Dual-responsive supramolecular photodynamic nanomedicine with activatable immunomodulation for enhanced antitumor therapy

A major challenge facing photodynamic therapy (PDT) is that the activity of the immune-induced infiltrating CD8+ T cells is subject to the regulatory T lymphocytes (Tregs), leaving the tumor at risk of recurrence and metastasis after the initial ablation. To augment the antitumor response and reprogram the immunosuppressive tumor microenvironment (TME), a supramolecular photodynamic nanoparticle (DACss) is constructed by the host-guest interaction between demethylcantharidin-conjugated β-cyclodextrin (DMC-CD) and amantadine-terminated disulfide-conjugated FFVLGGGC peptide with chlorin e6 decoration (Ad-ss-pep-Ce6) to achieve intelligent delivery of photosensitizer and immunomodulator for breast cancer treatment. The acid-labile β-carboxamide bond of DMC-CD is hydrolyzed in response to the acidic TME, resulting in the localized release of DMC and subsequent inhibition of Tregs. The guest molecule Ad-ss-pep-Ce6 can be cleaved by a high level of intracellular GSH, reducing photosensitizer toxicity and increasing photosensitizer retention in the tumor. With a significant increase in the CTL/Treg ratio, the combination of Ce6-based PDT and DMC-mediated immunomodulation adequately achieved spatiotemporal regulation and remodeling of the TME, as well as improved primary tumor and in situ lung metastasis suppression with the aid of PD-1 antibody.

Membrane heat shock protein 70: a theranostic target for cancer therapy.

Members of the 70 kDa stress protein family are found in nearly all subcellular compartments of nucleated cells where they fulfil a number of chaperoning functions. Heat shock protein 70 (HSP70), also termed HSPA1A, the major stress-inducible member of this family is overexpressed in a large variety of different tumour types. Apart from its intracellular localization, a tumour-selective HSP70 membrane expression has been determined. A membrane HSP70-positive tumour phenotype is associated with aggressiveness and therapy resistance, but also serves as a recognition structure for targeted therapies. Furthermore, membrane-bound and extracellularly residing HSP70 derived from tumour cells play pivotal roles in eliciting anti-tumour immune responses. Herein, we want to shed light on the multiplicity of different activities of HSP70, depending on its intracellular, membrane and extracellular localization with the goal to use membrane HSP70 as a target for novel therapies including nanoparticle-based approaches for the treatment of cancer.This article is part of the theme issue 'Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective'.

Sequential delivery of PD-1/PD-L1 blockade peptide and IDO inhibitor for immunosuppressive microenvironment remodeling via an MMP-2 responsive dual-targeting liposome

Intelligent responsive drug delivery system opens up new avenues for realizing safer and more effective combination immunotherapy. Herein, a kind of tumor cascade-targeted responsive liposome (NLG919@Lip-pep1) is developed by conjugating polypeptide inhibitor of PD-1 signal pathway (AUNP-12), which is also a targeted peptide that conjugated with liposome carrier through matrix metalloproteinase-2 (MMP-2) cleavable peptide (GPLGVRGD). This targeted liposome is prepared through a mature preparation process, and indoleamine-2,3-dioxygenase (IDO) inhibitor NLG919 was encapsulated into it. Moreover, mediated by the enhanced permeability and retention effect (EPR effect) and AUNP-12, NLG919@Lip-pep1 first targets the cells that highly express PD-L1 in tumor tissues. At the same time, the over-expressed MMP-2 in the tumor site triggers the dissociation of AUNP-12, thus realizing the precise block of PD-1 signal pathway, and restoring the activity of T cells. The exposure of secondary targeting module II VRGDC-NLG919@Lip mediated tumor cells targeting, and further relieved the immunosuppressive microenvironment. Overall, this study offers a potentially appealing paradigm of a high efficiency, low toxicity, and simple intelligent responsive drug delivery system for targeted drug delivery in breast cancer, which can effectively rescue and activate the body's anti-tumor immune response and furthermore achieve effective treatment of metastatic breast cancer.

