Engineered cyclodextrin glucanotransferases from Bacillus sp. G-825-6 produce large-ring cyclodextrins with high specificity
Christian Sonnendecker, Susanne Melzer, Wolfgang Zimmermann
https://doi.org/10.1002/mbo3.757
https://onlinelibrary.wiley.com/doi/10.1002/mbo3.757?prg140729=460f467a-f170-4d4b-b399-851e46f8066f

Bacillus subtilis contains a cyclodextrin-binding protein which is part of a putative ABC-transporter
https://academic.oup.com/femsle/article-abstract/204/1/55/632811

Both cyclodextrins and specific bacteria can interact with and utilize the keratin in human skin, though they do so through entirely different mechanisms—cyclodextrins acting as chemical carriers for therapeutic purposes and bacteria acting as biological agents that can degrade or manipulate the skin barrier.

Cyclodextrins and Skin Keratin

Cyclodextrins (CDs) are cyclic oligosaccharides frequently used in dermatology to enhance the solubility and stability of drugs.

• Interaction with Keratinocytes: Hydroxypropyl-beta-cyclodextrin (HP-β-CD) is used in dermatological formulations. Studies show that at low, safe concentrations, these can promote the proliferation and migration of keratinocytes (skin cells that produce keratin), aiding in wound healing and skin barrier remodeling.

• Safety and Efficacy: While high concentrations (0.5–1%) can show cytotoxic effects on keratinocytes, lower, controlled amounts do not disrupt the skin barrier, and in some cases, are used to deliver drugs that treat skin conditions.

• No Active Degradation: Cyclodextrins do not "consume" or metabolize keratin; rather, they interact with the skin environment to manage the delivery of active compounds, sometimes affecting collagen and keratinocyte activity.

Bacterial Filamentation and Skin Keratin

Certain bacteria can produce filamentation (long, thread-like structures) and use keratin as a substrate in the context of skin infections.

• Morgellons Disease: Research indicates that the peculiar multicolored dermal filaments found in Morgellons disease are actually bio-fibers composed of keratin and collagen. These filaments result from the proliferation and activation of keratinocytes and fibroblasts in the skin.

• Bacterial Role: This condition is strongly associated with Borrelia burgdorferi (the agent of Lyme disease) and other spirochetes, suggesting that these bacteria trigger the skin to produce these filaments as a response to infection.

• Keratin Degradation (Keratinases): Bacteria such as Bacillus licheniformis, B. subtilis, and Stenotrophomonas maltophilia secrete keratinases, which are enzymes that can break down keratin. These microbes use the keratin in skin, hair, or feathers as a nutrient source.

Summary of Differences

• Cyclodextrins: Act as non-toxic, biocompatible carriers in creams and gels to improve drug delivery to skin cells (keratinocytes) and aid in healing.

• Bacterial Filamentation: A pathological process where bacteria (often Borrelia) cause host keratinocytes to produce abnormal filaments and/or produce enzymes that actively break down skin keratin.

Characterization and evolution of dermal filaments from patients with Morgellons disease
Marianne J Middelveen 1, Peter J Mayne 1, Douglas G Kahn 2, Raphael B Stricker 1,✉

https://pmc.ncbi.nlm.nih.gov/articles/PMC3544355/

Bacillus species, particularly alkalophilic strains, are primary producers of cyclodextrin glycosyltransferase (CGTase), an enzyme that converts starch into cyclodextrins (CDs)—cyclic oligosaccharides used to encapsulate molecules. These bacteria utilize CGTase to produce -, -, and -CDs, with applications in pharmaceuticals and food to improve solubility and stability.

• Production Mechanism: Alkalophilic Bacillus (e.g., B. clausii, B. pseudofirmus, B. macerans) are ideal for industrial CD production because their CGTase works well in high pH and temperature environments.

• Optimal Conditions: Studies show that 5% (w/v) cassava starch with Bacillus CGTase at 56°C and pH 6.4 can yield up to 66% conversion to cyclodextrins.

• Types of Cyclodextrins: Bacillus strains produce different ratios of , and CDs, with some specifically optimized for CD (7 glucose units).

• Applications: In addition to production, Bacillus subtilis has specialized proteins (CycB) to utilize these cyclodextrins as a carbon source, with high affinity for

  -cyclodextrin.

• Enhanced Fermentation: Cyclodextrins can be used to mitigate product inhibition in Bacillus licheniformis fermentation, boosting biosurfactant yield by up to 41.43%.

