Biodegradable mixed MPEG-SS-2SA/TPGS micelles for triggered intracellular release of paclitaxel and reversing multidrug resistance

Construction and evaluation of a nanosystem that combines acidification promoted chemodynamic therapy and intracellular drug release monitoring

Triple-negative breast cancer (TNBC) is a highly invasive subtype of breast cancer that seriously affects women's physical and mental health. Chemodynamic therapy (CDT) induces cell death by specifically generating Fenton/Fenton-like reactions within tumor cells. However, the weak acidity of the tumor microenvironment (TME) greatly weakens the effectiveness of CDT. This work constructed a kind of P-CAIDF/PT nanoparticles (NPs), composed of two Pluronic F127 (PF127) based polymers: one was PF127-CAI (P-CAI), composed by connecting PF127 with the carbonic anhydrase IX (CA IX) inhibitor (CAI); the other was PF127-SS-TPE (PT), composed of PF127 and the aggregation-induced emission molecule, tetraphenylethylene (TPE), via the linkage of disulfide bonds. The two polymers were employed to construct the doxorubicin (DOX) and ferrocene (Fc) co-loaded P-CAIDF/PT NPs through the film dispersion method. After being administrated via i.v., P-CAIDF/PT could be accumulated in the TME by the enhanced permeability and retention (EPR) effect and engulfed by tumor cells. P-CAI induced intracellular acidification by inhibiting the overexpressed CA IX, thus promoting CDT by enhancing the Fc-mediated Fenton reaction. The acidification-enhanced CDT combined with the DOX-mediated chemotherapy could improve the therapeutic effect on TNBC. Moreover, P-CAIDF/PT also monitored the intracellular drug release processes through the fluorescence resonance energy transfer (FRET) effect depending on the inherent DOX/TPE pair. In conclusion, the P-CAIDF/PT nanosystem can achieve the combination therapy of acidification-enhanced CDT and chemotherapy as well as therapy monitoring, thus providing new ideas for the design and development of TNBC therapeutic agents.

A reliable elasticity sensing method for analysis of cell entosis using microfluidic cytometer

Cell entosis is a novel cell death process starting from cell-in-cell invasion. In general, cancer cells own higher incidence rate of cell entosis comparing to non-cancerous cells. Studies arguing whether cell entosis is a tumor suppressing process or a tumor accelerating process can deepen our understanding of tumor development. Cell elasticity is recognized as one of tumor malignant biomarkers. There have been some researchers studying cell elasticity in cell entosis. However, existing cell elasticity sensing technique (i.e. micropipette aspiration) can hardly be reliable neither high-throughput. In this work, we introduce an elasticity sensing method for quantifying both cell elasticity in cell-in-cell structures and single floating cells using a microfluidic cytometer. We not only argue our cell elasticity sensing method is reliable for already occurred entosis but also apply such method on predicting the "outer" cells in entosis of different cell types. The elasticity sensing method proposed in this manuscript is able to provide an effective and reliable way to further study deeper mechanism in cell entosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13534-023-00264-0.

Modification of α-Tocopherol Succinate with a Tumor-targeting Peptide Conjugate Enhances the Antitumor Efficacy of a Paclitaxel-loaded Lipid Aggregate

Paclitaxel (PTX) is a widely used chemotherapeutic agent in the clinic. However, its clinical benefit is limited due to its low water solubility, off-target toxicity, and for being a multidrug-resistant (MDR) substrate. To overcome these limitations in this study, a tumor-targeting peptide (CRGDK peptide, a ligand for NRP-1 receptor) conjugate of α-tocopheryl succinate (α-TOS) was synthesized and modified on PTX-loaded lipid aggregate (TL-PTX) to leverage the benefits of α-TOS, which include a) anti-cancer activity, b) increased PTX loading, and c) inhibition of MDR activity. Use of peptide conjugate of α-TOS (α-TOS-CRGDK) in lipid aggregate increased PTX entrapment efficiency by 20%, helped in NRP-1 specific cellular uptake and significantly enhanced apoptotic and cell killing activity (p <0.01) of PTX compared to control formulation (CL-PTX) by inhibiting MDR-activity in melanoma resulting in ∼70% increment in overall survival of melanoma tumor-bearing mice. In conclusion, CRGDK- α-TOS conjugate in association with PTX-loaded liposome provided a unique NRP-1 targeted, drug-resistant reversing anticancer regimen for treating aggressive melanoma.

