5-aminolevulinic Acid Research Articles

Efficacy of Aminolevulinic Acid Mediated Photodynamic Therapy in the Treatment of Oral Premalignant Lesions: A Systematic Review.

Aminolevulinic acid (ALA) mediated photodynamic therapy (PDT) is considered as an effective treatment option for oral premalignant lesions. ALA is a Food and Drug Administration (FDA) approved second-generation photosensitizer (PS) used both orally as well as topically. This systematic review aims to evaluate the efficacy of ALA-PDT for the treatment of oral premalignant lesions. The focused question was, "Is ALA-PDT effective in the treatment of oral premalignant lesions?"A literature search was made in PubMed/Medline and GoogleScholar using different combinations of the following keywords: photodynamic therapy, oral premalignant lesions, oral leukoplakia (OL), erythroplakia, oral erythroleukoplakia (OEL), oral verrucous hyperplasia (OVH); and oral lichen planus (OLP). Review articles, preclinical studies, case-reports, commentaries, letters to the Editor, unpublished articles, studies on photodynamic therapy used in areas other than the oral cavityand, articles published in languages other than English were excluded. The relevant information was summarized. There were initially 64 results for the above parameters; 47 studies were excluded, leaving 17 studies for analysis. Characteristics of the included studies, PS, and PDT protocol were summarized. The outcome of the included studies suggested that ALA-PDT is an effective, easy to perform technique, well tolerated treatment with encouraging achievements in the treatment of oral premalignant lesions. No systemic side effects and skin photosensitivity were reported with topical ALA even within initial 48 hours after PDT, and patients were not required to avoid exposure to light following treatment. The clinical outcome of the ALA-PDT application, as reported in the studies, was also very promising, with either diminution in the size of the lesion or complete remission or improvement in signs and symptoms as well as reduced recurrence.

MdWRKY71 as a positive regulator involved in 5-aminolevulinic acid-induced salt tolerance in apple

5-Aminolevulinic acid (ALA), is a novel plant growth regulator that can enhance plant tolerance against salt stress. However, the molecular mechanism of ALA is not well studied. In this study, ALA improved salt tolerance of apple (Malus × domestica 'Gala') when the detached leaves or cultured calli were used as the materials. The expression of MdWRKY71, a WRKY transcription factor (TF) gene was found to be responsive to NaCl as well as ALA treatment. Functional analysis showed that overexpressing (OE)-MdWRKY71 significantly improved the salt tolerance of the transgenic apple, while RNA interfering (RNAi)-MdWRKY71 reduced the salt tolerance. However, exogenous ALA alleviated the salt damage in the RNAi-MdWRKY71 apple. When MdWRKY71 was transferred into tobacco, the salt tolerance of transgenic plants was enhanced, which was further improved by exogenous ALA. Subsequently, MdWRKY71 bound to the W-box of promoters of MdSOS2, MdNHX1, MdCLC-g, MdSOD1, MdCAT1 and MdAPX1, transcriptionally activating the gene expressions. Since the genes are responsible for Na+ and Cl− transport and antioxidant enzyme activity respectively, it can be concluded that MdWRKY71, a new TF, is involved in ALA-improved salt tolerance by regulating ion homeostasis and redox homeostasis. These results provided new insights into the transcriptional regulatory mechanism of ALA in enhancing apple salt tolerance.

Assessment of the efficacy and safety of auricular keloids excision followed by 5-aminolevulinic acid photodynamic therapy