Hollow copper sulfide nanoparticles carrying ISRIB for the sensitized photothermal therapy of breast cancer and brain metastases through inhibiting stress granule formation and reprogramming tumor-associated macrophages

As known, the benefits of photothermal therapy (PTT) are greatly limited by the heat tolerance of cancer cells resulting from overexpressed heat shock proteins (HSPs). Then HSPs further trigger the formation of stress granules (SGs) that regulate protein expression and cell viability under various stress conditions. Inhibition of SG formation can sensitize tumor cells to PTT. Herein, we developed PEGylated pH (low) insertion peptide (PEG-pHLIP)-modified hollow copper sulfide nanoparticles (HCuS NPs) encapsulating the SG inhibitor ISRIB, with the phase-change material lauric acid (LA) as a gate-keeper, to construct a pH-driven and NIR photo-responsive controlled smart drug delivery system (IL@H-PP). The nanomedicine could specifically target slightly acidic tumor sites. Upon irradiation, IL@H-PP realized PTT, and the light-controlled release of ISRIB could effectively inhibit the formation of PTT-induced SG to sensitize tumor cells to PTT, thereby increasing the antitumor effect and inducing potent immunogenic cell death (ICD). Moreover, IL@H-PP could promote the production of reactive oxygen species (ROS) by tumor-associated macrophages (TAMs), repolarizing them towards the M1 phenotype and remodeling the immunosuppressive microenvironment. In vitro/vivo results revealed the potential of PTT combined with SG inhibitors, which provides a new paradigm for antitumor and anti-metastases.

Co-delivery of photosensitizer and diclofenac through sequentially responsive bilirubin nanocarriers for combating hypoxic tumors

Considering that photodynamic therapy (PDT)-induced oxygen consumption and microvascular damage could exacerbate hypoxia to drive more glycolysis and angiogenesis, a novel approach to potentiate PDT and overcome the resistances of hypoxia is avidly needed. Herein, morpholine-modified PEGylated bilirubin was proposed to co-deliver chlorin e6, a photosensitizer, and diclofenac (Dc). In acidic milieu, the presence of morpholine could enable the nanocarriers to selectively accumulate in tumor cells, while PDT-generated reactive oxidative species (ROS) resulted in the collapse of bilirubin nanoparticles and rapid release of Dc. Combining with Dc showed a higher rate of apoptosis over PDT alone and simultaneously triggered a domino effect, including blocking the activity and expression of lactate dehydrogenase A (LDHA), interfering with lactate secretion, suppressing the activation of various angiogenic factors and thus obviating hypoxia-induced resistance-glycolysis and angiogenesis. In addition, inhibition of hypoxia-inducible factor-1α (HIF-1α) by Dc alleviated hypoxia-induced resistance. This study offered a sequentially responsive platform to achieve sufficient tumor enrichment, on-demand drug release and superior anti-tumor outcomes in vitro and in vivo.

Erratum: Author correction to "A nanocleaner specifically penetrates the blood‒brain barrier at lesions to clean toxic proteins and regulate inflammation in Alzheimer's disease" Acta Pharmaceutica Sinica B 12, (2021) 4032-4044

[This corrects the article DOI: 10.1016/j.apsb.2021.04.022.].

Self-propelled nanomotor reconstructs tumor microenvironment through synergistic hypoxia alleviation and glycolysis inhibition for promoted anti-metastasis

Solid tumors always exhibit local hypoxia, resulting in the high metastasis and inertness to chemotherapy. Reconstruction of hypoxic tumor microenvironment (TME) is considered a potential therapy compared to directly killing tumor cells. However, the insufficient oxygen delivery to deep tumor and the confronting "Warburg effect" compromise the efficacy of hypoxia alleviation. Herein, we construct a cascade enzyme-powered nanomotor (NM-si), which can simultaneously provide sufficient oxygen in deep tumor and inhibit the aerobic glycolysis to potentiate anti-metastasis in chemotherapy. Catalase (Cat) and glucose oxidase (GOx) are co-adsorbed on our previously reported CAuNCs@HA to form self-propelled nanomotor (NM), with hexokinase-2 (HK-2) siRNA further condensed (NM-si). The persistent production of oxygen bubbles from the cascade enzymatic reaction propels NM-si to move forward autonomously and in a controllable direction along H

A nanocleaner specifically penetrates the blood‒brain barrier at lesions to clean toxic proteins and regulate inflammation in Alzheimer's disease

Insurmountable blood‒brain barrier (BBB) and complex pathological features are the key factors affecting the treatment of Alzheimer's disease (AD). Poor accumulation of drugs in lesion sites and undesired effectiveness of simply reducing A

