Bridging molecular photosensitizer and catalyst on carbon nanotubes toward enhanced selectivity and durability for CO2 photoreduction

Homogenous molecular photocatalysts for CO2 reduction, especially metal complex-based photosensitizer‒catalyst assemblages, have been attracting extensive research interests due to their efficiency and customizability. However, their low durability and recyclability limit practical applications. In this work, we immobilized the catalysts of metal terpyridyl complexes and the photosensitizer of [Ru(bpy)3]Cl2 onto the surface of carbon nanotubes through covalent bonds and electrostatic interactions, respectively, transforming the homogeneous system into a heterogeneous one. Our characterizations prove that these metal complexes are well dispersed on CNTs with a high loading (ca. 12 wt.%). Photocatalytic measurements reveal that catalytic activity is remarkably enhanced when the molecular catalysts are anchored, which is three times higher than that of homogeneous molecular catalysts. Moreover, when the photosensitizer of [Ru(bpy)3]Cl2 is immobilized, the side reaction of hydrogen evolution is completely suppressed and the selectivity for CO production reaches 100%, with its durability also significantly improved. This work provides an effective pathway for constructing heterogeneous photocatalysts based on rational assembly of efficient molecular photosensitizers and catalysts.

Phototoxicity in vitro and safety in vivo of the emulsion photosensitizer based on furanocoumarins of Heracleum sosnowskyi

The use of plants such as giant hogweed as raw materials for the manufacture of dosage forms has been little explored. In this study, we utilized furanocoumarins from the Heracleum sosnowskyi plant to create an experimental emulsion dosage form (EmFHS). The EmFHS was finely dispersed (481.8 nm ± 71.1 nm), shelf-stable, and contained predominantly 8-methoxypsoralen at a concentration of 1 mg/ml. Phototoxicity analysis of EmFHS for THP-1 cells under UV (365 nm) irradiation showed an IC50 of 19.1 µg/ml (24 h) and 6.3 µg/ml (48 h). In relation to spheroids (L929), EmFHS exhibited a phototoxic effect in the concentration range of 31.25-125 µg/ml8-MOP. A full phototoxic effect was observed 48 h after UV irradiation. The phototoxic effect of EmFHS in vitro was dose-dependent and comparable to the effect of emulsion synthetic 8-methoxypsoralen and chlorin e6 solution. EmFHS cytotoxicity was caused solely by UV radiation, and toxicity in the dark was minimal. EmFHS, administered at a dose of 3 mg/kg8-MOP, was found to be safe after a single intravenous administration to rats. It had a photosensitizing effect in the form of local photodermatitis when exposed to UV irradiation at a dose of 44 J/cm2. The biokinetics of emulsion furanocoumarins showed that the phototoxic effect of EmFHS is due to the high penetration ability of the emulsion into cells of spheroids. At the same time, it has a low degree of cumulation when administered intravenously. The obtained data suggest that EmFHS may be a promising treatment for PUVA therapy of various dermatological diseases. Additionally, the plant Heracleum sosnowskyi shows potential as a basis for creating new dosage forms with phototherapeutic effects.

Tel-Aviv Protocol for Postrefractive Surgery Corneal Ectasia: A Case Series

PURPOSE

The aim of this study was to describe the safety and efficacy of the Tel-Aviv Protocol (epithelial photorefractive keratectomy and corneal cross-linking) as a treatment for postrefractive surgery corneal ectasia.

METHODS

This study includes 8 eyes from 7 patients, each diagnosed with postrefractive surgery ectasia years after refractive surgery and treated with the Tel-Aviv Protocol. The procedure included transepithelial PRK using the EX500 excimer laser, a 50-μm laser ablation of the epithelium and anterior stroma, delivered on the visual axis with cyclotorsion correction, treating up to 50% of refractive astigmatism. After the epithelial photorefractive keratectomy, all patients underwent corneal cross-linking.

RESULTS

The mean keratometry (K) and maximal K both decreased [from 43.37 ± 2.23 to 41.84 ± 2.01 ( P = 0.03) and from 44.95 ± 3.08 to 42.78 ± 2.19 ( P = 0.03), respectively]. Astigmatism was significantly reduced (from 3.53 ± 2.36 to 0.88 ± 0.89 diopter; P = 0.02). Uncorrected visual acuity improved significantly in all patients from a mean of 0.56 ± 0.32 to 0.15 ± 0.14 logMAR ( P = 0.01). Best-corrected visual acuity improved from 0.22 ± 0.24 to 0.06 ± 0.06 logMAR ( P = 0.07; 1-tail P = 0.04). All patients maintained visual acuity during the follow-up period, up to 25 months, mean = 329 days. The Tel-Aviv Protocol was found to be safe [mean safety index: 1.63 ± 1.03 (range: 1.00-4)] and effective [mean efficacy index: 1.29 ± 0.66 (range: 0.71-2.1)].

CONCLUSIONS

The Tel-Aviv Protocol, developed initially for keratoconus treatment, is a safe and promising procedure to stop postrefractive surgery ectasia progression while significantly improving vision, thereby avoiding keratoplasty.

Dual Optical Response Strategy for the Detection of Cytochrome c Using Highly Luminescent Lanthanide-Based Nanotubular Sensor Arrays

Here, we demonstrate a label-free dual optical response strategy for the detection of cytochrome c (Cyt c) with ultrahigh sensitivity using highly luminescent lanthanides containing inorganic-organic hybrid nanotubular sensor arrays. These sensor arrays are formed by the sequential incorporation of the photosensitizers 2,3-dihydroxynaphthalene (DHN) or 1,10-phenanthroline (Phen), and trivalent lanthanide terbium ions (Tb3+) into sodium lithocholate (NaLC) nanotube templates. Our sensing platform relies on the detection and quantification of Cyt c in solution by providing dual photoluminescence quenching responses from the nanotubular hybrid arrays in the presence of Cyt c. The large quenching of the sensitized Tb3+ emission within the DHN/Phen-Tb3+-NaLC nanotubular sensor arrays caused by the strong binding of the photosensitizers to Cyt c provides an important signal response for the selective detection of Cyt c. This long-lived lanthanide emission response-based sensing strategy can be highly advantageous for the detection of Cyt c in a cellular environment eliminating background fluorescence and scattering signals through time-gated measurements. The DHN containing nanotubular sensor arrays (DHN-NaLC and DHN-Tb3+-NaLC) provide an additional quenching response characterized by a unique spectral valley splitting with quantized quenching dip on the DHN fluorescence emission. This spectral quenching dip resulting from efficient FRET between the protein bound DHN photosensitizer and the heme group of Cyt c serves as an important means for specific detection and quantification of Cyt c in the concentration range of 0-30 μM with a low detection limit of around 20 nM.

Algal Extracellular Organic Matter Induced Photochemical Oxidation of Mn(II) to Solid Mn Oxide: Role of Mn(III)-EOM Complex and Its Ability to Remove 17α-Ethinylestradiol

Photosensitizer-mediated abiotic oxidation of Mn(II) can yield soluble reactive Mn(III) and solid Mn oxides. In eutrophic water systems, the ubiquitous algal extracellular organic matter (EOM) is a potential photosensitizer and may have a substantial impact on the oxidation of Mn(II). Herein, we focused on investigating the photochemical oxidation process from Mn(II) to solid Mn oxide driven by EOM. The results of irradiation experiments demonstrated that the generation of Mn(III) intermediate was crucial for the successful photo oxidization of Mn(II) to solid Mn oxide mediated by EOM. EOM can serve as both a photosensitizer and a ligand, facilitating the formation of the Mn(III)-EOM complex. The complex exhibited excellent efficiency in removing 17α-ethinylestradiol. Furthermore, the complex underwent decomposition as a result of reactions with reactive intermediates, forming a solid Mn oxide. The presence of nitrate can enhance the photochemical oxidation process, facilitating the conversion of Mn(II) to Mn(III) and then to solid Mn oxide. This study deepens our grasp of Mn(II) geochemical processes in eutrophic water and its impact on organic micropollutant fate.

Design of AsLOV2 domain as a carrier of light-induced dissociable FMN photosensitizer

Flavin mononucleotide (FMN) is a highly efficient photosensitizer (PS) yielding singlet oxygen (1 O2 ). However, its 1 O2 production efficiency significantly decreases upon isoalloxazine ring encapsulation into the protein matrix in genetically encoded photosensitizers (GEPS). Reducing isoalloxazine ring interactions with surrounding amino acids by protein engineering may increase 1 O2 production efficiency GEPS, but at the same time weakened native FMN-protein interactions may cause undesirable FMN dissociation. Here, in contrast, we intentionally induce the FMN release by light-triggered sulfur oxidation of strategically placed cysteines (oxidation-prone amino acids) in the isoalloxazine-binding site due to significantly increased volume of the cysteinyl side residue(s). As a proof of concept, in three variants of the LOV2 domain of Avena sativa (AsLOV2), namely V416C, T418C, and V416C/T418C, the effective 1 O2 production strongly correlated with the efficiency of irradiation-induced FMN dissociation (wild type (WT) < V416C < T418C < V416C/T418C). This alternative approach enables us: (i) to overcome the low 1 O2 production efficiency of flavin-based GEPSs without affecting native isoalloxazine ring-protein interactions and (ii) to utilize AsLOV2, due to its inherent binding propensity to FMN, as a PS vehicle, which is released at a target by light irradiation.