Biodegradable Polymeric Nanoparticles for Drug Delivery to Solid Tumors

Advances in nanotechnology have favored the development of novel colloidal formulations able to modulate the pharmacological and biopharmaceutical properties of drugs. The peculiar physico-chemical and technological properties of nanomaterial-based therapeutics have allowed for several successful applications in the treatment of cancer. The size, shape, charge and patterning of nanoscale therapeutic molecules are parameters that need to be investigated and modulated in order to promote and optimize cell and tissue interaction. In this review, the use of polymeric nanoparticles as drug delivery systems of anticancer compounds, their physico-chemical properties and their ability to be efficiently localized in specific tumor tissues have been described. The nanoencapsulation of antitumor active compounds in polymeric systems is a promising approach to improve the efficacy of various tumor treatments.

Recent Advances of D-α-tocopherol Polyethylene Glycol 1000 Succinate Based Stimuli-responsive Nanomedicine for Cancer Treatment

D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) is a pharmaceutical excipient approved by Chinese NMPA and FDA of USA. It's widely applied as a multifunctional drug carrier for nanomedicine. The advantages of TPGS include P-glycoprotein (P-gp) inhibition, penetration promotion, apoptosis induction via mitochondrial-associated apoptotic pathways, multidrug resistant (MDR) reversion, metastasis inhibition and so on. TPGS-based drug delivery systems which are responding to external stimulus can combine the inhibitory functions of TPGS towards P-gp with the environmentally responsive controlled release property and thus exerts a synergistic anti-cancer effect, through increased intracellular drug concentration in tumors cells and well-controlled drug release behavior. In this review, TPGS-based nano-sized delivery systems responsive to different stimuli were summarized and discussed, including pH-responsive, redoxresponsive and multi-responsive systems in various formulations. The achievements, mechanisms and different characteristics of TPGS-based stimuli-responsive drug-delivery systems in tumor therapy were also outlined.

Icariin protects against sodium azide-induced neurotoxicity by activating the PI3K/Akt/GSK-3β signaling pathway

Background

Icariin (ICA) is one of the major active flavonoids extracted from the traditional Chinese herb Epimedium brevicornum Maxim and has been shown to have neuroprotective effects. This study was designed to investigate the effect of ICA on sodium azide (NaN₃)-induced rat adrenal pheochromocytoma (PC12) cell damage and to further examine the underlying mechanisms.

Methods

To explore its possible mechanism, we used NaN₃ (50 mM)-induced neuronal PC12 cell damage. Cell viability was evaluated by CCK-8 and lactate dehydrogenase (LDH) assays. Mitochondrial membrane potential (MMP) was detected by JC-1. Glucose concentration was assessed by the glucose oxidase method. The role of ICA in the PI3K/Akt/GSK-3β signaling pathway was explored by Western blotting.

Results

The results indicate that pretreatment with ICA reduced NaN₃-induced cell damage and significantly reduced the leakage rate of LDH in PC12 cells. ICA pretreatment increased the MMP and a decrease in glucose concentration indicate increased glucose consumption. Furthermore, the protein levels of p-PI3K (p85), PI3K-110α, p-Ser473-Akt and p-Ser9-GSK-3β were markedly decreased in PC12 cells after NaN₃ treatment for 24 h, whereas these effects were reverted after pretreatment with ICA. Tau phosphorylation at the Ser396/404 and Thr217 sites was significantly decreased by pretreatment with ICA.

Conclusions

These results suggest that ICA protects against NaN₃-induced neurotoxicity in PC12 cells by activating the PI3K/Akt/GSK-3β signaling pathway.