The progress and perspective of nanoparticle-enabled tumor metastasis treatment

As one of the most serious threats to human being, cancer is hard to be treated when metastasis happens. What's worse, there are few identified targets of metastasis for drug development. Therefore, it is important to develop strategies to prevent metastasis or treat existed metastasis. This review focuses on the procedure of metastasis, and first summarizes the targeting delivery strategies, including primary tumor targeting drug delivery, tumor metastasis targeting drug delivery and hijacking circulation cells. Then, as a promising treatment, the application of immunotherapy in tumor metastasis treatment is introduced, and strategies that stimulating immune response are reviewed, including chemotherapy, photothermal therapy, photodynamic therapy, ferroptosis, sonodynamic therapy, and nanovaccines. Finally, the challenges and perspective about nanoparticle-enabled tumor metastasis treatment are discussed.

The construction of nasal cavity-mimic M-cell model, design of M cell-targeting nanoparticles and evaluation of mucosal vaccination by nasal administration

In order to better evaluate the transport effect of nanoparticles through the nasal mucosa, an nasal cavity-mimic model was designed based on M cells. The differentiation of M cells was induced by co-culture of Calu-3 and Raji cells in invert model. The ZO-1 protein staining and the transport of fluorescein sodium and dexamethasone showed that the inverted co-culture model formed a dense monolayer and possessed the transport ability. The differentiation of M cells was observed by up-regulated expression of Sialyl Lewis A antigen (SLAA) and integrin 1, and down-regulated activity of alkaline phosphatase. After targeting M cells with iRGD peptide (cRGDKGPDC), the transport of nanoparticles increased. , the co-administration of iRGD could result in the increase of nanoparticles transported to the brain through the nasal cavity after intranasal administration. In the evaluation of immune effect , the nasal administration of OVA-PLGA/iRGD led to more release of IgG, IFN-, IL-2 and secretory IgA (sIgA) compared with OVA@PLGA group. Collectively, the study constructed M cell model, and proved the enhanced effect of targeting towards M cell with iRGD on improving nasal immunity.

GSH-responsive SN38 dimer-loaded shape-transformable nanoparticles with iRGD for enhancing chemo-photodynamic therapy

Accurate tumor targeting, deep penetration and superb retention are still the main pursuit of developing excellent nanomedicine. To achieve these requirements, a stepwise stimuli-responsive strategy was developed through co-administration tumor penetration peptide iRGD with shape-transformable and GSH-responsive SN38-dimer (d-SN38)-loaded nanoparticles (d-SN38@NPs/iRGD). Upon intravenous injection, d-SN38@NPs with high drug loading efficiency (33.92 ± 1.33%) could effectively accumulate and penetrate into the deep region of tumor sites with the assistance of iRGD. The gathered nanoparticles simultaneously transformed into nanofibers upon 650 nm laser irradiation at tumor sites so as to promote their retention in the tumor and burst release of reactive oxygen species for photodynamic therapy. The loaded d-SN38 with disulfide bond responded to the high level of GSH in tumor cytoplasm, which consequently resulted in SN38 release and excellent chemo-photodynamic effect on tumor.

Development and application of hyaluronic acid in tumor targeting drug delivery

Hyaluronic acid (HA) is a natural polysaccharide that has gained much attention due to its biocompatibility, enzyme degradation capacity and active tumor targeting capacity. Its receptor, CD44, is overexpressed in many kinds of cancers and is associated with tumor progress, infiltration and metastasis. Therefore, many researchers have developed various HA-based drug delivery systems for CD44-mediated tumor targeting. In this review, we systemically overview the basic theory of HA, its receptor and hyaluronidase, then we categorize the studies in HA-based drug delivery systems according to the functions of HA, including tumor-targeting materials, enzyme-sensitive biodegradable modality, pH-sensitive component, reduction-sensitive component, and the gel backbone. Finally, the perspective is discussed.