Recent Advances in Reprogramming Strategy of Tumor Microenvironment for Rejuvenating Photosensitizers-Mediated Photodynamic Therapy

Photodynamic therapy (PDT) has recently been considered a potential tumor therapy due to its time-space specificity and non-invasive advantages. PDT can not only directly kill tumor cells by using cytotoxic reactive oxygen species but also induce an anti-tumor immune response by causing immunogenic cell death of tumor cells. Although it exhibits a promising prospect in treating tumors, there are still many problems to be solved in its practical application. Tumor hypoxia and immunosuppressive microenvironment seriously affect the efficacy of PDT. The hypoxic and immunosuppressive microenvironment is mainly due to the abnormal vascular matrix around the tumor, its abnormal metabolism, and the influence of various immunosuppressive-related cells and their expressed molecules. Thus, reprogramming the tumor microenvironment (TME) is of great significance for rejuvenating PDT. This article reviews the latest strategies for rejuvenating PDT, from regulating tumor vascular matrix, interfering with tumor cell metabolism, and reprogramming immunosuppressive related cells and factors to reverse tumor hypoxia and immunosuppressive microenvironment. These strategies provide valuable information for a better understanding of the significance of TME in PDT and also guide the development of the next-generation multifunctional nanoplatforms for PDT.

Single-cell analysis of 5-aminolevulinic acid intraoperative labeling specificity for glioblastoma

OBJECTIVE

Glioblastoma (GBM) is the most common and aggressive malignant primary brain tumor, and resection is a key part of the standard of care. In fluorescence-guided surgery (FGS), fluorophores differentiate tumor tissue from surrounding normal brain. The heme synthesis pathway converts 5-aminolevulinic acid (5-ALA), a fluorogenic substrate used for FGS, to fluorescent protoporphyrin IX (PpIX). The resulting fluorescence is believed to be specific to neoplastic glioma cells, but this specificity has not been examined at a single-cell level. The objective of this study was to determine the specificity with which 5-ALA labels the diversity of cell types in GBM.

METHODS

The authors performed single-cell optical phenotyping and expression sequencing-version 2 (SCOPE-seq2), a paired single-cell imaging and RNA sequencing method, of individual cells on human GBM surgical specimens with macroscopically visible PpIX fluorescence from patients who received 5-ALA prior to surgery. SCOPE-seq2 allowed the authors to simultaneously image PpIX fluorescence and unambiguously identify neoplastic cells from single-cell RNA sequencing. Experiments were also conducted in cell culture and co-culture models of glioma and in acute slice cultures from a mouse glioma model to investigate cell- and tissue-specific uptake and secretion of 5-ALA and PpIX.

RESULTS

SCOPE-seq2 analysis of human GBM surgical specimens revealed that 5-ALA treatment resulted in labeling that was not specific to neoplastic glioma cells. The cell culture further demonstrated that nonneoplastic cells could be labeled by 5-ALA directly or by PpIX secreted from surrounding neoplastic cells. Acute slice cultures from mouse glioma models showed that 5-ALA preferentially labeled GBM tumor tissue over nonneoplastic brain tissue with significant labeling in the tumor margins, and that this contrast was not due to blood-brain barrier disruption.

CONCLUSIONS

Together, these findings support the use of 5-ALA as an indicator of GBM tissue but question the main advantage of 5-ALA for specific intracellular labeling of neoplastic glioma cells in FGS. Further studies are needed to systematically compare the performance of 5-ALA to that of potential alternatives for FGS.

Hypericin emulsomes combined with hollow microneedles as a non-invasive photodynamic platform for rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is a joint-destructive autoimmune disease that severely affects joint function. Despite the variability of treatment protocols, all of them are associated with severe side effects that compromise patient compliance. The main aim of the current study is to prepare localized effective RA treatment with reduced side effects by combining nanoencapsulation, photodynamic therapy (PDT) and hollow microneedles (Ho-MNs) to maximize the pharmacological effects of hypericin (HYP). To attain this, HYP-loaded emulsomes (EMLs) were prepared, characterized and administered through intradermal injection using AdminPen™ Ho-MNs combined with PDT in rats with an adjuvant-induced RA model. The prepared EMLs had a spherical shape and particle size was about 93.46 nm with an absolute entrapment efficiency. Moreover, confocal imaging indicated the interesting capability of Ho-MNs to deposit the HYP EMLs to a depth reaching 1560 µm into the subcutaneous tissue. In vivo, study results demonstrated that the group treated with HYP EMLs through Ho-MNs combined with PDT had no significant differences in joint diameter, TNF-α, IL1, HO-1, NRF2 and SD levels compared with the negative control group. Similarly, rats treated with the combination of HYP EMLs, Ho-MNs and PDT showed superior joint healing efficacy compared with the groups treated with HYP EMLs in dark, HYP ointment or HYP in microneedles in histopathological examination. These findings highlight the promising potential of photoactivated HYP EMLs when combined with Ho-MNs technology for RA management. The presented therapeutic EMLs-MNs platform could serve as a powerful game-changer in the development of future localized RA treatments.

Supercharged precision killers: Genetically engineered biomimetic drugs of screened metalloantibiotics against Acinetobacter baumanni

To eliminate multidrug-resistant bacteria of Acinetobacter baumannii, we screened 1100 Food and Drug Administration-approved small molecule drugs and accessed the broxyquinoline (Bq) efficacy in combination with various metal ions. Antibacterial tests demonstrated that the prepared Zn(Bq)2 complex showed ultralow minimum inhibitory concentration of ~0.21 micrograms per milliliter with no resistance after 30 passages. We then constructed the nano zeolitic imidazolate framework-8 (ZIF-8) as a drug carrier of Zn(Bq)2 and also incorporated the photosensitizer chlorin e6 (Ce6) to trace and boost the antibacterial effect. To further ensure the stable and targeted delivery, we genetically engineered outer membrane vesicles (OMVs) with the ability to selectively target A. baumannii. By coating the ZnBq/Ce6@ZIF-8 core with these OMV, the resulted drug (ZnBq/Ce6@ZIF-8@OMV) exhibited exceptional killing efficacy (>99.9999999%) of A. baumannii. In addition, in vitro and in vivo tests were also respectively carried out to inspect the remarkable efficacy of this previously unknown nanodrug in eradicating A. baumannii infections, including biofilms and meningitis.

High-Performance Photodynamic Therapy of Tongue Squamous Cell Carcinoma with Multifunctional Nano-Verteporfin

Background

The photodynamic therapy (PDT) showed promising potential in treating tongue squamous cell carcinoma (TSCC). The Food and Drug Administration approved Verteporfin (Ver) is a powerful alternative in this field for its penetrating power and high production of reactive oxygen species (ROS). However, its applications in the treatment of TSCC are still rare.

Methods

Ver was loaded onto Poly (lactic-co-glycolic acid) (PLGA) nanoparticles, followed by the modification with RGD peptide as the ligand. The nanostructured was named as RPV. In vitro assessments were conducted to evaluate the cytotoxicity of RPV through the Live/Dead assay analysis and Cell Counting Kit-8 (CCK-8) assay. Using the reactive oxygen species assay kit, the potential for inducing targeted tumor cell death upon laser irradiation by promoting ROS production was investigated. In vivo experiments involved with the biological distribution of RPV, the administration with RPV followed by laser irradiation, and the measurement of the tumor volumes. Immunohistochemical analysis was used to detect the Ki-67 expression, and apoptosis induced by RPV-treated group. Systemic toxicity was evaluated through hematoxylin-eosin staining and blood routine analysis. Real-time monitoring was employed to track RPV accumulation at tumor sites.

Results

The in vitro assessments demonstrated the low cytotoxicity of RPV and indicated its potential for targeted killing TSCC cells under laser irradiation. In vivo experiments revealed significant tumor growth inhibition with RPV treatment and laser irradiation. Immunohistochemical analysis showed a notable decrease in Ki-67 expression, suggesting the effective suppression of cell proliferation, and TUNEL assay indicated the increased apoptosis in the RPV-treated group. Pathological examination and blood routine analysis revealed no significant systemic toxicity. Real-time monitoring exhibited selective accumulation of RPV at tumor sites.

Conclusion

The findings collectively suggest that RPV holds promise as a safe and effective therapeutic strategy for TSCC, offering a combination of targeted drug delivery with photodynamic therapy.

Dynamic monitoring of oxygen partial pressure in photodynamic therapy using pump-probe-based photoacoustic tomography

Pump-probe-based photoacoustic tomography (PP-PAT) is an innovative and promising molecular imaging technique. In this study, we utilized PP-PAT for the first time, to the best of our knowledge, to monitor the dynamics of oxygen partial pressure (pO2) within murine tumors during photodynamic therapy (PDT) with methylene blue (MB). We developed, to our knowledge, a novel two-step fitting method to simultaneously map both the pO2 and the MB concentrations and implemented it with mexCuda to accelerate the pixel-wise-based calculation. The results demonstrated a penetration depth of up to 5 mm and revealed a significant decrease in pO2 during the PDT process, consistent with existing research findings. This study suggests that PP-PAT has the potential to become a valuable tool for intraoperative monitoring of PDT, thereby enhancing therapeutic efficacy.

