Photodynamic Therapy for Gastrointestinal Cancer

Inhibition of the STAT3-EPHX2 axis promotes regression of ulcerative colitis by treatment with novel porphyrin derivative

LD4, a novel porphyrin derivative, has attracted much attention for its excellent anti-inflammatory properties. It can promote the healing of colonic mucosa, reduce inflammatory response, regulate oxidative stress, and thus improve ulcerative colitis (UC) symptoms. However, the specific signaling pathways of LD4-PDT involved in UC have not been explored. The present study aimed to elucidate the effects of LD4 on UC and to investigate the underlying mechanisms both in vivo and in vitro. We classified and screened the LD4-PDT proteomic data to obtain key targets. Proteomic data revealed that EPHX2 and STAT3 are key targets of LD4-PDT for UC. Moreover, transcription factor STAT3 positively regulates the expression of EPHX2. Inhibiting EPHX2 can prevent the activation of NF-κB signaling pathway. Next, through pharmacological inhibition experiments, we confirmed that LD4-PDT can reduce intestinal inflammation by inhibiting STAT3-EPHX2 axis. However, by treating normal intestinal epithelial cells and colon cancer cells with TPPU and Stattic, our data confirmed that the STAT3-EPHX2 axis does not exist in colon cancer. In this study, we demonstrated that the transcription factor STAT3 can positively regulate the expression of EPHX2 in normal colon. LD4 can alleviate UC by inhibiting the STAT3-EPHX2 axis, but this axis does not exist in colon cancer. LD4-PDT may become a new and effective method for treating UC.

Accelerated clinical response achieved by combining short-term tumor-directed photodynamic therapy with immunotherapy-based systemic therapies in synchronous colorectal cancer with MSI-H and POLE mutation: a case report

Genetic sequencing has revolutionized immunotherapy in colorectal cancer (CRC). Recent clinical trials have revealed a positive response to immunotherapy-based systemic therapies in CRC patient subgroups with microsatellite instability (MSI)-High or DNA polymerase epsilon (POLE) mutation. However, the unsatisfactory response rates was the major limitation in real-world practice of the precision immunotherapy in CRC. Adding photodynamic therapy (PDT) to systemic immunotherapy has showed synergetic anti-tumor effect by modulating tumor microenvironment, while the eligible patient's subgroups which would benefit from this combination remained equivocal. Here we reported a synchronous colorectal cancer patient with MSI-High and POLE mutation who had accelerated response in less than 2 cycles (42 days) of immunotherapy-based systemic therapies after tumor-directed PDT and has remained progression-free by far. This case enlightened the synergetic effect of PDT in immunotherapy-treated CRC patients, with the MSI and POLE-mutation status as predictors of survival benefits.

The use of photodynamic therapy in medical practice

Cancer therapy, especially for tumors near sensitive areas, demands precise treatment. This review explores photodynamic therapy (PDT), a method leveraging photosensitizers (PS), specific wavelength light, and oxygen to target cancer effectively. Recent advancements affirm PDT's efficacy, utilizing ROS generation to induce cancer cell death. With a history spanning over decades, PDT's dynamic evolution has expanded its application across dermatology, oncology, and dentistry. This review aims to dissect PDT's principles, from its inception to contemporary medical applications, highlighting its role in modern cancer treatment strategies.

Clinical Impact of the Charlson Comorbidity Index on the Efficacy of Salvage Photodynamic Therapy Using Talaporfin Sodium for Esophageal Cancer

Introduction Photodynamic therapy (PDT) is a salvage treatment for local failure after chemoradiotherapy for esophageal cancer. Salvage PDT is the treatment available for vulnerable patients with various comorbidities at risk of salvage esophagectomy. This study assessed the impact of the Charlson comorbidity index (CCI) on the outcomes of salvage PDT using talaporfin sodium (TS) for esophageal cancer. Metohds Consecutive patients with esophageal cancer who underwent salvage TS-PDT from 2016 to 2022 were included in this retrospective study. We investigated the local complete response (L-CR), progression-free survival (PFS) and overall survival (OS) and evaluated the relationship between the CCI and therapeutic efficacy. Results In total, 25 patients were enrolled in this study. Overall, 12 patients (48%) achieved an L-CR, and the 2-year PFS and OS rates were 24.9% and 59.4%, respectively. In a multivariate analysis, a CCI ≥1 (p=0.041) and deeper invasion (p=0.048) were found to be significant independent risk factors for not achieving an L-CR. To evaluate the efficacy associated with comorbidities, we divided the patients into the CCI=0 group (n=11) and the CCI ≥1 group (n=14). The rate of an L-CR (p=0.035) and the 2-year PFS (p=0.029) and OS (p=0.018) rates in the CCI ≥1 group were significantly lower than those in the CCI=0 group. Conclusion This study found that the CCI was negatively associated with the efficacy of salvage TS-PDT for esophageal cancer.

Verteporfin fluorescence in antineoplastic-treated pancreatic cancer cells found concentrated in mitochondria

BACKGROUND

Traditional treatments for pancreatic cancer (PC) are inadequate. Photodynamic therapy (PDT) is non-invasive, and proven safe to kill cancer cells, including PC. However, the mitochondrial concentration of the photosensitizer, such as verteporfin, is key.

AIM

To investigate the distribution of fluorescence of verteporfin in PC cells treated with antitumor drugs, post-PDT.

METHODS

Workable survival rates of PC cells (AsPC-1, BxPC-3) were determined with chemotherapy [doxorubicin (DOX) and gemcitabine (GEM)] and non-chemotherapy [sirolimus (SRL) and cetuximab (CTX)] drugs in vitro, with or without verteporfin, as measured via MTT, flow cytometry, and laser confocal microscopy. Reduced cell proliferation was associated with GEM that was more enduring compared with DOX. Confocal laser microscopy allowed observation of GEM- and verteporfin-treated PC cells co-stained with 4',6-diamidino-2-phenylindole and MitoTracker Green to differentiate living and dead cells and subcellular localization of verteporfin, respectively.

RESULTS

Cell survival significantly dropped upon exposure to either chemotherapy drug, but not to SRL or CTX. Both cell lines responded similarly to GEM. The intensity of fluorescence was associated with the concentration of verteporfin. Additional experiments using GEM showed that survival rates of the PC cells treated with 10 μmol/L verteporfin (but not less) were significantly lower relative to nil verteporfin. Living and dead stained cells treated with GEM were distinguishable. After GEM treatment, verteporfin was observed primarily in the mitochondria.

CONCLUSION

Verteporfin was observed in living cells. In GEM -treated human PC cells, verteporfin was particularly prevalent in the mitochondria. This study supports further study of PDT for the treatment of PC after neoadjuvant chemotherapy.

