Topical Gentamicin for the Treatment of Genetic Skin Diseases

The interactive effects of medicinal dyes with conventional antimicrobials against skin pathogens

AIMS

This study aimed to explore potential synergistic effects of medicinal dyes with antimicrobials against pathogens responsible for skin infections.

METHODS AND RESULTS

Antimicrobial testing was conducted using minimum inhibitory concentrations and minimum bactericidal/fungicidal concentration assays. The fractional inhibitory index (ΣFIC) of combinations was calculated, and isobolograms were constructed on selected combinations. Toxicity studies were conducted using the brine-shrimp lethality assay. Combination (1:1 ratio) studies noted that 26% of dye-antibiotic combinations were synergistic against the Gram-positive strains, 15% against the Gram-negative strains, and 14% against the yeasts. The Mercurochrome: Betadine® combination noted synergy at ratios against all the Staphylococcus aureus strains with ΣFIC values ranging from 0.05 to 0.48. The combination of Gentian violet with Gentamycin noted a 15-fold decrease in toxicity, and a selectivity index of 977.50 against the Escherichia coli (DSM 22314) strain. Time-kill studies were conducted on the combinations with the highest safe selectivity index (SI) value and lowest safe SI value i.e. Gentian violet with Gentamycin and Malachite green with Neomycin. Both combinations demonstrated better antimicrobial activity in comparison to the independent values and the controls.

CONCLUSION

This study highlights the potential for medicinal dye combinations as a treatment for skin infections.

pH-sensitive bilayer electrospun nanofibers based on ethyl cellulose and Eudragit S-100 as a dual delivery system for treatment of the burn wounds; preparation, characterizations, and in-vitro/in-vivo assessment

A pH-sensitive bilayer electrospun nanofibrous mat containing both antibiotic (gentamicin sulfate, GEN) and non-steroidal anti-inflammatory (diclofenac sodium, DIC) drugs was fabricated for burn wound dressing by electrospinning technique, in which ethyl cellulose (EC) and ethyl cellulose/Eudragit S-100 (EC/ES-100) formed the top and bottom layers, respectively. The fabricated pH-sensitive bilayer electrospun nanofibrous mats were characterized from aspects of both structure and efficiency. Physicochemical properties were investigated via SEM, FTIR, and TGA. The swelling ratio and in vitro drug release of the fabricated nanofibrous mats were studied in different pHs. MTT was applied to assess the safety of the fiber mats. Finally, the in vivo efficiency of the designed pH-sensitive bilayer electrospun nanofibrous mats was examined on the male Wistar rats. Based on the histological analysis and wound healing test (in vivo animal experiments), the (ES100/EC-DIC/GEN)-(EC) pH-sensitive bilayer nanofibrous mat displayed faster wound healing than other bilayer nanofibrous mat. As a result, (ES100/EC-DIC/GEN)-(EC) bilayer nanofibrous mat with pH-responsion could accelerate the burn wound healing process via decreasing the adverse effects of GEN and DIC as topical antimicrobial and anti-inflammatory agents, receptively.

No country for old antibiotics! Antimicrobial peptides (AMPs) as next-generation treatment for skin and soft tissue infection

In recent years, the unprecedented rise of bacterial antibiotic resistance together with the lack of adequate therapies have made the treatment of skin infections and chronic wounds challenging, urging the scientific community to focus on the development of new and more efficient treatment strategies. In this context, there is a growing interest in the use of natural molecules with antimicrobial features, capable of supporting wound healing i.e., antimicrobial peptides (AMPs), for the treatment of skin and soft tissue infections. In this review, we give a short overview of the bacterial skin infections as well as some of the classic treatments used for topical application. We then summarize the AMPs classes, stressing the importance of the appropriate selection of the peptides based on their characteristics and physicochemical properties in order to maximize the antibacterial efficacy of the therapeutic systems against multi-drug resistant pathogens. Additionally, the present paper provides a comprehensive and rigorous assessment of the latest clinical trials investigating the efficacy of AMPs in the treatment of skin and soft tissue infections, highlighting the relevant outcomes. Seeking to obtain novel and improved compounds with synergistic activity, while also decreasing some of the known side effects of AMPs, we present two employed strategies using AMPs: (i) AMPs-conjugated nanosystems for systemic and topical drug delivery systems and (ii) antibiotics-peptide conjugates as a strategy to overcome antibiotics resistance. Finally, an important property of some of the AMPs used in wound treatment is highlighted: their ability to help in wound healing by generally promoting cell proliferation and migration, and in some cases re-epithelialization and angiogenesis among others. Thus, as the pursuit of improvement is an ongoing effort, this work presents the advances made in the treatment of skin and soft tissue infections along with their advantages and limitations, while the still remaining challenges are addressed by providing future prospects and strategies to overcome them.