Background: Auricular keloids are a significant clinical challenge, which adversely affect the life of the patient at the level of aesthetic and psychological well-being. Despite various treatment modalities, a universally effective therapy has yet to be established. Photodynamic therapy (PDT) offers a promising approach by inhibiting the abnormal proliferation of fibroblasts while minimizing damage to surrounding healthy cells and tissues. This study evaluates the clinical outcomes of auricular keloid patients treated with excision followed by 5-aminolevulinic acid photodynamic therapy (ALA-PDT). Methods: This study included 8 patients diagnosed with auricular keloids based on pathological examination and clinical presentation. Following surgical excision of the auricular keloids, topical 5-ALA solution was applied for 4 hours. Then each lesion was irradiated with 120 J/cm² using a red LED (635-nm laser) for 20 minutes. Patients received 3-5 courses of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) during and after the surgery. Results: Among the 8 patients treated, auricular keloids were completely controlled with the combination therapy. During a follow-up period of 2.7 years (range: 1.8-4.1 years), all patients exhibited excellent outcomes with no recurrence of keloids. Conclusions: The combination of surgical excision and 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is an effective and safe treatment for auricular keloids. This combined approach shows promise as an alternative clinical treatment for managing auricular keloids.

Sonodynamic therapy for adult-type diffuse gliomas: past, present, and future.

Intra-axial brain tumors persist as significant clinical challenges. Aggressive surgical resection carries risk of morbidity, and the blood-brain barrier (BBB) prevents optimal pharmacological interventions. There is a clear clinical demand for innovative and less invasive therapeutic strategies for patients, especially those that can augment established treatment protocols. Focused ultrasound (FUS) has emerged as a promising approach to manage brain tumors. Sonodynamic therapy (SDT), a subset of FUS, utilizes sonosensitizers activated by ultrasound waves to generate reactive oxygen species (ROS) and induce tumor cell death. This review explores the historical evolution and rationale behind SDT, focusing on its mechanisms of action and potential applications in brain tumor management. A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Preclinical studies have demonstrated the efficacy of various sonosensitizers, including 5-aminolevulinic acid (5-ALA), fluorescein, porphyrin derivatives, and nanoparticles, in conjunction with FUS for targeted tumor therapy and BBB disruption. Clinical trials have shown promising results in terms of safety and efficacy, although further research is needed to fully understand the potential adverse effects and optimize treatment protocols. Challenges such as skull thickness affecting FUS penetration, and the kinetics of BBB opening require careful consideration for the successful implementation of SDT in clinical practice. Future directions include comparative studies of different sonosensitizers, optimization of FUS parameters, and exploration of SDT's immunomodulatory effects. SDT represents a promising frontier in the treatment of aggressive brain tumors, offering hope for improved patient outcomes.

Intraoperative confocal laser endomicroscopy during 5-aminolevulinic acid-guided glioma surgery: significant considerations for resection at the tumor margin.

Because gliomas have poorly defined tumor margins, the ability to achieve maximal resection is limited. To better discern these margins, fluorescence-guided surgery has been used to aid maximal safe resection. The authors describe their experience with the simultaneous use of intraoperative fluorescein sodium (FNa) confocal laser endomicroscopy (CLE) and operating microscope 5-aminolevulinic acid (5-ALA) fluorescence imaging for glioma resection to improve CLE use for better margin discrimination. FNa CLE and 5-ALA wide-field imaging were used in 33 patients with gliomas. CLE imaging was enhanced with the use of a telesurgical pathology software platform that enables real-time conversation between the operating neurosurgeons and the pathologists located remotely. CLE was used for imaging tumor regions that were subjectively regarded as tumor margins under normal visualization with the operative microscope. After FNa CLE imaging, 5-ALA wide-field imaging was performed in the same regions. Tissue was biopsied at imaging locations, and interpretations of FNa CLE and 5-ALA wide-field imaging were compared to those of permanent histological sections. Eighty-eight deep- and superficial-margin regions of interest (ROIs) were imaged with FNa CLE and 5-ALA imaging. Most of the ROIs interpreted by the neuropathologist as infiltrative glioma based on FNa CLE imaging lacked 5-ALA-induced fluorescence. Permanent histological sections from the corresponding regions were concordant with the interpretation of FNa CLE images in 57 of 88 (65%) ROIs and with the interpretation of 5-ALA imaging in 43 of 88 (49%) ROIs. The sensitivity and specificity of FNa CLE for the interpretation of tumor margins were 73% and 41%, respectively, and those of 5-ALA were 38% and 82%, respectively. Positive and negative predictive values for CLE were 79% and 33%, respectively, and those for 5-ALA were 86% and 31%, respectively. Conventional intraoperative evaluation of tumor margins, based on MRI and wide-field fluorescence imaging, can underestimate the invasiveness of gliomas. FNa CLE showed higher accuracy in detecting regions with infiltrating tumors than intraoperative 5-ALA imaging. Future considerations should include more rigorous comparisons of FNa CLE imaging and 5-ALA-guided resections on a larger cohort of patients.

