Swin Transformer Improves the IDH Mutation Status Prediction of Gliomas Free of MRI-Based Tumor Segmentation.

Background: Deep learning (DL) could predict isocitrate dehydrogenase (IDH) mutation status from MRIs. Yet, previous work focused on CNNs with refined tumor segmentation. To bridge the gap, this study aimed to evaluate the feasibility of developing a Transformer-based network to predict the IDH mutation status free of refined tumor segmentation. Methods: A total of 493 glioma patients were recruited from two independent institutions for model development (TCIA; N = 259) and external test (AHXZ; N = 234). IDH mutation status was predicted directly from T2 images with a Swin Transformer and conventional ResNet. Furthermore, to investigate the necessity of refined tumor segmentation, seven strategies for the model input image were explored: (i) whole tumor slice; (ii-iii) tumor mask and/or not edema; (iv-vii) tumor bounding box of 0.8, 1.0, 1.2, 1.5 times. Performance comparison was made among the networks of different architectures along with different image input strategies, using area under the curve (AUC) and accuracy (ACC). Finally, to further boost the performance, a hybrid model was built by incorporating the images with clinical features. Results: With the seven proposed input strategies, seven Swin Transformer models and seven ResNet models were built, respectively. Based on the seven Swin Transformer models, an averaged AUC of 0.965 (internal test) and 0.842 (external test) were achieved, outperforming 0.922 and 0.805 resulting from the seven ResNet models, respectively. When a bounding box of 1.0 times was used, Swin Transformer (AUC = 0.868, ACC = 80.7%), achieved the best results against the one that used tumor segmentation (Tumor + Edema, AUC = 0.862, ACC = 78.5%). The hybrid model that integrated age and location features into images yielded improved performance (AUC = 0.878, Accuracy = 82.0%) over the model that used images only. Conclusions: Swin Transformer outperforms the CNN-based ResNet in IDH prediction. Using bounding box input images benefits the DL networks in IDH prediction and makes the IDH prediction free of refined glioma segmentation feasible.

Interfacial properties and micellization of triblock poly(ethylene glycol)-poly(ε-caprolactone)-polyethyleneimine copolymers.

This study aimed to explore the link between block copolymers' interfacial properties and nanoscale carrier formation and found out the influence of length ratio on these characters to optimize drug delivery system. A library of diblock copolymers of PEG-PCL and triblock copolymers with additional PEI (PEG-PCL-PEI) were synthesized. Subsequently, a systematic isothermal investigation was performed to explore molecular arrangements of copolymers at air/water interface. Then, structural properties and drug encapsulation in self-assembly were investigated with DLS, SLS and TEM. We found the additional hydrogen bond in the PEG-PCL-PEI contributes to film stability upon the hydrophobic interaction compared with PEG-PCL. PEG-PCL-PEI assemble into smaller micelle-like (such as PEG-PCL4006-PEI) or particle-like structure (such as PEG-PCL8636-PEI) determined by their hydrophilic and hydrophobic block ratio. The distinct structural architectures of copolymer are consistent between interface and self-assembly. Despite the disparity of constituent ratio, we discovered the arrangement of both chains guarantees balanced hydrophilic-hydrophobic ratio in self-assembly to form stable construction. Meanwhile, the structural differences were found to have significant influence on model drugs incorporation including docetaxel and siRNA. Taken together, these findings indicate the correlation between molecular arrangement and self-assembly and inspire us to tune block compositions to achieve desired nanostructure and drug loading.

Enhancing solid tumor therapy with sequential delivery of dexamethasone and docetaxel engineered in a single carrier to overcome stromal resistance to drug delivery.

Nanomedicines are often designed to target and treat solid tumors. Unfortunately, tumor and stroma composed of dense extracellular matrix, abnormal vascular barriers, elevated interstitial fluid pressure, et al., which impede the access and accumulation of nanomedicines into tumors. Strategies to disrupt these deterministic obstacles require a unique combination of promoter drugs and cytotoxic agents to target stroma and tumor simultaneously. Here, we engineered a novel strategy by co-delivery dexamethasone (DEX) and docetaxel (DTX) in the 2-in-1 liposome, namely (DEX + DTX)-Lip, with sequential release property. We proved that the engineered liposomal therapy approach could potentially achieve two objectives in tumor drug delivery: modulate tumor stroma and promote drug penetration and accumulation in tumor. Thus more DTX tenured in intratumoral site to kill tumor cells in a strong way with minimize systemic toxicity. The sequentially released liposomes won excellent antitumor efficacy in multifarious models, including KB, multidrug resistant KBv and metastatic 4 T1 tumor models and low toxicities compared with the combination of free drugs in vivo. Moreover, they demonstrated the potential of prevention tumor cells colonization and anti-metastasis in vivo models. These findings give insights in overcoming the deterministic stroma obstacles and provide a rational strategy to increase antitumor efficacy of combination nanomedicines with practical value.

