Dual-Function Antibody Conjugate-Enabled Photoimmunotherapy Complements Fluorescence and Photoacoustic Imaging of Head and Neck Cancer Spheroids.

Several molecular-targeted imaging and therapeutic agents are in clinical trials for image-guided surgery and photoimmunotherapy (PIT) for head and neck cancers. In this context, we have previously reported the development, characterization, and specificity of a dual-function antibody conjugate (DFAC) for multimodal imaging and photoimmunotherapy (PIT) of EGFR-overexpressing cancer cells. The DFAC reported previously and used in the present study comprises an EGFR-targeted antibody, cetuximab, conjugated to benzoporphyrin derivative (BPD) for fluorescence imaging and PIT and a Si-centered naphthalocyanine dye for photoacoustic imaging. We report here the evaluation and performance of DFAC in detecting microscopic cancer spheroids by fluorescence and photoacoustic imaging along with their treatment by PIT. We demonstrate that while fluorescence imaging can detect spheroids with volumes greater than 0.049 mm3, photoacoustic imaging-based detection was possible even for the smallest spheroids (0.01 mm3) developed in the study. When subjected to PIT, the spheroids showed a dose-dependent response, with smaller spheroids (0.01 and 0.018 mm3) showing a complete response with no recurrence when treated with 100 J/cm2. Together our results demonstrate the complementary imaging and treatment capacity of DFAC. This potentially enables fluorescence imaging to assess the presence of tumor on a macroscopic scale, followed by photoacoustic imaging for delineating tumor margins guiding surgical resection and elimination of any residual microscopic disease by PIT, in a single intraoperative setting.

A Dual Function Antibody Conjugate Enabled Photoimmunotherapy Complements Fluorescence and Photoacoustic Imaging of Head and Neck Cancer Spheroids.

Several molecular-targeted imaging and therapeutic agents are in clinical trials for image-guided surgery and photoimmunotherapy (PIT) of head and neck cancers. In this context, we have previously reported the development, characterization, and specificity of a dual function antibody conjugate (DFAC) for multi-modal imaging and photoimmunotherapy (PIT) of EGFR over-expressing cancer cells. The DFAC reported previously and used in the present study, comprises of an EGFR targeted antibody - Cetuximab conjugated to Benzoporphyrin derivative (BPD) for fluorescence imaging and PIT, and a Si-centered naphthalocyanine dye for photoacoustic imaging. We report here the evaluation and performance of DFAC in detecting microscopic cancer spheroids by fluorescence and photoacoustic imaging along with their treatment by PIT. We demonstrate that while fluorescence imaging can detect spheroids with volumes greater than 0.049 mm3, photoacoustic imaging-based detection was possible even for the smallest spheroids (0.01 mm3), developed in the study. When subjected to PIT, the spheroids showed a dose-dependent response with smaller spheroids (0.01 and 0.018 mm3) showing a complete response with no recurrence when treated with 100 J/cm2. Together our results demonstrate the complementary imaging and treatment capacity of DFAC. This potentially enables fluorescence imaging to assess tumor presence on a macroscopic scale followed by photoacoustic imaging for delineating tumor margins guiding surgical resection and elimination of any residual microscopic disease by PIT, in a single intra-operative setting.

Efficacy and safety of micro-needling combined with topical 5-fluorouracil and excimer light vs. excimer light alone in treatment of non-segmental vitiligo: A comparative study.

BACKGROUND/PURPOSE: Vitiligo is one of the most challenging dermatological diseases with little improvement promises. Various modalities of treatment both medical and surgical have been used in the treatment of vitiligo. Some proved to be effective, others with controversial results and the rest were effective less. The aim of the present study was to evaluate the additional effect of topical 5-fluorouracil after micro-needling to excimer light (308 nm) in treatment of non-segmental vitiligo. METHODS: Fifty patients were included in the present study, only 33 patients continued the treatment for 6 months. Two patches were selected in every patient to be treated, one patch with micro-needling then application of 5 FU and excimer (Group A), and the other with excimer only (Group B). RESULTS: The treatment with the combination of micro-needling then application of 5 FU and excimer showed significant earlier response versus excimer alone. Also, the percentage of re-pigmentation was higher in the patches treated with the combination especially in the face and trunk. The combination of 5 FU after micro-needling and Excimer is more suitable for localized and focal vitiligo. CONCLUSION: Topical 5 FU after micro-needling is a promising, rapid, and cost-effective therapeutic strategy for treatment of non-segmental vitiligo It had limited side effects, and the best response was reported for lesions affecting face and trunk.