Aptamer-Modified Homogeneous Catalysts, Heterogenous Nanoparticle Catalysts, and Photocatalysts: Functional "Nucleoapzymes", "Aptananozymes", and "Photoaptazymes"

Conjugation of aptamers to homogeneous catalysts ("nucleoapzymes"), heterogeneous nanoparticle catalysts ("aptananozymes"), and photocatalysts ("photoaptazymes") yields superior catalytic/photocatalytic hybrid nanostructures emulating functions of native enzymes and photosystems. The concentration of the substrate in proximity to the catalytic sites ("molarity effect") or spatial concentration of electron-acceptor units in spatial proximity to the photosensitizers, by aptamer-ligand complexes, leads to enhanced catalytic/photocatalytic efficacies of the hybrid nanostructures. This is exemplified by sets of "nucleoapzymes" composed of aptamers conjugated to the hemin/G-quadruplex DNAzymes or metal-ligand complexes as catalysts, catalyzing the oxidation of dopamine to aminochrome, oxygen-insertion into the Ar─H moiety of tyrosinamide and the subsequent oxidation of the catechol product into aminochrome, or the hydrolysis of esters or ATP. Also, aptananozymes consisting of aptamers conjugated to Cu2+ - or Ce4+ -ion-modified C-dots or polyadenine-stabilized Au nanoparticles acting as catalysts oxidizing dopamine or operating bioreactor biocatalytic cascades, are demonstrated. In addition, aptamers conjugated to the Ru(II)-tris-bipyridine photosensitizer or the Zn(II) protoporphyrin IX photosensitizer provide supramolecular photoaptazyme assemblies emulating native photosynthetic reaction centers. Effective photoinduced electron transfer followed by the catalyzed synthesis of NADPH or the evolution of H2 is demonstrated by the photosystems. Structure-function relationships dictate the catalytic and photocatalytic efficacies of the systems.

Nanoparticles as carriers of photosensitizers to improve photodynamic therapy in cancer

Photodynamic therapy (PDT) has emerged as a promising non invasive therapeutic approach for cancer treatment, offering unique advantages over conventional treatments. The combination of light activation and photosensitizing agents allows for targeted and localized destruction of cancer cells, reducing damage to surrounding healthy tissues. In recent years, the integration of nanoparticles with PDT has garnered significant attention due to their potential to enhance therapeutic outcomes. This review article aims to provide a comprehensive overview of the current state-of-the-art in utilizing nanoparticles for photodynamic therapy in cancer treatment. We summarized various nanoparticle-based approaches, their properties, and their implications in optimizing PDT efficacy, and discussed challenges and prospects in the field.

Analysis of the effectiveness of PDT with 5-aminolevulinic acid in comparison to blue/red light combined with intralesional triamcinolone injection in treatment of severe inflammatory acne: A retrospective study

OBJECTIVE

In this study, the therapeutic effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in comparison to blue/red light combined with intralesional triamcinolone injection for severe inflammatory acne was evaluated and analyzed.

METHODS

One hundred and four cases of severe inflammatory acne were analyzed in this study. They were divided into two groups as control and observation groups, 52 cases in each group. The control group (group A) received red and blue light combined with triamcinolone injection and lidocaine injection (1:4), while the observation group (Group B) was treated with ALA-PDT. Finally, the therapeutic effect and the occurrence of adverse reactions were compared between the two groups.

RESULTS

After 2, 4 and 6 weeks, the effectiveness rates of group B was 28.85%, 75.00%, and 86.54%, respectively while it was 9.62%, 51.92%, and 69.23%, respectively in group A. The difference between A and B was statistically remarkable (χ2 = 6.1905, 5.9713, 4.5217, p = 0.0128, 0.0145, 0.0335 at p < 0.05). In addition, the incidence of adverse reactions in B was 5.77%, lower than A (32.69%). This difference between A and B was statistically remarkable (χ2  = 12.1333, p = 0.0005). After 2, 4, and 6 weeks of treatment, the number of residual lesions in the group B group was remarkably lower than group A (p < 0.01). There was remarkable difference in the incidence of pain, burning sensation, pigmentation and erythema between the two groups.

CONCLUSIONS

The therapeutic effect of ALA-PDT in the treatment of severe acne is better than red blue light combined with triamcinolone injection and lidocaine injection. In addition, ALA-PDT has an ideal effect in the treatment of severe acne.

Structure Engineered High Piezo-Photoelectronic Performance for Boosted Sono-Photodynamic Therapy

Sono-photodynamic therapy is hindered by the limited tissue penetration depth of the external light source and the quick recombination of electron-hole owing to the random movement of charge carriers. In this study, orthorhombic ZnSnO3 quantum dots (QDs) with piezo-photoelectronic effects are successfully encapsulated in hexagonal upconversion nanoparticles (UCNPs) using a one-pot thermal decomposition method to form an all-in-one watermelon-like structured sono-photosensitizer (ZnSnO3 @UCNPs). The excited near-infrared light has high penetration depth, and the watermelon-like structure allows for full contact between the UCNPs and ZnSnO3 QDs, achieving ultrahigh Förster resonance energy transfer efficiency of up to 80.30%. Upon ultrasonic and near-infrared laser co-activation, the high temperature and pressure generated lead to the deformation of the UCNPs, thereby driving the deformation of all ZnSnO3 QDs inside the UCNPs, forming many small internal electric fields similar to isotropic electric domains. This piezoelectric effect not only increases the internal electric field intensity of the entire material but also prevents random movement and rapid recombination of charge carriers, thereby achieving satisfactory piezocatalytic performance. By combining the photodynamic effect arising from the energy transfer from UCNPs to ZnSnO3 , synergistic efficacy is realized. This study proposes a novel strategy for designing highly efficient sono-photosensitizers through structural design.

Protoporphyrin IX in serum of high-grade glioma patients: A novel target for disease monitoring via liquid biopsy

High-grade gliomas (HGG) carry a dismal prognosis. Diagnosis comprises MRI followed by histopathological evaluation of tissue; no blood biomarker is available. Patients are subjected to serial MRIs and, if unclear, surgery for monitoring of tumor recurrence, which is laborious. MRI provides only limited diagnostic information regarding the differentiation of true tumor progression from therapy-associated side effects. 5-aminolevulinic acid (5-ALA) is routinely used for induction of protoporphyrin IX (PpIX) accumulation in malignant glioma tissue, enabling improved tumor visualization during fluorescence-guided resection (FGR). We investigated whether PpIX can also serve as a serum HGG marker to monitor relapse. Patients (HGG: n = 23 primary, pHGG; n = 5 recurrent, rHGG) undergoing FGR received 5-ALA following standard clinical procedure. The control group of eight healthy volunteers (HCTR) also received 5-ALA. Serum was collected before and repeatedly up to 72 h after drug administration. Significant PpIX accumulation in HGG was observed after 5-ALA administration (ANOVA: p = 0.005, post-hoc: HCTR vs. pHGG p = 0.029, HCTR vs. rHGG p = 0.006). Separation of HCTR from pHGG was possible when maximum serum PpIX levels were reached (CI95% of tMax). ROC analysis of serum PpIX within CI95% of tMax showed successful classification of HCTR and pHGG (AUCROC 0.943, CI95% 0.884-1.000, p < 0.001); the optimal cut-off for diagnosis was 1275 pmol PpIX/ml serum, reaching 87.0% accuracy, 90.5% positive predictive and 84.0% negative predictive value. Baseline PpIX level was similar in patient and control groups. Thus, 5-ALA is required for PpIX induction, which is safe at the standard clinical dosage. PpIX is a new target for liquid biopsy in glioma. More extensive clinical studies are required to characterize its full potential.

Light-Induced Liposomal Drug Delivery with an Amphiphilic Porphyrin and Its Chlorin and Bacteriochlorin Analogues

The development of targeted drug delivery mechanisms in the human body is a matter of growing interest in medical science. The selective release of therapeutic agents at a specific target site can increase the therapeutical efficiency and at the same time reduce the side effects. Light-sensitive liposomes can release a drug by an externally controlled light trigger. Liposomes containing photosensitizers that can be activated in the longer wavelength range (650-800 nm) are particularly intriguing for medical purposes. This is because light penetration into a tissue is more efficient within this wavelength range, increasing their potential applications. For this study, liposomes with an encapsulated amphiphilic photosensitizer, the porphyrin 5,10-DiOH (5,10-di(4-hydroxyphenyl)-15,20-diphenyl-21,23H-porphyrin), its chlorin (5,10-DiOH-chlorin) and its bacteriochlorin (5,10-DiOH-bacteriochlorin) were synthesized. The porphyrin 5,10-DiOH showed previously effective cargo release after liposomal encapsulation when irradiated at a wavelength of 420 nm. The new synthesized chlorin and bacteriochlorin photosensitizers show additional absorption bands in the longer wavelength range, which would enable excitation in deeper layers of tissue. Effective cargo release with chlorin at a longer wavelength of 650 nm and bacteriochlorin at 740 nm was possible. Irradiation of chlorin allowed more than 75% of the cargo to be released and more than 60% for bacteriochlorin. The new liposomes would enable selective drug release in deeper tissue layers and expand the range of possible applications.