Deepened cellular/subcellular interface penetration and enhanced antitumor efficacy of cyclic peptidic ligand-decorated accelerating active targeted nanomedicines.

INTRODUCTION: Acceleration and improvement of penetration across cell-membrane interfaces of active targeted nanotherapeutics into tumor cells would improve tumor-therapy efficacy by overcoming the issue of poor drug penetration. Cell-penetrating peptides, especially synthetic polyarginine, have shown promise in facilitating cargo delivery. However, it is unknown whether polyarginine can work to overcome the membrane interface in an inserted pattern for cyclic peptide ligand-mediated active targeting drug delivery. Here, we conducted a study to test the hypothesis that tandem-insert nona-arginine (tiR9) can act as an accelerating component for intracellular internalization, enhance cellular penetration, and promote antitumor efficacy of active targeted cyclic asparagine-glycine-arginine (cNGR)-decorated nanoliposomes. METHODS: Polyarginine was coupled with the polyethylene glycol (PEG) chain and the cNGR moiety, yielding a cNGR-tiR9-PEG2,000-distearoylphosphatidylethanolamine conjugate. RESULTS: The accelerating active targeted liposome (Lip) nanocarrier (cNGR-tiR9-Lip-doxorubicin [Dox]) constructed in this study held suitable physiochemical features, such as appropriate particle size of ~150 nm and sustained-release profiles. Subsequently, tiR9 was shown to enhance cellular drug delivery of Dox-loaded active targeted systems (cNGR-Lip-Dox) significantly. Layer-by-layer confocal microscopy indicated that the tandem-insert polyarginine accelerated active targeted system entry into deeper intracellular regions based on observations at marginal and center locations. tiR9 enhanced the penetration depth of cNGR-Lip-coumarin 6 through subcellular membrane barriers and caused its specific accumulation in mitochondria, endoplasmic reticulum, and Golgi apparatus. It was also obvious that cNGR-tiR9-Lip-Dox induced enhanced apoptosis and activated caspase 3/7. Moreover, compared with cNGR-Lip-Dox, cNGR-tiR9-Lip-Dox induced a significantly higher antiproliferative effect and markedly suppressed tumor growth in HT1080-bearing nude mice. CONCLUSION: This active tumor-targeting nanocarrier incorporating a tandem-insert polyarginine (tiR9) as an accelerating motif shows promise as an effective drug-delivery system to accelerate translocation of drugs across tumor-cell/subcellular membrane barriers to achieve improved specific tumor therapy.

Prior anti-CAFs break down the CAFs barrier and improve accumulation of docetaxel micelles in tumor.

BACKGROUND: Abnormal expression of stromal cells and extracellular matrix in tumor stroma creates a tight barrier, leading to insufficient extravasation and penetration of therapeutic agents. Cancer-associated fibroblasts (CAFs) take on pivotal roles encouraging tumor progression. METHOD: To surmount the refractoriness of stroma, we constructed a multi-targeting combined scenario of anti-CAFs agent tranilast and antitumor agent docetaxel micelles (DTX-Ms). Tranilast cut down crosstalk between tumor cells and stromal cells, ameliorated the tumor microenvironment, and enhanced the antiproliferation efficacy of DTX-Ms on cancer cells. RESULTS: Diverse experiments demonstrated that tranilast enhanced DTX-Ms' antitumor effect in a two-stage pattern by CAFs ablation, tumor cell migration blocking, and metastasis inhibition. Along with activated CAFs decreasing in vivo, the two-stage therapy succeeded in reducing interstitial fluid pressure, normalizing microvessels, improving micelles penetration and retention, and inhibiting tumor growth and metastasis. Interestingly, tranilast alone failed to inhibit tumor growth in vivo, and it could only be used as an adjuvant medicine together with an antitumor agent. CONCLUSION: Our proposed two-stage therapy offers a promising strategy to enhance antitumor effects by breaking down CAFs barrier and increasing micellar delivery efficiency.

