One-pot peptide cyclisation and surface modification of photosensitiser-loaded red blood cells for targeted photodynamic therapy

Chu, Jacky; Shao, Chihao; Ha, Summer Y.Y.; Fong, Wing‐Ping; Wong, Chi‐Ming; Ng, Dennis K. P.

doi:10.1039/d1bm01306h

Cited by 12 publications

(9 citation statements)

References 37 publications

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“…After stirring for 30 min at room temperature, the mixture was filtered using a 3 kDa cutoff membrane filter to give the cyclic peptide-conjugated protein cEBP-GFP , which was characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) (Figure S2 in the Supporting Information). This one-pot bioligation methodology has previously been used by us to prepare cyclic RGD-conjugated red blood cells for targeted delivery of photosensitizers . We now extend it to synthesize cyclic peptide-conjugated proteins.…”

Section: Results and Discussionmentioning

confidence: 99%

“…To demonstrate that the bioligation method can be used to prepare functional proteins that can be delivered selectively into cancer cells, green fluorescent protein (GFP) was first chosen as a model substrate because of its impermeability through the cell membrane and strong fluorescence that can facilitate the visualization using confocal fluorescence microscopy. As shown in Figure a, the bifunctional linker 1 , which was prepared according to our previously described procedure, was treated with a mixture of trifluoroacetic acid (TFA) and water (1:1 v/v) to remove the acetal-protecting group, followed by coupling with the linear peptide AcNH-CMYIEALDRYAC-CONH 2 (labeled as EBP ) via site-specific dibenzylation with the two cysteine residues in borate buffer (pH 8.5, 1 mM). The resulting cyclic EBP -conjugated o -phthalaldehyde (labeled as cEBP-OPA ) could be purified readily by high-performance liquid chromatography (HPLC) and characterized by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (Figure S1 in the Supporting Information).…”

Section: Results and Discussionmentioning

confidence: 99%

“…The activation of gal-DSBDP by the extrinsic cRGD-β-Gal was then studied at the cellular level by confocal microscopy and flow cytometry, using a range of cell lines with different expression levels of α v β 3 integrin, including the integrin-positive U87-MG human glioblastoma cells , and MDA-MB-231 human breast adenocarcinoma cells, as well as the integrin-negative MCF-7 human breast adenocarcinoma cells ,, and HEK-293 human embryonic kidney normal cells. , These cells were incubated with gal-DSBDP (4 μM) for 30 min with or without pretreatment with cRGD-β-Gal or β-Gal (10 unit mL –1 ) for 1 h, followed by postincubation in a drug-free medium for further 3 h to provide sufficient time for the intracellular enzymatic reaction. As shown in the confocal images (Figure a), notable fluorescence could only be observed for the integrin-positive U87-MG and MDA-MB-231 cells being pretreated with cRGD-β-Gal .…”

Section: Results and Discussionmentioning

confidence: 99%

“…Because of these reasons, we believed β-Gal is an ideal candidate for extrinsic enzymes. To selectively deliver this enzyme into the cancer cells, it was modified with cyclic RGD peptide moieties that can target the α v β 3 integrin upregulated on most cancer cells, using our previously reported peptide cyclization strategy − and phthalaldehyde-amine capture (PAC) reaction. , It is worth mentioning that proteins are generally impermeable to the cells due to their high molecular weight. Various carriers, such as nanoparticles, polymers, and liposomes, have been utilized to assist the trafficking across the plasma membrane. − Cell-penetrating peptides have also been introduced for this purpose through protein expression, , covalent conjugation, or host–guest interactions .…”

Section: Introductionmentioning

confidence: 99%

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Specific Activation of Photosensitizer with Extrinsic Enzyme for Precisive Photodynamic Therapy

et al. 2022

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Delivery of functional proteins into the intracellular space has been a challenging task that could lead to a myriad of therapeutic applications. We report herein a novel bioconjugation strategy for enzyme modification and selective delivery into cancer cells for lock-and-key-type activation of photosensitizers. Using a bifunctional linker containing a bis(bromomethyl)phenyl group and an o-phthalaldehyde moiety, it could induce cyclization of the peptide sequence Ac-NH-CRGDfC-CONH2 through site-specific dibenzylation with the two cysteine residues and further coupling with β-galactosidase via the phthalaldehyde-amine capture reaction. This facile two-step one-pot procedure enabled the preparation of cyclic RGD-modified β-galactosidase readily, which could be internalized selectively into αvβ3 integrin-overexpressed cancer cells. Upon encountering an intrinsically quenched distyryl boron dipyrromethene-based photosensitizer conjugated with a galactose moiety through a self-immolative linker inside the cells, the extrinsic enzyme induced specific cleavage of the β-galactosidic bond followed by self-immolation to release an activated derivative, thereby restoring the photodynamic activities and causing cell death effectively. The high specificity of this extrinsic enzyme-activated photosensitizing system was also demonstrated in vivo using nude mice bearing an αvβ3 integrin-positive U87-MG tumor. The specific activation at the tumor site resulted in lighting up and complete eradication of the tumor upon laser irradiation, while by using the native β-galactosidase, the effects were largely reduced. In contrast to the conventional activation using intrinsic enzymes, this extrinsic enzyme activatable approach can further minimize the nonspecific activation toward precisive photodynamic therapy.