Quality assessment of anterior segment OCT images: Development and validation of quality criteria

BACKGROUND

The utility of medical imaging is dependant on image quality. We aimed to develop and validate quality criteria for ocular anterior segment optical coherence tomography (AS-OCT) images.

METHODS

We undertook a cross-sectional study using AS-OCT images from patients aged 6-16. A novel three-level grading system (good, limited or poor) was developed based on the presence of image artefact (categorised as lid, eyelash, cropping, glare, or movement artefact). Three independent experts graded 2825 images, with agreement assessed using confusion matrices and intraclass correlation coefficients (ICC) for each parameter.

RESULTS

There was very good inter-grader IQA agreement assessing image quality with ICC 0.85 (95 %CI: 0.84-0.87). The most commonly occurring artefact was eyelash artefact (1008/2825 images, 36 %). Graders labelled 621/2825 (22 %) images as good and 384 (14 %) as poor. There was complete agreement at either end of the confusion matrix with no 'good' images labelled as 'poor' by other graders, and vice versa. Similarly, there was very good agreement when assessing presence of lash (0.96,0.94-0.98), movement (0.97,0.96-0.99), glare (0.82,0.80-0.84) and cropping (0.90,0.88-0.92).

CONCLUSIONS

The novel image quality assessment criteria (IQAC) described here have good interobserver agreement overall, and excellent agreement on the differentiation between 'good' and 'poor' quality images. The large proportion of images graded as 'limited' suggests the need for refine this classification, using the specific IQAC features, for which we also report high interobserver agreement. These findings support the future potential for wider clinical and community care implementation of AS-OCT for the diagnosis and monitoring of ocular disease.

Red fluorescence intensity as a criterion for assessing remineralization efficacy in early carious lesions

OBJECTIVES

Evaluating early carious lesion activity with an objective and clinically valid approach is crucial for developing effective treatment plans. Therefore, we here assessed the activity of non-cavitated carious lesions using a quantitative light-induced fluorescence-digital (QLF-D) camera and compared the remineralization efficiency after fluoride treatment according to the lesion's activity level.

METHODS

Red fluorescence emission rate (ΔR) and fluorescence loss (ΔF) were evaluated in 44 non-cavitated carious lesions by using a QLF-D camera. Based on the ΔR level, the lesions were classified into 22 active (ΔR ≥37.55) and 22 inactive carious lesions (ΔR <37.55). Each lesion was treated with 1.23 % fluoride gel for 60 s and then immersed into artificial saliva for 7 days. Subsequently, ΔR and ΔF changes in the lesions were measured.

RESULTS

Significant interactions between lesion activity and time were found for both ΔR and ΔF (p < 0.001). ΔR of active lesions declined faster and ΔF increased more steeply than did inactive lesions. Specifically, on day 7 post-fluoride treatment, the ΔR reduction rate was 1.40-times higher in active lesions, and the ΔF recovery rate was 2.50-times higher, indicating that active lesions respond more markedly to fluoride application.

CONCLUSIONS

This study highlighted the significance of ΔR in predicting remineralization efficiency in non-cavitated carious lesions after fluoride application. It underscored the importance of accurately assessing caries activity when formulating effective treatment plans. Lesion activity, as determined by ΔR, not only influences the outcome of remineralization treatments but also provides a more objective measure for tailoring caries management strategies.

Cost-effective device for locating and circumscribing superficial tumors with contrast enhancement and fluorescence quantification

BACKGROUND

Two Bispectral contrast enhancement approaches for the fluorescence diagnosis with chlorine-e6 and a wide field-of-view imaging system with fluorescence excitation at 405 nm and time-resolved background suppression were analyzed and compared.

METHODS

Two techniques for the contrast enhancement of a fluorescent video system (Red/Green (R/G) ratio and Red-Green (R-G)) with time-resolved background suppression for fluorescent diagnosis (FD) were tested in four patients with basal cell carcinoma (BCC).

RESULTS

The results of both contrast enhancement methods were compared for the diagnostic efficiency for FD of BCC. Both techniques successfully determined the boundaries of the lesions and the fluorescence intensity.

CONCLUSIONS

Both contrast enhancement modes have proven effective in identifying tumor borders in cases of low contrast in BCC FD with Ce6. While the Red/Green (R/G) mode provides sharper lesion borders, the Red minus Green (R-G) mode visualizes more fluorescent features and makes it easier to assess the lesion margins.

Synthesis, and evaluation of photophysical properties of a potential DPP-derived photosensitizer for photodynamic therapy with D-A-D architecture

The study of a macromolecule derived from DPP and triphenylamine, (DPP-BisTPA) by computational chemistry, its synthesis by direct arylation, optical characterization (UV-Vis and fluorescence) and electrochemistry (cyclic voltammetry), as well as its evaluation as a generator of reactive oxygen species indirectly, through the degradation of uric acid. The results obtained by DFT using B3LYP/6-31G (d, p) and TD-DFT using CAM-B3LYP/6-31G (d, p) reveal values of energy levels of the first singlet and triplet excited state that indicate a possible intersystem crossover and the possible generation of reactive oxygen species by a type I mechanism. The compound presents an absorption region within the phototherapeutic window. The electrochemical bandgap is 1.64 eV which suggests a behavior as a semiconductor. DPP-BisTPa were processed as hemispherical nanoparticles with a size around 100 nm, and NPOs were evaluated as a photosensitizer with a ROS generation yield of 4% using a photodynamic therapy flashlight as the light source.

Effects of repeated etching cycles using 15% hydrochloric acid on enamel loss and relative attenuation coefficient in resin infiltration

BACKGROUND

Resin infiltration is used to mask enamel opacities and the recommended etching cycles are three. However, anecdotal evidence suggests that favorable esthetics outcomes can be obtained by increasing the etching cycles.

AIM

To determine the incremental and total enamel loss when enamel surfaces are exposed to multiple etching cycles and to assess the relative attenuation coefficient after multiple etching cycles and resin infiltration treatment.

METHODS

Ninety extracted sound human premolars teeth were divided into 9 groups (n = 10); with each consecutive group having one additional etching cycle up to 9 cycles. The teeth were scanned with optical coherence tomography and enamel loss and attenuation coefficient were measured with MATLAB software. Enamel loss (one-way ANOVA, p ≤ 0.05) and attenuation coefficient (two-way ANOVA, p ≤ 0.05) were statistically analyzed.

RESULTS

There was a significant total enamel loss of more than 33% found at the 7th etching cycle and more. There was no statistically significant difference in the incremental mean depth of penetration of resin between various etching cycles (F(8, 134) = [2.016], one-way ANOVA, p = 0.185).

CONCLUSION

This study recommends that etching should not be repeated more than seven cycles to prevent excessive enamel loss. Following eight etching cycles, resin infiltration penetration appears approximately equal to that of healthy enamel.

Comparisons of biometric parameters measurements by OPD-SCAN Ⅲ and Pentacam in cataract

BACKGROUND

Comparison of OPD-Scan III and Pentacam measurements of relevant parameters guiding the selection of multifocal intraocular lenses in cataract patients.

METHODS

A retrospective study included 120 patients (120 eyes) with cataract. Their chord kappa, chord alpha, corneal spherical aberration, and pupil size were measured by OPD-Scan Ⅲ and Pentacam. Pairwise t-tests, Pearson tests, and Bland-Altman analyses were used, respectively, to assess the difference, correlation, and agreement between the devices.

RESULTS

There was no significant difference in photopic chord kappa and corneal spherical aberration between the two instruments (P = 0.054, P = 0.065). Chord alpha and pupil size varied significantly between the two instruments (P < 0.001). OPD-Scan III results revealed a significant association between photopic chord kappa and mesopic chord kappa (r = 0.823, P < 0.001). There was a significant positive correlation between photopic and mesopic chord kappa measured by OPD-Scan Ⅲ and chord kappa measured by Pentacam (r = 0.840, r  = 0.757, P < 0.001). The chord alpha evaluated by the two tools had a moderate correlation (r = 0.442, P < 0.001) between them. Bland-Altman analysis showed that there was excellent agreement between the two instruments in measuring chord kappa and corneal spherical aberration, while the chord alpha and pupil size were not consistent.

CONCLUSIONS

The chord kappa and corneal spherical aberration measured by OPD-Scan III and Pentacam were consistent in the preoperative decision making of multifocal intraocular lens implantation in cataract patients, both of which have clinical guiding significance. In addition, OPD-Scan III provides more comprehensive day and night chord kappa and pupil diameters, which improves clinical advice for patients with complicated ocular diseases and high demands for nocturnal vision.

Rapid diagnosis of rheumatoid arthritis and ankylosing spondylitis based on Fourier transform infrared spectroscopy and deep learning

OBJECTIVE

Rheumatoid arthritis and Ankylosing spondylitis are two common autoimmune inflammatory rheumatic diseases that negatively affect activities of daily living and can lead to structural and functional disability, reduced quality of life. Here, this study utilized Fourier transform infrared (FTIR) spectroscopy on dried serum samples and achieved early diagnosis of rheumatoid arthritis and ankylosing spondylitis based on deep learning models.