Construction of Hyaluronic Tetrasaccharide Clusters Modified Polyamidoamine siRNA Delivery System.

The CD44 protein, as a predominant receptor for hyaluronan (HA), is highly expressed on the surface of multiple tumor cells. HA, as a targeting molecule for a CD44-contained delivery system, increases intracellular drug concentration in tumor tissue. However, due to the weak binding ability of hyaluronan oligosaccharide to CD44, targeting for tumor drug delivery has been restricted. In this study, we first use a HA tetrasaccharide cluster as the target ligand to enhance the binding ability to CD44. A polyamidoamine (PAMAM) dendrimer was modified by a HA tetrasaccharide cluster as a nonviral vector for small interfering RNA (siRNA) delivery. The dendrimer/siRNA nanocomplexes increased the cellular uptake capacity of siRNA through the CD44 receptor-mediated endocytosis pathway, allowing the siRNA to successfully escape the endosome/lysosome. Compared with the control group, nanocomplexes effectively reduced the expression of GFP protein and mRNA in MDA-MB-231-GFP cells. This delivery system provides a foundation to increase the clinical applications of PAMAM nanomaterials.

Intelligent "Peptide-Gathering Mechanical Arm" Tames Wild "Trojan-Horse" Peptides for the Controlled Delivery of Cancer Nanotherapeutics.

Cell-penetrating peptides (CPPs), also called "Trojan-Horse" peptides, have been used for facilitating intracellular delivery of numerous diverse cargoes and even nanocarriers. However, the lack of targeting specificity ("wildness" or nonselectivity) of CPP-nanocarriers remains an intractable challenge for many in vivo applications. In this work, we used an intelligent "peptide-gathering mechanical arm" (Int PMA) to curb CPPs' wildness and enhance the selectivity of R9-liposome-based cargo delivery for tumor targeting. The peptide NGR, serving as a cell-targeting peptide for anchoring, and peptide PLGLAG, serving as a substrate peptide for deanchoring, were embedded in the Int PMA motif. The Int PMA construct was designed to be sensitive to tumor microenvironmental stimuli, including aminopeptidase N (CD13) and matrix metalloproteinases (MMP-2/9). Moreover, Int PMA could be specifically recognized by tumor tissues via CD13-mediated anchoring and released for cell entry by MMP-2/9-mediated deanchoring. To test the Int PMA design, a series of experiments were conducted in vitro and in vivo. Functional conjugates Int PMA-R9-poly(ethylene glycol) (PEG)2000-distearoylphosphatidyl-ethanolamine (DSPE) and R9-PEG2000-DSPE were synthesized by Michael addition reaction and were characterized by thin-layer chromatography and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. The Int PMA-R9-modified doxorubicin-loaded liposomes (Int PMA-R9-Lip-DOX) exhibited a proper particle diameter (approximately 155 nm) with in vitro sustained release characteristics. Cleavage assay showed that Int PMA-R9 peptide molecules could be cleaved by MMP-2/9 for completion of deanchoring. Flow cytometry and confocal microscopy studies indicated that Int PMA-R9-Lip-DOX can respond to both endogenous and exogenous stimuli in the presence/absence of excess MMP-2/9 and MMP-2/9 inhibitor (GM6001) and effectively function under competitive receptor-binding conditions. Moreover, Int PMA-R9-Lip-DOX generated more significant subcellular dispersions that were especially evident within endoplasmic reticulum (ER) and Golgi apparatus. Notably, Int PMA-R9-Lip-DOX could induce enhanced apoptosis, during which caspase 3/7 might be activated. In addition, Int PMA-R9-Lip-DOX displayed enhanced in vitro and in vivo antitumor efficacy versus "wild" R9-Lip-DOX. On the basis of investigations at the molecular level, cellular level, and animals' level, the control of Int PMA was effective and promoted selective delivery of R9-liposome cargo to the target site and reduced nonspecific uptake. This Int PMA-controlled strategy based on aminopeptidase-guided anchoring and protease-triggered deanchoring effectively curbed the wildness of CPPs and bolstered their effectiveness for in vivo delivery of nanotherapeutics. The specific nanocarrier delivery system used here could be adapted using a variety of intelligent designs based on combinations of multifunctional peptides that would specifically and preferentially bind to tumors versus nontumor tissues for tumor-localized accumulation in vivo. Thus, CPPs have a strong advantage for the development of intelligent nanomedicines for targeted tumor therapy.