Photodynamic Therapy and Immunological View in Gastrointestinal Tumors

Gastrointestinal cancers are a specific group of oncological diseases in which the location and nature of growth are of key importance for clinical symptoms and prognosis. At the same time, as research shows, they pose a serious threat to a patient's life, especially at an advanced stage of development. The type of therapy used depends on the anatomical location of the cancer, its type, and the degree of progression. One of the modern forms of therapy used to treat gastrointestinal cancers is PDT, which has been approved for the treatment of esophageal cancer in the United States. Despite the increasingly rapid clinical use of this treatment method, the exact immunological mechanisms it induces in cancer cells has not yet been fully elucidated. This article presents a review of the current understanding of the mode of action of photodynamic therapy on cells of various gastrointestinal cancers with an emphasis on colorectal cancer. The types of cell death induced by PDT include apoptosis, necrosis, and pyroptosis. Anticancer effects are also a result of the destruction of tumor vasculature and activation of the immune system. Many reports exist that concern the mechanism of apoptosis induction, of which the mitochondrial pathway is most often emphasized. Photodynamic therapy may also have a beneficial effect on such aspects of cancer as the ability to develop metastases or contribute to reducing resistance to known pharmacological agents.

Electronic spectroscopy of gemcitabine and derivatives for possible dual-action photodynamic therapy applications

In this paper, we explore the molecular basis of combining photodynamic therapy (PDT), a light-triggered targeted anticancer therapy, with the traditional chemotherapeutic properties of the well-known cytotoxic agent gemcitabine. A photosensitizer prerequisite is significant absorption of biocompatible light in the visible/near IR range, ideally between 600 and 1000 nm. We use highly accurate multiconfigurational CASSCF/MS-CASPT2/MM and TD-DFT methodologies to determine the absorption properties of a series of gemcitabine derivatives with the goal of red-shifting the UV absorption band toward the visible region and facilitating triplet state population. The choice of the substitutions and, thus, the rational design is based on important biochemical criteria and on derivatives whose synthesis is reported in the literature. The modifications tackled in this paper consist of: (i) substitution of the oxygen atom at O2 position with heavier atoms (O → S and O → Se) to red shift the absorption band and increase the spin-orbit coupling, (ii) addition of a lipophilic chain at the N7 position to enhance transport into cancer cells and slow down gemcitabine metabolism, and (iii) attachment of aromatic systems at C5 position to enhance red shift further. Results indicate that the combination of these three chemical modifications markedly shifts the absorption spectrum toward the 500 nm region and beyond and drastically increases spin-orbit coupling values, two key PDT requirements. The obtained theoretical predictions encourage biological studies to further develop this anticancer approach.

Exploring Thioxanthone Derivatives as Singlet Oxygen Photosensitizers for Photodynamic Therapy at the Near-IR Region

In the lowest excited triplet state, the excited photosensitizer reacts with tissue oxygen and forms reactive oxygen species (ROS), which kills tissue cells in photodynamic therapy (PDT). Metal-free thio-based pure organic molecules and analogous nucleobases can be used as photosensitizers for PDT applications. Using quantum chemical methods, we studied one- and two-photon optical absorptions, fluorescence, and other excited-state properties of substituted thioxanthone derivatives for their potential as photosensitizers for PDT. Our calculated values were compared with the available experimental data. The calculation of the intersystem crossing rate constant for these photosensitizers explains the high quantum yield of the formation of ROS, as reported experimentally. The excited triplet-state population of the photosensitizer occurs through the 1π-π* → 3n-π* channel of intersystem crossing and increases in the presence of halogen substitution.

A promising natural anthraquinones mediated by photodynamic therapy for anti-cancer therapy

BACKGROUND

Experimental studies emphasize the therapeutic potential of plant-derived photosensitizers used in photodynamic therapy. Moreover, several in vitro and in vivo research present the promising roles of less-known anthraquinones that can selectively target cancer cells and eliminate them after light irradiation. This literature review summarizes the current knowledge of chosen plant-based-photosensitizers in PDT to show the results of emodin, aloe-emodin, parietin, rubiadin, hypericin, and soranjidiol in photodynamic therapy of cancer treatment and describe the comprehensive perspective of their role as natural photosensitizers.

METHODS

Literature searches of chosen anthraquinones were conducted on PubMed.gov with keywords: "emodin", "aloe-emodin", "hypericin", "parietin", "rubiadin", "soranjidiol" with "cancer" and "photodynamic therapy".

RESULTS

According to literature data, this review concentrated on all existing in vitro and in vivo studies of emodin, aloe-emodin, parietin, rubiadin, soranjidiol used as natural photosensitizers emphasizing their effectiveness and detailed mechanism of action in anticancer therapy. Moreover, comprehensive preclinical and clinical studies on hypericin reveal that the above-described substances may be included in the phototoxic treatment of different cancers.

CONCLUSIONS

Overall, this review presented less-known anthraquinones with their promising molecular mechanisms of action. It is expected that in the future they may be used as natural PSs in cancer treatment as well as hypericin.

The synthesis of novel water-soluble zinc (II) phthalocyanine based photosensitizers and exploring of photodynamic therapy activities on the PC3 cancer cell line

In this study, Schiff base substituted phthalocyanine complexes (Zn1c, Zn2c) and their quaternized derivatives (Q-Zn1c, Q-Zn2c) were synthesized for the first time. Their structures have been characterized by FT-IR, 1H-NMR, UV-Vis, mass spectrometry and elemental analysis as well as. The photophysicochemical properties (fluorescence, singlet oxygen and photodegradation quantum yield) of these novel complexes were investigated in dimethylsulfoxide (DMSO) for both non-ionic and quaternized cationic phthalocyanine complexes and in aqueous solution for quaternized cationic phthalocyanine complexes. Water soluble cationic phthalocyanine compounds gave good singlet oxygen quantum yield (0.65 for Q-Zn1c, 0.66 for Q-Zn2c in DMSO; 0.65 for Q-Zn2c in aqueous solution). The binding of Q-Zn1c and Q-Zn2c to BSA/DNA was studied by using UV-Vis and fluorescence spectroscopy and these. Studies indicate that the mechanism of BSA quenching by quaternized zinc(II) phthalocyanines was static quenching. Quaternized zinc(II) phthalocyanines interacted with ct-DNA by intercalation. Quaternized zinc(II) phthalocyanines caused a decrease in cell viability and triggered apoptotic cell death after PDT was applied at a concentration that did not have a toxic effect on their own. Q-Zn1c and Q-Zn2c mediated PDT reduced the activity of SOD, CAT, GSH while increased MDA level in the prostate cancer cells. Furthermore, expression of apoptotic proteins after PDT was examined. The results revealed that the synthesized water soluble quaternized zinc(II) phthalocyanine complexes (Q-Zn1c and Q-Zn2c) are promising potential photosensitizers for PDT.

Photodynamic Therapy: From the Basics to the Current Progress of N-Heterocyclic-Bearing Dyes as Effective Photosensitizers

Photodynamic therapy, an alternative that has gained weight and popularity compared to current conventional therapies in the treatment of cancer, is a minimally invasive therapeutic strategy that generally results from the simultaneous action of three factors: a molecule with high sensitivity to light, the photosensitizer, molecular oxygen in the triplet state, and light energy. There is much to be said about each of these three elements; however, the efficacy of the photosensitizer is the most determining factor for the success of this therapeutic modality. Porphyrins, chlorins, phthalocyanines, boron-dipyrromethenes, and cyanines are some of the N-heterocycle-bearing dyes' classes with high biological promise. In this review, a concise approach is taken to these and other families of potential photosensitizers and the molecular modifications that have recently appeared in the literature within the scope of their photodynamic application, as well as how these compounds and their formulations may eventually overcome the deficiencies of the molecules currently clinically used and revolutionize the therapies to eradicate or delay the growth of tumor cells.

