Zr-porphyrinic MOF PCN-224 enables sequential antibacterial and inflammation-modulating PDT for periodontitis.

Objectives: Antibiotics is the most common treatment for bacterial infections. However, bacteria can change their genetic material, develop antibiotic resistance and cannot be treated. This brings the need for new treatment methods. Antibacterial Photodynamic Therapy is becoming a promising approach to treat bacterial infections. It is based on the use of photosensitizer to be activated by light with an appropriate wavelength and it will result in reactive oxygen species which are responsible for the destruction of pathogens. In this study, Antibacterial Photodynamic Therapy was examined for the treatment of Pseudomonas aeruginosa with the help of ethanol and potassium iodide. Methods: The effect of Chlorin e6-based photoinactivation was studied on Multidrug resistant P. aeruginosa upon irradiation with 655-nm diode laser. Then ethanol and potassium iodide was added to the mechanism separately to increase the efficacy of photoinactivation. After each application, serial dilution method was used for the determination of viable cells. Results: Outcomes showed that only Antibacterial Photodynamic Therapy causes a mortality rate of 75%. Addition of ethanol causes a mortality rate of 93% and addition of potassium iodide causes a mortality rate of 99.9% with less amount of Chlorin e6 and light dose. Conclusions: Chlorin-e6 based photoinactivation did not provide high mortality rate on P. aeruginosa. The use of ethanol and potassium iodide increased the effect of photoinactivation. The highest mortality rate was obtained with potassium iodide. It was understood that potassium iodide was a better concomitant agent to increase the bactericidal effect of Antibacterial Photodynamic Therapy on P. aeruginosa.

We report the sonochemical synthesis of MOF (metal organic framework) nanoparticles of 30–200 nm in size and electrospraying of those particles on electrospun nanofibers to process a MOF-attached nanofibrous membrane. This membrane displayed significant selectivity towards CO2 and capacity of adsorbing with 4000–5000 ppm difference from a mixed gas flow of 1% CO2 and 99% N2. Applying ultrasonic waves during the MOF synthesis offered rapid dispersion and formation of crystalline MOF nanoparticles in room temperature. The MOF nanoparticles of 100–200 nm in size displayed higher surface area and adsorption capacity comparing to that of 30–60 nm in size. Nanofibrous membrane was produced by electrospinning of MOF blended PAN solution followed by electrospraying of additional MOF nanoparticles. This yielded uniform MOF deposition on nanofibers, occurred due to electrostatic attraction between highly charged nanoparticles and conductive nanofibers. A test bench for real-time CO2 adsorption at room temperature was built with non-dispersive Infrared (NDIR) CO2 sensors. Comparative tests were performed on the membrane to investigate its enhanced adsorption capacity. Three layers of the as-produced membranes displayed CO2 adsorption for approximately 2 h. Thermogravimetric analysis (TGA) of the membrane showed the thermal stability of the MOF and PAN up to 290 and 425 °C, respectively.

Antibacterial Photodynamic therapy (APDT) is a process utilizing light and light sensitive agents (named photosensitizer (PS)) and is usually applied in an oxygen-rich environment. The energy of the photons is absorbed by the photosensitizer and subsequently transferred to surrounding molecules. Consequently, reactive oxygen species and free radicals are formed. These oxidative molecules can damage bacterial macromolecules such as proteins, lipids and nucleic acids and may result in bacterial killing. Unlike antibiotics, APDT as a novel technique does not lead to the selection of mutant resistant strains, hence it has appealed to researchers in this field. The type of PS used in APDT is a major determinant regarding outcome. In this review, various types of PS that are used in antimicrobial Photodynamic therapy will be discussed. PSs are classified based on their chemical structure and origin. Synthetic dyes such as methylene blue and toluidine blue are the most commonly used photosensitizers in Antibacterial Photodynamic therapy (APDT). Other photosensitizers including natural PSs (e.g. curcumin and hypericin) and tetra-pyrrole structures like phthalocyanines and porphyrins have also been studied. Furthermore, nanostructures and their probable contribution to APDT will be discussed.