Treating metastatic triple negative breast cancer with CD44/neuropilin dual molecular targets of multifunctional nanoparticles.

Metastasis of cancer makes up the vast majority of cancer-related deaths, and it usually initiates from tumor cells invasiveness and develops through tumor neovasculature. In this work, we have fabricated a CD44/neuropilin dual receptor-targeting nanoparticulate system (tLyP-1-HT NPs) with endogenous or FDA approved components for treating metastatic triple negative breast cancer (TNBC). The enhanced specific targeting of tLyP-1-HT NPs to both metastatic tumor cells and metastasis-supporting tumor neovasculature was contributed by means of CD44/neuropilin dual receptor-mediated interaction. The NPs not only effectively suppress the invasive capability of tumor cells themselves, but also significantly restrain the metastasis incidence via extravasation as well as the eventual colonization in lungs. In all the three types of TNBC-bearing mice models, orthotopic, post-metastasis and metastasis prevention models, the docetaxel-loaded tLyP-1-HT NPs exhibited markedly enhanced anti-tumor and anti-metastasis efficacy. The inhibitory rates of tLyP-1-HT NPs against orthotopic tumor growth and lung metastasis achieved 79.6% and 100%, respectively. The metastasis inhibition rate and life extension rate of the tLyP-1-HT NPs against post-pulmonary metastasis mice reached 85.1% and up to 62.5%, respectively. All the results demonstrated the designed dual receptor-targeting multifunctional NPs hold great potential in treating metastatic TNBC and lung metastasis.

Combination therapy with micellarized cyclopamine and temozolomide attenuate glioblastoma growth through Gli1 down-regulation.

Glioblastoma multiforme (GBM) is the most common and deadly brain cancer, characterized by its aggressive proliferation to adjacent tissue and high recurrence rate. We studied the efficacy and related mechanisms of the combination of cyclopamine (Cyp, a Sonic-hedgehog pathway (Shh) inhibitor) and temozolomide (TMZ, the clinically most used chemotherapeutic agent) in anti-GBM treatment. The micellarized Cyp (MCyp) showed better performance than Cyp solution in inhibiting GBM cells proliferation (3.77-fold against U87 MG cells and 3.28-fold against DBTRG-05MG cells) and clonogenity (1.35-fold against U87 MG cells and 2.17-fold against DBTRG-05MG cells), and preferred behavior of inhibiting cell invasion, colony formation through attenuated Gli1 expression. In addition, combination of MCyp and TMZ exhibited synergistic cytotoxicity, correlating with their ability in inducing apoptosis and eliminating neurospheres formation, and the combination of TMZ was accompanied with the enhanced blockage of Shh pathway. The optimal ratio of MCyp combined to TMZ was 1:20. So we proposed to use TMZ to kill tumor parenchyma and MCyp as the cancer stem cells inhibitor to resist tumor recurrence. These findings demonstrated that combination of TMZ with micellarized Cyp is a promising strategy for exerting different functions of drugs for tumor treatment.

Enhancing siRNA-based cancer therapy using a new pH-responsive activatable cell-penetrating peptide-modified liposomal system.

As a potent therapeutic agent, small interfering RNA (siRNA) has been exploited to silence critical genes involved in tumor initiation and progression. However, development of a desirable delivery system is required to overcome the unfavorable properties of siRNA such as its high degradability, molecular size, and negative charge to help increase its accumulation in tumor tissues and promote efficient cellular uptake and endosomal/lysosomal escape of the nucleic acids. In this study, we developed a new activatable cell-penetrating peptide (ACPP) that is responsive to an acidic tumor microenvironment, which was then used to modify the surfaces of siRNA-loaded liposomes. The ACPP is composed of a cell-penetrating peptide (CPP), an acid-labile linker (hydrazone), and a polyanionic domain, including glutamic acid and histidine. In the systemic circulation (pH 7.4), the surface polycationic moieties of the CPP (polyarginine) are "shielded" by the intramolecular electrostatic interaction of the inhibitory domain. When exposed to a lower pH, a common property of solid tumors, the ACPP undergoes acid-catalyzed breakage at the hydrazone site, and the consequent protonation of histidine residues promotes detachment of the inhibitory peptide. Subsequently, the unshielded CPP would facilitate the cellular membrane penetration and efficient endosomal/lysosomal evasion of liposomal siRNA. A series of investigations demonstrated that once exposed to an acidic pH, the ACPP-modified liposomes showed elevated cellular uptake, downregulated expression of polo-like kinase 1, and augmented cell apoptosis. In addition, favorable siRNA avoidance of the endosome/lysosome was observed in both MCF-7 and A549 cells, followed by effective cytoplasmic release. In view of its acid sensitivity and therapeutic potency, this newly developed pH-responsive and ACPP-mediated liposome system represents a potential platform for siRNA-based cancer treatment.