Theranostic nanoparticles with tumor-specific enzyme-triggered size reduction and drug release to perform photothermal therapy for breast cancer treatment

Although progress has been indeed made by nanomedicines, their efficacies for cancer treatment remain low, consequently leading to failures in translation to clinic. To improve the drug delivery efficiency, nanoparticles need to change size so as to fully utilize the enhanced permeability and retention (EPR) effect of solid tumor, which is the golden principle of nanoparticles used for cancer treatment. Herein, we employed cationic small-sized red emission bovine serum albumin (BSA) protected gold nanocluster (AuNC@CBSA, 21.06 nm) to both load indocyanine green (ICG) and act as imaging probe to realize theranostic. Then AuNC@CBSA-ICG was fabricated with negatively charged hyaluronic acid (HA) to form AuNC@CBSA-ICG@HA, which was about 200 nm to easily retain at tumor site and could be degraded by tumor-specific hyaluronidase into small nanoparticles for deep tumor penetration. The HA shell also endowed AuNC@CBSA-ICG@HA with actively targeting ability and hyaluronidase-dependent drug release. Furthermore, the quenching and recovery of fluorescence revealed the interaction between ICG and carrier, which was essential for the investigation of pharmacokinetic profiles. No matter or , AuNC@CBSA-ICG@HA showed markedly anti-tumor effect, and could suppress 95.0% of tumor growth on mice breast cancer model. All results demonstrated AuNC@CBSA-ICG@HA was potential for breast cancer therapy.

Recent progress in drug delivery

Drug delivery systems (DDS) are defined as methods by which drugs are delivered to desired tissues, organs, cells and subcellular organs for drug release and absorption through a variety of drug carriers. Its usual purpose to improve the pharmacological activities of therapeutic drugs and to overcome problems such as limited solubility, drug aggregation, low bioavailability, poor biodistribution, lack of selectivity, or to reduce the side effects of therapeutic drugs. During 2015-2018, significant progress in the research on drug delivery systems has been achieved along with advances in related fields, such as pharmaceutical sciences, material sciences and biomedical sciences. This review provides a concise overview of current progress in this research area through its focus on the delivery strategies, construction techniques and specific examples. It is a valuable reference for pharmaceutical scientists who want to learn more about the design of drug delivery systems.

Progress and perspectives on targeting nanoparticles for brain drug delivery

Due to the ability of the blood-brain barrier (BBB) to prevent the entry of drugs into the brain, it is a challenge to treat central nervous system disorders pharmacologically. The development of nanotechnology provides potential to overcome this problem. In this review, the barriers to brain-targeted drug delivery are reviewed, including the BBB, blood-brain tumor barrier (BBTB), and nose-to-brain barrier. Delivery strategies are focused on overcoming the BBB, directly targeting diseased cells in the brain, and dual-targeted delivery. The major concerns and perspectives on constructing brain-targeted delivery systems are discussed.

A cascade targeting strategy for brain neuroglial cells employing nanoparticles modified with angiopep-2 peptide and EGFP-EGF1 protein.

Targeted drug delivery to selected brain cell types is a crucial step in enhancing therapeutic effects while limiting side effects in non-target cells. Here we report on the development and evaluation of a new cascade targeting delivery system that employs PEG-PCL nanoparticles modified with both an angiopep-2 peptide and a EGFP-EGF1 protein for precise targeting of brain neuroglial cells. Angiopep-2 penetrates the blood-brain barrier and EGFP-EGF1 binds neuroglial cells, providing the system with two stages of targeting. In vitro studies demonstrated that both bEnd.3 cells and neuroglial cells had a higher uptake of angiopep-2 and EGFP-EGF1 conjugated nanoparticles (AENP) as compared to unmodified nanoparticles. Ex vivo imaging showed that AENP had higher accumulation in the brain over unmodified nanoparticles and EGFP-EGF1 modified nanoparticles. Fluorescent in situ hybridization of brain slides demonstrated that AENP co-localized with neuroglial cells. Transmission electron microscopy further showed that AENP could target and enter neuroglial cells. This newly developed cascade targeting delivery system that precisely targets neuroglial cells has great potential in the diagnosis and treatment of neuroglial related diseases. Replacing EGFP-EGF1 and angiopep-2 with other ligands may extend the utility of the system to diagnose and treat organ diseases beyond brain.