Nonsense Suppression Therapy: An Emerging Treatment for Hereditary Skin Diseases

Nonsense mutations cause the premature termination of protein translation via premature termination codons (PTCs), leading to the synthesis of incomplete functional proteins and causing large numbers of genetic disorders. The emergence of nonsense suppression therapy is considered to be an effective method for the treatment of hereditary diseases, but its application in hereditary skin diseases is relatively limited. This review summarizes the current research status of nonsense suppression therapy for hereditary skin diseases, and discusses the potential opportunities and challenges of applying new technologies related to nonsense suppression therapy to dermatology. Further research is needed into the possible use of nonsense suppression therapy as a strategy for the safer and specific treatment of hereditary skin diseases.

Two novel mutations of SERPINB7 in eight cases of Nagashima-type palmoplantar keratosis in the Chinese population

Nagashima‐type palmoplantar keratosis (NPPK) is a diffuse, autosomal recessive, and non‐epidermolytic palmoplantar keratosis caused by mutations in the SERPINB7 gene, a member of the serine protease inhibitor superfamily. Genetic studies and case reports suggest that NPPK is the most common palmoplantar keratosis in East Asia but rare in Western countries. This study reports eight NPPK patients in seven pedigrees of the Chinese Han ethnicity with two novel (c.530T>C and c.643A>G) and two recurrent mutations (c.796C>T and c.455G>T) in SERPINB7. The diagnosis of NPPK is now well‐defined because of the typical manifestations and pathogenic gene tests. However, its pathomechanism is still obscure, and treatment remains a challenge. This study reviewed all 15 pathogenic mutations and related data in the 1000 Genomes Project to elucidate the founder effect of SERPINB7. Also, several latest cases of NPPK in areas outside East Asia are presented, including France, Finland, and Thailand. Further clinical investigation and genetic studies are crucial for identifying the pathomechanism of NPPK. Also, large‐scale control studies are required to determine the safety and curative effects of available therapies.

Application of topical gentamicin-a new era in the treatment of genodermatosis

BACKGROUND

The clinical use of gentamicin always lies in its antimicrobial activity in the past as an aminoglycoside antibiotic. However, in the past decade, there were considerable interests in therapeutic approaches in treating hereditary diseases. Some of the genodermatosis is caused by nonsense mutations that create premature termination codons and lead to the production of truncated or non-functional proteins. Gentamicin could induce readthrough of nonsense mutations and enable the synthesis of full-length proteins. We focus on previous publications on topical application of gentamicin and review its utility in genetic skin diseases.

DATA SOURCES

We search the MEDLINE through PubMed, EMBASE databases, and the Clinical Trials Registry Platform from January 1960 to July 2020 using the key search terms "gentamicin, topical gentamicin, genodermatosis, genetic skin diseases".

RESULTS

The application of gentamicin in genodermatosis yielded promising results, both in vivo and in vitro, including Nagashima-type palmoplantar keratosis, epidermolysis bullosa, Hailey-Hailey disease, hereditary hypotrichosis simplex of the scalp, etc. CONCLUSIONS: Topical gentamicin is a potential treatment option for genodermatosis caused by nonsense mutation.

Nagashima-Type Palmoplantar Keratosis: Clinical Characteristics, Genetic Characterization, and Clinical Management

Nagashima-type palmoplantar keratosis (NPPK) is the most prevalent palmoplantar keratoderma (PPK) in East Asia. Homozygous or compound heterozygous loss-of-function mutations in serpin peptidase inhibitor, clade B (ovalbumin), and member 70 (SERPINB7), which encodes members of the serine protease inhibitor superfamily, have been identified as the cause of NPPK. Clinical manifestations of NPPK include well-demarcated erythema, mild to moderate hyperkeratosis on the whole palm, and sole with transgrediens, extending to the dorsal surfaces of the hands and feet, inner wrists, ankles, and the Achilles tendon areas. In this study, we perform a review of relevant clinical cases aimed at elucidating the clinical characteristics, genetic characterization, differential diagnoses, and clinical management of NPPK. A better understanding of the clinical characteristics and pathogenic gene characterization of NPPK will enhance the diagnosis of NPPK, identify related diseases, and inform on the precise therapy and prognosis. Moreover, it will promote the awareness of NPPK in non-Asian regions.