Non-syndromic congenital sideroblastic anaemia; phenotype, and genotype of 15 Indian patients.

Sideroblastic anaemias are a diverse group of congenital and acquired bone marrow failure disorders marked by the presence of ring sideroblasts, ineffective erythropoiesis, and systemic iron overload. Congenital Sideroblastic anaemia (CSA) is mainly caused by gene mutations associated with heme synthesis, iron-sulfur [Fe-S] cluster, and mitochondrial protein synthesis pathways. The most prevalent form of CSA is caused by mutations in the erythroid-specific -amino levulinate synthase (ALAS2) gene, which encodes the first enzyme in the heme synthesis pathway in red blood cells. The second most prevalent form of CSA is caused by a mutation in the Solute carrier family 25 member 38 (SLC25A38) gene, which codes for an erythroid-specific protein of the inner mitochondrial membrane. Additionally, 15-20 genes are altogether associated with CSA. In this study, we aim to identify the CSA patients, understand their genetics and establish genotype-phenotype correlation. We have identified fifteen cases of CSA using our targeted NGS (t-NGS) panel. The major clinical findings in our cohort were microcytic anaemia, ring sideroblasts, and dyserythropoiesis in the bone marrow. Currently, two patients are responsive to pyridoxine, while the rest are on blood transfusion support. We have identified ten variants in three different genes of CSA (ALAS2, SLC25A38 & HSPA9). Five patients harbour four hemizygous variants- p.Ala282Ser, p.Arg170Cys, p.Arg204Gln and exon 2 duplication in the ALAS2 gene. In seven patients, we have identified three homozygous mutations - p.Pro190Arg, p.Arg187Gln and p.Arg134Cys in the SLC25A38 gene. These mutations have been predominantly identified in the European population. Three patients revealed three heterozygous variants p. Thr463Ile, D326Tyr, and Arg284Trp in the HSPA9 gene. PyMoL was used to evaluate the functional effects of these variations and understand their effect on the structure of the protein. We believe that by combining a bone marrow examination with genetic sequencing, CSA patients can acquire a definitive diagnosis.

5-Aminolevulinic acid-mediated photodynamic therapy in combination with kinase inhibitor lapatinib enhances glioblastoma cell death.

5-Aminolevulinic acid (ALA) is an intraoperative imaging agent approved for protoporphyrin IX (PpIX) fluorescence-guided resection of glioblastoma (GBM). It is currently under clinical evaluation for photodynamic therapy (PDT) after the completion of GBM surgery. We previously showed that lapatinib, a clinical kinase inhibitor of epidermal growth factor receptor 1 & 2 (EGFR and HER2), enhanced PpIX fluorescence in a panel of GBM cell lines by blocking ABCG2 (ATP-binding cassette super-family G member 2)-mediated PpIX efflux, which suggests its potential for improving ALA for GBM surgery and PDT. Here we show that lapatinib enhanced PDT-induced cytotoxicity by promoting GBM cell death with the induction of apoptosis followed by necrosis. While the induction of tumor cell apoptosis was massive and rapid in the H4 cell line with no detectable Bcl-2 and a low level of Bcl-xL, it was delayed and much less in extent in A172, U-87 and U-118 cell lines with higher levels of pro-survival Bcl-2 family proteins. Lapatinib treatment alone neither reduced GBM cell viability nor had any significant effect on EGFR downstream signaling. Its enhancement of ALA-PDT was largely due to the increase of intracellular PpIX particularly in the mitochondria, resulting in the activation of mitochondria-mediated apoptosis in H4 cells. Our present study demonstrates that lapatinib inhibits ABCG2-mediated PpIX efflux and sensitizes GBM cells to ALA-PDT by inducing tumor cell death.

