Cyclodextrin-mediated self-associating chitosan micro-platelets act as a drug booster against Candida glabrata mucosal infection in immunocompetent mice

Cyclodextrin-based supramolecular nanogels decorated with mannose for short peptide encapsulation

Nanogels are aqueous dispersions of hydrogel particles formed by physically or chemically cross-linked polymer networks of nanoscale size. Herein, we devised a straightforward technique to fabricate a novel class of physically cross-linked nanogels via a self-assembly process in water involving α-cyclodextrin and a mannose molecule that was hydrophobically modified using an alkyl chain. The alkyl chain-modified mannose was synthesized in five steps, starting with D-mannose. Subsequently, nanogels were formed by subjecting α-cyclodextrin and the hydrophobically modified mannose to magnetic stirring in water. By adjusting the mole ratio between the hydrophobically modified mannose and α-cyclodextrin, nanogels with an average 100-150 nm diameter were obtained. Physicochemical and structural analyses by 1H NMR and X-ray diffraction unveiled a supramolecular and hierarchical mechanism underlying the creation of these nanogels. The proposed mechanism of nanogel formation involves two distinct steps: initial interaction of hydrophobically modified mannose with α-cyclodextrin resulting in the formation of inclusion complexes, followed by supramolecular interactions among these complexes, ultimately leading to nanogel formation after 72 h of stirring. We demonstrated the nanogels' ability to encapsulate a short peptide ([p-tBuF2, R5]SHf) as a water-soluble drug model. This discovery holds promise for potentially utilizing these nanogels in drug delivery applications.

Hyaluronan nanoplatelets exert an intrinsic anti-inflammatory activity in a rat model of bladder painful syndrome/interstitial cystitis

Glycosaminoglycan (GAG) replenishment therapy consists of the instillation of GAG solutions directly in the bladder to alleviate Bladder Painful Syndrome/Interstitial Cystitis (BPS/IC). However, several issues were reported with this strategy because the GAG solutions are rapidly eliminated from the bladder by spontaneous voiding, and GAG have low bioadhesive behaviors. Herein, GAG nanomaterials with typical flattened morphology were obtained by a self-assembly process. The formation mechanism of those nanomaterials, denoted as nanoplatelets, involves the interaction of α-cyclodextrin cavity and alkyl chains covalently grafted on the GAG. Three GAG were used in this investigation, hyaluronan (HA), chondroitin sulfate (CS), and heparin (HEP). HA NP showed the best anti-inflammatory activity in an LPS-induced in vitro inflammation model of macrophages. They also exhibited the best therapeutic efficacy in a BPS/IC rat inflammation model. Histological examinations of the bladders revealed that HA NP significantly reduced bladder inflammation and regenerated the bladder mucosa. This investigation could open new perspectives to alleviate BPS/IC through GAG replenishment therapy.

The isolation and identification of Candida glabrata from avian species and a study of the antibacterial activities of Chinese herbal medicine in vitro

Previously, a fungus was isolated from a diseased pigeon group clinically suspected of being infected with Candida. The fungus was subsequently identified as Candida glabrata using morphology, physiology, biochemistry, and molecular biology testing methods. In the present study, to determine the controlling effects of Chinese herbal medicine for C. glabrata, the bacteriostatic effects of the ethanol extracts Acorus gramineus, Sophora flavescens, Polygonum hydropiper, Cassia obtusifolia, Pulsatilla chinensis, Dandelion, and Cortex phellodendri on C. glabrata in vitro were analyzed. The results showed that the minimum inhibitory concentrations (MIC₈₀) of Cortex phellodendri was 0.25 μg/μL. Meanwhile, that of S. flavescens was 32 μg/μL; C. obtusifolia was 56 μg/μL; A. gramineus and Polygonum hydropiper was 64 μg/μL; and P. chinensis was 112 μg/μL. However, MIC₈₀ for Dandelion was undetectable. In addition, improved drug sensitivity tests revealed that colonies had grown after 24 h in the blank group, as well as the Polygonum hydropiper, P. chinensis, Dandelion, and ethanol groups. The colonies first appeared at the 48-hour point in the other drug-sensitive medium of Chinese herbal medicine. However, no colony growth was found in Cortex phellodendri medium, and the formation of the maximum colony diameter in that group was later than the blank group (e.g., 96 h in the blank group and 120 h in the Chinese herbal medicine group). It was observed that only 17 colony-forming units had grown in 125 μg/μL of the S. flavescens medium, which was significantly different from other groups. Also, the final colony diameter was significantly smaller than that of the other experimental groups. Therefore, it was determined that the A. gramineus, S. flavescens, Polygonum hydropiper, Cassia obtusifolia, P. chinensis, and Cortex phellodendri had certain inhibitory effects on the growth of the C. glabrata. Among those, it was observed that the Cortex phellodendri had the strongest inhibitory effects, followed by the S. flavescens. In the future, these Chinese herbal medicines are expected to be used to treat the fungal infections related to C. glabrata in poultry to improve production performance.

A Review: Uses of Chitosan in Pharmaceutical Forms

Chitosan is a natural polysaccharide widespread in nature. It has many unique and attractive properties for the pharmaceutical field: it is biodegradable, safe, hypoallergenic, biocompatible with the body, free of toxicity, with proven anticholesterolemic, antibacterial, and antimycotic action. In this review we highlighted the physical, chemical, mechanical, mucoadhesive, etc. properties of chitosan to be taken into account when obtaining various pharmaceutical forms. The methods by which the pharmaceutical forms based on chitosan are obtained are very extensive, and in this study only the most common ones were presented.