Spotlight on Photoactivatable Liposomes beyond Drug Delivery: An Enabler of Multitargeting of Molecular Pathways.

The potential of photoactivating certain molecules, photosensitizers (PS), resulting in photochemical processes, has long been realized in the form of photodynamic therapy (PDT) for the management of several cancerous and noncancerous pathologies. With an improved understanding of the photoactivation process and its broader implications, efforts are being made to exploit the various facets of photoactivation, PDT, and the associated phenomenon of photodynamic priming in enhancing treatment outcomes, specifically in cancer therapeutics. The parallel emergence of nanomedicine, specifically liposome-based nanoformulations, and the convergence of the two fields of liposome-based drug delivery and PDT have led to the development of unique hybrid systems, which combine the exciting features of liposomes with adequate complementation through the photoactivation process. While initially liposomes carrying photosensitizers (PSs) were developed for enhancing the pharmacokinetics and the general applicability of PSs, more recently, PS-loaded liposomes, apart from their utility in PDT, have found several applications including enhanced targeting of drugs, coloading multiple therapeutic agents to enhance synergistic effects, imaging, priming, triggering drug release, and facilitating the escape of therapeutic agents from the endolysosomal complex. This review discusses the design strategies, potential, and unique attributes of these hybrid systems, with not only photoactivation as an attribute but also the ability to encapsulate multiple agents for imaging, biomodulation, priming, and therapy referred to as photoactivatable multiagent/inhibitor liposomes (PMILS) and their targeted versions─targeted PMILS (TPMILS). While liposomes have formed their own niche in nanotechnology and nanomedicine with several clinically approved formulations, we try to highlight how using PS-loaded liposomes could address some of the limitations and concerns usually associated with liposomes to overcome them and enhance their preclinical and clinical utility in the future.

Photoimmunotherapy Retains Its Anti-Tumor Efficacy with Increasing Stromal Content in Heterotypic Pancreatic Cancer Spheroids.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease characterized by increased levels of desmoplasia that contribute to reduced drug delivery and poor treatment outcomes. In PDAC, the stromal content can account for up to 90% of the total tumor volume. The complex interplay between stromal components, including pancreatic cancer-associated fibroblasts (PCAFs), and PDAC cells in the tumor microenvironment has a significant impact on the prognoses and thus needs to be recapitulated in vitro when evaluating various treatment strategies. This study is a systematic evaluation of photodynamic therapy (PDT) in 3D heterotypic coculture models of PDAC with varying ratios of patient-derived PCAFs that simulate heterogeneous PDAC tumors with increasing stromal content. The efficacy of antibody-targeted PDT (photoimmunotherapy; PIT) using cetuximab (a clinically approved anti-EGFR antibody) photoimmunoconjugates (PICs) of a benzoporphyrin derivative (BPD) is contrasted with that of liposomal BPD (Visudyne), which is currently in clinical trials for PDT of PDAC. We demonstrate that both Visudyne-PDT and PIT were effective in heterotypic PDAC 3D spheroids with a low stromal content. However, as the stromal content increases above 50% in the 3D spheroids, the efficacy of Visudyne-PDT is reduced by up to 10-fold, while PIT retains its efficacy. PIT was found to be 10-, 19-, and 14-fold more phototoxic in spheroids with 50, 75, and 90% PCAFs, respectively, as compared to Visudyne-PDT. This marked difference in efficacy is attributed to the ability of PICs to penetrate and distribute homogeneously within spheroids with a higher stromal content and the mechanistically different modes of action of the two formulations. This study thus demonstrates how the stromal content in PDAC spheroids directly impacts their responsiveness to PDT and proposes PIT to be a highly suited treatment option for desmoplastic tumors with particularly high degrees of stromal content.

Dual Function Antibody Conjugates for Multimodal Imaging and Photoimmunotherapy of Cancer Cells.