Drug Delivery Strategies for the Treatment of Pancreatic Cancer

Pancreatic cancer is fast becoming a global menace and it is projected to be the second leading cause of cancer-related death by 2030. Pancreatic adenocarcinomas, which develop in the pancreas' exocrine region, are the predominant type of pancreatic cancer, representing about 95% of total pancreatic tumors. The malignancy progresses asymptomatically, making early diagnosis difficult. It is characterized by excessive production of fibrotic stroma known as desmoplasia, which aids tumor growth and metastatic spread by remodeling the extracellular matrix and releasing tumor growth factors. For decades, immense efforts have been harnessed toward developing more effective drug delivery systems for pancreatic cancer treatment leveraging nanotechnology, immunotherapy, drug conjugates, and combinations of these approaches. However, despite the reported preclinical success of these approaches, no substantial progress has been made clinically and the prognosis for pancreatic cancer is worsening. This review provides insights into challenges associated with the delivery of therapeutics for pancreatic cancer treatment and discusses drug delivery strategies to minimize adverse effects associated with current chemotherapy options and to improve the efficiency of drug treatment.

Up-regulation of ABCG2 by MYBL2 deletion drives Chlorin e6-mediated photodynamic therapy resistance in colorectal cancer

OBJECTIVE

Photodynamic therapy (PDT) is an effective therapeutic strategy for colorectal cancer at an early stage. However, malignant cells' resistance to photodynamic agents can lead to treatment failure. MYBL2 (B-Myb) is an oncogene in colorectal carcinogenesis and development, for which little research has focused on its effect on drug resistance.

MATERIALS AND METHODS

In the present work, a colorectal cancer cell line with a stable knockdown of MYBL2 (ShB-Myb) was constructed first. Chlorin e6 (Ce6) was utilized to induced PDT. The anti-cancer efficacy was measured by CCK-8, PI staining, and Western blots. The drug uptake of Ce6 was assayed by flow cytometry and confocal microscopy. The ROS generation was detected by the CellROX probe. DDSB and DNA damage were assayed through comet experiment and Western blots. The over-expression of MYBL2 was conducted by MYBL2 plasmid.

RESULTS

The findings indicated that the viability of ShB-Myb treated with Ce6-PDT was not decreased compared to control SW480 cells (ShNC), which were resistant to PDT. Further investigation revealed reduced photosensitizer enrichment and mitigated oxidative DNA damage in colorectal cancer cells with depressed MYBL2. It turned out that SW480 cells knocking down MYBL2 showed phosphorylation of NF-κB and led to up-regulation of ABCG2 expression thereupon. When MYBL2 was replenished back in MYBL2-deficient colorectal cancer cells, phosphorylation of NF-κB was blocked and ABCG2 expression up-regulation was suppressed. Additionally, replenishment of MYBL2 also increased the enrichment of Ce6 and the efficacy of PDT.

CONCLUSION

In summary, MYBL2 absence in colorectal cancer contributes to drug resistance by activating NF-κB to up-regulate ABCG2 and thereby leading to photosensitizer Ce6 efflux. This study provides a novel theoretical basis and strategy for how to effectively improve the anti-tumor efficacy of PDT.

A phase I clinical trial of sonodynamic therapy combined with temozolomide in the treatment of recurrent glioblastoma

PURPOSE

The prognosis of recurrent glioblastoma (rGBM) is poor, and there is currently no effective treatment strategy. Sonodynamic therapy (SDT) is a new method for cancer treatment that uses a combination of low-frequency ultrasound and sonosensitisers to produce antitumor effects, which have shown good therapeutic effects in preclinical studies. Therefore, we initiated an open, prospective pilot study to evaluate the safety, tolerability, and efficacy of SDT for the treatment of rGBM.

METHODS

Nine patients with rGBM were enrolled who had received multiple treatments, but the nidus continued to progress without additional standard treatments. After MRI localisation, porphyrin drugs were injected, and intermittent low-frequency ultrasound therapy was performed for five days.

RESULTS

None of the nine patients in this clinical trial showed any clinical, neurological, haematological, or skin-targeted adverse effects associated with SDT. After the completion of the trial, one patient maintained stable disease, and eight patients experienced disease progression. Among the eight with progressive disease, the median progression-free survival time was 84 days. Four patients died, and the median overall survival duration after recurrence was 202.5 days.

CONCLUSION

The number of patients in this study was small; therefore, a long-term survival benefit was not demonstrated. However, this study suggests that SDT has potential as a treatment for rGBM and warrants further exploration. Trial information: Chinese Clinical Trial Registry ( http://www.chictr.org.cn/ ): ChiCTR2200065992. November 2, 2022, retrospectively registered.

Bromo- and glycosyl-substituted BODIPYs for application in photodynamic therapy and imaging

The introduction of heavy atoms into the BODIPY-core structure has proven to be a straightforward strategy for optimizing the design of such dyes towards enhanced generation of singlet oxygen rendering them suitable as photosensitizers for photodynamic therapy (PDT). In this work, BODIPYs are presented by combining the concept of bromination with nucleophilic aromatic substitution (S_NAr) of a pentafluorophenyl or a 4-fluoro-3-nitrophenyl moiety to introduce functional groups, thus improving the phototoxic effect of the BODIPYs as well as their solubility in the biological environment. The nucleophilic substitution enabled functionalization with various amines and alcohols as well as unprotected thiocarbohydrates. The phototoxic activity of these more than 50 BODIPYs has been assessed in cellular assays against four cancer cell lines in order to more broadly evaluate their PDT potential, thus accounting for the known variability between cell lines with respect to PDT activity. In these investigations, dibrominated polar-substituted BODIPYs, particularly dibrominated glyco-substituted compounds, showed promising potential as photomedicine candidates. Furthermore, the cellular uptake of the glycosylated BODIPYs has been confirmed via fluorescence microscopy.

Antimicrobial Formulation of a Bacterial Nanocellulose/Propolis-Containing Photosensitizer for Biomedical Applications

With the aim of contributing to the development of more efficient materials for wound care, new topical formulations based on bacterial nanocellulose (BNC) hydrogels containing propolis were produced. Characterizations confirmed the incorporation of propolis into the BNC matrix, maintaining its structure and properties. Rheological analysis confirmed that the hydrogels showed thixotropic behavior appropriate for topical application. Chromatographic profiles showed sustained release of propolis biomarkers for at least 20 h. The formulations did not present mutagenicity. For application in photodynamic inactivation (PDI), BNC/propolis hydrogels were prepared with the photosensitizers methylene blue (MB). Spectroscopy and confocal fluorescence microscopy confirmed the interaction of MB and propolis in BNC hydrogels, as well as the formation of a new composite material. In the antibacterial assays, formulations containing MB and propolis significantly reduced Staphylococcus aureus growth. In the presence of light, BNC/MB hydrogels completely inhibited the microorganism. Therefore, the results suggest potential materials for the prevention or treatment of Staphylococcus aureus infections in wounds.

