability and degradation, this study may serve technologists as a reference point to design polyester-based scaffolds for biomedical applications.

Download Full-text

Changing chemosusceptibility in the second-stage larvae of Toxocara canis by long-term incubation

Journal of Helminthology ◽

10.1017/s0022149x00013031 ◽

1993 ◽

Vol 67 (2) ◽

pp. 145-150 ◽

Cited By ~ 3

Author(s):

Nobuaki Akao ◽

Yoshihisa Goto ◽

Kaoru Kondo ◽

Yoshisuke Tsuda

Keyword(s):

Decanoic Acid ◽

Toxocara Canis ◽

Second Stage ◽

One Year

AbstractSecond-stage larvae of Toxocara canis were maintained in vitro for one year. Susceptibility of the larvae to drugs was evaluated by means of minimal larvicidal concentration (MLC) and larval bursting percentage. MLCs of citral and decanoic acid were almost constant throughout all stages of incubation. However, bursting percentage markedly varied within the first 20 weeks of incubation. Therefore, while larvae are available for use in the MLC assay at any stage of incubation, those beyond the first 20 weeks after incubation should be used for the bursting assay to obtain reproducible results.

Download Full-text

Vehiculation of Active Principles as a Way to Create Smart and Biofunctional Textiles

Materials ◽

10.3390/ma11112152 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2152 ◽

Cited By ~ 5

Author(s):

Manuel Lis Arias ◽

Luisa Coderch ◽

Meritxell Martí ◽

Cristina Alonso ◽

Oscar García Carmona ◽

...

Keyword(s):

Structural Characteristics ◽

Controlled Drug Delivery ◽

Diffusion Chamber ◽

Active Principle ◽

Arabic Gum ◽

In Vitro Methods ◽

In Vitro Experiment ◽

Citronella Oil

In some specific fields of application (e.g., cosmetics, pharmacy), textile substrates need to incorporate sensible molecules (active principles) that can be affected if they are sprayed freely on the surface of fabrics. The effect is not controlled and sometimes this application is consequently neglected. Microencapsulation and functionalization using biocompatible vehicles and polymers has recently been demonstrated as an interesting way to avoid these problems. The use of defined structures (polymers) that protect the active principle allows controlled drug delivery and regulation of the dosing in every specific case. Many authors have studied the use of three different methodologies to incorporate active principles into textile substrates, and assessed their quantitative behavior. Citronella oil, as a natural insect repellent, has been vehicularized with two different protective substances; cyclodextrine (CD), which forms complexes with it, and microcapsules of gelatin-arabic gum. The retention capability of the complexes and microcapsules has been assessed using an in vitro experiment. Structural characteristics have been evaluated using thermogravimetric methods and microscopy. The results show very interesting long-term capability of dosing and promising applications for home use and on clothes in environmental conditions with the need to fight against insects. Ethyl hexyl methoxycinnamate (EHMC) and gallic acid (GA) have both been vehicularized using two liposomic-based structures: Internal wool lipids (IWL) and phosphatidylcholine (PC). They were applied on polyamide and cotton substrates and the delivery assessed. The amount of active principle in the different layers of skin was determined in vitro using a Franz-cell diffusion chamber. The results show many new possibilities for application in skin therapeutics. Biofunctional devices with controlled functionality can be built using textile substrates and vehicles. As has been demonstrated, their behavior can be assessed using in vitro methods that make extrapolation to their final applications possible.

Download Full-text

The Bordetella Bps Polysaccharide Is Critical for Biofilm Development in the Mouse Respiratory Tract

Journal of Bacteriology ◽

10.1128/jb.00785-07 ◽

2007 ◽

Vol 189 (22) ◽

pp. 8270-8276 ◽

Cited By ~ 79

Author(s):

Gina Parise Sloan ◽

Cheraton F. Love ◽

Neelima Sukumar ◽

Meenu Mishra ◽

Rajendar Deora

Keyword(s):