Taming the Wildness of "Trojan-Horse" Peptides by Charge-Guided Masking and Protease-Triggered Demasking for the Controlled Delivery of Antitumor Agents.

Cell-penetrating peptide (CPP), also called "Trojan Horse" peptide, has become a successful approach to deliver various payloads into cells for achieving the intracellular access. However, the "Trojan Horse" peptide is too wild, not just to "Troy", but rather widely distributed in the body. Thus, there is an urgent need to tame the wildness of "Trojan Horse" peptide for targeted delivery of antineoplastic agents to the tumor site. To achieve this goal, we exploit a masked CPP-doxorubicin conjugate platform for targeted delivery of chemotherapeutic drugs using charge-guided masking and protease-triggered demasking strategies. In this platform, the cell-penetrating function of the positively CPP (d-form nonaarginine) is abrogated by a negatively shielding peptide (masked CPP), and between them is a cleavable substrate peptide by the protease (MMP-2/9). Protease-triggered demasking would occur when the masked CPP reached the MMP-2/9-riched tumor. The CPP-doxorubicin conjugate (CPP-Dox) and the masked CPP-Dox conjugate (mCPP-Dox) were used as models for the evaluation of masking and demasking processes. It was found that exogenous MMP-2/9 could effectively trigger the reversion of CPP-cargo in this conjugate, and this trigger adhered to the Michaelis-Menten kinetics profile. This conjugate was sensitive to the trigger of endogenous MMP-2/9 and could induce enhanced cytotoxicity toward MMP-2/9-rich tumor cells. In vivo antitumor efficacy revealed that this masked conjugate had considerable antitumor activity and could inhibit the tumor growth at a higher level relative to CPP-cargo. Low toxicity in vivo showed the noticeably decreased wildness of this conjugate toward normal tissues and more controllable entry of antitumor agents into "Troy". On the basis of analyses in vitro and in vivo, this mCPP-cargo conjugate delivery system held an improved selectivity toward MMP-2/9-rich tumors and would be a promising strategy for tumor-targeted treatment.

Delivering siRNA and Chemotherapeutic Molecules Across BBB and BTB for Intracranial Glioblastoma Therapy.

For aggressive brain glioblastoma, the therapy is significantly impaired by blood-brain barrier (BBB) and blood-tumor barrier (BTB). Choosing more than one target from the pool of tumor-stroma interactions is profoundly beneficial to therapeutic approaches. Thus, a multifunctional liposomal system based on anchoring two receptor-specific and penetrable peptides was designed for the combination delivery of BBB-impermeable siRNA and chemotherapeutic docetaxel to brain glioblastoma. Both macroscopic and microscopic specific distributions and targeting effect of the liposomes in the intracranial glioblastoma were confirmed. Superiority in therapeutic efficacies of the siRNA and DTX combination delivery system was revealed from encouraged VEGF gene silencing, tumor cell apoptosis, prolonged survival time, subdued glioblastoma cells in intracranial glioblastoma, and negligible system toxicities after systemic application. Furthermore, the liposomes made better modulation of glioblastoma microenvironment such as the down-regulation of CD31-positive tumor vessels and HIF-1α expression. The transport mechanism of the liposomes delivering the cargos across BBB via receptor-mediated transcytosis without destroying the integrity of BBB has been evaluated from in vitro and in vivo. Therefore, the dual peptides-modified liposomal system provides a safe and noninvasive approach for the delivery of siRNA and chemotherapeutic molecules across the BBB and BTB to target therapy of brain glioblastoma.

Synthetic low-density lipoprotein (sLDL) selectively delivers paclitaxel to tumor with low systemic toxicity.