Glioblastoma in the real-world setting: patterns of care and outcome in the Austrian population.

We present results of a retrospective population-based investigation of patterns of care and outcome of glioblastoma patients in Austria. In this nation-wide cooperative project, all Austrian glioblastoma patients newly diagnosed between 2014 and 2018 and registered in the ABTR-SANOnet database were included. Histological typing used criteria of the WHO classification of CNS tumors, 4th edition 2016. Patterns of care were assessed, and all patients were followed until the end of 2019. 1,420 adult glioblastoma cases were identified. 813 (57.3%) patients were male and 607 (42.7%) female. Median age at diagnosis was 64years (range: 18-88). Median overall survival (OS) was 11.6months in the total cohort and 10.9months in patients with proven IDH-wildtype. Median OS in the patient group ≤ 65years receiving postoperative standard of care therapy was 16.1months. In the patient group > 65years with postoperative therapy, median OS was 11.2months. Follow-up ≥ 5years identified 13/264 (4.9%) long-term survivors. Brain tumor surgery frequently was assisted by 5-aminolevulinic acid (5-ALA) fluorescence (up to 55%). Postoperative treatment was initiated around one month after surgery (median: 31days) following standardized protocols in 1,041/1,420 (73.3%) cases. In 830 patients (58.5%), concomitant radiochemotherapy was started according to the established standard of care. Treatment in case of progressive disease was considerably variable. 170/1,420 patients (12.0%) underwent a second surgical procedure, 467 (33.0%) received systemic treatment after progression, and 173 (12.2%) were re-irradiated. Our data illustrate and confirm nation-wide translation of effective standard of care to Austrian glioblastoma patients in the recent past. In the case of progressive disease, highly variable therapeutic approaches were used, most frequently accompanied by anti-angiogenic therapy. Long-term survival was observed in a minor proportion of mostly younger patients who typically had gross total tumor resection, a favorable postoperative ECOG score, and standard of care therapy.

Synthetic Efforts toward the Synthesis of a Fluorinated Analog of 5-Aminolevulinic Acid: Practical Synthesis of Racemic and Enantiomerically Defined 3-Fluoro-5-aminolevulinic Acid.

In 2017, the FDA authorized 5-aminolevulinic acid (5-ALA) for intraoperative optical imaging of suspected high-grade gliomas. This was the first authorized optical imaging agent for brain tumor surgery to enhance the visualization of malignant tissue. Herein we report the synthesis of a racemic and enantiopure fluorinated analog of 5-ALA, i.e., 3-fluoro-5-aminolevulinic acid (3F-5-ALA). We anticipate that these studies will provide the foundation for the future construction of a fluorine-18-labeled 5-ALA PET tracer to be used for functional and metabolic imaging of gliomas.

PpIX-enabled fluorescence-based detection and photodynamic priming of platinum-resistant ovarian cancer cells under fluid shear stress.

Over 75% percent of ovarian cancer patients are diagnosed with advanced-stage disease characterized by unresectable intraperitoneal dissemination and the presence of ascites, or excessive fluid build-up within the abdomen. Conventional treatments include cytoreductive surgery followed by multi-line platinum and taxane chemotherapy regimens. Despite an initial response to treatment, over 75% of patients with advanced-stage ovarian cancer will relapse and succumb to platinum-resistant disease. Recent evidence suggests that fluid shear stress (FSS), which results from the movement of fluid such as ascites, induces epithelial-to-mesenchymal transition and confers resistance to carboplatin in ovarian cancer cells. This study demonstrates, for the first time, that FSS-induced platinum resistance correlates with increased cellular protoporphyrin IX (PpIX), the penultimate downstream product of heme biosynthesis, the production of which can be enhanced using the clinically approved pro-drug aminolevulinic acid (ALA). These data suggest that, with further investigation, PpIX could serve as a fluorescence-based biomarker of FSS-induced platinum resistance. Additionally, this study investigates the efficacy of PpIX-enabled photodynamic therapy (PDT) and the secretion of extracellular vesicles under static and FSS conditions in Caov-3 and NIH:OVCAR-3 cells, two representative cell lines for high-grade serous ovarian carcinoma (HGSOC), the most lethal form of the disease. FSS induces resistance to ALA-PpIX-mediated PDT, along with a significant increase in the number of EVs. Finally, the ability of PpIX-mediated photodynamic priming (PDP) to enhance carboplatin efficacy under FSS conditions is quantified. These preliminary findings in monolayer cultures necessitate additional studies to determine the feasibility of PpIX as a fluorescence-based indicator, and mediator of PDP, to target chemoresistance in the context of FSS.