Are Antimicrobial Peptide Dendrimers an Escape from ESKAPE?

Significance: The crisis of antimicrobial resistance (AMR) increases dramatically despite all efforts to use available antibiotics or last resort antimicrobial agents. The spread of the AMR, declared as one of the most important health-related issues, warrants the development of new antimicrobial strategies. Recent Advances: Antimicrobial peptides (AMPs) and AMP dendrimers (AMPDs), as well as polymer dendrimers are relatively new and promising strategies with the potential to overcome drug resistance issues arising in ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) colonizing chronic wounds. Critical Issues: AMPs-AMPDs suffer from limited efficacy, short-lasting bioactivity, and concerns of toxicity. To circumvent these drawbacks, their covalent coupling to biopolymers and/or encapsulation into different drug carrier systems is investigated, with a special focus on topical applications. Future Directions: Scientists and the pharmaceutical industry should focus on this challenging subject to either improve the activity of existing antimicrobial agents or find new drug candidates. The focus should be put on the discovery of new drugs or the combination of existing drugs for a better synergy, taking into account all kinds of wounds and existing pathogens, and more specifically on the development of next-generation antimicrobial peptides, encompassing the delivery carrier toward improved pharmacokinetics and efficacy.

Hailey-Hailey Disease: An Update Review with a Focus on Treatment Data

Hailey-Hailey disease is a rare blistering dermatosis first described in 1939 by the brothers Howard and Hugh Hailey. Its incidence is estimated at 1/50,000. The inheritance is autosomal dominant with complete penetrance, but a variable expressivity in affected family members. Clinically, Hailey-Hailey disease presents between the third and fourth decade as flaccid vesicles and blisters on erythematous skin, giving rise to erosions, fissures, and vegetations. Maceration and superinfections are frequent. The lesions are typically distributed symmetrically within intertriginous regions such as the retroauricular folds, lateral aspects of the neck, axillae, umbilicus, inguinal, and perianal regions. The disease is characterized by a chronic relapsing course with spontaneous remissions and multiple recurrences. Severe disease can be very frustrating and have a major psychological and social impact. Given the dearth of evidence-based guidelines and large clinical trials, the assessment of the efficacy and safety of treatments is difficult. Treatments include topical and systemic agents, and procedural therapy such as lasers and surgery. This review provides a systematic search of the literature with a focus on classical and emerging treatment options for Hailey-Hailey disease.

Hereditary Palmoplantar Keratoderma: A Practical Approach to the Diagnosis

The ridged skin of the palms and soles has several unique features: (i) presence of dermatoglyphics created by alternating ridges and grooves forming a unique pattern, (ii) presence of the highest density of eccrine sweat glands and absence of pilosebaceous units, and (iii) differential expression of keratins compared to the glabrous skin. These features explain the preferential localization of palmoplantar keratoderma (PPK) and several of its characteristic clinical features. PPK develops as a compensatory hyperproliferation of the epidermis and excessive production of stratum corneum in response to altered cornification of the palmoplantar skin due to mutations in the genes encoding several of the proteins involved in it. PPK can manifest as diffuse, focal, striate, or punctate forms per se or as a feature of several dermatological or systemic diseases. There is a wide genetic and phenotypic heterogeneity in hereditary PPK, due to which reaching an accurate diagnosis only on the basis of clinical features may be sometimes challenging for the clinicians in the absence of molecular studies. Nevertheless, recognizing the clinical patterns of keratoderma, extent of involvement, degree of mutilation, and associated appendageal and systemic involvement may help in delineating different forms. Molecular studies, despite high cost, are imperative for accurate classification, recognizing clinical patterns in resource poor settings is important for appropriate diagnosis, genetic counseling, and management. This review intends to develop a practical approach for clinical diagnosis of different types of hereditary PPK with reasonable accuracy.