Pyrobacteriopheophorbide-a derivatives possessing various hydrophilic esterifying groups at the C17-propionate residues for photodynamic therapy

Aiming at the application to photodynamic therapy, natural bacteriochlorophyll-a was converted to chemically stable free-base derivatives possessing different kinds of hydrophilic C17-propionate residues. These semi-synthetic bacteriochlorins were found to have self-assembling ability in an aqueous environment and formed stable J-type aggregates in a cell culture medium containing 0.2% DMSO. The electronic absorption spectra of all the sensitizers showed Qy absorption maxima at 754 nm in DMSO as their monomeric states, while a drastic shift of the red-most bands to ca. 880 nm was observed in the aqueous medium. The circular dichroism spectra in the medium showed much intense signals compared to those measured in DMSO, supporting the formation of well-ordered supramolecular structures. By introducing hydrophilic side chains, the bacteriochlorin sensitizers could be dispersed in the aqueous medium as their J-aggregates without the use of any surfactants. Cellular uptake efficiencies as well as photodynamic activities were evaluated using human cervical adenocarcinoma HeLa cells. Among the 11 photosensitizers investigated, the best result was obtained for a charged derivative possessing trimethylammonium terminal (17-CH2CH2COOCH2CH2N+(CH3)3I-) and photocytotoxicity of EC50 = 0.09 μM was achieved by far-red light illumination of 35 J/cm2 from an LED panel (730 nm).

Nanotechnology-mediated photodynamic therapy: Focus on overcoming tumor hypoxia

The oxygen level in the tumor is a critical marker that determines response to different treatments. Cancerous cells can adapt to hypoxia and low pH conditions within the tumor microenvironment (TME) to regulate tumor metabolism, proliferation, and promote tumor metastasis as well as angiogenesis, consequently leading to treatment failure and recurrence. In recent years, widespread attempts have been made to overcome tumor hypoxia through different methods, such as hyperbaric oxygen therapy (HBOT), hyperthermia, O2 carriers, artificial hemoglobin, oxygen generator hydrogels, and peroxide materials. While oxygen is found to be an essential agent to improve the treatment response of photodynamic therapy (PDT) and other cancer treatment modalities, the development of hypoxia within the tumor is highly associated with PDT failure. Recently, the use of nanoparticles has been a hot topic for researchers and exploited to overcome hypoxia through Oxygen-generating hydrogels, O2 nanocarriers, and O2 -generating nanoparticles. This review aimed to discuss the role of nanotechnology in tumor oxygenation and highlight the challenges, prospective, and recent advances in this area to improve PDT outcomes. This article is categorized under: Nanotechnology Approaches to Biology > Cells at the Nanoscale Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Unleashing the power of porphyrin photosensitizers: Illuminating breakthroughs in photodynamic therapy

This comprehensive review provides the current trends and recent developments of porphyrin-based photosensitizers. We discuss their evolution from first-generation to third-generation compounds, including cutting-edge nanoparticle-integrated derivatives, and explores their pivotal role in advancing photodynamic therapy (PDT) for enhanced cancer treatment. Integrating porphyrins with nanoparticles represents a promising avenue, offering improved selectivity, reduced toxicity, and heightened biocompatibility. By elucidating recent breakthroughs, innovative methodologies, and emerging applications, this review provides a panoramic snapshot of the dynamic field, addressing challenges and charting prospects. With a focus on harnessing reactive oxygen species (ROS) through light activation, PDT serves as a minimally invasive therapeutic approach. This article offers a valuable resource for researchers, clinicians, and PDT enthusiasts, highlighting the potential of porphyrin photosensitizers to improve the future of cancer therapy.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2017-2018

This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2018. Also included are papers that describe methods appropriate to glycan and glycoprotein analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, new methods, matrices, derivatization, MALDI imaging, fragmentation and the use of arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Most of the applications are presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. The reported work shows increasing use of combined new techniques such as ion mobility and highlights the impact that MALDI imaging is having across a range of diciplines. MALDI is still an ideal technique for carbohydrate analysis and advancements in the technique and the range of applications continue steady progress.

Lima K, Alves de Matos P, Tsubone TM, Gonçalves RR, Ferrari JL. Upconversion rare Earths nanomaterials applied to photodynamic therapy and bioimaging

Light-based therapies and diagnoses including photodynamic therapy (PDT) have been used in many fields of medicine, including the treatment of non-oncological diseases and many types of cancer. PDT require a light source and a light-sensitive compound, called photosensitizer (PS), to detect and destroy cancer cells. After absorption of the photon, PS molecule gets excited from its singlet ground state to a higher electronically excited state which, among several photophysical processes, can emit light (fluorescence) and/or generate reactive oxygen species (ROS). Moreover, the biological responses are activated only in specific areas of the tissue that have been submitted to exposure to light. The success of the PDT depends on many parameters, such as deep light penetration on tissue, higher PS uptake by undesired cells as well as its photophysical and photochemical characteristics. One of the challenges of PDT is the depth of penetration of light into biological tissues. Because photon absorption and scattering occur simultaneously, these processes depend directly on the light wavelength. Using PS that absorbs photons on “optical transparency windows” of biological tissues promises deeper penetration and less attenuation during the irradiation process. The traditional PS normally is excited by a higher energy photon (UV-Vis light) which has become the Achilles’ heel in photodiagnosis and phototreatment of deep-seated tumors below the skin. Thus, the need to have an effective upconverter sensitizer agent is the property in which it absorbs light in the near-infrared (NIR) region and emits in the visible and NIR spectral regions. The red emission can contribute to the therapy and the green and NIR emission to obtain the image, for example. The absorption of NIR light by the material is very interesting because it allows greater penetration depth for in vivo bioimaging and can efficiently suppress autofluorescence and light scattering. Consequently, the penetration of NIR radiation is greater, activating the biophotoluminescent material within the cell. Thus, materials containing Rare Earth (RE) elements have a great advantage for these applications due to their attractive optical and physicochemical properties, such as several possibilities of excitation wavelengths – from UV to NIR, strong photoluminescence emissions, relatively long luminescence decay lifetimes (µs to ms), and high sensitivity and easy preparation. In resume, the relentless search for new systems continues. The contribution and understanding of the mechanisms of the various physicochemical properties presented by this system is critical to finding a suitable system for cancer treatment via PDT.