The diagnostic potential of urine in paediatric patients undergoing initial treatment for tuberculous meningitis

Tuberculous meningitis (TBM)—the extrapulmonary form of tuberculosis, is the most severe complication associated with tuberculosis, particularly in infants and children. The gold standard for the diagnosis of TBM requires cerebrospinal fluid (CSF) through lumbar puncture—an invasive sample collection method, and currently available CSF assays are often not sufficient for a definitive TBM diagnosis. Urine is metabolite-rich and relatively unexplored in terms of its potential to diagnose neuroinfectious diseases. We used an untargeted proton magnetic resonance (1H-NMR) metabolomics approach to compare the urine from 32 patients with TBM (stratified into stages 1, 2 and 3) against that from 39 controls in a South African paediatric cohort. Significant spectral bins had to satisfy three of our four strict cut-off quantitative statistical criteria. Five significant biological metabolites were identified—1-methylnicotinamide, 3-hydroxyisovaleric acid, 5-aminolevulinic acid, N-acetylglutamine and methanol—which had no correlation with medication metabolites. ROC analysis revealed that methanol lacked diagnostic sensitivity, but the other four metabolites showed good diagnostic potential. Furthermore, we compared mild (stage 1) TBM and severe (stages 2 and 3) TBM, and our multivariate metabolic model could successfully classify severe but not mild TBM. Our results show that urine can potentially be used to diagnose severe TBM.

Plant competition cues activate a singlet oxygen signaling pathway in Arabidopsis thaliana.

Oxidative stress responses of Arabidopsis to reflected low red to far-red signals (R:FR ≈ 0.3) generated by neighboring weeds or an artificial source of FR light were compared with a weed-free control (R:FR ≈1.6). In the low R:FR treatments, induction of the shade avoidance responses (SAR) coincided with increased leaf production of singlet oxygen (1O2). This 1O2 increase was not due to protochlorophyllide accumulation and did not cause cell death. Chemical treatments, however, with 5-aminolevulinic acid (the precursor of tetrapyrrole biosynthesis) and glutathione (a quinone A reductant) enhanced cell death and growth inhibition. RNA sequencing revealed that transcriptome responses to the reflected low R:FR light treatments minimally resembled previously known Arabidopsis 1O2 generating systems that rapidly generate 1O2 following a dark to light transfer. The upregulation of only a few early 1O2 responsive genes (6 out of 1931) in the reflected low R:FR treatments suggested specificity of the 1O2 signaling. Moreover, increased expression of two enzyme genes, the SULFOTRANSFERASE ST2A (ST2a) and the early 1O2-responsive IAA-LEUCINE RESISTANCE (ILR)-LIKE6 (ILL6), which negatively regulate jasmonate level, suggested that repression of bioactive JAs may promote the shade avoidance (versus defense) and 1O2 acclimation (versus cell death) responses to neighboring weeds.