Manipulate tumor hypoxia for improved photodynamic therapy using nanomaterials

Due to its low adverse effects, minimal invasiveness, and outstanding patient compliance, photodynamic therapy (PDT) has drawn a great deal of interest, which is achieved through incomplete reduction of O₂ by a photosensitizer under light illumination that produces amounts of reactive oxygen species (ROS). However, tumor hypoxia significantly hinders the therapeutic effect of PDT so that tumor cells cannot be eliminated, which results in tumor cells proliferating, invading, and metastasizing. Additionally, O₂ consumption during PDT exacerbates hypoxia in tumors, leading to several adverse events after PDT treatment. In recent years, various investigations have focused on conquering or using tumor hypoxia by nanomaterials to amplify PDT efficacy, which is summarized in this review. This comprehensive review's objective is to present novel viewpoints on the advancement of oxygenation nanomaterials in this promising field, which is motivated by hypoxia-associated anti-tumor therapy.

Exosomal LncRNAs in Gastrointestinal Cancer: Biological Functions and Emerging Clinical Applications

Due to the lack of specific and effective biomarkers and therapeutic targets, the early diagnosis and treatment of gastrointestinal cancer remain unsatisfactory. As a type of nanosized vesicles derived from living cells, exosomes mediate cell-to-cell communication by transporting bioactive molecules, thus participating in the regulation of many pathophysiological processes. Recent evidence has revealed that several long non-coding RNAs (lncRNAs) are enriched in exosomes. Exosomes-mediated lncRNAs delivery is critically involved in various aspects of gastrointestinal cancer progression, such as tumor proliferation, metastasis, angiogenesis, stemness, immune microenvironment, and drug resistance. Exosomal lncRNAs represent promising candidates to act as the diagnosis biomarkers and anti-tumor targets. This review introduces the major characteristics of exosomes and lncRNAs and describes the biological functions of exosomal lncRNAs in gastrointestinal cancer development. The preclinical studies on using exosomal lncRNAs to monitor and treat gastrointestinal cancer are also discussed, and the opportunities and challenges for translating them into clinical practice are evaluated.

Combination of photodynamic therapy and endoscopic mucosal resection for recurrent esophageal squamous cell carcinoma after chemoradiotherapy

Photodynamic therapy (PDT) was developed for residual or recurrent esophageal cancer after radiotherapy. Here, we report a case of successful treatment of highly elevated esophageal squamous cell carcinoma (ESCC) that recurred after definitive chemoradiotherapy (dCRT) using PDT combined with endoscopic resection (ER). An 86-year-old man was found to have an ESCC in the mid-thoracic esophagus. One year and two months after dCRT, a local recurrence was seen. The recurrent ESCC had a highly elevated component. The ESCC was estimated to have invaded the deep submucosa at the highly elevated component. PDT was selected as a treatment option since no lymph node or distant metastases were found. However, there was concern that the laser would not be able to penetrate deep into the ESCC due to its high elevated component. Therefore, ER was performed to remove the highly elevated component, and PDT was performed later. However, after the ER, the circumference of the recurrent ESCC was found to be approximately half the circumference, and post-PDT stenosis was also a concern due to the wide circumference of the ESCC. Therefore, we limited the area of laser irradiation in one session of PDT. Four sessions of PDT were needed over 13 months, but a local complete response was achieved without adverse events.

Advancements in photodynamic therapy of esophageal cancer

The poor prognosis of patients with esophageal cancer leads to the constant search for new ways of treatment of this disease. One of the methods used in high-grade dysplasia, superficial invasive carcinoma, and sometimes palliative care is photodynamic therapy (PDT). This method has come a long way from the first experimental studies to registration in the treatment of esophageal cancer and is constantly being improved and refined. This review describes esophageal cancer, current treatment methods, the introduction to PDT, the photosensitizers (PSs) used in esophageal carcinoma PDT, PDT in squamous cell carcinoma (SCC) of the esophagus, and PDT in invasive adenocarcinoma of the esophagus. For this review, research and review articles from PubMed and Web of Science databases were used. The keywords used were "photodynamic therapy in esophageal cancer" in the years 2000-2020. The total number of papers returned was 1,000. After the review was divided into topic blocks and the searched publications were analyzed, 117 articles were selected.

Immunotherapy-based novel nanoparticles in the treatment of gastrointestinal cancer: Trends and challenges

Gastrointestinal cancer (GIC) is the most common cancer with a poor prognosis. Currently, surgery is the main treatment for GIC. However, the high rate of postoperative recurrence leads to a low five-year survival rate. In recent years, immunotherapy has received much attention. As the only immunotherapy drugs approved by the Food and Drug Administration (FDA), immune checkpoint blockade (ICB) drugs have great potential in cancer therapy. Nevertheless, the efficacy of ICB treatment is greatly limited by the low immunogenicity and immunosuppressive microenvironment of GIC. Therefore, the targets of immunotherapy have expanded from ICB to increasing tumor immunogenicity, increasing the recruitment and maturation of immune cells and reducing the proportion of inhibitory immune cells, such as M2-like macrophages, regulatory T cells and myeloid-derived suppressor cells. Moreover, with the development of nanotechnology, a variety of nanoparticles have been approved by the FDA for clinical therapy, so novel nanodrug delivery systems have become a research focus for anticancer therapy. In this review, we summarize recent advances in the application of immunotherapy-based nanoparticles in GICs, such as gastric cancer, hepatocellular carcinoma, colorectal cancer and pancreatic cancer, and described the existing challenges and future trends.

An Analysis of the Effects of In Vitro Photodynamic Therapy on Prostate Cancer Tissue by Histopathological Examination and Magnetic Resonance Imaging

Prostate cancer can significantly shorten the lifetime of a patient, even if he is diagnosed at an early stage. The development of minimally-invasive focal therapies such as photodynamic therapy to reduce the number of neoplastic cells while sparing delicate structures is extremely advantageous for treating prostate cancer. This study investigates the effect of photodynamic therapy performed in prostate tissue samples in vitro, using quantitative magnetic resonance imaging and histopathological analysis. Prostate tissue samples were treated with oxygenated solutions of Rose Bengal (RB) or protoporphyrin IX disodium salt (PpIX), illuminated with visible light, and then analyzed for changes in morphology by microscopy and by measurement of spin–lattice and spin–spin relaxation times at 1.5 Tesla. In the treated prostate tissue samples, histopathological images revealed chromatin condensation and swelling of the stroma, and in some cases, thrombotic necrosis and swelling of the stroma accompanied by pyknotic nuclei occurred. Several samples had protein fragments in the stroma. Magnetic resonance imaging of the treated prostate tissue samples revealed differences in the spin–lattice and spin–spin relaxation times prior to and post photodynamic action.

Association between Submucosal Fibrosis and Endoscopic Submucosal Dissection of Recurrent Esophageal Squamous Cell Cancers after Chemoradiotherapy

Simple Summary

The efficacy and safety of endoscopic submucosal dissection for early esophageal cancer after chemoradiotherapy have not been established. In this study, we focused on the fibrosis of the submucosa. As a result, we found that endoscopic submucosal dissection for early esophageal cancer can be performed reliably without adverse events, but the procedure takes longer for lesions with strong fibrosis of the submucosa.