Low density lipoprotein (LDL), which is a principal carrier for the delivery of cholesterol, has been used as a great candidate for the delivery of drugs to tumor based on the great requirements for cholesterol of many cancer cells. Mimicking the structure and composition of LDL, we designed a synthetic low-density lipoprotein (sLDL) to encapsulate paclitaxel-alpha linolenic acid (PALA) for tumor therapy. The PALA loaded sLDL (PALA-sLDL) and PALA-loaded microemulsion (PALA-ME, without the binding domain for LDLR) displayed uniform sizes with high drug loading efficiency (> 90%). In vitro studies demonstrated PALA-sLDL exhibited enhanced cellular uptake capacity and better cytotoxicity to LDLR over-expressed U87 MG cells as compared to PALA-ME. The uptake mechanisms of PALA-sLDL were involved in a receptor mediated endocytosis and macropinocytosis. Furthermore, the in vivo biodistribution and tumor growth inhibition studies of PALA-sLDL were investigated in xenograft U87 MG tumor-bearing mice. The results showed that PALA-sLDL exhibited higher tumor accumulation than PALA-ME and superior tumor inhibition efficiency (72.1%) compared to Taxol® (51.2%) and PALA-ME (58.8%) but with lower toxicity. These studies suggested that sLDL is potential to be used as a valuable carrier for the selective delivery of anticancer drugs to tumor with low systemic toxicity.

Tumor-specific penetrating peptides-functionalized hyaluronic acid-d-α-tocopheryl succinate based nanoparticles for multi-task delivery to invasive cancers.

Poor site-specific delivery and incapable deep-penetration into tumor are the intrinsic limitations to successful chemotherapy. Here, the tumor-homing penetrating peptide tLyP-1-functionalized nanoparticles (tLPTS/HATS NPs), composed of two modularized amphiphilic conjugates of tLyP-1-PEG-TOS (tLPTS) and TOS-grafted hyaluronic acid (HATS), had been fabricated for tumor-targeted delivery of docetaxel (DTX). The prepared tLPTS/HATS NPs had about 110 nm in mean diameter, high drug encapsulation efficiency (93%), and sustained drug release behavior. In vitro studies demonstrated that the tLPTS/HATS NPs exhibited enhanced intracellular delivery and much better anti-invasion ability, cytotoxicity, and apoptosis against both invasive PC-3 and MDA-MB-231 cells as compared to the non-tLyP-1-functionalized HATS NPs. The remarkable penetrability and inhibitory effect on both PC-3 and MDA-MB-231 multicellular tumor spheroids were also identified for the tLPTS/HATS NPs. In vivo biodistribution imaging demonstrated the tLPTS/HATS NPs possessed much more lasting accumulation and extensive distribution throughout tumor regions than the HATS NPs. The higher in vivo therapeutic efficacy with lower systemic toxicity of the tLPTS/HATS NPs was also verified by the PC-3 xenograft model in athymic nude mice. These results suggested that the designed novel tLPTS/HATS NPs were endowed with tumor recognition, internalization, penetration, and anti-invasion, and thus might be a promising anticancer drug delivery vehicle for targeted cancer therapy.

[The application of enzyme-sensitive activatable cell-penetrating peptides to targeted delivery system].

Cell-penetrating peptides (CPPs) offer a non-selective and receptor-independent mode to promote cellular uptake. Although the non-specificity of CPP-mediated internalization allows this approach applicable to a wide range of tumor types potentially, their universality is a significant obstacle to their clinical utility for targeted delivery of cancer therapeutics and imaging agents. Accordingly, many reports have focused on selective switching of systemically delivered inert CPPs into their active form in lesions (tumor). In this review, our attention is mainly confined to such an enzyme-sensitive domain incorporated delivery system with activatable CPPs (ACPPs), which have displayed the exciting strength in balancing the CPPs' pros and cons, and potential in the treatment and diagnosis of some diseases.

Enhance Cancer Cell Recognition and Overcome Drug Resistance Using Hyaluronic Acid and α-Tocopheryl Succinate Based Multifunctional Nanoparticles.