METHOD

A total of 243 dried serum samples were collected in this study, including 81 samples each from ankylosing spondylitis, rheumatoid arthritis, and healthy controls. Three multi-scale convolutional modules with different specifications were designed based on the multi-scale convolutional neural network (MSCNN) to effectively fuse the local features to enhance the generalization ability of the model. The FTIR was then combined with the MSCNN model to achieve a non-invasive, fast, and accurate diagnosis of ankylosing spondylitis, rheumatoid arthritis, and healthy controls.

RESULTS

Spectral analysis shows that the curves and waveforms of the three spectral graphs are similar. The main differences are distributed in the spectral regions of 3300-3250 cm-1, 3000-2800 cm-1, 1750-1500 cm-1, and 1500-1300 cm-1, which represent: Amides, fatty acids, cholesterol, proteins with a carboxyl group, amide II, free amino acids, and polysaccharides. Four classification models, namely artificial neural network (ANN), convolutional neural network (CNN), improved AlexNet model, and multi-scale convolutional neural network (MSCNN) were established. Through comparison, it was found that the diagnostic AUC value of the MSCNN model was 0.99, and the accuracy rate was as high as 0.93, which was much higher than the other three models.

CONCLUSION

The study demonstrated the superiority of MSCNN in distinguishing ankylosing spondylitis from rheumatoid arthritis and healthy controls. FTIR may become a rapid, sensitive, and non-invasive means of diagnosing rheumatism.

Comparative study of the vascular structures of the retina and choroid in Chinese Han and Uygur populations with proliferative diabetic retinopathy: An OCTA study

BACKGROUND

To compare the vascular structures of the retina and choroid in Chinese Han and Uygur populations with proliferative diabetic retinopathy (PDR) using swept-source OCTA (SS-OCTA).

METHODS

Fifty-three eyes of 53 healthy volunteers (25 from Hans and 28 from Uygurs) and 40 eyes of 40 PDR patients (20 from Hans and 20 from Uygurs) were included. Retinal and choroidal parameters, including thickness, vessel flow density (VFD), foveal avascular zone (FAZ) area, choroidal vascularity volume and index (CVV and CVI) were evaluated.

RESULTS

Compared with the respective controls, superficial capillary plexus (SCP)-VFD and deep capillary plexus (DCP)-VFD, the areas of FAZ in SCP and DCP were significantly decreased in both Han and Uygur PDR patients. choroidal parameters analysis found that Uygur controls had substantially higher choroidal thickness (CT) than Han controls (p = 0.020) and PDR eyes showed significantly decreased CT. Both races with PDR exhibited significantly reduced choriocapillaris layer-VFD, large and medium choroidal vessel (LMCV) layer-VFD, CVV and CVI, however, Uygur PDR patients had significant lower LMCV layer-VFD, CVV and CVI compared to Han PDR patients. Diabetes duration was the most significant factor affecting CVV and CVI.

CONCLUSION

Both Han and Uygur PDR patients had significantly lower CT and decreased vessel densities compared to controls, but the Uygur PDR patients had more severe choroidal damage than Han PDR patients, which is most likely related to worse visual prognosis. These findings indicate that more frequent screenings and prompt therapy are urgent for Uygur PDR patients.

COVID-19 related changes in corneal curvature and endothelium after mild infection

PURPOSE

To investigate subclinical corneal changes using corneal topography in the evaluation of corneal curvature and specular microscopy in the evaluation of the endothelial layer after mild coronavirus disease 2019 (COVID-19).

METHODS

In this prospective study, 112 eyes of 56 individuals with mild COVID-19 who recovered were investigated. Mean cell density (CD), mean coefficient of variation (CV), mean percentage of hexagonal cells, mean cell area (AVG), and central corneal thickness (CCT) were recorded from specular microscopy. K readings, including simulated keratometry flat (K1), simulated keratometry steep (K2), average keratometry (Kmean) and maximum keratometry (Kmax), pachymetric measurement and central corneal thickness (CCT), corneal volume (CV), topographic astigmatism (TA), curvature asymmetry front (CAf) and curvature asymmetry back (CAb) were recorded from corneal topography. Best corrected visual acuity (BCVA), spherical equivalant and biometric measurements were recorded.

RESULTS

The mean time interval between examinations before and after COVID-19 infection was approximately one year. Analysis of specular microscopy data showed a statistically significant change in all endothelial cell parameters (p<0.001) except the cell count (p = 0.358). The median (range) endothelial cell density (ECD) value was significantly lower after COVID-19 at 2356 (2289-2400) than before, when it was 2596 (2545-2640). Furthermore, CCT values showed a significant increase (p<0.001). The topographic values including K2, Kmax and TA and biometric measurements did not change. The Spherical Equivalant (SE) values showed significant myopic progression after COVID-19 (p<0.001).

CONCLUSION

Endothelial parameters changed more than the changes in corneal curvature and ocular biometric measurements after mild COVID-19. The decrease in endothelial cell number and hexagonality and increase in polymorphism after COVID-19 were striking.

Hyperspectral imaging for non-invasive blood oxygen saturation assessment

Hyperspectral Imaging (HSI) seamlessly integrates imaging and spectroscopy, capturing both spatial and spectral data concurrently. With widespread applications in medical diagnostics, HSI serves as a noninvasive tool for gaining insights into tissue characteristics. The distinctive spectral profiles of biological tissues set HSI apart from traditional microscopy in enabling in vivo tissue analysis. Despite its potential, existing HSI techniques face challenges such as alignment issues, low light throughput, and tissue heating due to intense illumination. This study introduces an innovative HSI system featuring active sequential bandpass illumination seamlessly integrated into conventional optical instruments. The primary focus is on analyzing oxyhemoglobin and deoxyhemoglobin saturation in animal tissue samples using multivariate linear regression. This approach holds promise for enhancing noninvasive medical diagnostics. A key feature of the system, active bandpass illumination, effectively prevents tissue overheating, thereby bolstering its suitability for medical applications.

A novel Foley catheter made of high-intensity near-infrared fluorescent silicone rubber for image-guided surgery of lower rectal cancer

BACKGROUND

Urethral injury occurs in 1-6 % of male cases during minimally invasive surgery of lower rectal cancer. A Foley catheter emitting near-infrared (NIR) fluorescence of sufficient intensity has been expected to locate the urethra during image-guided surgery. Although it has been difficult to impart NIR fluorescent properties to biocompatible thermosetting polymers, we have recently succeeded in developing a NIR fluorescent compound for silicone rubber and a NIR fluorescent Foley catheter (HICARL). Here, we evaluated its NIR fluorescence properties and visibility performance using porcine anorectal isolation specimens.

METHODS

The HICARL catheter was made of a mixture of solid silicone rubber and a NIR fluorescent compound that emits fluorescence with a wavelength of 820-880 nm, while a conventional transparent Foley catheter was made of solid silicone rubber only. As a standard for comparison of the intensity of NIR fluorescence, a transparent Foley catheter the lumen of which was filled with a mixture of indocyanine green (ICG) and human plasma was used. As a comparison to assess the visibility performance of the HICARL catheter, a transparent Foley catheter into which a commercially available NIR fluorescent polyurethane ureteral catheter (NIRC) was placed was used.

RESULTS

A NIR fluorescence quantitative imaging analysis revealed that the Foley-NIRC catheter and the HICARL catheter emitted 3.42 ± 0.42 and 6.43 ± 0.07 times more fluorescence than the Foley-ICG catheter, respectively. The location of the HICARL catheter placed in the anorectum with a wall thickness of 3.8 ± 0.1 mm was clearly delineated in its entirety by NIR fluorescence, while that of the Foley-NIRC catheter was faintly or only partially visible.

CONCLUSIONS

The HICARL catheter emitting NIR fluorescence of sufficient intensity is a promising and easy-to-use tool for urethral visualization during image-guided surgery of lower rectal cancer.

Label-free screening of common urinary system tumors from blood plasma based on surface-enhanced Raman spectroscopy

BACKGROUND

The incidence of common urinary system tumors has been rising rapidly in recent years, and most urinary system-derived tumors lack specific biomarkers.

OBJECTIVES

To explore the efficacy of surface-enhanced Raman spectroscopy (SERS) of blood plasma in screening three common urinary system tumors, including bladder cancer (BC), prostate cancer (PCa), and renal cell carcinoma (RCC).

METHODS

SERS plasma spectra from 125 plasma samples, including 25 PCa, 38 RCC, 24 BC patients, and 38 normal volunteers, were collected. All candidates had no other comorbidities. The Diagnosis was based on the combination of Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), and the effectiveness of the diagnostic algorithms was verified using the Receiver Operating Characteristic Curve (ROC).

RESULTS

There are significant differences in SERS signals between PCa, BC, RCC, and normal plasma, especially at 639, 889, 1010, 1136, and 1205 cm-1. The PCA-LDA results show that high sensitivity (100 %), specificity (100 %), and accuracy (100 %) could be achieved for screening the PCa, RCC, BC group vs. the normal group, the PCa group vs. the BC and RCC group, respectively. The diagnostic sensitivity, specificity, and accuracy for the BC group vs. the RCC group are 79.2 %, 71.1 %, and 75.15 %, respectively. The integrated area under the ROC curve (AUC) is 1.0, 1.0, and 1.0 for the PCa, RCC, and BC group vs. the normal group, respectively. The AUC of the PCa group vs. the BC group and RCC group and the BC group vs. the RCC group are 1.0, 1.0, and 0.842, respectively.