Abstract

Endoscopic resection is a treatment of choice for a metachronous early-stage esophageal squamous cell carcinoma (ESCC) appearing after a radical cure of esophageal cancer by chemoradiotherapy (CRT). However, non-curative resection, and procedural complications including perforation due to radiation-induced submucosal fibrosis, are a concern. This study aimed to evaluate the association between submucosal fibrosis and the usefulness and safety of endoscopic submucosal dissection (ESD) in ESCC after CRT. This study retrospectively analyzed 13 lesions in 11 patients in our institute. Submucosal fibrosis under the lesion (F score) was classified into three levels (F0: none or mild, F1: moderate, and F2: severe) based on endoscopic and histopathologic findings. All lesions were F1 or greater (F1: 8 lesions and F2: 5 lesions). En bloc and R0 resection rates were both 100%. The procedural speed was slower in F2 than in F1 (F1 vs. F2; 15.1 mm²/min vs. 7.1 mm²/min, p = 0.019), without procedure-related adverse events. At a median follow-up of 42 months (range: 14–117 months) after ESD, 7 of 11 (63.6%) patients were alive without recurrence, and without ESCC-related death. ESCC after CRT reliably and safely resected en bloc by ESD but was more difficult in lesions with strong submucosal fibrosis.

Bibliometric Analysis of Global Research on Cancer Photodynamic Therapy: Focus on Nano-Related Research

A growing body of research has illuminated that photodynamic therapy (PDT) serves as an important therapeutic strategy in oncology and has become a hot topic in recent years. Although numerous papers related to cancer PDT (CPDT) have been published, no bibliometric studies have been conducted to summarize the research landscape, and highlight the research trends and hotspots in this field. This study collected 5,804 records on CPDT published between 2000 and 2021 from Web of Science Core Collection. Bibliometric analysis and visualization were conducted using VOSviewer, CiteSpace, and one online platform. The annual publication and citation results revealed significant increasing trends over the past 22 years. China and the United States, contributing 56.24% of the total publications, were the main driving force in this field. Chinese Academy of Sciences was the most prolific institution. Photodiagnosis and Photodynamic Therapy and Photochemistry and Photobiology were the most productive and most co-cited journals, respectively. All keywords were categorized into four clusters including studies on nanomaterial technology, clinical applications, mechanism, and photosensitizers. “nanotech-based PDT” and “enhanced PDT” were current research hotspots. In addition to several nano-related topics such as “nanosphere,” “nanoparticle,” “nanomaterial,” “nanoplatform,” “nanomedicine” and “gold nanoparticle,” the following topics including “photothermal therapy,” “metal organic framework,” “checkpoint blockade,” “tumor microenvironment,” “prodrug” also deserve further attention in the near future.

Novel Tumor-Targeting Nanoparticles for Cancer Treatment-A Review

Being one of the leading causes of death and disability worldwide, cancer represents an ongoing interdisciplinary challenge for the scientific community. As currently used treatments may face limitations in terms of both efficiency and adverse effects, continuous research has been directed towards overcoming existing challenges and finding safer specific alternatives. In particular, increasing interest has been gathered around integrating nanotechnology in cancer management and subsequentially developing various tumor-targeting nanoparticles for cancer applications. In this respect, the present paper briefly describes the most used cancer treatments in clinical practice to set a reference framework for recent research findings, further focusing on the novel developments in the field. More specifically, this review elaborates on the top recent studies concerning various nanomaterials (i.e., carbon-based, metal-based, liposomes, cubosomes, lipid-based, polymer-based, micelles, virus-based, exosomes, and cell membrane-coated nanomaterials) that show promising potential in different cancer applications.

Photodynamic Therapy in Combination with Chemotherapy, Targeted, and Immunotherapy As a Successful Therapeutic Approach for Advanced Gastric Adenocarcinoma: A Case Report and Literature Review

Objective: To explore the efficacy of photodynamic therapy combined with chemotherapy, targeted therapy, and immunotherapy in poorly differentiated gastric adenocarcinoma (GAC). Background: Advanced GAC has high malignancy and mortality rate. To date, no study has applied photodynamic treatment (PDT) combined with chemo-, targeted, and immunotherapy to treat this cancer. Patient and methods: Clinical data of a patient diagnosed with poorly differentiated GAC admitted to the department of oncology of the Lanzhou University Second Hospital were retrospectively analyzed. The patient underwent four PDT procedures combined with chemo-, targeted, and immunotherapy. Results: A 72-year-old male patient received combination therapy of PDT. This treatment resolved the cancerous tissues and levels of tumor markers. There was no recurrence and metastasis during a 7-month follow-up. Conclusions: Combination therapy of PDT can effectively treat tumors and may be a method suitable for elderly patients with advanced GAC.

Lasers in Live Cell Microscopy

Due to their unique properties—coherent radiation, diffraction limited focusing, low spectral bandwidth and in many cases short light pulses—lasers play an increasing role in live cell microscopy. Lasers are indispensable tools in 3D microscopy, e.g., confocal, light sheet or total internal reflection microscopy, as well as in super-resolution microscopy using wide-field or confocal methods. Further techniques, e.g., spectral imaging or fluorescence lifetime imaging (FLIM) often depend on the well-defined spectral or temporal properties of lasers. Furthermore, laser microbeams are used increasingly for optical tweezers or micromanipulation of cells. Three exemplary laser applications in live cell biology are outlined. They include fluorescence diagnosis, in particular in combination with Förster Resonance Energy Transfer (FRET), photodynamic therapy as well as laser-assisted optoporation, and demonstrate the potential of lasers in cell biology and—more generally—in biomedicine.

Smart nanocomposite assemblies for multimodal cancer theranostics

Despite great strides in anticancer research, performance statistics of current treatment modalities remain dismal, highlighting the need for safe, efficacious strategies for tumour mitigation. Non-invasive fusion technology platforms combining photodynamic, photothermal and hyperthermia therapies have emerged as alternate strategies with potential to meet many of the unmet clinical demands in the domain of cancer. These therapies make use of metallic and magnetic nanoparticles with light absorbing properties, which are manipulated to generate either reactive cytotoxic oxygen species or heat for tumour ablation. Combination therapies integrating light, heat and magnetism-mediated nanoplatforms with the conventional approaches of chemotherapy, radiotherapy and surgery are emerging as precision medicine for targeted interventions against cancer. This article aims to compile recent developments of advanced nanocomposite assemblies that integrate multimodal therapeutics for cancer treatment. Amalgamation of various effective, non-invasive technological platforms such as photodynamic therapy (PDT), photothermal therapy (PTT), magnetic hyperthermia (MHT), and chemodynamic therapy (CDT) have tremendous potential in presenting safe and efficacious solutions to the formidable challenges in cancer therapeutics.

Some Natural Photosensitizers and Their Medicinal Properties for Use in Photodynamic Therapy

Despite significant advances in early diagnosis and treatment, cancer is one of the leading causes of death. Photodynamic therapy (PDT) is a therapy for the treatment of many diseases, including cancer. This therapy uses a combination of a photosensitizer (PS), light irradiation of appropriate length and molecular oxygen. The photodynamic effect kills cancer cells through apoptosis, necrosis, or autophagy of tumor cells. PDT is a promising approach for eliminating various cancers but is not yet as widely applied in therapy as conventional chemotherapy. Currently, natural compounds with photosensitizing properties are being discovered and identified. A reduced toxicity to healthy tissues and a lower incidence of side effects inspires scientists to seek natural PS for PDT. In this review, several groups of compounds with photoactive properties are presented. The use of natural products has been shown to be a fruitful approach in the discovery of novel pharmaceuticals. This review focused on the anticancer activity of furanocoumarins, polyacetylenes, thiophenes, tolyporphins, curcumins, alkaloid and anthraquinones in relation to the light-absorbing properties. Attention will be paid to their phototoxic and anti-cancer effects on various types of cancer.

