Therapeutic textiles: A promising approach for human skin dysbiosis?

The close interaction between skin and clothing has become an attractive cornerstone for the development of therapeutic textiles able to alleviate skin disorders, namely those correlated to microbiota dysregulation. Skin microbiota imbalance is known in several skin diseases, including atopic dermatitis (AD), psoriasis, seborrheic dermatitis, rosacea, acne and hidradenitis suppurative (HS). Such microbiota dysregulation is usually correlated with inflammation, discomfort and pruritus. Although conventional treatments, that is, the administration of steroids and antibiotics, have shown some efficacy in treating and alleviating these symptoms, there are still disadvantages that need to be overcome. These include their long-term usage with side effects negatively impacting resident microbiota members, antibiotic resistance and the elevated rate of recurrence. Remarkably, therapeutic textiles as a non-pharmacological measure have emerged as a promising strategy to treat, alleviate the symptoms and control the severity of many skin diseases. This systematic review showcases for the first time the effects of therapeutic textiles on patients with skin dysbiosis, focusing on efficacy, safety, adverse effects and antimicrobial, antioxidant and anti-inflammatory properties. The main inclusion criteria were clinical trials performed in patients with skin dysbiosis who received treatment involving the use of therapeutic textiles. Although there are promising outcomes regarding clinical parameters, safety and adverse effects, there is still a lack of information about the impact of therapeutic textiles on the skin microbiota of such patients. Intensive investigation and corroboration with clinical trials are needed to strengthen, define and drive the real benefit and the ideal biomedical application of therapeutic textiles.

Probiotic Adhesion to Skin Keratinocytes and Underlying Mechanisms.

The effects of probiotics on the skin are not yet well understood. Their topical application and benefits derived thereafter have recently been investigated. Improvements in different skin disorders such as atopic dermatitis, acne, eczema, and psoriasis after their use have, however, been reported. One of the mechanisms through which such benefits are documented is by inhibiting colonization by skin pathogens. Bacterial adhesion is the first step for colonization to occur; therefore, to avoid pathogenic colonization, inhibiting adhesion is crucial. In this study, invasion and adhesion studies have been carried out using keratinocytes. These showed that Escherichia coli is not able to invade skin keratinocytes, but adhered to them. Lacticaseibacillus rhamnosus and Propioniferax innocua decreased the viable counts of the three pathogens under study. L. rhamnosus significantly inhibited S. aureus adhesion. P. innocua did not inhibit pathogenic bacteria adhesion, but when added simultaneously with S. aureus (competition assay) a significant adhesion reduction (1.12 ± 0.14 log10CFU/mL) was observed. Probiotic bacteria seem to use carbohydrates to adhere to the keratinocytes, while S. aureus uses proteins. Lacticaseibacillus rhamnosus showed promising results in pathogen inhibition in both in vitro and ex vivo experiments and can potentially be used as a reinforcement of conventional therapies for skin dysbiosis.

Image Analysis Semi-Automatic System for Colony-Forming-Unit Counting.

BACKGROUND: Accurate quantitative analysis of microorganisms is recognized as an essential tool for gauging safety and quality in microbiology settings in a wide range of fields. The enumeration process of viable microorganisms via traditional culturing techniques are methodically convenient and cost-effective, conferring high applicability worldwide. However, manual counting can be time-consuming, laborious and imprecise. Furthermore, particular cases require an urgent and accurate response for effective processing. METHODS: To reduce time limitations and discrepancies, this work introduces an image processing method capable of semi-automatically quantifying the number of colony forming units (CFUs). This rapid enumeration technique enables the technician to provide an expeditious assessment of the microbial load of a given sample. To test and validate the system, three bacterial species were cultured, and a labeled database was created, with subsequent image acquisition. RESULTS: The system demonstrated acceptable classification measures; the mean values of Accuracy, Recall and F-measure were: (1) 95%, 95% and 0.95 for E. coli; (2) 91%, 91% and 0.90 for P. aeruginosa; and (3) 84%, 86% and 0.85 for S. aureus. CONCLUSIONS: Evidence related to the time-saving potential of the system was achieved; the time spent on quantification tasks of plates with a high number of colonies might be reduced to a half and occasionally to a third.

Distinction of Different Colony Types by a Smart-Data-Driven Tool.