CONCLUSIONS

Label-free plasma-SERS technology with PCA-LDA analysis could be a useful screening method for detecting urinary system tumors (PCa, RCC, and BC) in this exploratory study.

Deferoxamine-related bilateral maculopathy with optical coherence tomography findings

BACKGROUND

We present a case of bilateral maculopathy associated with deferoxamine mesylate (DFO) treatment.

METHODS

A 53-year-old man with myelodysplastic syndrome (MDS) received DFO therapy due to elevated ferritin levels. He was then referred to ophthalmology clinic due to blurred vision. He was diagnosed as bilateral neurosensory retinal detachment of the macula. During follow up, best corrected visual acuity (BCVA), optical coherence tomography (OCT), fundus fluorescein angiography (FFA), and fundus autofluorescence (FAF) were evaluated.

RESULTS

At first visit, OCT showed bilateral foveal neurosensory detachment. Hyperfluorescence of the macula and the peripapillary region were found on FFA. After discontinuation of DFO, BCVA improved from 20/120 to 20/60 with resolution of the foveal detachments on OCT scan. Four weeks later, FAF showed bilateral mottled hyperautofluorescence and hypoautofluorescence at the macula and the peripapillary region.

CONCLUSION

Deferoxamine can cause acute retinal toxicity. Haematologists should be alert to visual complaints associated with DFO therapy, as early diagnosis and discontinuation of the medication allows recovery of visual function with residual fundus findings.

Canal disinfection using photo-chemically activated micro-bubble emulsion, Emblica officinalis, and Nd: YAP laser on smear layer and push-out bond strength of resin-based root canal sealer to the radicular dentin

AIMS

Evaluation of the effects of the latest root canal disinfectants i.e., Micro-bubble emulsion (MBE), Neodymium-doped yttrium aluminum perovskite (Nd: YAP), Emblica officinalis (E. officinalis) on the removal of smear layer (SL) and push out bond strength (PBS) of resin-based root canal sealer to the radicular dentin.

METHODS

The coronal portion of sixty single-rooted human mandibular premolar teeth was precisely sectioned at the cementoenamel junction. The canals were prepared to utilize ProTaper universal rotary files till F3. All the study specimens were divided into four groups based on the disinfection regime (n = 15) Group 1: 5.25% NaOCl, Group 2: MBE, Group 3: Nd: YAP laser and Group 4: E. officinalis extract. All the canals were then finally irrigated using 17% EDTA solution as a final disinfecting agent. SL removal assessment was performed on five samples from each group using a scanning electron microscope (SEM). Ten samples from each group were then filled with root canal filling material and the roots were sectioned. Push-out test and failure mode analysis were performed using the universal testing machine (UTM) and stereomicroscope respectively. The mean scores of PBS and SL removal were compared using a one-way analysis of variance (ANOVA) and Post Hoc Tukey's HSD test p = 0.05.

RESULTS

Group-2 (MBE + EDTA) coronal section (1.50 ± 0.23) exhibited the most effective eradication of SL from the canal space. The apical third of Group-1 (NaOCl+EDTA) (2.68 ± 0.82) samples demonstrated the least effective removal of SL from the radicular canal. The maximum score of PBS of AH plus sealer to the canal dentin was exhibited by the coronal section of Group-2 (MBE + EDTA) (9.55 ± 0.45 MPa) samples. However, the apical third of Group-1 (NaOCl+ EDTA) specimens (5.16 ± 0.32 MPa) demonstrated the minimum EBS.

CONCLUSION

MBE+ EDTA displayed better smear layer removal and bond integrity of AH plus sealer to the root canal dentin. Nd: YAP+ EDTA laser and E.officinalis displayed comparable outcomes to that of control NaOCl+ EDTA.

Serum vitamin D level alterations in retinal vascular occlusions

AIM

To evaluate serum vitamin D levels in sub-types of retinal vascular occlusions and compare the levels in ischemic and non-ischemic presentations.

METHODS

This study included 50 patients of retinal vascular occlusions comprising central retinal vein occlusion, branch retinal vein occlusion, central retinal artery occlusion, branch retinal artery occlusion (study group) diagnosed on basis of clinical characteristics as well as investigations and an age and gender-matched healthy control group (control group). The study group was further classified into ischemic and non-ischemic subtypes and serum vitamin D levels were analysed and compared.

RESULTS

There were 50 patients of various sub-types of retinal vascular occlusions comprising 13 cases of CRVO, 30 cases of BRVO, 05 cases of CRAO, 02 cases of BRAO and 50 age and sex-matched controls. Mean BCVA and CMT in RVO patients was +1.12 log MAR, 346.72 ± 27.93 µm while in control group was +0.37 log MAR, 236.22 ± 3.71 µm which were statistically significant (p = 0.004; p = 0.002). The mean serum vitamin D value in study group was 18.39 ng/dl as compared to 32.31 ng/dl in control group which was statistically significant (p = 0.001). The difference in the baseline vitamin D value between the ischemic and non -ischemic sub groups among total vascular occlusion was found to be statistically significant (p = 0.010). However, baseline vitamin D levels difference among ischemic and non-ischemic cases in individual sub-types of vascular occlusion was statistically insignificant.

CONCLUSION

High prevalence of low serum vitamin D levels is seen in patients of retinal vascular occlusion spectrum diseases. Moreover, ischemic types of retinal vascular occlusion have significantly lower serum vitamin D levels as compared to non - ischemic despite having fewer no of patients in arterial occlusion sub-types. Therefore, vitamin D supplements may be considered as possible future targeted therapy in optimizing the severity of disease.

Advances in the detection and diagnosis of tuberculosis using optical-based devices

Tuberculosis (TB), a bacterial infection caused by Mycobacterium tuberculosis, is highly contagious and can lead to severe health complications if left untreated. This review article discusses the importance of early detection and treatment and its global incidence and epidemiology, emphasizing its impact on vulnerable populations and its role as a major cause of death worldwide. Furthermore, it highlights the challenges faced with diagnosing TB. To overcome these challenges, point-of-care devices have emerged as promising tools for rapid and accurate TB detection. These include devices such as nucleic acid amplification tests (NAATs), lateral flow assays (LFAs), and microfluidic-based assays, which offer advantages such as rapid results, portability, and the ability to detect drug-resistant strains. Optical-based devices, such as photonic micro-ring sensors, silicon platform-based sensors, plasmonic-based platforms, microfluidics, and smartphone imaging, are some of the highlighted optical-based devices with the potential to detect TB. These devices can detect TB in sputum samples with high sensitivity and specificity. Optical-based diagnostic devices have the potential to offer the advantages of detecting low concentrations of target molecules and being adaptable to detect multiple targets simultaneously. Using these devices in a clinical setting makes them suitable for their application in improving access to diagnostic testing that enables earlier detection and treatment of TB. Furthermore, these devices would improve TB's global health issue, which requires comprehensive research, prevention, and treatment efforts.

Posterior segment parameters after uveitic cataract surgery: A prospective study with 1-year results

PURPOSE

To evaluate the changes in posterior segment after uncomplicated cataract surgery in uveitic patients.

METHODS

Retinal nerve fiber layer thickness (RNFLT), ganglion cell layer thickness (GCLT), central macular thickness (CMT), and choroidal thickness (CT) of 38 eyes of 28 patients were measured pre- and postoperatively on day 1, week 1, and month 1, 3, 6, 9, and 12.

RESULTS

The RNFLT increased after surgery. Although the measurements taken were higher than the baseline CMT at all postoperative times, no significant difference was detected between the paired comparisons. The GCLT was found to be higher than the baseline value in all quadrants at the 12th month. A decrease in CT was observed at 5 measured points on the 1st day compared to the baseline.

CONCLUSION

During the 1-year follow-up, the effect of cataract surgery on the retina and choroid in uveitic eyes was most evident at the postoperative month 1.

Aptamer-functionalized MOFs and AI-driven strategies for early cancer diagnosis and therapeutics

Metal-Organic Frameworks (MOFs) have exceptional inherent properties that make them highly suitable for diverse applications, such as catalysis, storage, optics, chemo sensing, and biomedical science and technology. Over the past decades, researchers have utilized various techniques, including solvothermal, hydrothermal, mechanochemical, electrochemical, and ultrasonic, to synthesize MOFs with tailored properties. Post-synthetic modification of linkers, nodal components, and crystallite domain size and morphology can functionalize MOFs to improve their aptamer applications. Advancements in AI and machine learning led to the development of nonporous MOFs and nanoscale MOFs for medical purposes. MOFs have exhibited promise in cancer therapy, with the successful accumulation of a photosensitizer in cancer cells representing a significant breakthrough. This perspective is focused on MOFs' use as advanced materials and systems for cancer therapy, exploring the challenging aspects and promising features of MOF-based cancer diagnosis and treatment. The paper concludes by emphasizing the potential of MOFs as a transformative technology for cancer treatment and diagnosis.

Evaluating an oral health education program for Korean soldiers during the COVID-19 era: Applying quantitative light-induced fluorescent technology-A pilot study

PURPOSE

This study aimed to provide a basis for the development of a remote oral health education program for soldiers enlisted during the COVID-19 era(August-September 2021) by conducting oral health education using quantitative light-induced fluorescent technology and then comparing Quigley-Hein Plaque Index (QHPI) and oral health knowledge, awareness, and behavior.