Cyclodextrin-mediated quorum quenching in the Aliivibrio fischeri bioluminescence model system – Modulation of bacterial communication

• December 2020

• International Journal of Pharmaceutics 594(1):120150

• DOI:10.1016/j.ijpharm.2020.120150

• License

• CC BY 4.0

Authors: Mónika Molnár
Budapest University of Technology and Economics
Éva Fenyvesi
CycloLab - Cyclodextrin Research & Development Laboratory
Zsófia Berkl
Imre Németh

Show all 10 authors

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Abstract and Figures

Bacterial Quorum Sensing is a cell-to-cell communication process, in which, bacteria, performing cooperative behaviour, produce and detect extracellular signalling chemicals, to monitor cell population density. Numerous bacterial processes including bioluminescence, virulence factor production, biofilm formation etc. are known to be influenced by this bacterial communication network. Interest in QS systems has emerged in response to the fact that these processes have significant impact on the environment, human health as well as agriculture. Cyclodextrins-mediated quorum quenching is an innovative approach and the available information about their effects is very scarce. We selected Aliivibrio fischeri, a bacterium, producing light, based on Quorum Sensing, to be the first to investigate the cyclodextrins’ effect on this bioluminescence. A systematic study was performed with twelve different cyclodextrin compounds in order to determine their concentration- and time-dependent bioluminescence inhibitory effect in the A. fischeri model system. Especially high quorum quenching effect was found for α-cyclodextrin: 10 mM α-cyclodextrin at 120 min contact time which caused ∼64% inhibition of bioluminescence. Experiments with the co-administration of α-cyclodextrin and N-(3-oxohexanoyl)-L-homoserine lactone, the signalling molecule of A. fischeri clearly showed, that the stimulating effect of this signal was diminished by α-cyclodextrin, suggesting, that complexation was responsible for the observed Quorum Sensing suppression. Although β-cyclodextrin and its hydroxypropyl derivative significantly inhibited bioluminescence at as low as 0.156 mM concentration, their efficiency did not reach the level of α-cyclodextrin. According to our results, the autoinducer-dependent quorum sensing mechanism in Aliivibrio fischeri was markedly inhibited, the quorum quenching effect of cyclodextrins was clearly demonstrated. The efficiency was influenced by several parameters; the size of the interior cavity, the structure and the concentration of the cyclodextrins, as well as the contact time with the cells. The application of a cyclodextrin-trap for complexation of signal molecules may be a novel, promising method for influencing QS interfering strategies, for example, to enhance the efficiency of various biotechnologies, as well as to find alternative approaches against bacterial proliferation and infections. Furthermore, our results could also serve as a basis for further research with bacterial or plant model systems, in which the same chemical signals may induce physiological responses.

DEVELOPING HYDROGELS WITH SELF-ORGANIZED M13 FILAMENTOUS PHAGE
https://prod-ms-be.lib.mcmaster.ca/server/api/core/bitstreams/b30a3a49-b800-4b25-b142-3b70316b903d/content

Lay Abstract

Filamentous phage are viruses that infect bacteria. These bio-filaments are ~1 𝜇𝑚 long, 6-8 nm in diameter and can propagate themselves by infecting bacteria. This means one bio-filament can make 300-1000 particles only by infecting a bacterial host, a characteristic that drastically increases their utility over synthetic filamentous nanomaterial. Filamentous phage can be readily genetically engineered to express foreign receptors on their surface. In this thesis, I demonstrate how these bio-filaments can self-organize at high concentrations and can be crosslinked to make hydrogels that can adsorb up to 12 times their weight in water. These hydrogels can also heal themselves if broken or cut and exhibit autofluorescence, which are very useful properties for hydrogels used for biomedical applications. We further demonstrate that adding small proteins to the bio-filaments can expand the range of hydrogel formation, to the extent that even low concentrations of bio-filament can form hydrogels.

The Impact of Cyclodextrins on the Physiology of Candida boidinii: Exploring New Opportunities in the Cyclodextrin Application

Rita Márton 1, Márk Margl 1, Lilla Kinga Tóth 1, Éva Fenyvesi 2, Lajos Szente 2, Mónika Molnár 1,*

Editor: Georgia N Valsami

PMCID: PMC11313686 PMID: 39125102

Abstract

Cyclodextrins, commonly used as excipients in antifungal formulations to improve the physicochemical properties and availability of the host molecules, have not been systematically studied for their effects and bioactivity without a complex active substance. This paper evaluates the effects of various cyclodextrins on the physiology of the test organism Candida boidinii. The research examines their impact on yeast growth, viability, biofilm formation and morphological changes. Native ACD, BCD, randomly methylated α- and β-CD and quaternary ammonium α-CD and β-CD were investigated in the 0.5–12.5 mM concentration range in both static and dynamic systems. The study revealed that certain cyclodextrins exhibited notable antifungal effects (up to ~69%) in dynamic systems; however, the biofilm formation was enhanced in static systems. The magnitude of these effects was influenced by several variables, including the size of the internal cavity, the concentration and structure of the cyclodextrins, and the contact time. Furthermore, the study found that CDs exhibited distinct effects in both static and dynamic systems, potentially related to their tendency to form aggregates. The findings suggest that cyclodextrins may have the potential to act as antifungal agents or growth promoters, depending on their structure and surrounding environments.

https://pmc.ncbi.nlm.nih.gov/articles/PMC11313686/

Synthetic biocompatible cyclodextrin-based constructs for local gene delivery to improve cutaneous wound healing
Nathalie C Bellocq 1 , David W Kang, Xuehui Wang, Gregory S Jensen, Suzie H Pun, Thomas Schluep, Monica L Zepeda, Mark E Davis
https://pubmed.ncbi.nlm.nih.gov/15546185/
Affiliations