BACKGROUND: Colony morphology (size, color, edge, elevation, and texture), as observed on culture media, can be used to visually discriminate different microorganisms. METHODS: This work introduces a hybrid method that combines standard pre-trained CNN keras models and classical machine-learning models for supporting colonies discrimination, developed in Petri-plates. In order to test and validate the system, images of three bacterial species (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) cultured in Petri plates were used. RESULTS: The system demonstrated the following Accuracy discrimination rates between pairs of study groups: 92% for Pseudomonas aeruginosa vs. Staphylococcus aureus, 91% for Escherichia coli vs. Staphylococcus aureus and 84% Escherichia coli vs. Pseudomonas aeruginosa. CONCLUSIONS: These results show that combining deep-learning models with classical machine-learning models can help to discriminate bacteria colonies with good accuracy ratios.

Chitosan and Hydroxyapatite Based Biomaterials to Circumvent Periprosthetic Joint Infections.

Every year, worldwide, millions of people suffering from joint pain undergo joint replacement. For most patients, joint arthroplasty reduces pain and improve function, though a small fraction will experience implant failure. One of the main reasons includes prosthetic joint infection (PJI), involving the prosthesis and adjacent tissues. Few microorganisms (MO) are required to inoculate the implant, resulting in the formation of a biofilm on its surface. Standard treatment includes not only removal of the infected prosthesis but also the elimination of necrotic bone fragments, local and/or systemic administration of antibiotics, and revision arthroplasty with a new prosthesis, immediately after the infection is cleared. Therefore, an alternative to the conventional therapeutics would be the incorporation of natural antimicrobial compounds into the prosthesis. Chitosan (Ch) is a potential valuable biomaterial presenting properties such as biocompatibility, biodegradability, low immunogenicity, wound healing ability, antimicrobial activity, and anti-inflammatory potential. Regarding its antimicrobial activity, Gram-negative and Gram-positive bacteria, as well as fungi are highly susceptible to chitosan. Calcium phosphate (CaP)-based materials are commonly utilized in orthopedic and dentistry for their excellent biocompatibility and bioactivity, particularly in the establishment of cohesive bone bonding that yields effective and rapid osteointegration. At present, the majority of CaP-based materials are synthetic, which conducts to the depletion of the natural resources of phosphorous in the future due to the extensive use of phosphate. CaP in the form of hydroxyapatite (HAp) may be extracted from natural sources as fish bones or scales, which are by-products of the fish food industry. Thus, this review aims to enlighten the fundamental characteristics of Ch and HAp biomaterials which makes them attractive to PJI prevention and bone regeneration, summarizing relevant studies with these biomaterials to the field.

A quitosana como biomaterial odontológico: estado da arte / Chitosan as a dental biomaterial: state of the art

A impossibilidade de erradicar completamente os microrganismos da cavidade oral ou dos canais radiculares estimula a procura de novos materiais que permitam cada vez mais eficazmente, controlar ou prevenir o aparecimento de infeções. A quitosana é um biopolímero com uma estrutura química e características únicas que permitem que apresente excelente biocompatibilidade e que seja facilmente processado. A panóplia de aplicações é tão fascinante como ainda mal conhecida. A constatação do potencial e do valor industrial deste biopolímero conduziu à sua utilização em muitas aplicações de interesse tecnológico e, de uma forma acentuada, na área biomédica. As suas propriedades anti-oxidantes, anti-microbianas, anti-inflamatórias, cicatrizante e de inibição da formação de biofilmes tornam a sua aplicação na odontologia particularmente interessante. Com este trabalho pretendeu-se rever a literatura existente sobre aplicações da quitosana na área odontológica.

The impossibility to completely eradicate the microorganisms from the oral cavity or from root canals has stimulated the search for new materials that efficiently prevent infections. Chitosan is a biopolymer with a unique chemical structure that renders it with outstanding biocompatibility and easy processing characteristics. The array of applications available is fascinating, as well as poorly understood. The industrial possibilities led to its use in several applications of varied technological interests, and especially in the biomedical area. Furthermore, its anti-oxidant, anti-microbial, anti-inflammatory, wound healing and biofilm inhibiting properties make it especially attractive to be used in the odontological arena. In this review, we address the state of the art on chitosan-based applications for odontology.