Regulating intracellular ROS signal by a dual pH/reducing-responsive nanogels system promotes tumor cell apoptosis

Purpose: The levels of reactive oxygen species (ROS) in tumor cells are much higher than that in normal cells, and rise rapidly under the influence of exogenous or endogenous inducing factors, eventually leading to the apoptosis of tumor cells. Therefore, this study prepared a dual pH/reducing-responsive poly (N-isopropylacrylamide-co-Cinnamaldehyde-co-D-α-tocopheryl polyethylene glycol 1000 succinate, PssNCT) nanogels, which employed two exogenous ROS inducers, cinnamaldehyde (CA) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), to selectively induce apoptosis by regulating ROS levels in tumor cells. Methods: The PssNCT nanogels were prepared by the free radical precipitation polymerization under the crosslink between pH-sensitive hydrazone and reducing-sensitive disulfide bonds, followed by the physicochemical and morphological characteristics investigations. Plasma stability, dual pH/reducing responsive degradation and in vitro release were also assessed. In cell experiments, cytotoxicity in different cells were first detected. The intracellular ROS levels and mitochondrial functions of tumor cells were then evaluated. Moreover, the apoptosis and western-blot assays were employed to verify the association between ROS levels elevation and apoptosis in tumor cells. Results: The nanogels exhibited a round-like hollow structure with the diameter smaller than 200nm. The nanogels were stable in plasma, while showed rapid degradation in acidic and reducing environments, thus achieving significant release of CA and TPGS in these media. Furthermore, the sufficient amplification of ROS signals was induced by the synergistically function of CA and TPGS on mitochondria, which resulted in the opening of the mitochondrial apoptotic pathway and enhanced cytotoxicity on MCF-7 cells. However, nanogels barely affected L929 cells owing to their lower intracellular ROS basal levels. Conclusion: The specific ROS regulation method achieved by these nanogels could be explored to selectively kill tumor cells according to the difference of ROS signals in different kinds of cells.

Mechanical Characterization of 3D Ovarian Cancer Nodules Using Brillouin Confocal Microscopy

Introduction

The mechanical interaction between cells and their microenvironment is emerging as an important determinant of cancer progression and sensitivity to treatment, including in ovarian cancer (OvCa). However, current technologies limit mechanical analysis in 3D culture systems. Brillouin Confocal Microscopy is an optical non-contact method to assess the mechanical properties of biological materials. Here, we validate the ability of this technology to assess the mechanical properties of 3D tumor nodules.

Methods

OvCa cells were cultured in 3D using two established methods: (1) overlay cultures on Matrigel; (2) spheroids in ultra-low attachment plates. To alter the mechanical state of these tumors, nodules were immersed in PBS with varying levels of sucrose to induce osmotic stress. Next, nodule mechanical properties were measured by Brillouin microscopy and validated with standard stress-strain tests: Atomic Force Microscopy (AFM) and a parallel plate compression device (Microsquisher). Finally, the nodules were treated with a chemotherapeutic commonly used to manage OvCa, carboplatin, to determine treatment-induced effects on tumor mechanical properties.

Results

Brillouin microscopy allows mechanical analysis with limited penetration depth (~ 92 µm for Matrigel method; ~ 54 µm for low attachment method). Brillouin microscopy metrics displayed the same trends as the corresponding "gold-standard" Young's moduli measured with stress-strain methods when the osmolality of the medium was increased. Nodules treated with carboplatin showed a decrease in Brillouin frequency shift.

Conclusion

This validation study paves the way to evaluate the mechanics of 3D nodules, with micron-scale three-dimensional resolution and without contact, thus extending the experimental possibilities.

Triphenylphosphonium-modified mitochondria-targeted paclitaxel nanocrystals for overcoming multidrug resistance

Mitochondria are currently known as novel targets for treating cancer, especially for tumors displaying multidrug resistance (MDR). This present study aimed to develop a mitochondria-targeted delivery system by using triphenylphosphonium cation (TPP⁺)-conjugated Brij 98 as the functional stabilizer to modify paclitaxel (PTX) nanocrystals (NCs) against drug-resistant cancer cells. Evaluations were performed on 2D monolayer and 3D multicellular spheroids (MCs) of MCF-7 cells and MCF-7/ADR cells. In comparison with free PTX and the non-targeted PTX NCs, the targeted PTX NCs showed the strongest cytotoxicity against both 2D MCF-7 and MCF-7/ADR cells, which was correlated with decreased mitochondrial membrane potential. The targeted PTX NCs exhibited deeper penetration on MCF-7 MCs and more significant growth inhibition on both MCF-7 and MCF-7/ADR MCs. The proposed strategy indicated that the TPP⁺-modified NCs represent a potentially viable approach for targeted chemotherapeutic molecules to mitochondria. This strategy might provide promising therapeutic outcomes to overcome MDR.