The escalating threat of antibiotic resistance has prompted the search for alternative antibacterial therapies. Antibacterial photodynamic therapy (aPDT), which utilizes light-activated photosensitizers to generate reactive oxygen species (ROS), offers a promising, non-invasive approach. The aim of this review is to analyze recent advances in nanoparticle-mediated aPDT and synthesize crucial design principles necessary to overcome the current translational barriers, thereby establishing a roadmap for future clinically applicable antimicrobial treatments. Emerging nanoparticle platforms, including upconverting nanoparticles (UCNPs), carbon dots (CDs), mesoporous silica nanoparticles (MSNs), liposomes, and metal–organic frameworks (MOFs), have demonstrated improved photosensitizer delivery, enhanced ROS generation, biofilm disruption, and targeted bacterial eradication. Synergistic effects are observed when aPDT is integrated with photothermal, chemodynamic, or immunotherapeutic approaches. The review further examines the mechanisms of action, biocompatibility, and antibacterial performance of these nanoparticle systems, particularly against drug-resistant strains and in challenging environments such as chronic wounds. Overall, nanomaterial-mediated aPDT presents a highly promising and versatile solution to antimicrobial resistance. Future perspectives include the integration of artificial intelligence to personalize aPDT by predicting optimal light dosage and nanoplatform design based on patient-specific data, rigorous clinical validation through trials, and the development of safer, more efficient nanoparticle platforms.

MMP-9 deficiency accelerates the progress of periodontitis

Visible light-activated cobalt phthalocyanine/UiO-67 composite: A novel approach to photodynamic antibacterial therapy.

The aim of this study was to test the null hypothesis that there is no difference in the alveolar bone thickness, bone loss or incidence of fenestrations between upper and lower incisors in skeletal Class I bidentoalveolar protrusive patients before orthodontic treatment. Three-dimensional (3D) cone beam CT (CBCT) images were taken of 24 patients from the Republic of Korea (17 females and 7 males). Reformatted CBCT images were used to measure labial and lingual alveolar bone thickness (ABT) of the 4 upper incisors and 4 lower incisors of the 24 patients (total n = 192 incisors) at every 1/10 of root length (Level 0, cementoenamel junction (CEJ) area; Level 10, root apex area) as well as alveolar bone area (ABA) and alveolar bone loss (%BL) rate to dental root length. The numbers of fenestration teeth were also tallied. All anterior teeth were supported by <1 mm of ABT on the labial surfaces up to root length Level 8. ABA was statistically greater on the lingual aspect than the labial aspect in lower incisors. The %BL was 26.98% in the lower labial region, 19.27% in upper labial aspect and most severe on the lower lingual plate 31.25% compared with the labial plate. There were no significant differences in %BL between subgroups when categorized by sex or age. Fenestrations were 1.37 times more frequent on lower incisors (37) than upper incisors (27). The null hypothesis was rejected, confirming that incisor periodontal support is poor and alveolar bone loss is severe even prior to the start of orthodontic treatment. Careful diagnosis using 3D CBCT images is needed to avoid iatrogenic degeneration of periodontal support around anterior teeth, particularly in the lower lingual bone plate region.

Persistent biofilm infections pose a critical health threat with their relentless presence and amplified antibiotic resistance. Traditional antibacterial photodynamic therapy can inhibit bacteria extracellularly but struggles to control biofilm formation and virulence. Thus, there is an urgent need to develop photosensitizers, such as ultra‐small gold nanoclusters (AuNCs), that can penetrate biofilms and internalize into bacteria. However, AuNCs still face the challenge of insufficient reactive oxygen species (ROS) production and limited near‐infrared light absorption. This study develops a model of indocyanine green (ICG)‐sensitized AuNCs with atomic‐precision size effect. This approach achieved near‐infrared light absorption while inhibiting radiation transitions, thereby regulating the generation of ROS. Notably, different‐sized AuNCs (Au10NCs, Au15NCs, Au25NCs) yielded varied ROS types, resulting from different energy level distributions and electron transfer rates. ICG‐Au15NCs achieved a treatment efficacy of 99.94% against Staphylococcus aureus infections in vitro and significantly accelerated wound healing in vivo. Moreover, this study highlights the unique role of ICG‐AuNCs in suppressing quorum sensing, virulence, and ABC transporters compared to their larger counterparts. This strategy demonstrates that atomic‐precision size effect of AuNCs paves the way for innovative approaches in antibacterial photodynamic therapy for infection control.