• PMID: 15546185

• DOI: 10.1021/bc0498119

Abstract

The localized, sustained delivery of growth factors for wound healing therapy is actively being explored by gene transfer to the wound site. Biocompatible matrices such as bovine collagen have demonstrated usefulness in sustaining gene therapy vectors that express growth factors in local sites for tissue repair. Here, new synthetic biocompatible materials are prepared and shown to deliver a protein to cultured cells via the use of an adenoviral delivery vector. The synthetic construct consists of a linear, beta-cyclodextrin-containing polymer and an adamantane-based cross-linking polymer. When the two polymers are combined, they create an extended network by the formation of inclusion complexes between the cyclodextrins and adamantanes. The properties of the network are altered by controlling the polymer molecular weights and the number of adamantanes on the cross-linking polymer, and these modifications and others such as replacement of the beta-cyclodextrin (host) and adamantane (guest) with other cyclodextrins (hosts such as alpha, gamma, and substituted members) and inclusion complex forming molecules (guests) provide the ability to rationally design network characteristics. Fibroblasts exposed to these synthetic constructs show proliferation rates and migration patterns similar to those obtained with collagen. Gene delivery (green fluorescent protein) to fibroblasts via the inclusion of adenoviral vectors in the synthetic construct is equivalent to levels observed with collagen. These in vitro results suggest that the synthetic constructs are suitable for in vivo tissue repair applications.

Impact of Skin Microbiome on Attractiveness to Arthropod Vectors and Pathogen Transmission
N. Verhulst, N. Boulanger, J. Spitzen
Published 2018
Environmental Science, Biology
https://www.semanticscholar.org/paper/Impact-of-Skin-Microbiome-on-Attractiveness-to-and-Verhulst-Boulanger/130c490a9b60677f74887b7628b76264263031d9

Lights, camera, and action: vertebrate skin sets the stage for immune cell interaction with arthropod-vectored pathogens

Shu Zhen Chong1* Maximilien Evrard1,2 Lai Guan Ng1*

• 1Functional Immune Imaging, Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Biopolis, Singapore

• 2School of Biological Sciences, Nanyang Technological University (NTU), Singapore

Despite increasing studies targeted at host-pathogen interactions, vector-borne diseases remain one of the largest economic health burdens worldwide. Such diseases are vectored by hematophagous arthropods that deposit pathogens into the vertebrate host’s skin during a blood meal. These pathogens spend a substantial amount of time in the skin that allows for interaction with cutaneous immune cells, suggesting a window of opportunity for development of vaccine strategies. In particular, the recent availability of intravital imaging approaches has provided further insights into immune cell behavior in living tissues. Here, we discuss how such intravital imaging studies have contributed to our knowledge of cutaneous immune cell behavior and specifically, toward pathogen and tissue trauma from the arthropod bite. We also suggest future imaging approaches that may aid in better understanding of the complex interplay between arthropod-vectored pathogens and cutaneous immunity that could lead to improved therapeutic strategies.

Introduction

“Now, here, you see, it takes all the running you can do, to keep in the same place” – a statement made by the Red Queen to Alice in Lewis Carroll’s Through the Looking Glass in her explanation of the nature of Wonderland.

In 1973, Leigh Van Valen proposed the metaphor of an evolutionary arms race coined the Red Queen Hypothesis, which suggests that microbial pathogens and their host co-evolve continuously to maintain a state of balance (1). This continuous microbial challenge is believed to result in specialized immune cell subsets in the host (2) that reside in specific anatomical sites, which allows immune cells to defend against foreign pathogens yet maintain tolerance toward commensal flora (3, 4).

The Stage and Actors: Vertebrate Skin, Immune Cells, and Arthropod Vectors

The skin serves as a primary example of an evolutionary adaptation of vertebrates. As the primary interface between the host’s body and environment, it provides a first line of defense against microbial pathogens and physical insults. Anatomically, the skin can be categorized into two distinct layers separated by a basement membrane: the dermis and the epidermis (Figure 1). The epidermis is a non-vascularized compartment consisting mainly of keratinocytes, which are critical in shaping and maintaining the immune response (5). Langerhans cells (LCs) and a subset of γδ T-cells found in mice, known as dendritic epidermal T-cells (DETCs), are the major immune cell types in the epidermis and are both characterized by their defined dendritic-like yet sessile behavior (6–8). In contrast to the epidermis, the highly vascularized dermis compartment bustles with activity and consists of a variety of immune cells including dermal dendritic cells (dDCs), mast cells, macrophages, neutrophils, and both αβ and γδT-cells. The majority of these cells display crawling or scouting behaviors and utilize extracellular matrix (ECM) fibers, such as collagen and elastin fibers, as scaffolds for their navigation (9–14). These cells may also enter and leave the dermis via blood and lymphatic vessels respectively through a series of highly coordinated events involving the use of integrins and chemokine gradients (1, 15–17).
https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2013.00286/full

Mechanisms of Arthropod Transmission of Plant and Animal Viruses
https://journals.asm.org/doi/10.1128/mmbr.63.1.128-148.1999