Jasmonic acid priming and foliar application of spermidine up-regulates the tolerance mechanisms to alleviate the damaging effects of cadmium stress on growth and photosynthesis in wheat

The study examined the effects of jasmonic acid (100 nmol, JA) priming and foliar application of spermidine (1 mM, Spd), both individually and combined, on mitigating cadmium (100 µM, Cd) stress-induced oxidative damage in wheat. Cadmium stress reduced plant height and dry mass, but JA priming and/or Spd treatment increased resistance. Cd stress significantly decreased carotenoids, total chlorophylls, glutamate 1-semialdehyde (GSA), and δ-aminolevulinic acid (ALA), but JA and Spd treatments counteracted these reductions. Photosynthetic parameters improved under JA and Spd treatments, with combined treatment showing greater alleviation. Cd exposure increased lipid peroxidation, hydrogen peroxide, electrolyte leakage, and superoxide, but these oxidative stress indicators were significantly reduced after JA and Spd treatment. Antioxidant enzyme activity was upregulated by JA priming and Spd application, both under unstressed and Cd-stressed conditions. JA and/or Spd treatments also increased ascorbic acid, lowered glutathione concentration, and upregulated glyoxylase activity, reducing methylglyoxal accumulation. Additionally, secondary compounds (phenols and flavonoids) and osmolytes (proline and glycine betaine) levels improved. Proline oxidase activity decreased, indicating controlled proline buildup, while γ-glutamyl kinase activity increased. JA and/or Spd treatments significantly reduced Cd accumulation in seedlings. The study concluded that JA and Spd treatments enhance the plant's defensive mechanisms against oxidative stress by boosting antioxidant enzymes and secondary metabolism.

Efficacy of fluorescence-guided techniques compared to conventional methods: a comprehensive review

Background: Glioblastoma (GBM) is a highly aggressive brain tumour with a poor prognosis. Surgical resection, aimed at achieving maximal safe resection, is crucial for improving patient outcomes. Conventional surgical techniques often fall short in accurately delineating tumour margins, necessitating advancements such as fluorescence-guided surgery (FGS). Objectives: This review aims to compare the effectiveness of advanced fluorescence-guided surgery with conventional surgical techniques in newly diagnosed glioblastoma patients, focusing on complete resection rates and postoperative complications. Methods: A systematic literature search was conducted to identify peer-reviewed articles, clinical trials, meta-analyses, and systematic reviews published in English within the last 15 years. Studies involving newly diagnosed glioblastoma patients and comparing FGS with conventional techniques were included. Data on complete resection rates and postoperative complications were extracted and analyzed. Discussions: The review findings indicate that FGS, particularly with 5-aminolevulinic acid (5-ALA) and fluorescein sodium, significantly improves complete resection rates and may reduce postoperative complications compared to conventional methods. The enhanced visualization of tumor margins facilitates more precise resection, potentially leading to better patient outcomes. However, challenges such as the variability in fluorophore efficacy and the cost of FGS technology remain. Further research is needed to optimize FGS and validate its long-term benefits.

Tongue squamous cell carcinoma treated by 5-aminolevulinic acid administrated through Microdrop method

BackgroundPostoperative recurrence of tongue squamous cell carcinoma (TSCC) has always been a clinical problem for patients and doctors. Surgery and radiotherapy are the main treatment methods for TSCC, but reoperation often leads to functional impairment. Side effects of radiotherapy include mucosal gland damage, dry mouth, weakened or lost taste. Improved treatment is needed. ObjectiveTo evaluate the clinical outcome of a patient with TSCC treated with Microdrop aminolevulinic acid (ALA) photodynamic treatment (PDT) twice. MethodsALA was dissolved in 5 % lidocaine and the concentration of ALA was 20 % by Microdrop method. Then, the tumor tissue was expanded 1 cm outward, and the injection points were evenly distributed with an upper and lower left and right interval of 2–3 mm. The 1 ml syringe was used to perform the injection in the skin of the tumor area, and there was a small cuticle at each injection point. A pathologically confirmed patient with TSCC received twice Microdrop ALA-PDT treatments, which were evaluated at 1 month and 4 months later. ResultsAfter 3 h of Microdrop ALA injection, the wavelength of semiconductor laser was set to 630 nm, and the energy of 300 mW /cm2 was irradiated for 30 min. After two treatments, the lesions were not visible, and no recurrence occurred after 4 months of follow-up. The patient's tongue function was well preserved and the cosmetic effect was good. ConclusionMicrodrop ALA-PDT may be effective in the salvage treatment of select tongue squamous cell carcinoma.