Nanomedicine in Clinical Photodynamic Therapy for the Treatment of Brain Tumors

The current treatment for malignant brain tumors includes surgical resection, radiotherapy, and chemotherapy. Nevertheless, the survival rate for patients with glioblastoma multiforme (GBM) with a high grade of malignancy is less than one year. From a clinical point of view, effective treatment of GBM is limited by several challenges. First, the anatomical complexity of the brain influences the extent of resection because a fine balance must be struck between maximal removal of malignant tissue and minimal surgical risk. Second, the central nervous system has a distinct microenvironment that is protected by the blood–brain barrier, restricting systemically delivered drugs from accessing the brain. Additionally, GBM is characterized by high intra-tumor and inter-tumor heterogeneity at cellular and histological levels. This peculiarity of GBM-constituent tissues induces different responses to therapeutic agents, leading to failure of targeted therapies. Unlike surgical resection and radiotherapy, photodynamic therapy (PDT) can treat micro-invasive areas while protecting sensitive brain regions. PDT involves photoactivation of photosensitizers (PSs) that are selectively incorporated into tumor cells. Photo-irradiation activates the PS by transfer of energy, resulting in production of reactive oxygen species to induce cell death. Clinical outcomes of PDT-treated GBM can be advanced in terms of nanomedicine. This review discusses clinical PDT applications of nanomedicine for the treatment of GBM.

Interstitial Photodynamic Therapy for Glioblastomas: A Standardized Procedure for Clinical Use

Simple Summary

The most frequent primary high-grade brain tumors are glioblastomas (GBMs). The current standard of care for GBM is maximal surgical resection followed by radiotherapy and chemotherapy. Despite all these treatments, the overall survival is still limited, with a median of 15 months. The challenge is to improve the local control of this infiltrative disease. Interstitial photodynamic therapy (iPDT) is a minimally invasive treatment relying on the interaction of light, a photosensitizer and oxygen. It consists of introducing optical fibers inside the tumor to illuminate the cancer cells which have been sensitized to light thanks to a natural photosensitizer agent. Herein, we propose a standardized and reproducible workflow for the clinical application of iPDT to GBM. This workflow, which involves intraoperative imaging, a dedicated treatment planning system (TPS) and robotic assistance for the implantation of stereotactic optical fibers, represents a key step in the deployment of iPDT for the treatment of GBM.

Abstract

Glioblastomas (GBMs) are high-grade malignancies with a poor prognosis. The current standard of care for GBM is maximal surgical resection followed by radiotherapy and chemotherapy. Despite all these treatments, the overall survival is still limited, with a median of 15 months. For patients harboring inoperable GBM, due to the anatomical location of the tumor or poor general condition of the patient, the life expectancy is even worse. The challenge of managing GBM is therefore to improve the local control especially for non-surgical patients. Interstitial photodynamic therapy (iPDT) is a minimally invasive treatment relying on the interaction of light, a photosensitizer and oxygen. In the case of brain tumors, iPDT consists of introducing one or several optical fibers in the tumor area, without large craniotomy, to illuminate the photosensitized tumor cells. It induces necrosis and/or apoptosis of the tumor cells, and it can destruct the tumor vasculature and produces an acute inflammatory response that attracts leukocytes. Interstitial PDT has already been applied in the treatment of brain tumors with very promising results. However, no standardized procedure has emerged from previous studies. Herein, we propose a standardized and reproducible workflow for the clinical application of iPDT to GBM. This workflow, which involves intraoperative imaging, a dedicated treatment planning system (TPS) and robotic assistance for the implantation of stereotactic optical fibers, represents a key step in the deployment of iPDT for the treatment of GBM. This end-to-end procedure has been validated on a phantom in real operating room conditions. The thorough description of a fully integrated iPDT workflow is an essential step forward to a clinical trial to evaluate iPDT in the treatment of GBM.

Implications of photodynamic cancer therapy: an overview of PDT mechanisms basically and practically

BACKGROUND

Tumor eradication is one of the most important challengeable categories in oncological studies. In this account, besides the molecular genetics methods including cell therapy, gene therapy, immunotherapy, and general cancer therapy procedures like surgery, radiotherapy, and chemotherapy, photodynamic adjuvant therapy is of great importance. Photodynamic therapy (PDT) as a relatively noninvasive therapeutic method utilizes the irradiation of an appropriate wavelength which is absorbed by a photosensitizing agent in the presence of oxygen. In this procedure, a series of events lead to the direct death of malignant cells such as damage to the microvasculature and also the induction of a local inflammatory function. PDT has participated with other treatment modalities especially in the early stage of malignant tumors and has resulted in decreasing morbidity besides improving survival rate and quality of life. High spatial resolution of PDT has attracted considerable attention in the field of image-guided photodynamic therapy combined with chemotherapy of multidrug resistance cancers. Although PDT outcomes vary across the different tumor types, minimal natural tissue toxicity, minor systemic effects, significant reduction in long-term disease, lack of innate or acquired resistance mechanisms, and excellent cosmetic effects, as well as limb function, make it a valuable treatment option for combination therapies.

SHORT CONCLUSION

In this review article, we tried to discuss the potential of PDT in the treatment of some dermatologic and solid tumors, particularly all its important mechanisms.

Research Progress in the Synthesis of Targeting Organelle Carbon Dots and Their Applications in Cancer Diagnosis and Treatment

With increasing knowledge about diseases at the histological, cytological to sub-organelle level, targeting organelle therapy has gradually been envisioned as an approach to overcome the shortcomings of poor specificity and multiple toxic side effects on tissues and cell-level treatments using the currently available therapy. Organelle carbon dots (CDs) are a class of functionalized CDs that can target organelles. CDs can be prepared by a "synchronous in situ synthesis method" and "asynchronous modification method." The superior optical properties and good biocompatibility of CDs can be preserved, and they can be used as targeting particles to carry drugs into cells while reducing leakage during transport. Given the excellent organelle fluorescence imaging properties, targeting organelle CDs can be used to monitor the physiological metabolism of organelles and progression of human diseases, which will provide advanced understanding and accurate diagnosis and targeted treatment of cancers. This study reviews the methods used for preparation of targeting organelle CDs, mechanisms of accurate diagnosis and targeted treatment of cancer, as well as their application in the area of cancer diagnosis and treatment research. Finally, the current difficulties and prospects for targeting organelle CDs are prospected.

Is interstitial photodynamic therapy for brain tumors ready for clinical practice? A systematic review

BACKGROUND

Interstitial photodynamic therapy (iPDT), inserting optical fibers inside brain tumors, has been proposed for more than 30 years. While a promising therapeutic option, it is still an experimental treatment, with different ways of application, depending on the team performing the technique.

OBJECTIVE

In this systematic review, we reported the patient selection process, the treatment parameters, the potential adverse events and the oncological outcomes related to iPDT treatment applied to brain tumors.