Multidrug resistance (MDR) presents a clinical obstacle to cancer chemotherapy. The main purpose of this study was to evaluate the potential of a hyaluronic acid (HA) and α-tocopheryl succinate (α-TOS) based nanoparticle to enhance cancer cell recognition and overcome MDR, and to explore the underlying mechanisms. A multifunctional nanoparticle, HTTP-50 NP, consisted of HA-α-TOS (HT) conjugate and d-α-tocopheryl polyethylene glycol succinate (TPGS) with docetaxel loaded in its hydrophobic core. The promoted tumor cell recognition and accumulation, cytotoxicity, and mitochondria-specific apoptotic pathways for the HTTP-50 NP were confirmed in MCF-7/Adr cells (P-gp-overexpressing cancer model), indicating that the formulated DTX and the conjugated α-TOS in the HTTP-50 NP could synergistically circumvent the acquired and intrinsic MDR in MCF-7/Adr cells. In vivo investigation on the MCF-7/Adr xenografted nude mice models confirmed that HTTP-50 NP possessed much higher tumor tissue accumulation and exhibited pronouncedly enhanced antiresistance tumor efficacy with reduced systemic toxicity compared with HTTP-0 NP and Taxotere. The mechanisms of the multifunctional HTTP-50 NP to overcome MDR and enhance antiresistance efficacy may be contributed by CD44 receptor-targeted delivery and P-gp efflux inhibition, and meanwhile to maximize antitumor efficacy by synergism of DTX and mitocan of α-TOS killing tumor cells.

Roles of ligand and TPGS of micelles in regulating internalization, penetration and accumulation against sensitive or resistant tumor and therapy for multidrug resistant tumors.

There are several obstacles in the process of successful treatment of malignant tumors, including toxicity to normal cells, inefficiency of drug permeation and accumulation into the deep tissue of solid tumor, and multidrug resistance (MDR). In this work, we prepared docetaxel (DTX)-loaded hybrid micelles with DSPE-PEG and TPGS (TPGS/DTX-M), where TPGS serves as an effective P-gp inhibitor for overcoming MDR, and active targeting hybrid micelles (FA@TPGS/DTX-M) with targeting ligand of folate on the hybrid micelles surface offering active targeting to folate receptor-overexpressed tumor cells. A systematic comparative evaluation of these micelles on cellular internalization, sub-cellular distribution, antiproliferation, mitochondrial membrane potential, cell apoptosis and cell cycle, permeation and inhibition on 3-dimensional multicellular tumor spheroids, as well as antitumor efficacy and safety assay in vivo were well performed between sensitive KB tumors and resistant KBv tumors, and among P-gp substrate or not. We found that the roles of folate and TPGS varied due to the sensitivity of tumors and the loaded molecules in the micelles. Folate and folate receptor-mediated endocytosis played a leading role in internalization, permeation and accumulation for sensitive tumors and non-substrates of P-gp. On the contrary, TPGS played the predominant role which dramatically decreased the efflux of drugs both when the tumor is resistant and for P-gp substrate. These findings are very meaningful for guiding the design of carrier delivery system to treat tumors. The antitumor efficacy in xenograft nude mice model and safety assay showed that the TPGS/DTX-M and FA@TPGS/DTX-M significantly exhibited higher antitumor activity against resistant KBv tumors than the marketed formulation and normal micelles owing to the small size (approximately 20 nm), hydrophilic PEGylation, TPGS inhibition of P-gp function, and folate receptor-modified endocytosis, permeation and accumulation in solid tumor, as well as synergistic effects of DTX-induced cell division inhibition, growth restraint and TPGS-triggered mitochondrial apoptosis in tumor cells. In conclusion, folate-modified TPGS hybrid micelles provide a synergistic strategy for effective delivery of DTX into KBv cells and overcoming MDR.

Therapeutic potential of targeted multifunctional nanocomplex co-delivery of siRNA and low-dose doxorubicin in breast cancer.

Malignant tumors remain a major health burden throughout the world, and effective therapeutic strategies are urgently needed. Combining gene therapy with chemotherapeutics in a single delivery system is more effective than co-treatment of cancer with individual delivery systems carrying either gene or drug. In this study, a multifunctional folate-decorated and pH-responsive PHD/PPF/siVEGF nanocomplex is developed via a self-assembly process utilizing ternary pre-functionalized polymers with vascular endothelial growth factor targeted siRNA. Antitumor effects of the combination therapy are evaluated in both in vitro and in vivo orthotopic xenograft models of breast cancer with systemic administration. The improved therapeutic response was supported by the observation of over 70% and 55% down-regulation of VEGF mRNA expressed in vitro and in vivo, effective antiproliferation and inhibition of tumor spheroids in vitro, significant decrease in tumor microvessel density in vivo, dramatic increase in life span of mice with a tumor xenograft and a decrease in toxicity in vivo. In addition, the current studies demonstrated the potential of combination of antiangiogenic therapy of siVEGF and killing off tumor cells of DOX, with the incorporation of tumor microenvironment sensitivity and target modified into a single nanoparticulate formulation for profound therapeutic effect.