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Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Specific Activation of Photosensitizer with Extrinsic Enzyme for Precisive Photodynamic Therapy

et al. 2022

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“…[ 14–16 ] Surface modification of RGD peptides can endow RBCs with specific affinity for integrin α v β 3 that plays an important role in tumor angiogenesis, benefitting tumor‐targeted delivery of anticancer drugs. [ 17,18 ] RBCs used as the carriers of phototherapeutic agents can promote drug release at specific diseased sites by photolysis. [ 19 ] Oxyhemoglobin (oxyHb) enriched in RBCs can supply adequate oxygen to facilitate PDT, [ 20 ] making RBCs more suitable for carrying photosensitizers.…”

Section: Introductionmentioning

confidence: 99%

Versatile Red Blood Cells for Triple‐Negative Breast Cancer Treatment via Stepwise Photoactivations

Cheng

Chen

Qian

et al. 2022

Adv Healthcare Materials

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Phototherapies have many advantages for triple-negative breast cancer (TNBC) treatment. However, their effects are often limited by short blood circulation time, poor tumor selectivity and weak penetration of phototherapeutic agents, and tumor hypoxia. For overcoming these limitations, a versatile biomimetic system is developed based on red blood cells (RBCs). Photothermal agent new indocyanine green (IR820) is conjugated with the cell/tissue-penetrating TAT peptide and further efficiently encapsulated into the intact RBCs by crossing cell membranes to realize the long blood circulation. Meanwhile, cyclic RGD peptide (cRGD) is linked to the surfaces of RBCs through phospholipid insertion to obtain tumor vessel-targeting ability. Photosensitizer temoporfin (mTHPC) is next loaded into the membranes of RBCs by spontaneous transferring. The acquired biomimetic system (cRGD-RBC@mTHPC/TAT-IR820) exhibits potent photodynamic performance upon 652 nm laser irradiation with the facilitation of oxyhemoglobin, which could not only trigger TAT-IR820 release but also destroy tumor vessels. TAT-IR820 penetrates deeply into tumor tissue via the mediation of TAT peptide, exerting greatly promoted photothermal ablation against TNBC upon 808 nm laser irradiation. In situ generated tumor antigens further induce robust immune responses to suppress TNBC recurrence and metastasis. In summary, this study provides a versatile biomimetic system for comprehensive TNBC treatment via stepwise photodynamic and photothermal activations.

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O‐Phthalaldehyde: A Versatile Chemical with its Roles and Future Perspectives

Misra,

Mondal,

Alam Mondal

2024

Asian J Org Chem

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Ortho‐Phthaldehyde (OPA) is one of the isomers of benzenedicarbaldehydes. It exhibits distinctive chemical properties stemming from the closely attached dicarbaldehyde groups. Since its development, it has been widely employed as a potent disinfectant, owing to its inherent antimicrobial properties. OPA has the ability to form a fluorescent product with primary amines, making it useful for detecting and estimating various biogenic amines, peptides, and proteins in bodily fluids. Moreover, the combination of thiol and amine with OPA produces a more sensitive fluorogenic compound, significantly enhancing the sensitivity and specificity of OPA‐based analytical techniques. This review summarizes recent developments in biochemical analysis using OPA. It also discusses key achievements in the development of photoactive polymers. Additionally, it covers the use of OPA as a synthetic precursor to achieve small molecules with unique structures that have become increasingly important in various fields of scientific research from 2004.

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One-pot peptide cyclisation and surface modification of photosensitiser-loaded red blood cells for targeted photodynamic therapy

Abstract: We report herein a one-pot approach to cyclise a tumour-targeting peptide and conjugate it on the surface of red blood cells loaded with a boron dipyrromethene-based photosensitiser using a bifunctional...

Cited by 12 publications

References 37 publications

Specific Activation of Photosensitizer with Extrinsic Enzyme for Precisive Photodynamic Therapy

Specific Activation of Photosensitizer with Extrinsic Enzyme for Precisive Photodynamic Therapy

Versatile Red Blood Cells for Triple‐Negative Breast Cancer Treatment via Stepwise Photoactivations

O‐Phthalaldehyde: A Versatile Chemical with its Roles and Future Perspectives

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