METHODS

We performed a search in PubMed, Embase and Medline based on the following Mesh terms: "interstitial" AND "photodynamic therapy" AND "brain tumor" OR "glioma" OR glioblastoma" from January 1990 to April 2020. We screened 350 studies. Twelve matched all selection criteria.

RESULTS

251 patients underwent iPDT. Tumors were mainly de novo or recurrent high-grade gliomas (171 (68%) of glioblastomas), located supratentorial, with a median volume of 12 cm³. Hematoporphyrin derive agent (HpD) or protoporphyrin IX (PpIX) induced by 5-aminolevulinic acid (5-ALA) was used as a photosensitizer. Up to 6 optical fibers were introduced inside the tumor, delivering 200 mW/cm at a wavelength of 630 nm. Overall mortality was 1%. Transient and persistent morbidity were both 5%. No permanent deficit occurred using 5-ALA PDT. Tumor response rate after iPDT was 92% (IQR, 67; 99). Regarding glioblastomas, progression-free-survival was respectively 14.5 months (IQR, 13.8; 15.3) for de novo lesions and 14 months (IQR, 7; 30) for recurrent lesions, while overall survival was respectively 19 months (IQR, 14; 20) and 8 months (IQR, 6.3; 8.5). In patients harboring high-grade gliomas, 33 (13%) were considered long-term survivors (> 2 years) after iPDT.

CONCLUSION

Regardless of heterogeneity in its application, iPDT appears safe and efficient to treat brain tumors, especially high-grade gliomas. Stand-alone iPDT (i.e., without combined craniotomy and intracavitary PDT) using 5-ALA appears to be the best option in terms of controlling side effects: it avoids the occurrence of permanent neurological deficits while reducing the risks of hemorrhage and sepsis.

Clinical Practice of Photodynamic Therapy Using Talaporfin Sodium for Esophageal Cancer

Photodynamic therapy (PDT) using a conventional photosensitizer was approved for esophageal cancer in the early 1990s; however, it was replaced by other conventional treatment modalities in clinical practice because of the high frequency of cutaneous phototoxicity and esophageal stricture after the procedure. The second-generation photosensitizer, talaporfin sodium, which features more rapid clearance from the body, was developed to reduce skin phototoxicity, and talaporfin sodium can be excited at longer-wavelength lights comparing with a conventional photosensitizer. Endoscopic PDT using talaporfin sodium was initially developed for the curative treatment of central-type early lung cancer in Japan, and was approved in the early 2000s. After preclinical experiments, PDT using talaporfin sodium was investigated for patients with local failure after chemoradiotherapy, which was the most serious unmet need in the practice of esophageal cancer. According to the favorable results of a multi-institutional clinical trial, PDT using talaporfin sodium was approved as an endoscopic salvage treatment for patients with local failure after chemoradiotherapy for esophageal cancer. While PDT using talaporfin sodium is gradually spreading in clinical practice, further evaluation at the point of clinical benefit is necessary to determine the importance of PDT in the treatment of esophageal cancer.

Application of photodynamic therapy in immune-related diseases

Photodynamic therapy (PDT) is a therapeutic modality that utilizes photodamage caused by photosensitizers and oxygen after exposure to a specific wavelength of light. Owing to its low toxicity, high selectivity, and minimally invasive properties, PDT has been widely applied to treat various malignant tumors, premalignant lesions, and infectious diseases. Moreover, there is growing evidence of its immunomodulatory effects and potential for the treatment of immune-related diseases. This review mainly focuses on the effect of PDT on immunity and its application in immune-related diseases.

Antimicrobial and antimycotic photodynamic therapy (review of literature)

This review highlights the possibilities of photodynamic therapy (PDT) using drugs based on chlorin e6, aluminum phthalocyanine, methylene blue as photosensitizers for bacterial and fungal pathologies. This method was developed initially to treat tumor diseases, where it had shown its high efficiency and safety. Now photodynamic therapy is actively used in the treatment of cancers of the skin, bronchi, stomach, cervix, larynx, or other regions. However, numerous studies have been carried out for the entire existence of the method, demonstrating new possibilities of its application. This review highlights a number of studies in which the efficacy and safety of antimicrobial and antimycotic PDT were studied in vivo and in vitro. It has been proven to have a positive effect on the reparative processes in the wound. An experimental study was carried out to study the effectiveness of photodynamic therapy in the treatment of peritonitis in mice. Demonstrated anti-inflammatory potential in the treatment of autoimmune diseases.

Photodynamic Therapy—An Up-to-Date Review

The healing power of light has attracted interest for thousands of years. Scientific discoveries and technological advancements in the field have eventually led to the emergence of photodynamic therapy, which soon became a promising approach in treating a broad range of diseases. Based on the interaction between light, molecular oxygen, and various photosensitizers, photodynamic therapy represents a non-invasive, non-toxic, repeatable procedure for tumor treatment, wound healing, and pathogens inactivation. However, classic photosensitizing compounds impose limitations on their clinical applications. Aiming to overcome these drawbacks, nanotechnology came as a solution for improving targeting efficiency, release control, and solubility of traditional photosensitizers. This paper proposes a comprehensive path, starting with the photodynamic therapy mechanism, evolution over the years, integration of nanotechnology, and ending with a detailed review of the most important applications of this therapeutic approach.

Fluoroscopy-Guided Salvage Photodynamic Therapy Combined with Nanoparticle Albumin-Bound Paclitaxel for Locally Advanced Esophageal Cancer after Chemoradiotherapy: A Case Report and Literature Review

Background: Among the total cancer deaths, esophageal cancer ranks sixth in mortality. Radiotherapy and chemotherapy remain the main treatments for unresectable, locally advanced esophageal cancer, but a relapse and drug resistance are still common. The optimized choice for therapeutic schemes with low toxicity and a high quality of life is unclear when local progression occurs after radiotherapy and chemotherapy. Fluoroscopy-guided photodynamic therapy (PDT) on patients with recurrent esophageal cancer in whom the endoscope cannot pass may be used as a salvage treatment, and nanoparticle albumin-bound paclitaxel (Nab-P) has been shown to be effective for advanced esophageal cancer. The combination of PDT and Nab-P might be an effective and tolerable option for advanced esophageal cancer. Case summary: The authors present a 65-year-old male patient diagnosed with esophageal squamous cell carcinoma (ESCC) and confirmed to have developed local progression after receiving radiotherapy and chemotherapy. Severe esophageal stenosis, mild malnutrition and anemia, and radiation pneumonia were found when he was admitted to the authors' hospital. For rapid reduction of tumor burden and to restore normal diet, he received PDT by the X-ray fluoroscopy positioning method and Nab-P chemotherapy. The patient obtained clinical benefit from these treatments, and his quality of life improved. Conclusions: This case demonstrates the potential advantages of fluoroscopy-guided PDT combined with Nab-P in reducing the tumor load, preserving organ function, and improving the quality of life, as well as the beneficial effect on locally advanced esophageal cancer after radiotherapy and chemotherapy. This combination therapy provides an alternative for the clinical treatment of locally advanced esophageal cancer and it has broad prospects in treatment of the disease. Core tip: Herein, the authors report a case of a patient with ESCC who suffered locally progressive disease after chemotherapy and radiotherapy as well as malnutrition and mild anemia because of feeding difficulties. The patient was treated with PDT, which was assisted by a new positioning technique of X-ray fluoroscopy and Nab-P chemotherapy, and finally achieved clinical benefits. In addition, a modified transnasal feeding tube was also applied in the process of fluoroscopy-guided PDT in this article.