Whooping Cough ◽

Three Dimensional ◽

Respiratory Pathogens ◽

Adolescents And Adults ◽

The Stability ◽

Inert Surfaces ◽

Biofilm Development

ABSTRACT Bordetellae are respiratory pathogens that infect both humans and animals. Bordetella bronchiseptica establishes asymptomatic and long-term to life-long infections of animal nasopharynges. While the human pathogen Bordetella pertussis is the etiological agent of the acute disease whooping cough in infants and young children, it is now being increasingly isolated from the nasopharynges of vaccinated adolescents and adults who sometimes show milder symptoms, such as prolonged cough illness. Although it has been shown that Bordetella can form biofilms in vitro, nothing is known about its biofilm mode of existence in mammalian hosts. Using indirect immunofluorescence and scanning electron microscopy, we examined nasal tissues from mice infected with B. bronchiseptica. Our results demonstrate that a wild-type strain formed robust biofilms that were adherent to the nasal epithelium and displayed architectural attributes characteristic of a number of bacterial biofilms formed on inert surfaces. We have previously shown that the Bordetella Bps polysaccharide encoded by the bpsABCD locus is critical for the stability and maintenance of three-dimensional structures of biofilms. We show here that Bps is essential for the formation of efficient nasal biofilms and is required for the colonization of the nose. Our results document a biofilm lifestyle for Bordetella in mammalian respiratory tracts and highlight the essential role of the Bps polysaccharide in this process and in persistence of the nares.

Download Full-text

Pre-Formulation Studies: Physicochemical Characteristics and In Vitro Release Kinetics of Insulin from Selected Hydrogels

Pharmaceutics ◽

10.3390/pharmaceutics13081215 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1215

Author(s):

Aneta Ostróżka-Cieślik ◽

Małgorzata Maciążek-Jurczyk ◽

Jadwiga Pożycka ◽

Barbara Dolińska

Keyword(s):

Release Kinetics ◽

Polymer Network ◽

In Vitro Release ◽

Methyl Cellulose ◽

Physicochemical Characteristics ◽

Diabetic Patients ◽

Tertiary Structures ◽

Duration Of Action ◽

The Stability

Insulin loaded to the polymer network of hydrogels may affect the speed and the quality of wound healing in diabetic patients. The aim of our research was to develop a formulation of insulin that could be applied to the skin. We chose hydrogels commonly used for pharmaceutical compounding, which can provide a form of therapy available to every patient. We prepared different gel formulations using Carbopol® UltrezTM 10, Carbopol® UltrezTM 30, methyl cellulose, and glycerin ointment. The hormone concentration was 1 mg/g of the hydrogel. We assessed the influence of model hydrogels on the pharmaceutical availability of insulin in vitro, and we examined the rheological and the texture parameters of the prepared formulations. Based on spectroscopic methods, we evaluated the influence of model hydrogels on secondary and tertiary structures of insulin. The analysis of rheograms showed that hydrogels are typical of shear-thinning non-Newtonian thixotropic fluids. Insulin release from the formulations occurs in a prolonged manner, providing a longer duration of action of the hormone. The stability of insulin in hydrogels was confirmed. The presence of model hydrogel carriers affects the secondary and the tertiary structures of insulin. The obtained results indicate that hydrogels are promising carriers in the treatment of diabetic foot ulcers. The most effective treatment can be achieved with a methyl cellulose-based insulin preparation.

Download Full-text

Morphological and anatomical features of narrow-leaved lavender plants with prolonged conservation under in vitro genebank

BIO Web of Conferences ◽

10.1051/bioconf/20202400015 ◽

2020 ◽

Vol 24 ◽

pp. 00015

Author(s):

Valentina Brailko ◽

Natalya Ivanova ◽

Irina Zhdanova ◽

Olga Mitrofanova

Keyword(s):

Leaf Shape ◽

Wild Plant ◽

Prolonged Storage ◽

Vascular Bundles ◽

Anatomical Features ◽

Wild Plant Species ◽

Functional Features ◽

The Stability

Optimization of plants long-term conservation under in vitro conditions and identification of their structural and functional features during preservation is the basis for the creation of a genebank of cultured and wild plant species in vitro. The aim of our work was to study morphological and anatomical features of plants in lavender cultivar ‘Sineva’ after two years of in vitro storage at low positive temperatures. The plant material was evaluated after 24 months of conservation. A significant decrease in the linear parameters of leaves in the preserved plants was noted. Leaf shape altered from narrowly linear to oblong. With prolonged storage, the thickness of the leaf blade slightly increased. The integumentary tissues were thinner, compared with the plants cultured under standard in vitro conditions, the cuticle was not clear. The number of stomata decreased. The number of small vascular bundles decreased. The obtained data demonstrate viability of in vitro preserved explants, despite significant differences in structure, preservation of chlorophyll-containing tissues, a decrease in transpiration, and an increase of trichomes number. The stability of the vegetative organs functioning was revealed.

Download Full-text