Bacterial resistance to antimicrobial photodynamic therapy: A critical update.

Bacterial antibiotic resistance is one of the most significant challenges for public health. The increase in bacterial resistance, mainly due to microorganisms harmful to health, and the need to search for alternative treatments to contain infections that cannot be treated by conventional antibiotic therapy has been aroused. An alternative widely studied in recent decades is antimicrobial photodynamic therapy (aPDT), a treatment that can eliminate microorganisms through oxidative stress.

Biocompatibility and inflammatory response of silver tungstate, silver molybdate, and silver vanadate microcrystals.

Silver tungstate (α-AgWO), silver molybdate (β-AgMoO), and silver vanadate (α-AgVO) microcrystals have shown interesting antimicrobial properties. However, their biocompatibility is not yet fully understood. Cytotoxicity and the inflammatory response of silver-containing microcrystals were analyzed in THP-1 and THP-1 differentiated as macrophage-like cells, with the alamarBlue™ assay, flow cytometry, confocal microscopy, and ELISA.

Potential Use of Brazilian Green Propolis Extracts as New Photosensitizers for Antimicrobial Photodynamic Therapy against Cariogenic Microorganisms.

The synergic effect of and increases dental caries severity. Antimicrobial photodynamic therapy (aPDT) is a non-invasive treatment for antimicrobial aspects. However, the current photosensitizers (PS) have many downsides for dental applications.

Efficacy of the combination of P5 peptide and photodynamic therapy mediated by bixin and chlorin-e6 against Cutibacterium acnes biofilm.

In this study, the action of antimicrobial peptide (AMP) P5 and antimicrobial photodynamic therapy (aPDT) mediated by bixin and chlorin-e6 (Ce6) on Cutibacterium acnes (C. acnes) in planktonic phase and biofilm were evaluated both as monotherapies and combined therapies. Microbial viability after treatments were quantified by colony-forming units per milliliter of the sample (CFU/mL) and have demonstrated that all treatments employed exerted bactericidal activity, reducing the microbial load by more than 3 log CFU/mL, also demonstrating for the first time in the literature the antimicrobial photodynamic effect of bixin that occurs mostly through type I mechanism which was proved by the quantification of superoxide anion production.

Advanced methylene blue - nanoemulsions for in vitro photodynamic therapy on oral and cervical human carcinoma.

Photodynamic therapy (PDT) is a therapeutic modality with high contributions in the treatment of cancer. This approach is based on photophysical principles, which presents as a less invasive strategy than conventional therapies. Combined with nanotechnology, the therapy becomes more efficient because nanoparticles (NPs) have advantageous characteristics such as biocompatibility, controlled, and targeted release, promoting solubility and decreasing the toxicity and side effects involved.

Combining Coaxial Electrospinning and 3D Printing: Design of Biodegradable Bilayered Membranes with Dual Drug Delivery Capability for Periodontitis Treatment.

Periodontitis is a chronic inflammatory disease that can lead to significant destruction of tooth-supporting tissues, compromising dental function and patient's health. Although the currently employed treatment approaches can limit the advance of the disease, the development of multifunctional and hierarchically structured materials is still in demand for achieving successful tissue regeneration. Here, we combine coaxial electrospinning and 3D printing techniques to prepare bilayered zein-based membranes as a potential dual drug delivery platform for periodontal tissue regeneration.

Orodispersible Film Loaded with CRL183 Presents Anti- Biofilm Activity In Vitro.

Background: Probiotic bacteria have been emerging as a trustworthy choice for the prevention and treatment of spp. infections. This study aimed to develop and characterize an orodispersible film (ODF) for delivering the potentially probiotic CRL 183 into the oral cavity, evaluating its in vitro antifungal activity against .

Photodynamic potential of curcumin in bioadhesive formulations: Optical characteristics and antimicrobial effect against biofilms.

Background: Although Curcumin (CUR) has great potential as a photosensitizer, the low solubility in water impairs its clinical performance in photodynamic inactivation (PDI). This study sought to establish an effective antimicrobial protocol for PDI using CUR in three different bioadhesive formulations.

Methods: A CUR-loaded chitosan hydrogel with a poloxamer (CUR-CHIH), a CUR-loaded liquid crystal precursor system (CUR-LCP), a CUR-loaded microemulsion (CUR-ME), and CUR in dimethylsulfoxide (DMSO) solution (CUR-S; control formulation) were tested against in vitro and in situ oral biofilms.

Current applications of drug delivery nanosystems associated with antimicrobial photodynamic therapy for oral infections.

The oral cavity is colonized by several species of microorganisms that can cause dental caries, periodontal diseases, candidiasis, endodontic infections, and, among other diseases related to the dental field. Conventional treatment consists of mechanical removal associated with systemic administration of antimicrobials, which can cause various side effects and microbial resistance. In this context, alternative therapies have been developed, including Antimicrobial Photodynamic Therapy (aPDT).

Conjugation of superparamagnetic iron oxide nanoparticles and curcumin photosensitizer to assist in photodynamic therapy.

In this work, we describe the synthesis and characterization of the SPIONP-CUR conjugate between curcumin (CUR) and superparamagnetic iron oxide nanoparticles (SPIONPs), in addition to its application in photodynamic therapy (PDT) using a protocol free of organic solvents as a dispersant. The SPIONP-CUR conjugate was characterized by X-ray diffraction, transmission electron microscopy, zeta potential measurements, Fourier transform infrared spectroscopy, thermogravimetry, magnetometry and magnetic hyperthermia assays. The SPIONP-CUR conjugation occurred by bonding between the keto-enol moiety of CUR and the iron atoms present on the surfaces of the SPIONPs.

