A Novel Z-Scheme Heterostructured Bi2 S3 /Cu-TCPP Nanocomposite with Synergistically Enhanced Therapeutics against Bacterial Biofilm Infections in Periodontitis

Porphyrin-based antibacterial photodynamic therapy (aPDT) has found widespread applications in treating periodontitis. However, its clinical use is limited by poor energy absorption, resulting in limited reactive oxygen species (ROS) generation. To overcome this challenge, a novel Z-scheme heterostructured nanocomposite of Bi2 S3 /Cu-TCPP is developed. This nanocomposite exhibits highly efficient light absorption and effective electron-hole separation, thanks to the presence of heterostructures. The enhanced photocatalytic properties of the nanocomposite facilitate effective biofilm removal. Theoretical calculations confirm that the interface of the Bi2 S3 /Cu-TCPP nanocomposite readily adsorbs oxygen molecules and hydroxyl radicals, thereby improving ROS production rates. Additionally, the photothermal treatment (PTT) using Bi2 S3 nanoparticles promotes the release of Cu2+ ions, enhancing the chemodynamic therapy (CDT) effect and facilitating the eradication of dense biofilms. Furthermore, the released Cu2+ ions deplete glutathione in bacterial cells, weakening their antioxidant defense mechanisms. The synergistic effect of aPDT/PTT/CDT demonstrates potent antibacterial activity against periodontal pathogens, particularly in animal models of periodontitis, resulting in significant therapeutic effects, including inflammation alleviation and bone preservation. Therefore, this design of semiconductor-sensitized energy transfer represents an important advancement in improving aPDT efficacy and the treatment of periodontal inflammation.

In situ infrared CO detection using silver loaded EMT zeolite films

Ag cluster catalyst-based oxidation of CO to CO2 is an important way to remove CO at low temperatures. However, the instability of silver clusters seriously limits the catalytic application. Herein, sub-nanosized EMT zeolite nanoparticles served as Ag cluster carriers with high selectivity, low coordination, and unsaturated atom active sites. The silver clusters with sub-nanometer size can be controlled with different charge states and loading rates. A detection film with 500 nm was further prepared by assembling the Ag-EMT composites with a small amount of Nalco as an adhesive. For CO detection, a completely enclosed gas sensing device based on in situ infrared spectroscopy was employed without air interference. CO was accurately introduced into the detection chamber and catalysed into CO2 by silver loaded EMT zeolite films, and the whole process was accurately recorded by infrared spectroscopy. CO with a detection range of 2-50 ppm was realized, showing great application potential in gas monitoring.

Upconversion fluorescence-based PDT nanocomposites with self-oxygenation for malignant tumor therapy

Upconversion fluorescence-based-PDT nanocomposites with self-oxygenation have excellent anti-tumor properties, including deep penetration of the excitation light source and the ability to remodel the anoxic microenvironment, and has feasibility in clinical application.

Nanometric Surface-Selective Regulation of Au/In2O3 Nanofibers as an Exhaled H2S Chemiresistor for Periodontitis Diagnosis

As one of the most prevalent diseases in the world, timely early intervention for periodontitis is a great challenge because the indicator is imperceptible. The exhaled H₂S is considered to be a promising biomarker for fast and invasive periodontitis screening; however, the high-performance H₂S gas sensor with excellent selectivity and sensitivity which is applicable to the oral cavity remains technically challenging. Herein, a self-assembled monolayer (SAM)-functionalized Au/In₂O₃ nanofiber (NF) sensor for H₂S exhalation analysis was developed to flexibly and effectively modulate the selectivity of the sensor. Through optimizing the specific binding capacity to H₂S by systematic adjustment with terminal groups and alkyl chains of SAMs, the sensing performance of the SAM-functionalized Au/In₂O₃ NF sensor is greatly enhanced. In the optimal (Au/In₂O₃-MPTES) sensor, the functionalization of the MPTES molecule could achieve significant response enhancement because of the stronger interaction between the sulfhydryl group at the end of the MPTES and H₂S. Density functional theory simulation supports the proposed selective sensing mechanism via the analysis of adsorption energy and charge density distribution. The sensor exhibited a high response to H₂S (1505.3-10 ppm) at an operating temperature of 100 °C with a low practical detection limit of 10 ppb and 13-145 fold enhanced selectivity. Furthermore, the Au/In₂O₃-MPTES sensor was successfully applied to distinguish the breath of healthy individuals and patients with severe periodontitis. This study provides novel design insights for the development of highly selective gas sensors for clinical aids in the diagnosis and detection of oral diseases such as periodontitis.

Intrinsic Blue Fluorescence of 2.0G PAMAM-DCM Polymer Dots and Its Applications for Fe3+ Sensing

A typical and environment-friendly fluorescent polyamine-amine (PAMAM) features good compatibility and unique surface modification, while it is restricted by a low fluorescence property performance and an unclear fluorescence mechanism. In this work, we prepared blue fluorescent PAMAM polymer dots (PDs) via a simple hydrothermal method based on dichloromethane (DCM) and 2.0G PAMAM. The quantum yield achieved was 32.1%, which was 25 times stronger than that of 2.0G PAMAM due to the lone-pair electron leap of the amine groups, the aggregation of carbonyl groups, as well as the crosslinking induced by DCM inside the PAMAM. In addition, the fluorescent 2.0G PAMAM-DCM PDs show a great Fe3+ sensing property with the detection limit of 56.6 nM, which is much lower than the safety limits (5.36 μM) in drinking water, indicating its great potential for Fe3+ detection in aqueous media.