Higher pulse frequency of near-infrared laser irradiation increases penetration depth for novel biomedical applications

BACKGROUND

The clinical efficiency of laser treatments is limited by the low penetration of visible light used in certain procedures like photodynamic therapy (PDT). Second Harmonic Generation (SHG) PDT is an innovative technique to overcome this limitation that enables the use of Near Infrared (NIR) light instead of visible light. NIR frequency bands present an optical window for deeper penetration into biological tissue. In this research, we compare the penetration depths of 405 and 808 nm continuous wave (CW) lasers and 808 nm pulsed wave (PW) laser in two different modes (high and low frequency).

METHODS

Increasing thicknesses of beef and chicken tissue samples were irradiated under CW and PW lasers to determine penetration depths.

RESULTS

The 808 nm CW laser penetrates 2.3 and 2.4 times deeper than the 405 nm CW laser in beef and chicken samples, respectively. 808 nm PW (pulse frequency-500 Hz) penetrates deeper than CW laser at the same wavelength. Further, increasing the pulse frequency achieves higher penetration depths. High frequency 808 nm PW (pulse frequency-71.4 MHz) penetrates 7.4- and 6.0-times deeper than 405 nm CW laser in chicken and beef, respectively.

CONCLUSIONS

The results demonstrate the higher penetration depths of high frequency PW laser compared to low frequency PW laser, CW laser of the same wavelength and CW laser with half the wavelength. The results indicate that integrating SHG in the PDT process along with pulsed NIR light may allow the treatment of 6-7 times bigger tumours than conventional PDT using blue light.

An update in clinical utilization of photodynamic therapy for lung cancer

Lung cancer is one of the leading causes of cancer-related death worldwide, with nearly 1.8 million-diagnosis and 1.59 million deaths. Surgery, radiotherapy, and chemotherapy in individual or combination are commonly used to treat lung cancers. Photodynamic therapy (PDT) is a highly selective method for the destruction of cancer cells by exerting cytotoxic activity on malignant cells. PDT has been the subject of numerous clinical studies and has proven to be an effective strategy for cancer therapy. Clinical studies revealed that PDT could prolong survival in patients with inoperable cancers and significantly improve quality of life. For inoperable lung cancer cases, PDT could be an effective therapy. Despite the clinical success reported, PDT is still currently underutilized to treat lung cancer and other tumors. PTD is still a new treatment approach for lung cancer mainly due to the lack of enough clinical research evaluating its' effectiveness and side effects. In this review, we discuss the current prospects and future potentials of PDT in lung cancer treatment.

Progress in Clinical Trials of Photodynamic Therapy for Solid Tumors and the Role of Nanomedicine

Current research to find effective anticancer treatments is being performed on photodynamic therapy (PDT) with increasing attention. PDT is a very promising therapeutic way to combine a photosensitive drug with visible light to manage different intense malignancies. PDT has several benefits, including better safety and lower toxicity in the treatment of malignant tumors over traditional cancer therapy. This reasonably simple approach utilizes three integral elements: a photosensitizer (PS), a source of light, and oxygen. Upon light irradiation of a particular wavelength, the PS generates reactive oxygen species (ROS), beginning a cascade of cellular death transformations. The positive therapeutic impact of PDT may be limited because several factors of this therapy include low solubilities of PSs, restricting their effective administration, blood circulation, and poor tumor specificity. Therefore, utilizing nanocarrier systems that modulate PS pharmacokinetics (PK) and pharmacodynamics (PD) is a promising approach to bypassing these challenges. In the present paper, we review the latest clinical studies and preclinical in vivo studies on the use of PDT and progress made in the use of nanotherapeutics as delivery tools for PSs to improve their cancer cellular uptake and their toxic properties and, therefore, the therapeutic impact of PDT. We also discuss the effects that photoimmunotherapy (PIT) might have on solid tumor therapeutic strategies.

Photodynamic Therapy Using Talaporfin Sodium for Local Failure after Chemoradiotherapy or Radiotherapy for Esophageal Cancer: A Single Center Experience

A phase II study of second-generation photodynamic therapy (PDT) using talaporfin sodium has shown excellent treatment results for esophageal cancer with local failure after chemoradiotherapy (CRT) or radiotherapy (RT). However, only a few studies have reported this therapy in clinical practice. This study aimed to confirm the efficacy and safety of salvage PDT using talaporfin sodium for esophageal cancer in various clinical situations. Twelve patients with esophageal cancer with local failure after definitive CRT or RT who underwent PDT using talaporfin sodium were enrolled from April 2016 to January 2020. Overall, 10 patients (83.3%) achieved a local complete response. No skin phototoxicity was observed, but esophageal stricture occurred in five patients (41.7%). Esophageal stricture was improved with endoscopic balloon dilation in all patients, and subsequent analysis found no significant factors causing esophageal stricture after PDT. Two patients with synchronous tumors were successfully rescued by combination therapy with endoscopic submucosal dissection. Two patients with carcinoma in situ of larger than 1/2 circumference were rescued by repeated PDT. The 2-year overall survival was 80.0% (95% confidence interval 0.409–0.946). PDT using talaporfin sodium was an effective and safe salvage treatment for esophageal cancer with local failure after CRT or RT in various clinical situations.

Nomogram-based prediction of survival in unresectable or metastatic gastric cancer patients with good performance status who received first-line chemotherapy

Background

Good performance status (PS) is widely acknowledged to have a high prognostic ability, although the prognostic parameters of cancer patients with good PS are still uncertain. This study was conducted to establish and validate a point-based nomogram to assist with predicting prognosis in unresectable or metastatic gastric cancer (GC) patients who had good PS and underwent first-line chemotherapy.

Methods

At random, a total of 309 patients with GC were split into 2 cohorts: a training cohort (n=259) and an internal validation cohort (n=50). An independent external validation cohort comprising 147 patients was also recruited. Both univariate and multivariate Cox regression analyses were used to evaluate patients based on the overall survival (OS) to develop the nomogram, which was subsequently validated using the concordance index (c-index), calibration curve, and decision curve analysis (DCA).

Results

The nomogram contained 3 independent prognostic variables in the training cohort: the number of distant metastatic sites (P<0.001), carbohydrate antigen 199 (CA199) level (P=0.002), and fibrinogen (P=0.020). The nomogram predicted an OS with a c-index of 0.623 (95% CI, 0.58–0.67) in the training cohort. The internal validation showed that the nomogram had a c-index of 0.614 (95% CI, 0.51–0.72). For external validation, the c-index was 0.638 (95% CI, 0.58–0.70).

Conclusions

A reliable point-based nomogram for predicting the prognosis of patients who had unresectable or metastatic GC and good PS who underwent first-line chemotherapy was developed and validated.

Keywords

Nomogram-based prediction; overall survival; unresectable gastric cancer; metastatic gastric cancer; good performance status; first-line chemotherapy