Chitosan Contribution to Therapeutic and Vaccinal Approaches for the Control of Leishmaniasis

The control of leishmaniases, a complex parasitic disease caused by the protozoan parasite Leishmania, requires continuous innovation at the therapeutic and vaccination levels. Chitosan is a biocompatible polymer administrable via different routes and possessing numerous qualities to be used in the antileishmanial strategies. This review presents recent progress in chitosan research for antileishmanial applications. First data on the mechanism of action of chitosan revealed an optimal in vitro intrinsic activity at acidic pH, high-molecular-weight chitosan being the most efficient form, with an uptake by pinocytosis and an accumulation in the parasitophorous vacuole of Leishmania-infected macrophages. In addition, the immunomodulatory effect of chitosan is an added value both for the treatment of leishmaniasis and the development of innovative vaccines. The advances in chitosan chemistry allows pharmacomodulation on amine groups opening various opportunities for new polymers of different size, and physico-chemical properties adapted to the chosen routes of administration. Different formulations have been studied in experimental leishmaniasis models to cure visceral and cutaneous leishmaniasis, and chitosan can act as a booster through drug combinations with classical drugs, such as amphotericin B. The various architectural possibilities given by chitosan chemistry and pharmaceutical technology pave the way for promising further developments.

Trichomonas vaginalis Motility Is Blocked by Drug-Free Thermosensitive Hydrogel

Trichomonas vaginalis motility in biological fluids plays a prominent, but understudied, role in parasite infectivity. In this study, the ability of a thermosensitive hydrogel (pluronic F127) to physically immobilize T. vaginalis was investigated. Blocking parasite motility could prevent its attachment to the mucosa, thus reducing the acquisition of the infection. The trajectory of individual parasites was monitored by multiple particle tracking. Mean square displacement, diffusivity, and velocity were calculated from x, y coordinates during time. Major results are that T. vaginalis exhibited different types of trajectories in a diluted solution composed of lactate buffer similar to "run-and-tumble" motion reported for flagellated bacteria. The fastest T. vaginalis specimen moves with a velocity of 19 μm/s. Observation of T. vaginalis movements showed that the cell body remains rigid during swimming and that the propulsive forces necessary to generate the movement are the result of flagellar beating. Parasite motility was partially slowed down using hydroxyethylcellulose hydrogel, used as a reference for the development of vaginal microbicides, while 100% of T. vaginalis were immobile in F127 hydrogel. Once completed by biological investigations on mice, this report suggests using drug-free formulation composed of F127 as a new strategy to prevent T. vaginalis attachment to the mucosa. The concept will be extended to other flagellated organisms where the motility is driven by cilia and flagella.

Permeability Characteristics of a New Antifungal Topical Amphotericin B Formulation with γ-Cyclodextrins

Amphotericin B is a low soluble broad-spectrum antifungal agent. Cyclodextrins can be added to amphotericin formulations to enhance both their solubility and antifungal properties. Semisolid amphotericin formulations containing gamma cyclodextrin (AGCD) were prepared and compared with two reference formulations—one of them without any solubility enhancer (A) and the other with DMSO (ADMSO). Rheological, the permeability through hairless mouse skin and antifungal characteristics of the different formulations were evaluated. All three semisolid formulations show low thixotropy characteristics. ADMSO was the formulation with the least consistency, lowest viscosity, and greatest extensibility. The AGCD formulation had the opposite behavior and had both the greatest consistency and viscosity and the lowest extensibility. The lowest permeability was obtained with the reference A formulation while both AGCD and ADMSO had a similar permeability enhancement. According to the antimicrobial in vitro efficacy trials, the AGCD formulation showed 45–60% more activity than the reference A formulation. It can be concluded that γ-cyclodextrin is a useful excipient to improve the solubility, permeability, and antifungal activity of amphotericin B in semisolid topical formulations.

Fabrication and characterization of dual acting oleyl chitosan functionalised iron oxide/gold hybrid nanoparticles for MRI and CT imaging

Bionanocomposites fabricated using metal nanoparticles serve a wide range of biomedical applications viz., site targeted drug delivery, imaging etc. Theranostics emerge as an important field of science, which focuses on the use of single entity for both disease diagnosis and treatment. The present work aimed at designing a multifunctional nanocomposite comprising of iron/gold hybrid nanoparticles, coated with oleyl chitosan and conjugated with methotrexate. The HR-TEM images revealed the spherical nature of the composite, while it's nontoxic and biocompatible property was proved by the MTT assay in NIH 3T3 cells and hemolysis assay. Though the VSM results exhibited the magnetic property, the MRI phantom images and X-ray contrast images demonstrated the potential of the composite to be used as contrast agent. Thus the prepared nanocomposite possess good cytocompatibility, magnetic property and also high X-ray attenuation, wherein it could serve as a novel platform for both MRI and CT diagnosis, as well as drug conjugation could aid in targeted drug delivery.

Strategies for Prevention and Treatment of Trichomonas vaginalis Infections

The last estimated annual incidence of Trichomonas vaginalis worldwide exceeds that of chlamydia and gonorrhea combined. This critical review updates the state of the art on advances in T. vaginalis diagnostics and strategies for treatment and prevention of trichomoniasis. In particular, new data on treatment outcomes for topical administration of formulations are reviewed and discussed.