Influence of light intensity and irradiation mode on methylene blue, chlorin-e6 and curcumin-mediated photodynamic therapy against Enterococcus faecalis.

This study aimed to evaluate the effect of the continuous irradiation with low intensity (continuous mode) and fractioned irradiation with high intensity (fractionated mode), keeping the same dose of light by using Light Emitting Diode (LEDs) with wavelength emission centered at 450 and at 660 nm, using methylene blue (MB), chlorin-e6 (Ce) and curcumin (CUR) as photosensitizers (PSs) against planktonic phase of E. faecalis. Cell viability was assessed by counting colonies forming per mL (CFU/mL), and the quantification of reactive species was performed by fluorescence with the photodegradation rate evaluated by measurements of absorbance of PSs at different times.

Antimicrobial photodynamic therapy against metronidazole-resistant dental plaque bactéria.

The antimicrobial photodynamic therapy (aPDT) has stood out as an alternative and promising method of disinfection and has been exploited for the treatment of oral bacteria. In this study, we evaluate in vitro the action of aPDT, mediated by methylene blue, chlorin-e6, and curcumin against clinical subgingival plaques that were resistant to metronidazole. The sensitivity profile of the samples to metronidazole was analyzed by the agar dilution method.

Antimicrobial activity of RP-1 peptide conjugate with ferrocene group.

Parasitic diseases are a neglected and serious problem, especially in underdeveloped countries. Among the major parasitic diseases, Leishmaniasis figures as an urgent challenge due to its high incidence and severity. At the same time, the indiscriminate use of antibiotics by the population is increasing together with resistance to medicines.

Core-sheath nanostructured chitosan-based nonwovens as a potential drug delivery system for periodontitis treatment.

Core-sheath nanofibers were successfully prepared via coaxial electrospinning by using chitosan with well-defined structural characteristics as the shell layer and poly (vinyl alcohol) (PVA) containing tetracycline hydrochloride (TH) as the core layer. The effects of the average degree of deacetylation (DD‾) of chitosan and the post-electrospinning genipin crosslinking on physicochemical and biological properties of resulting nonwovens were evaluated. Defect-free and geometrically uniform nanofibers with diameters predominantly in the range of 100-300 nm were prepared, and transmission electron microscopy (TEM) revealed the core-sheath structures and its preservation after crosslinking.

Chlorin, Phthalocyanine, and Porphyrin Types Derivatives in Phototreatment of Cutaneous Manifestations: A Review.

Recent scientific research has shown the use of chlorin, phthalocyanines, and porphyrins derivatives as photosensitizers in photodynamic therapy in the treatment of various pathologies, including some of the major skin diseases. Thus, the main goal of this critical review is to catalog the papers that used these photosensitizers in the treatment of acne vulgaris, psoriasis, papillomavirus infections, cutaneous leishmaniasis, and skin rejuvenation, and to explore the photodynamic therapy mechanisms against these conditions alongside their clinical benefits.

Effect of Photodynamic Therapy on Microorganisms Responsible for Dental Caries: A Systematic Review and Meta-Analysis.

The aim of this study was to perform a systematic review of the literature followed by a meta-analysis about the efficacy of photodynamic therapy (PDT) on the microorganisms responsible for dental caries. The research question and the keywords were constructed according to the PICO strategy. The article search was done in Embase, Lilacs, Scielo, Medline, Scopus, Cochrane Library, Web of Science, Science Direct, and Pubmed databases.

Chitosan-Based Drug Delivery Systems for Optimization of Photodynamic Therapy: a Review.

Drug delivery systems (DDS) can be designed to enrich the pharmacological and therapeutic properties of several drugs. Many of the initial obstacles that impeded the clinical applications of conventional DDS have been overcome with nanotechnology-based DDS, especially those formed by chitosan (CS). CS is a linear polysaccharide obtained by the deacetylation of chitin, which has potential properties such as biocompatibility, hydrophilicity, biodegradability, non-toxicity, high bioavailability, simplicity of modification, aqueous solubility, and excellent chemical resistance.

Assessment of Chitosan-Based Hydrogel and Photodynamic Inactivation against Propionibacterium acnes.

Chitosan (CH) is a biopolymer that exhibits a number of interesting properties such as anti-inflammatory and antibacterial activity and is also a promising platform for the incorporation of photosensitizing agents. This study aimed to evaluate the efficacy of antimicrobial activity of chitosan hydrogel formulation alone and in combination with the methylene blue (MB) associated with antimicrobial photodynamic therapy (aPDT) against planktonic and biofilm phase of . Suspensions were sensitized with 12.

Susceptibility of Enterococcus faecalis and Propionibacterium acnes to antimicrobial photodynamic therapy.

Bacterial resistance to available antibiotics nowadays is a global threat leading researchers around the world to study new treatment modalities for infections. Antimicrobial photodynamic therapy (aPDT) has been considered an effective and promising therapeutic alternative in this scenario. Briefly, this therapy is based on the activation of a non-toxic photosensitizing agent, known as photosensitizer (PS), by light at a specific wavelength generating cytotoxic singlet oxygen and free radicals.