Isomeric sp2-C-conjugated porous organic polymer-mediated photo- and sono-catalytic detoxification of sulfur mustard simulant under ambient conditions

The relationship between bone mineral density and tooth loss in men is unclear. The aim of this retrospective cohort study was to determine if relative metacarpal bone area (MCA) predicts tooth loss in a cohort of 273 male participants in the Dental Longitudinal Study and Normative Aging Study of the Department of Veterans Affairs. Outer and inner cortical bone widths of the middle metacarpal of the nondominant hand were measured on anteroposterior hand radiographs approximately 11 y apart. Baseline MCA was computed and categorized into quartiles. The men were followed from 1971 to 2015. Incident tooth loss during 2 intervals was examined: concurrent with the MCA measurements and long term over the total follow-up (17 ± 7 y). Radiographic alveolar bone loss (ABL) was measured on periapical radiographs as a percentage of the distance from the cementoenamel junction to root apex, and the number of teeth with ABL >40% was computed. Negative binomial generalized linear regression models estimated the mean number of teeth with ABL >40% and the number lost (concurrent and total), controlling for age, smoking, number of teeth at baseline, percentage teeth with ≥1 decayed/filled surface, and years of follow-up. At baseline, MCA was inversely related to number of teeth with >40% ABL. Men in the lowest MCA quartile (Q1) lost the most teeth, both concurrent with MCA measurements and long term, but the association differed by caries level (≤55% or >55% decayed/filled teeth). At the low caries level, the numbers lost in Q1 were 29% greater than in the highest MCA quartile (Q4). At the high caries level, the numbers lost in Q1 were more than twice those in Q4. Associations were attenuated when further controlled for number of teeth with ABL>40%. These findings suggest that systemic bone status plays a role in tooth loss and that the association may be mediated by alveolar bone loss. Knowledge Transfer Statement: Low relative metacarpal bone area was related to loss of alveolar bone and incident tooth loss in men. This information extends previous research, primarily studies of women, showing that osteoporosis adversely affects oral health. Knowledge of a patient's systemic bone status may be important for managing his or her periodontal disease. Tooth loss in the absence of periodontal inflammation may signify systemic bone loss. Interprofessional communication is central to maintaining optimal oral and bone health.

A post-polymerization method for metal–organic frameworks (MOFs) and silica nanoparticles have been developed to produce super-acidic solid nanoparticle. Thus, silica and amino-functionalized metal−organic framework [NH2-MIL-101(Al)] were functionalized with 4.4′-Azobis(4-cyanovaleric acid) (ACVA) from hydroxyl and amine groups to yield initiator anchored silica and MOF nanoparticles. Then, sulfonated polymer/MOF and sulfonated polymer/silica hybrid nanoparticles were prepared by free radical polymerization of 2-acrylamido-2-methyl-1-propane sulfonic acid [(MOF-g-PAMPS) and (Si-g-PAMPS)], initiated onto the surfaces of initiator functionalized nanoparticles. Synthesis and modification of nanoparticles were characterized by fourier transform infrared (FTIR), thermogravimetric analysis (TGA). Also, the attachment of ACVA modifier agent on the surface of silica nanoparticles was studied using X-ray photoelectron spectroscopy (XPS). FTIR and TGA results indicated that AMPS monomer was successfully grafted onto the MOF and silica nanoparticles. The grafting efficiency of PAMPS polymer onto the silica and MOF nanoparticles were estimated from TGA thermograms to be 17 and 35 % for silica and MOF nanoparticles, respectively. Morphology of MOF and silica nanoparticles before and after modification processes were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively.

