Propionibacterium acnes induction of IL-1 cytokines through the NLRP3 inflammasome was recently highlighted as a dominant etiological factor for acne vulgaris. Therefore, therapeutics targeting both the stimulus and the cascade would be ideal. Nitric oxide (NO), a potent biological messenger, has documented broad-spectrum antimicrobial and immunomodulatory properties. To harness these characteristics to target acne, we utilized an established nanotechnology capable of generating/releasing nitric oxide over time (NO-np). P. acnes was found to be highly sensitive to all concentrations of NO-np tested, though human keratinocyte, monocyte, and embryonic zebra fish assays revealed no cytotoxicity. NO-np significantly suppressed IL-1β, TNF-α, IL-8 and IL-6 from human monocytes and IL-8 and IL-6 from human keratinocytes respectively. Importantly, silencing of NLRP3 expression by small interfering RNA did not limit NO-np inhibition of IL-1 β secretion from monocytes, and neither TNF-α, nor IL-6 secretion nor inhibition by NO-np was found to be dependent on this pathway. The observed mechanism by which NO-np impacts IL-1β secretion was through inhibition of caspase-1 and IL-1β gene expression. Together, these data suggest that NO-np can effectively prevent P. acnes induced inflammation by both clearing the organism and inhibiting microbial stimulation of the innate immune response.

Antimicrobial photodynamic inhibition (aPI) utilizes radical stress generated from the excitation of a photosensitizer (PS) with light to destroy pathogens. Its use against Trichophyton rubrum, a dermatophytic fungus with increasing incidence and resistance, has not been well characterized. Our aim was to evaluate the mechanism of action of aPI against T. rubrum using curcumin as the PS in both free and nanoparticle (curc-np) form. Nanocarriers stabilize curcumin and allow for enhanced solubility and PS delivery. Curcumin aPI, at optimal conditions of 10 μg/mL of PS with 10 J/cm2 of blue light (417 ± 5 nm), completely inhibited fungal growth (p<0.0001) via induction of reactive oxygen (ROS) and nitrogen species (RNS), which was associated with fungal death by apoptosis. Interestingly, only scavengers of RNS impeded aPI efficacy, suggesting that curcumin acts potently via a nitrosative pathway. The curc-np induced greater NO• expression and enhanced apoptosis of fungal cells, highlighting curc-np aPI as a potential treatment for T. rubrum skin infections.

Abstract:Hair is a significant indicator of health and can have a major impact on an individual's cosmetic appearance. Research within the cosmetics industry has revealed that when nanomaterials are engineered into hair care, they can enhance the benefits of active ingredients in order to improve hair cosmesis. Within the cosmetics arena, the unique size and intrinsic properties of nanoparticles can be tailored to target the hair follicle and shaft. This review aims to provide an overview of cosmetic nanocarriers that can be employed to improve the appearance of hair.

Increasing rates of antimicrobial resistance have left a significant gap in the standard antimicrobial armament. Nanotechnology holds promise as a new approach to combating resistant microbes. Chitosan, a form of deacetylated chitin, has been used extensively in medicine, agriculture and industry due to its ease of production, biocompatibility and antimicrobial activity. Chitosan has been studied extensively as a main structural component and additive for nanomaterials. Specifically, numerous studies have demonstrated its potent microbicidal activity and its efficacy as an adjuvant to vaccines, including mucosally administered vaccines. In this review, we present fundamental information about chitosan and chitosan nanoparticles as well as the most recent data about their antimicrobial mechanism and efficacy as a nanotechnology-based drug delivery system.

These authors contributed equally to this work.

Dermatologic physiology and aesthetics are profoundly connected. Inflammatory stimuli abound in the environment, and have the potential to impact both the physiology and aesthetics of the integument. Inflammation results in a compromised epidermal barrier, impaired moisture retention, erythema, scale and pigment alteration. The advent of nanotechnology has introduced a variety of new approaches to preserving skin cosmesis in the face of inflammation. In this article, we review the architecture and physiology of the epidermal barrier, describe the pathological and aesthetic effects of inflammation, and report recent advances in the development of nanomaterials to offset the aesthetic impact of inflammation.

Systemic therapies are preferred for treating dermal dermatophytosis due to inadequate penetration of topical agents. However, systemic antifungals are associated with off-target effects and limited tissue penetration, and antimicrobial resistance is a growing concern. To address this, we investigated topical nitric oxide-releasing nanoparticles (NO-np), which have been used against superficial fungal infections and bacterial abscesses. In addition to enhanced penetration and permeation conferred by nanoparticles, nitric oxide, a broad-spectrum multi-mechanistic antimicrobial agent, offers decreased likelihood of resistance development. In the current study, NO-np inhibited Trichophyton rubrum in vitro, as well as in a murine model of dermal dermatophytosis. In mice, NO-np reduced fungal burden after three days, with complete clearance after seven. Furthermore, NO-np decreased tissue IL-2, 6, 10 and TNFα, indicating earlier attenuation of the host inflammatory response and decreased tissue morbidity. Thus, topical NO-np represent an attractive alternative to systemic therapy against dermal T. rubrum infection.

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