Antibacterial Zeolite Imidazole Frameworks with Manganese Doping for Immunomodulation to Accelerate Infected Wound Healing

Numerous nanomedicines currently emerge to reduce the dramatic threat in antibiotics resistance for antibacterial application against severe bacterial infections, while it is restricted by over-reacted immune response to pathogenic bacteria. Herein, enzymatic activity is introduced into the zeolitic imidazolate framework-8 (ZIF-8) to achieve sterilization by releasing Zn ions, as well as inflammation regulation through the variable valence of Mn ions that are uniformly doped into its framework. Within this simple metal organic framework (MOF) structure design, Mn-ZIF-8 possesses the co-existence of Mn²⁺ /Mn⁴⁺ to endow the nanocomposite with the anti-inflammatory capabilities, which can be adjusted through the redox environment. The enzymatic activity of Mn ions and superiority of pore structure of ZIF-8 are effectively combined to realize the substrate selection via reactant molecular size and high-efficiency internal catalytic performance. By such design, this nanocomposite would not only exhibit an excellent antibacterial performance against pathogenic bacteria, but also reshape the inflammatory immunity by regulating macrophage polarization to suppress over-reacted inflammation, leading to a favorably therapeutic efficiency on bacteria-infected wound healing in animal models. Taken together, this nanoplatform provides effective approach for accelerating infected wound healing via bacteria killing and inflammation modulation, and may be extended for the therapy of other severe bacteria-induced infections.

Current Trends on Repurposing and Pharmacological Enhancement of Andrographolide

Andrographolide, the main bioactive component separated from Andrographis paniculata in 1951, has been scrutinized with a modern drug discovery approach for anti-inflammatory properties since 1984. Identification of new uses of existing drugs can be facilitated by searching for evidence linking them to known or yet undiscovered drug targets and human disease states to develop new therapeutic indications.Furthermore, a wide spectrum of biological properties of andrographolide such as anticancer, antibacterial, antiviral, hepatoprotective, antioxidant, anti-malarial, anti-atherosclerosis are also reported. However, poor water solubility and instability limit its clinical application. It becomes crucial to enhance its pharmacological function and find a new treatment option for more diseases. Therefore, this article reviews the major recent developments in andrographolide, including repurposing applications in different diseases and underlying mechanisms, particularly focusing on pharmacological enhancement of andrographolide such as derivatives, chemical modifications with potent biological activity and drug delivery. The repurposing and pharmacological enhancement of andrographolide would not only have exciting therapeutic potential to different diseases to facilitate drug marketing, but also decrease the economic burden on healthcare worldwide.

Drug delivery based pharmacological enhancement and current insights of quercetin with therapeutic potential against oral diseases

The heavy burden of oral diseases such as oral cancers, dental caries, periodontitis, etc. and their consequence on the patient's quality of life demonstrated an urgent demand for developing effective therapeutics. Quercetin as a natural derived flavonoid, could be utilized in the therapeutic formulation of various diseases such as diabetes, breast cancer and asthma, owing to its prominent pharmacological values. In the last decade, the applications of quercetin as a natural compound in oral treatment have attracted increasing interest due to its multifunction including antioxidant, antibacterial, anti-inflammatory and antineoplastic activities. Besides, considering the low bioavailability of quercetin, great efforts have been made in its drug delivery systems to address the problem of limited application. Therefore, this review summarized the cutting-edge researches on versatile effects and enhanced bioavailability of quercetin resulting from innovative drug delivery systems, particularly focused on its potential against oral diseases. The application of quercetin would provide novel and promising therapeutic approach for clinical treatment, promoting the development of global dental public health.

Ce6-C6-TPZ co-loaded albumin nanoparticles for synergistic combined PDT-chemotherapy of cancer

Photodynamic therapy (PDT), as an essential tumor treatment method, has received great attention; however, there are still some challenges such as hydrophobicity of most of the photosensitizers, safety of in vivo transport, and characteristics of oxygen consumption. Herein, we used albumin as the nanocarrier for the loading of Chlorin e6 (Ce6) photosensitizer. In the meantime, tirapazaming (TPZ) was co-loaded onto the nanocomposite, which could be activated by hypoxia caused by PDT for enhanced therapy. Considering the over irradiation problem, a strategy for measuring PDT degree by ratio fluorescence was utilized. The PDT monitoring design relies on ratio emissions of C6 (Coumarin 6) and Ce6 molecules since the red emission of Ce6 is dependent on the PDT capability. Based on the characterization of the albumin nanocomposites, we further explored the combined therapy effect at both the in vitro and in vivo levels and attained the corresponding results.

Understanding the noble metal modifying effect on In2O3 nanowires: highly sensitive and selective gas sensors for potential early screening of multiple diseases

Sensor arrays consisting of In₂O₃ NWs loaded with different NMNPs can accurately distinguish different trace VOC biomarkers in simulated exhaled breath.

Theoretical study on the allosteric regulation of an oligomeric protease from Pyrococcus horikoshii by Cl- Ion

The thermophilic intracellular protease (PH1704) from Pyrococcus horikoshii that functions as an oligomer (hexamer or higher forms) has proteolytic activity and remarkable stability. PH1704 is classified as a member of the C56 family of peptidases. This study is the first to observe that the use of Cl- as an allosteric inhibitor causes appreciable changes in the catalytic activity of the protease. Theoretical methods were used for further study. Quantum mechanical calculations indicated the binding mode of Cl- with Arg113. A molecular dynamics simulation explained how Cl- stabilized distinct contact species and how it controls the enzyme activity. The new structural insights obtained from this study are expected to stimulate further biochemical studies on the structures and mechanisms of allosteric proteases. It is clear that the discovery of new allosteric sites of the C56 family of peptidases may generate opportunities for pharmaceutical development and increases our understanding of the basic biological processes of this peptidase family.