Antibacterial photodynamic therapy (APDT) has emerged as one of the intriguing strategies to combat bacterial resistance. However, the antibacterial efficacy of APDT is found to be severely impacted by the hydrogen sulfide (H2 S)-overproduced bacterial infection microenvironment. Herein, a multifunctional APDT platform is developed by assembling Cu2+ and chlorin e6 (Ce6), which exhibits unique H2 S-activatable fluorescence (FL) and antibacterial features. Noteworthily, the assembly conditions are crucial for achievement of Cu-Ce6 nanoassemblies (NAs) with the on-demand responsive properties. The quenched FL and photosensitization of Cu-Ce6 NAs can be selectively activated by the overexpressed H2 S in infected area, enabling specific recognition of bacterial infection and localized antibacterial therapy with minimized side effects. Significantly, amplified oxidative stress is achieved owning to the effective consumption of H2 S by Cu2+ in the NAs, leading to an enhanced APDT. The antibacterial mechanisms including broad-spectrum APDT activity of released Ce6, inherent sterilization effects of produced copper polysulfides and the accompanying disturbance of bacterial sulphide metabolism are further identified. This study may pave a new avenue for the rational design of intelligent APDT platform using minimalist biological building units and thus facilitating the clinical translation of nano-antibacterial agents.

Alveolar bone loss is caused by a host response to periodontal pathogens, and its progression is often enhanced by systemic conditions such as insulin resistance. Alveolar bone dehiscence has been observed in KK-A(y) mice, which are metabolic syndrome model mice with type 2 diabetes. The aim of this study was to investigate inducements responsible for alveolar bone dehiscence in the KK-A(y) mice. The expression of endothelial nitric oxide synthase in the mandibles of mice was detected using immunohistochemical staining and the reverse transcription-polymerase chain reaction. After administration of N-acetylcysteine, an antioxidant, to KK-A(y) mice, alveolar bone loss and the expression of endothelial nitric oxide synthase protein in gingival keratinocytes and of hydrogen peroxide concentrations in plasma, were analyzed. The effect of hydrogen peroxide on endothelial nitric oxide synthase expression in keratinocytes was examined using cultured keratinocytes. The expression of endothelial nitric oxide synthase was decreased in gingival keratinocytes from KK-A(y) mice compared with gingival keratinocytes from control mice. Administration of N-acetylcysteine to the mice restored endothelial nitric oxide synthase expression in the gingival keratinocytes, suppressed the alveolar bone loss and decreased the hydrogen peroxide concentrations in plasma without the improvement of obesity or diabetes. In vitro, stimulation with hydrogen peroxide decreased the expression level of endothelial nitric oxide synthase in cultured keratinocytes, which was restored by the addition of N-acetylcysteine. Reactive oxygen species, such as hydrogen peroxide, are responsible for the alveolar bone loss accompanied by decreased endothelial nitric oxide synthase expression in KK-A(y) mice. Therefore, we propose a working hypothesis that the generation of oxidative stress is an underlying systemic condition that enhances alveolar bone loss in periodontitis occurring as a complication of diabetes.

Skin, our first interface to the external environment, is subjected to oxidative stress caused by a variety of factors such as solar ultraviolet, infrared and visible light, environmental pollution, including ozone and particulate matters, and psychological stress. Excessive reactive species, including reactive oxygen species and reactive nitrogen species, exacerbate skin pigmentation and aging, which further lead to skin tone unevenness, pigmentary disorder, skin roughness and wrinkles. Besides these, skin microbiota are also a very important factor ensuring the proper functions of skin. While environmental factors such as UV and pollutants impact skin microbiota compositions, skin dysbiosis results in various skin conditions. In this review, we summarize the generation of oxidative stress from exogenous and endogenous sources. We further introduce current knowledge on the possible roles of oxidative stress in skin pigmentation and aging, specifically with emphasis on oxidative stress and skin pigmentation. Meanwhile, we summarize the science and rationale of using three well-known antioxidants, namely vitamin C, resveratrol and ferulic acid, in the treatment of hyperpigmentation. Finally, we discuss the strategy for preventing oxidative stress-induced skin pigmentation and aging.

ATP-responsive zeolitic imidazolate framework-90 for superoxide dismutase delivery to reduce reactive oxygen species in MG-63 cells