Pressure-enhanced sensing of tissue oxygenation via endogenous porphyrin: Implications for dynamic visualization of cancer in surgery

Fluorescence guidance is routinely used in surgery to enhance perfusion contrast in multiple types of diseases. Pressure-enhanced sensing of tissue oxygenation (PRESTO) via fluorescence is a technique extensively analyzed here, that uses an FDA-approved human precursor molecule, 5-aminolevulinic acid (ALA), to stimulate a unique delayed fluorescence signal that is representative of tissue hypoxia. The ALA precontrast agent is metabolized in most tissues into a red fluorescent molecule, protoporphyrin IX (PpIX), which has both prompt fluorescence, indicative of the concentration, and a delayed fluorescence, that is amplified in low tissue oxygen situations. Applied pressure from palpation induces transient capillary stasis and a resulting transient PRESTO contrast, dominant when there is near hypoxia. This study examined the kinetics and behavior of this effect in both normal and tumor tissues, with a prolonged high PRESTO contrast (contrast to background of 7.3) across 5 tumor models, due to sluggish capillaries and inhibited vasodynamics. This tissue function imaging approach is a fundamentally unique tool for real-time palpation-induced tissue response in vivo, relevant for chronic hypoxia, such as vascular diseases or oncologic surgery.

Sequential delivery of photosensitizers and checkpoint inhibitors by engineered bacteria for enhanced cancer photodynamic immunotherapy.

Engineered bacteria-based cancer therapy has increasingly been considered to be a promising therapeutic strategy due to the development of synthetic biology. Wherein, engineering bacteria-mediated photodynamic therapy (PDT)-immunotherapyshows greater advantages and potential in treatment efficiency than monotherapy. However, the unsustainable regeneration of photosensitizers (PSs) and weak immune responses limit the therapeutic efficiency. Herein, we developed an engineered bacteria-based delivery system for sequential delivery of PSs and checkpoint inhibitors in cancer PDT-immunotherapy. The biosynthetic pathway of 5-aminolevulinic acid (5-ALA) was introduced into Escherichia coli, yielding a supernatant concentration of 172.19 mg/L after 10 h of growth. And another strain was endowed with the light-controllable releasement of anti-programmed cell death-ligand 1 nanobodies (anti-PD-L1). This system exhibited a collaborative effect, where PDT initiated tumor cell death and the released tumor cell fragments stimulated immunity, followed by the elimination of residual tumor cells. The tumor inhibition rate reached 74.97%, and the portion of activated T cells and inflammatory cytokines were reinforced. The results demonstrated that the engineered bacteria-based collaborative system could sequentially deliver therapeutic substance and checkpoint inhibitors, and achieve good therapeutic therapy. This paper will provide a new perspective for the cancer PDT-immunotherapy.

Sodium fluorescein and 5-aminolevulinic acid fluorescence- guided biopsy in brain lesions: a systematic review and meta-analysis.

Stereotactic brain biopsies are highly efficient for diagnosing intracerebral pathologies, particularly when surgical resection is infeasible. Fluorescence-based agents such as 5-aminolevulinic acid (5-ALA) and fluorescein sodium (NaFl) can enhance diagnostic accuracy and safety, improving the visualization of lesional tissues. This meta-analysis aimed to evaluate their effect on diagnostic yield and complication rates of brain biopsies. This study adhered to Cochrane and PRISMA guidelines. We assessed studies for diagnostic yield and complication rates. Data was analyzed using a random-effects model in RStudio. Diagnostic accuracy measures such as sensitivity and predictive values were calculated based on fluorescence visibility in biopsy samples. Thirty-two non-randomized studies were included, comprising 947 patients, with a mean age ranging from 37 to 77years, and a mean sample number ranging from 1 to 15 specimens. Diagnostic yields were high: 93% for NaFl and 96% for 5-ALA. Major complications occurred in 3% of procedures with both agents, while minor complications were reported in 7% and 5% with NaFl and 5-ALA respectively. The Negative-predictive-value (NPV) of 5-ALA and NaFl were 8-11% and 60-80% respectively. NaFl demonstrates higher sensitivity and specificity at 84% and 100% compared to 5-ALA's 66%. and 85% respectively. 5-ALA and NaFl provide high diagnostic yields with acceptable safety profiles in stereotactic biopsies. NaFl showed higher sensitivity and specificity. NaFl outperforms 5ALA in terms of NPV making it more efficient for small lesions near eloquent regions or major blood vessels. The significance of these findings can be further ascertained through randomized trials.