METHODS

Thirty soldiers serving in a military hospital in South Korea were classified into two groups using simple random sampling. The experimental group implemented oral health education and self-managed using quantitative light-induced fluorescent technology, whereas the control group implemented oral health education alone. It was performed for 8 weeks at 2-week intervals. Thereafter, oral health knowledge, awareness, and behavior were surveyed, and QHPI was measured. Changes between and within groups over time were analyzed.

RESULTS

QHPI was statistically significantly reduced in the experimental group over time. Oral health knowledge, awareness, and behavior scores were higher in the experimental group than in the control group, with statistically significant differences. Oral health education considering the characteristics of soldiers, who utilized quantitative light-induced fluorescent technology, was shown to be effective, and this effect requires further research through a longitudinal study.

CONCLUSION

This study demonstrated that oral health education based on quantitative light-induced fluorescent technology should be a useful tool for improving the oral hygiene status, oral health knowledge, awareness, and behavior of Korean soldiers.

The effect of polycythemia vera on choroidal thickness and retrobulbar blood flow

BACKGROUND

To evaluate the choroidal thickness and retrobulbar hemodynamic parameters in polycythemia vera (PV) patients in comparison with healthy individuals, and to investigate the relationship of these values with blood hematocrit levels.

METHODS

This prospective study included the 35 eyes of 35 PV patients and the 30 eyes of 30 healthy individuals. Choroidal thickness was measured at the subfoveal area and at 500 µm intervals nasal and temporal to the fovea up to a distance of 1500 µm. Color Doppler ultrasonography (CDU) was used to evaluate the retrobulbar vessels. Complete blood count values were recorded.

RESULTS

Choroidal thickness was found to be significantly lower in the PV group than in the control group at the subfoveal, nasal 500, and temporal 500 and 1000 µm measurement points (p = 0.01, p = 0.011, p = 0.04, p = 0.045, respectively). The central retinal artery (CRA) peak systolic velocity (PSV) and end diastolic velocity (EDV) values and the ophthalmic artery (OA) PSV value were significantly lower in the PV group than in the control group (p < 0.001, p < 0.001, p = 0.019, respectively). No significant difference was present between the groups in terms of CRA and OA resistive index (RI) and pulsatile index (PI) values (p = 0.388, p = 0.564, p = 0.897, p = 0.693, respectively). A negative correlation was found between the blood hematocrit levels and the subfoveal, nasal 500 µm, and temporal 500 µm choroidal thickness measurements and the CRA PSV and EDV and the OA PSV values.

CONCLUSIONS

PV may cause microvascular changes and lead to ocular vascular complications by affecting the choroidal and retrobulbar blood flow.

Comparison of choroidal structural changes between term and preterm children with and without retinopathy of prematurity

PURPOSE

To evaluate the effects of prematurity and retinopathy of prematurity (ROP) treatment on choroidal structure using the image binarization method and compare with term children.

METHODS

Children aged 6-11 years were included in this prospective case-control study. There were 36 (72 eyes) term children and 52 (103 eyes) preterm children included in the study. Subfoveal choroidal thickness (SFCT) and choroidal thickness (CT) at 500, 1500, and 2500 μm temporal and nasal from the fovea were measured. Images were binarized using the Image J program. The choroidal vascularity index (CVI) was calculated by dividing the luminal area by the total subfoveal choroidal area.

RESULTS

There was no significant difference in SCFT between children born at term (290.44±57.617 μm) and preterm (288±69.270 μm) (p = 0.800). CVI was found to be significantly higher in term children (71.90±2.60 %) than in preterm children (69.58±2.72 %) (p<0.001), and the difference was also significant when compared to preterm children without ROP (p = 0.033). In the preterm subgroups, although CVI was higher in preterm children without ROP (70.42±2.24 %) than in those with spontaneous regression (69.34±3.30 %) and those treated with laser photocoagulation (68.91±2.35 %), there was no significant difference (p = 0.330, p = 0.089 respectively). CVI was similar between children with spontaneous regression and those treated with laser photocoagulation (p = 0.909). CVI and logMAR best corrected visual acuity (BCVA) were inversely correlated (r=-0.295 p<0.001).

CONCLUSION

Reduced CVI in preterm children indicates that prematurity is related to the choroid. Choroidal vascularity index appears to be a more reliable marker than CT for evaluating the relationship between choroid and ROP.

Evaluation of tissue blood supply during esophagectomy using fluorescent diagnostics and diffuse scattering spectroscopy in visible region

BACKGROUND

The success of the surgical treatment of a tumor or obstruction of the esophagus with subsequent anastomosis application depends on the level of blood supply to the stitched tissues. Intraoperative assessment of blood flow is widely used in medicine and can be used as a diagnostic method that affects the outcome of surgery and reduces the frequency of postoperative complications for the patient.

METHODS

In this work, the assessment of blood supply during esophageal resection operations was carried out using two techniques sequentially: fluorescent diagnostics with indocyanine green and measurement of hemoglobin oxygen saturation by diffuse scattering spectroscopy in the visible wavelength range. The first method was used to assess the integrity of the vascular network structure in the area of anastomosis and blood flow through the sutured tissues, the second one - for local assessment of hemoglobin oxygen saturation in the investigated area.

RESULTS

Conducted clinical study involved the participation of nine patients with malignant neoplasms (six cases) or esophageal obstruction (three cases). The presence of postoperative complications was compared with the measurement results. Anastomosis failure was observed in only one patient. According to the results of the study, with the use of the investigated method of assessing blood supply, there is a tendency towards a decrease in the frequency of anastomosis leaks (11.1 % compared with 21.4 %).

CONCLUSIONS

Therefore, fluorescent diagnostics with indocyanine green and measurement of hemoglobin oxygen saturation using diffuse scattering spectroscopy were affirmed as methods that allow increasing the safety of surgical procedures by assessing the risk of postoperative complications, including anastomosis failures.

Macular blood flow changes in dysthyroid optic neuropathy after high-dose intravenous pulse methylprednisolone (IVMP)

OBJECTIVE

To investigate the changes in macular vessel density (VD) of the superficial layer of retina (SLR) and deep layer of retina (DLR) in dysthyroid optic neuropathy (DON) after high-dose intravenous pulse methylprednisolone (IVMP).

MATERIALS AND METHODS

Eighteen DON patients (29 eyes) who completed high-dose IVMP and 16 healthy individuals (32 eyes) were enrolled in this study. Optical coherence tomography angiography (OCTA) image analysis and comprehensive ophthalmic examinations were performed, including the SLR macular whole-image VD (SLR-mwiVD) and DLR-mwiVD, best-corrected visual acuity (BCVA), the mean deviation of visual field (VF-MD), pattern standard deviation of visual field (VF-PSD) and the other parameters.

RESULTS

The SLR-mwiVD (41.39 ± 4.71 vs. 48.13 ± 3.68, p < 0.001) and DLR-mwiVD (40.77 ± 5.85 vs. 49.14 ± 7.02, p < 0.001) were decreased in DON compared to control eyes. After IVMP, visual function parameters were improved, and SLR-mwiVD (49.41 ± 3.18, p < 0.001) and DLR-mwiVD (50.41 ± 4.04, p < 0.001) were increased in the DON group compared to pretreatment. The increased SLR-mwiVD and DLR-mwiVD were significantly correlated with improvements in BCVA (Log MAR: from 0.62 ± 0.49 to -0.01 ± 0.03, p < 0.001), VF-MD (from - 6.89 ± 2.89 dB to - 1.75 ± 1.29 dB, p < 0.001) and VF-PSD (from 4.38 ± 2.52 dB to 2.32 ± 1.64 dB, p < 0.001).

CONCLUSION

The increase in macular VD was significantly correlated with the improvement in visual function in DON after IVMP. Macular VD changes on OCTA may be a useful indicator for the response in DON after IVMP.

Portable color retinography findings in COVID-19 patients admitted to the ward

Retinal lesions, including cotton-wool exudates, microbleeds, vascular occlusions and vasculitis, occur in a minority of Coronavirus Disease-19 (COVID-19) patients. Retinal assessments using retinography can help document these lesions. The objective of this work was to identify retinal changes in patients admitted to the ward with a positive Real Time Quantitative Polymerase Chain Reaction (RT-qPCR) exam for COVID-19. A cross-sectional, observational study was carried out of patients with mild and moderate symptoms admitted to the Hospital de Base in São José do Rio Preto. The Eyer® portable retinal camera (Phelcom® Technologies) was used to evaluate 30 male and 21 female patients. The ages ranged from 21 to 83 years (mean: 47 years). Systemic arterial hypertension was identified in 21 (41.2 %) and diabetes mellitus in 12 (23.5 %) patients. Six (11.7 %) reported worsening visual acuity, however, none of these patients had ocular findings to justify this complaint. Ten patients (19.6 %) had intraretinal hemorrhages; one (1.9 %) had cotton-wool exudates and seven (13.7 %) had dilations of veins. Thirteen patients (25.4 %) had vascular tortuosity and six (11.7 %) had pathological arteriovenous crossings. Portable retinography is useful to evaluate patients admitted to isolation wards due to COVID-19. It is important to remember that some of the patients investigated had comorbidities like diabetic maculopathy and systemic arterial hypertension. Hence, some care should be taken in attributing these observations uniquely to COVID-19 infection.