Precision imaging, utilizing molecular targeted agents, is an important tool in cancer diagnostics and guiding therapies. While there are limitations associated with single mode imaging probes, multimodal molecular imaging probes enabling target visualization through complementary imaging technologies provides an attractive alternative. However, there are several challenges associated with designing molecular probes carrying contrast agents for complementary multimodal imaging. Here, we propose a dual function antibody conjugate (DFAC) comprising an FDA approved photosensitizer Benzoporphyrin derivative (BPD) and a naphthalocyanine-based photoacoustic dye (SiNc(OH)) for multimodal infrared (IR) imaging. While fluorescence imaging, through BPD, provides sensitivity, complementing it with photoacoustic imaging, through SiNc(OH), provides a depth-resolved spatial resolution much beyond the optical diffusion limits of fluorescence measurements. Through a series of in vitro experiments, we demonstrate the development and utilization of DFACs for multimodal imaging and photodynamic treatment of squamous cell carcinoma (A431) cell line. The proposed DFACs have potential use in precision imaging applications such as guiding tumor resection surgeries and photodynamic treatment of residual microscopic disease thereby minimizing local recurrence. The data demonstrated in this study merits further investigation for its preclinical and clinical translation.

Photodynamic therapy, priming and optical imaging: Potential co-conspirators in treatment design and optimization - a Thomas Dougherty Award for Excellence in PDT paper.

Photodynamic therapy is a photochemistry-based approach, approved for the treatment of several malignant and non-malignant pathologies. It relies on the use of a non-toxic, light activatable chemical, photosensitizer, which preferentially accumulates in tissues/cells and, upon irradiation with the appropriate wavelength of light, confers cytotoxicity by generation of reactive molecular species. The preferential accumulation however is not universal and, depending on the anatomical site, the ratio of tumor to normal tissue may be reversed in favor of normal tissue. Under such circumstances, control of the volume of light illumination provides a second handle of selectivity. Singlet oxygen is the putative favorite reactive molecular species although other entities such as nitric oxide have been credibly implicated. Typically, most photosensitizers in current clinical use have a finite quantum yield of fluorescence which is exploited for surgery guidance and can also be incorporated for monitoring and treatment design. In addition, the photodynamic process alters the cellular, stromal, and/or vascular microenvironment transiently in a process termed photodynamic priming, making it more receptive to subsequent additional therapies including chemo- and immunotherapy. Thus, photodynamic priming may be considered as an enabling technology for the more commonly used frontline treatments. Recently, there has been an increase in the exploitation of the theranostic potential of photodynamic therapy in different preclinical and clinical settings with the use of new photosensitizer formulations and combinatorial therapeutic options. The emergence of nanomedicine has further added to the repertoire of photodynamic therapy's potential and the convergence and co-evolution of these two exciting tools is expected to push the barriers of smart therapies, where such optical approaches might have a special niche. This review provides a perspective on current status of photodynamic therapy in anti-cancer and anti-microbial therapies and it suggests how evolving technologies combined with photochemically-initiated molecular processes may be exploited to become co-conspirators in optimization of treatment outcomes. We also project, at least for the short term, the direction that this modality may be taking in the near future.

Vitamin D deficiency and osteoporosis in hemophilic children: an intermingled comorbidity.

The aim of this study is to investigate bone state and factors affecting it in children with hemophilia. This is a case-control study that included 37 children with hemophilia and 37 healthy controls. The patients were selected from the outpatient pediatric hematology clinic of Fayoum University Hospital, Egypt. Bone mineral density, serum vitamin D, parathormone, calcium, phosphorus, and calcium creatinine ratio levels were evaluated. Vitamin D level and bone mineral density were significantly lower in hemophiliacs than in control group (P < 0.0001). About 43.2% of cases had moderate vitamin D deficiency, whereas 35.1% had mild deficiency. Vitamin D positively correlated with bone mineral density Z-score, whereas it negatively correlated with total joint score. Positive correlation between bone mineral density and age was also found. Serum levels of urea, urinary calcium creatinine ratio, and parathormone were found to be higher in cases than in control. Also, serum calcium level was found to be lower in patients than in controls. We concluded that vitamin D deficiency is an essential cause of decreased bone mineral density in hemophilic children. Hemophilic arthropathy with consecutive immobilization plays an important role in vitamin D deficiency and decreased bone mineral density.