A Novel PAMAM G3 Dendrimer-Based Foam with Polyether Polyol and Castor Oil Components as Drug Delivery System into Cancer and Normal Cells.

One of the intensively developed tools for cancer therapy is drug-releasing matrices. Polyamidoamine dendrimers (PAMAM) are commonly used as nanoparticles to increase the solubility, stability and retention of drugs in the human body. Most often, drugs are encapsulated in PAMAM cavities or covalently attached to their surface. However, there are no data on the use of PAMAM dendrimers as a component of porous matrices based on polyurethane foams for the controlled release of drugs and biologically active substances. Therefore, in this work, porous materials based on polyurethane foam with incorporated third-generation poly(amidoamine) dendrimers (PAMAM G3) were synthesized and characterized. Density, water uptake and morphology of foams were examined with SEM and XPS. The PAMAM was liquefied with polyether polyol (G441) and reacted with polymeric 4,4'-diphenylmethane diisocyanate (pMDI) in the presence of silicone, water and a catalyst to obtain foam (PF1). In selected compositions, the castor oil was added (PF2). Analogs without PAMAM G3 were also synthesized (F1 and F2, respectively). An SEM analysis of foams showed that they are composed of thin ribs/walls forming an interconnected network containing hollow bubbles/pores and showing some irregularities in the structure. Foam from a G3:G441:CO (PF2) composition is characterized by a more regular structure than the foam from the composition without castor oil. The encapsulation efficiency of drugs determined by the XPS method shows that it varies depending on the matrix and the drug and ranges from several to a dozen mass percent. In vitro biological studies with direct contact and extract assays indicated that the F2 matrix was highly biocompatible. Significant toxicity of dendrimeric matrices PF1 and PF2 containing 50% of PAMAM G3 was higher against human squamous carcinoma cells than human immortalized keratinocytes. The ability of the matrices to immobilize drugs was demonstrated in the example of perspective (Nimesulide, 8-Methoxypsolarene) or approved anticancer drugs (Doxorubicin-DOX, 5-Aminolevulinic acid). Release into the culture medium and penetration of DOX into the tested SCC-15 and HaCaT cells were also proved. The results show that further modification of the obtained matrices may lead to their use as drug delivery systems, e.g., for anticancer therapy.

Combined Fluorescence-Guided Surgery with 5-Aminolevulinic Acid and Fluorescein in Glioblastoma: Technical Description and Report of 100 Cases.

Fluorescence-guided resection (FGR) of glioblastomas has been previously explored with the use of 5-amivelulinic acid (5-ALA) and sodium fluoresceine (SF), allowing us to maximize the extent of resection (EoR). In this study, we highlight the most relevant concerns regarding this technique and present the methods and results from the experience of our center. A case series of 100 patients operated on in AOU Città della Salute e della Scienza in Turin with a histological diagnosis of glioblastoma (grade IV, according to WHO 2021) was retrospectively analyzed. Both 5-ALA and SF were administered and intraoperatively assessed with an optical microscope. 5-ALA is the only approved drug for FGR in glioblastoma, reporting an increased EoR. Nevertheless, SF can be positively used in addition to 5-ALA to reduce the risk of false positives without increasing the rate of adverse effects. In our experience, SF was used to guide the initial phase of resection while 5-ALA was used to visualize tumor spots within the surgical cavity. In 96% of cases, gross total resection was achieved, with supra-maximal resection in 11% of cases. Combined FGR using 5-ALA and SF seems to be a promising method of increasing the extent of resection and to improving the prognosis in glioblastoma patients.