Tumor-targeting dual peptides-modified cationic liposomes for delivery of siRNA and docetaxel to gliomas.

Combinations of drugs promoting anti-angiogenesis and apoptosis effects are meaningful for cancer therapy. In the present study, dual peptides-modified liposomes were designed by attaching two receptor-specific peptides, specifically low-density lipoprotein receptor-related protein receptor (Angiopep-2) and neuropilin-1 receptor (tLyP-1) for brain tumor targeting and tumor penetration. Vascular endothelial growth factor (VEGF) siRNA and chemotherapeutic docetaxel (DTX) were chosen as the two payloads because VEGF is closely associated with angiogenesis, and DTX can kill tumor cells efficiently. Binding to glioma cells, co-delivery of siRNA and DTX in human glioblastoma cells (U87 MG) and murine brain microvascular endothelial cells (BMVEC), VEGF gene silencing, antiproliferation and anti-tumor effects of the dual peptides-modified liposomes were evaluated in vitro and in vivo. The dual peptides-modified liposomes persisted the binding ability to glioma cells, enhanced the internalization via specific receptor mediated endocytosis and tissue penetration, thus the dual peptides-modified liposomes loading VEGF siRNA and DTX possessed stimulative gene silencing and antiproliferation activity compared with non-modified and single peptide-modified liposomes. The co-delivery research revealed different intracellular behavior of hydrophilic large molecular and lipophilic small molecule, the former involves endocytosis and subsequent escape of endosome/lysosomes, while the latter experiences passive diffusion of lipophilic small drugs after its release. Furthermore, the dual peptides-modified liposomes showed superiority in anti-tumor efficacy, combination of anti-angiogenesis by VEGF siRNA and apoptosis effects by DTX, after both intratumor and system application against mice with U87 MG tumors, and the treatment did not activate system-associated toxicity or the innate immune response. Combination with the dual peptides-guided tumor homing and penetration, the dual peptides-modified liposomes provide a strategy for effective targeting delivery of siRNA and DTX into the glioma cell and inhibition of tumor growth in a synergistic manner.

PSA-responsive and PSMA-mediated multifunctional liposomes for targeted therapy of prostate cancer.

In the hormone-refractory stage of prostate cancer (PC), the expression of prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) often remains highly active. Accumulating studies have demonstrated that these two proteins are attractive targets for specific delivery of functional molecules to advanced PC, not merely as potential sensitive markers for PC detection. In this study, we constructed a dual-modified liposome that incorporated PSA-responsive and PSMA-mediated liposomes and potentially offers double selectivity for PC. The folate moiety binds quickly to PSMA-positive tumors, and the PSA-responsive moiety is cleaved by PSA that was enriched in tumor tissues. The activated liposomes (folate and cell-penetrating peptides dual-modifications) are subsequently taken up by the tumor cells via polyarginine's penetrating effects and receptor-mediated endocytosis. To corroborate these assumptions, a series of experiments were conducted, including PSA-responsive peptide hydrolysis kinetics, cellular uptake, internalization mechanism and escape from endosomes in PC-3 and/or 22Rv1 cells, biodistribution and antitumor activity of siRNA-loaded liposomes after systemic administration, gene silencing and cell apoptosis in vitro and in vivo. The results reveal that multivalent interactions play a key role in enhancing PC cell recognition and uptake while reducing nonspecific uptake. The dual-modified liposomes carrying small interfering RNA (siRNA) have significant advantages over the control liposomes, including single-modified (folate, CPP, PSA-responsive only) and non-modified liposomes. The dual-modified liposomes elevated cellular uptake, downregulated expression of polo-like kinase 1 (PLK-1) and augmented cell apoptosis in prostate tumor cells. The entry of the dual-modified liposomes into 22Rv1 cells occurred via multiple endocytic pathways, including clathrin-mediated endocytosis and macropinocytosis, followed by an effective endosomal escape of the entrapped siRNA into the cytoplasm. In vivo studies conducted on a 22Rv1 xenograft murine model demonstrated that the dual-modified liposomes demonstrated the maximized accumulation, retention and knockdown of PLK-1 in tumor cells, as well as the strongest inhibition of tumor growth and induction of tumor cell apoptosis. In terms of targeting capacity and therapeutic potency, the combination of a PSA-responsive and PSMA-mediated liposome presents a promising platform for therapy and diagnosis of PSMA/PSA-positive PC.