The construction of cell-penetrating peptide R8 and pH sensitive cleavable polyethylene glycols co-modified liposomes / 药学学报

The purpose of the study is to construct R8 peptide (RRRRRRRR) and pH sensitive polyethylene glycols (PEG) co-modified liposomes (Cl-Lip) and utilize them in breast cancer treatment. The co-modified liposomes were prepared with soybean phospholipid, cholesterol, DSPE-PEG2K-R8 and PEG5K-Hz-PE (pH sensitive PEG). The size and zeta potential of Cl-Lip were also characterized. The in vitro experiment demonstrated that the Cl-Lip had high serum stability in 50% fetal bovine serum. The cellular uptake of Cl-Lip under different pre-incubated conditions was evaluated on 4T1 cells. And the endocytosis pathway, lysosome escape ability and tumor spheroid penetration ability were also evaluated. The results showed the particle size of the Cl-Lip was (110.4 ± 5.2) nm, PDI of the Cl-Lip was 0.207 ± 0.039 and zeta potential of the Cl-Lip was (-3.46 ± 0.05) mV. The cellular uptake of Cl-Lip on 4T1 cells was pH sensitive, as the cellular uptake of Cl-Lip pre-incubated in pH 6.0 was higher than that of pH 7.4 under each time point. The main endocytosis pathways of Cl-Lip under pH 6.0 were micropinocytosis and energy-dependent pathway. At the same time, the Cl-Lip with pre-incubation in pH 6.0 had high lysosome escape ability and high tumor spheroid penetration ability. All the above results demonstrated that the Cl-Lip we constructed had high pH sensitivity and is a promising drug delivery system.

Fluorescent carbon dots and the application in biomedicine / 药学学报

As a new type of carbon nanomaterials, fluorescent carbon dots (fluorescent CDs) have many advantages when compared with the traditional fluorescent probes. They are photoluminescence stable and resistance to photo bleaching. Moreover, they are excellent in biocompatibility, low-toxic and easy to modify. All these above make them a promising optical image material as a probe in optical image. This article reviews structure, the common carbon sources, the preparation methods, and the light-emitting principles of the carbon dots. We also introduce the research progress of fluorescent carbon dots in biomedicine, and the problems need to be resolved in the study of fluorescent CDs.

A detachable coating of cholesterol-anchored PEG improves tumor targeting of cell-penetrating peptide-modified liposomes

Cell-penetrating peptides (CPPs) have been widely used to enhance the membrane translocation of various carriers for many years, but the non-specificity of CPPs seriously limits their utility in vivo. In this study, cholesterol-anchored, reduction-sensitive PEG (first synthesized by our laboratory) was applied to develop a co-modified liposome with improved tumor targeting. Following optimization of the formulation, the in vitro and in vivo properties of the co-modified liposome were evaluated. The co-modified liposome had a much lower cellular uptake and tumor spheroid uptake, but a much higher tumor accumulation compared to CPP-modified liposome, indicating the non-specific penetration of CPPs could be attenuated by the outer PEG coating. With the addition of exogenous reducing agent, both the in vitro and in vivo cellular uptake was markedly increased, demonstrating that the reduction-sensitive PEG coating achieved a controllable detachment from the surface of liposomes and did not affect the penetrating abilities of CPPs. The present results demonstrate that the combination of cholestervsitive PEG and CPPs is an ideal alternative for the application of CPP-modified carriers in vivo.

Cell penetrating peptide TAT and brain tumor targeting peptide T7 dual modified liposome preparation and in vitro targeting evaluation / 药学学报

The purpose of this study is to prepare T7 and TAT dual modified liposomes (T7-TAT-LIP) to penetrate through blood brain barrier and target to brain tumor cells. The liposomes were prepared with CFPE, T7 modified PEG-DSPE, TAT modified PEG-DSPE, soybean phospholipid, PEG-DSPE and cholesterol. The CFPE was used to track the cellular uptake efficiency. The density of T7 and TAT and the length of PEG were optimized, and then the liposomes were characterized by particle size, zeta potential, morphology and stability. Afterwards, the cellular uptake by bEnd.3 and C6 cells were evaluated. The results showed that the optimized parameters were 6% of T7, 0.5% of TAT, the molecular weight of PEG for T7 was 2000 and the molecular weight of PEG for TAT was 1000. After optimization, the particle size of T7-TAT-LIP was 118 nm, the zeta potential was -6.32 mV and the particles were spherical. The turbidity and particle size of liposomes were not obviously changed after 24 h incubation in PBS at 37 °C. The particle size and polydispersity index were also stable during 1 month incubation at 4-8 °C. The cellular uptake by both bEnd.3 and C6 cells of T7-TAT-LIP was higher than that of T7 or TAT modified liposomes, suggesting dual modified liposomes possessed better blood brain barrier targeting ability and brain tumor targeting ability than the single ligand modified liposomes.