Angle Kappa and angle Alpha agreement between Pentacam Scheimpflug system, swept source optical coherence tomography and ray-tracing aberrometry

PURPOSE

To compare the consistency of Pentacam Scheimpflug system (Pentacam® HR), ray-tracing aberrometry (iTrace), and swept source optical coherence tomography (IOLMaster 700) measurements for Angle Kappa and angle Alpha.

METHODS

A prospective randomized cohort study. 86 individuals (86 eyes) aged 19-45 years with best corrected vision of 4.9 or better were randomly selected from January 2022 to December 2022 in a tertiary-level hospital. Angle Kappa and angle Alpha were measured or calculated using Pentacam, iTrace, and IOLMaster 700, respectively.

RESULTS

The mean difference of angle Kappa between any two instruments was not statistically significant, but the mean difference of angle Alpha between both Pentacam and iTrace, Pentacam and IOLMaster 700, and iTrace and IOLMaster 700 was statistically significant (p value <0.001, 0.003, <0.001). The highest consistency of angle Kappa and the narrowest 95% LoA (-0.20 to 0.21) were found between Pentacam and iTrace according to Bland Altman plots, but between Pentacam and IOLMaster 700 according to Mountain plots. Both Bland Altman plots and Mountain plots showed the highest consistency of angle Alpha and the narrowest 95% LoA (-0.14 to 0.24) between Pentacam and iTrace.

CONCLUSION

The mean angle Kappa among Pentacam® HR, iTrace, and IOLMaster 700 had good agreement, and the value of angle Kappa could be output directly, making it more convenient for clinical application. The measured or calculated angle Alpha had poor agreement, and ophthalmologists could refer to measurements from multiple instruments.

Gold nanoparticle-mediated photothermal therapy guidance with multi-wavelength photomagnetic imaging

Difficulty in heating tumors with high spatial selectivity while protecting surrounding healthy tissues from thermal harm is a challenge for cancer photothermal treatment (PTT). To mitigate this problem, PTT mediated by photothermal agents (PTAs) has been established as a potential therapeutic technique to boost selectivity and reduce damage to surrounding healthy tissues. Various gold nanoparticles (AuNP) have been effectively utilized as PTAs, mainly using strategies to target cancerous tissue and increase selective thermal damage. Meanwhile, imaging can be used in tandem to monitor the AuNP distribution and guide the PTT. Mainly, the parameters impacting the induced temperature can be determined using simulation tools before treatment for effective PTT. However, accurate simulations can only be performed if the amount of AuNPs accumulated in the tumor is known. This study introduces Photo-Magnetic Imaging (PMI), which can appropriately recover the AuNP concentration to guide the PTT. Using multi-wavelength measurements, PMI can provide AuNP concentration based on their distinct absorption spectra. Tissue-simulating phantom studies are conducted to demonstrate the potential of PMI in recovering AuNP concentration for PTT planning. The recovered AuNP concentration is used to model the temperature increase accurately in a small inclusion representing tumor using a multiphysics solver that takes into account the light propagation and heat diffusion in turbid media.

Comparative efficacy of 2% minoxidil alone against combination of 2% minoxidil and low-level laser therapy in female pattern hair loss-A randomized controlled trial in Chinese females

OBJECTIVES

To investigate the effectiveness and safety of combination of 655 nm low level laser helmet device with topical 2 % minoxidil solution at FPHL in Chinese population.

MATERIALS AND METHODS

Randomized, parallel, controlled, single-blind clinical trial was conducted. FPHL subjects were randomly allocated into 2 % minoxidil group and combination group. The 2 % minoxidil group received 1 ml topical 2 % minoxidil solution twice daily for 24 weeks. The combination group received 1 ml topical 2 % minoxidil solution twice daily together with 20 min 655 nm low-level laser helmet once every other day for 24 weeks. Hair parameters in two scalp areas including midscalp and vertex were evaluated at baseline, 12th week and 24th week.

RESULTS

In midscalp area, the combination group showed a lower increase in intermediate hair percentage than 2 % minoxidil group, which was statistically significant. Besides, the combination group had statistically significant increase than 2 % minoxidil group in mean hair diameter. Reported relative adverse events included slightly hair loss (27.8 %), desquamation (19.0 %), pruritus (15.2 %), seborrhea (2.5 %) and hypertrichosis (2.5 %).

CONCLUSION

In our trial, LLLT was demonstrated as a useful supplementary treatment for FPHL and the combination with 2 % minoxidil accomplished better improvement in intermediate hair enlargement and hair diameter of midscalp for FPHL.

Fluorescence spectroscopic profiling of urine samples for predicting kidney transplant rejection

Rejection is the primary factor affecting the functionality of a kidney post-transplant, where its prompt prediction of risk significantly influences therapeutic strategies and clinical outcomes. Current graft health assessment methods, including serum creatinine measurements and transplant kidney puncture biopsies, possess considerable limitations. In contrast, urine serves as a direct indicator of the graft's degenerative stage and provides a more accurate measure than peripheral blood analysis, given its non-invasive collection of kidney-specific metabolite. This research entailed collecting fluorescent fingerprint data from 120 urine samples of post-renal transplant patients using hyperspectral imaging, followed by the development of a learning model to detect various forms of immunological rejection. The model successfully identified multiple rejection types with an average diagnostic accuracy of 95.56 %.Beyond proposing an innovative approach for predicting the risk of complications post-kidney transplantation, this study heralds the potential introduction of a non-invasive, rapid, and accurate supplementary method for risk assessment in clinical practice.

Effects of repeated low-level red-light therapy on macular retinal thickness and microvascular system in children with myopia

OBJECTIVE

The objective of the study was to use optical coherence tomography angiography (OCTA) to analyze the effects of repeated low-level red-light (LLLT) therapy on macular retinal thickness and the microvascular system in children with myopia to evaluate the safety of this therapy.

METHODS

This prospective study included 40 school-age children with myopia (80 eyes), aged 7-14 years, who received therapy using a LLLT instrument. At baseline and therapy for 1 month, 3 months, 6 months, all children underwent comprehensive ophthalmological examinations, including slit-lamp examination, uncorrected visual acuity, best-corrected visual acuity, spherical equivalent degree, axial length, and OCTA. The vessel densities of the superficial retinal capillary plexus, macular inner retinal thickness, and full-layer retinal thickness were measured.

RESULTS

The macular inner retinal thickness increased at 1 month and remained unchanged thereafter, It differed significantly in nine areas at 1, 3, and 6 months compared to the thicknesses before therapy (P < 0.05); however, we observed no significant differences between the different time points (P > 0.05). The macular full-layer retinal thickness increased at 1 month and remained unchanged thereafter; the changes showed significant differences at 1 month and 3 months compared to before therapy, for the inner nasal region (P < 0.05). The other eight areas showed significant differences at 1, 3, and 6 months compared with before therapy (P < 0.05); however, no significant difference was observed between the different time points after therapy (P > 0.05). The vessel density of the superficial retinal capillary plexus did not differ significantly among the four groups (P > 0.05).

CONCLUSIONS

LLLT therapy was safe. The school-aged children exhibited macular thickening after LLLT therapy, which had no significant effect on macular microcirculation.

Are intravitreal hyperreflective particles alike in eyes with acute toxoplasma chorioretinitis and non-infectious uveitis?

BACKGROUND

To compare distinctive features of hyperreflective particles observed on spectral-domain optical coherence tomography (OCT) sections in eyes with acute toxoplasma chorioretinitis (TC) and non-infectious uveitis (NIU).

METHODS

Medical records and the spectral-domain OCT images of the patients with TC and NIU were retrospectively reviewed. The TC and NIU groups were compared in terms of age, sex, mean OCT image quality, mean central macular thickness (CMT), presence of intraretinal fluid (IRF), presence of subretinal fluid (SRF), number of hyperreflective particles in the posterior vitreous area and mean particle measurement in the posterior vitreous area.

RESULTS

Non-infectious uveitis group included nine patients (60 %) with Behcet's uveitis, five patients (33.3 %) with idiopathic posterior uveitis or panuveitis, and the remaining patient (6.7 %) with HLA-B27 associated uveitis. Comparison of the mean age, sex distribution, mean OCT image quality, mean CMT, presence of IRF, presence of SRF and the mean number of hyperreflective particles in the posterior vitreous area between the two groups showed no statistically significant differences (p = 0.085, p = 0.051, p = 0.748, p = 0.431, p = 0.109, p = 0.080 and p = 0.152, respectively). However, the mean length of the hyperreflective particles in the posterior vitreous area was 27.22 ± 8.60 μm in the TC group, and 21.91 ± 3.58 μm in the NIU group, with a significant difference between the two groups (p = 0.036).

CONCLUSION

This pilot study aimed to assess the hyperreflective particles in the posterior vitreous area using spectral-domain OCT images and image processing software. Despite its limitations, such as the small sample size, limited understanding of the nature of hyperreflective particles, and the absence of differentiation between acute and chronic uveitis, our study points out the potential role of the measurement of the hyperreflective particle length located in the posterior vitreous in differentiating the acute infectious versus non-infectious uveitis as the hyperreflective particles tend to be larger in infectious cases.