D-Mannose-appended 5,15-diazaporphyrin for photodynamic therapy

5,15-Diazaporphyrin appended with D-mannose moieties was prepared through Suzuki-Miyaura cross-coupling reaction and S_N2 alkylation. The resultant diazaporphyrin was hydrophilic enough to exhibit sufficient solubility in aqueous media. Because of the photosensitizing ability of diazaporphyrins, the in vitro activity of the D-mannose-appended diazaporphyrin in photodynamic therapy (PDT) was investigated. The specific internalization of the functionalized diazaporphyrin into human breast adenocarcinoma (MDA-MB-231) cells through mannose receptors was confirmed by confocal microscopy imaging. We also demonstrated the strong PDT activity of the functionalized diazaporphyrin at a nanomolar level with short light irradiation time.

Fototerapia – metoda wykorzystywana w leczeniu przewlekłych schorzeń dermatologicznych

Wykorzystanie energii świetlnej w terapii schorzeń o różnej etiologii towarzyszy człowiekowi od czasów starożytnych. Elementem decydującym o powodzeniu terapii jest dobranie odpowiedniej długości promieniowania (terapia NB-UVB, BB-UVB i UVA1) lub wystąpienie interakcji między substancją światłoczułą skumulowaną w zmienionej chorobowo tkance a zastosowanym promieniowaniem (terapia PUVA oraz terapia fotodynamiczna). Metody terapeutyczne wykorzystujące energię świetlną są klasyfikowane na podstawie wykorzystywanego zakresu promieniowania. Obecnie wyróżnia się fototerapię UV, wykorzystującą promieniowanie UVA lub UVB oraz terapię fotodynamiczną (PDT; photodynamic therapy), podczas której stosowane jest promieniowanie o długości fali 350-700 nm.

Fototerapia UV wykorzystywana jest do leczenia schorzeń dermatologicznych, takich jak łuszczyca, bielactwo oraz atopowe zapalenie skóry, ze względu na jej działanie immunosupresyjne i antyproliferacyjne. Jest dostępna w postaci terapii PUVA polegającej na wykorzystaniu synergicznego działania promieniowania ultrafioletowego (UVA) oraz związków o działaniu światłouczulającym (8-metoksypsolaren, 5-metoksypsolaren). Ponadto wyróżniono monoterapię promieniowaniem ultrafioletowym A1 (UVA1), szerokozakresowym UVB (BB-UVB) i wąskozakresowym UVB (NB-UVB). Terapia fotodynamiczna obok konwencjonalnych metod leczenia jest nowoczesną i nieinwazyjną alternatywą wykorzystywaną zarówno w diagnostyce, jak i terapii chorób o różnej etiologii. W 90% przypadków PDT jest stosowana w schorzeniach dermatologicznych, takich jak trądzik pospolity czy łuszczyca. Selektywna aktywność cytotoksyczna wykazywana w kierunku złośliwych komórek nowotworowych powoduje, że terapia fotodynamiczna stosowana jest także z powodzeniem w leczeniu zmian onkologicznych. Duży postęp, przejawiający się zarówno w opracowywaniu innowacyjnych substancji światłoczułych, jak i nowych źródeł promieniowania, sprawia, iż zakres stosowalności terapii fotodynamicznej ciągle się poszerza.

W artykule przedstawiono obecnie dostępne formy fototerapii poprzez opis mechanizmu ich działania, zastosowania oraz możliwości powstania skutków niepożądanych.

Photodynamic therapy - mechanisms, photosensitizers and combinations

Photodynamic therapy (PDT) is a modern and non-invasive form of therapy, used in the treatment of non-oncological diseases as well as cancers of various types and locations. It is based on the local or systemic application of a photosensitive compound - the photosensitizer, which is accumulated in pathological tissues. The photosensitizer molecules absorb the light of the appropriate wavelength, initiating the activation processes leading to the selective destruction of the inappropriate cells. The photocytotoxic reactions occur only within the pathological tissues, in the area of photosensitizer distribution, enabling selective destruction. Over the last decade, a significant acceleration in the development of nanotechnology has been observed. The combination of photosensitizers with nanomaterials can improve the photodynamic therapy efficiency and eliminate its side effects as well. The use of nanoparticles enables achievement a targeted method which is focused on specific receptors, and, as a result, increases the selectivity of the photodynamic therapy. The object of this review is the anticancer application of PDT, its advantages and possible modifications to potentiate its effects.