Evaluation of aging, diabetes mellitus, and skin wounds by scanning acoustic microscopy with protease digestion

Scanning acoustic microscopy (SAM) can assess tissue stiffness by calculating the speed of sound (SOS) through tissues. SOS increases as tissue stiffness increases. Sensitivity to protease digestion depends on protein type, concentration, and modification. We analyzed the SOS images of formalin-fixed paraffin-embedded skin sections from elderly, young, diabetic, and nondiabetic subjects, as well as chronic and acute wounds. SAM provided high-resolution histology similar to LM and revealed characteristic SOS alteration following pepsin treatment. SOS values of dermis samples from elderly subjects (especially females) were lower than those of younger adults, which was indicative of age-related dermal softening and loosening. SOS values of elderly females were lower than those of younger females and elderly males. Dermal SOS showed a positive correlation with epidermal thickness. SOS values of epidermis of elderly subjects were higher than those of younger adults and showed a rapid decline 0.5h after protease digestion. Reticular dermis of diabetic patients exhibited greater pepsin resistance than that of nondiabetic patients. Chronic wounds exhibited greater SOS values and pepsin resistance than acute wounds. SOS variation with aging, diabetes mellitus, and wound fibrosis reflected histological and mechanical changes associated with senescence and disease duration. Epidermal thickness reflects age-related changes in dermal stiffness.

Triphenylphosphonium and D-α-tocopheryl polyethylene glycol 1000 succinate-modified, tanshinone IIA-loaded lipid-polymeric nanocarriers for the targeted therapy of myocardial infarction

Background

Cardiovascular diseases (CVDs) are the leading causes of mortality worldwide. Currently, the best treatment options for myocardial infarction focus on the restoration of blood flow as soon as possible, which include reperfusion therapy, percutaneous coronary intervention, and therapeutic thrombolytic drugs.

Materials and methods

In the present study, we report the development of lipid-polymeric nanocarriers (LPNs) for mitochondria-targeted delivery of tanshinone IIA (TN). D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) was linked to the triphenylphosphonium (TPP) cation. The LPNs were fabricated by nanoprecipitation method. LPNs were evaluated in vitro and in vivo in comparison with free drugs and other similar nanocarriers.

Results

The mean diameter of TN/nanoparticles (NPs) was 89.6 nm, while that of TN/LPNs was 121.3 nm. The zeta potential of TN/NPs and TN/LPNs was −33.6 and −22.3 mV, respectively. Compared with free TN and TN/NPs, TN/LPNs exhibited significantly improved compatibility and therapeutic efficiency. In addition, the in vivo pharmacokinetics, biodistribution, and infarct therapy studies in Sprague Dawley rats showed that TPP-TPGS/TN/LPNs had better efficiency than their nonmodified TN/LPNs counterparts in all respects.

Conclusion

These results indicated that the TPP-TPGS/TN/LPNs were promising nanocarriers for efficient delivery of cardiovascular drugs and other therapeutic agents for the treatment of CVDs.

Synthesis and characterization of paclitaxel-imprinted microparticles for controlled release of an anticancer drug

In this study, novel molecularly imprinted polymer (MIP) microparticles containing methacryl polyhedral oligomeric silsesquioxane (M-POSS) were synthesized through the RAFT precipitation polymerization (RAFTPP) method using paclitaxel (PTX) as the templates. During the course of this investigation, methacrylic acid (MAA) was used as the functional monomer, while ethylene glycol dimethacrylate (EGDMA) was utilized as a cross-linker. The effects of different molar ratios of M-POSS on the microparticles were characterized. The obtained MIP microparticles were confirmed by FT-IR and TGA-DSC. The results of SEM showed regular spherical-shaped MIP microparticles with diameters around 170-490 nm. The PTX loading quantity was closely correlated with the content of M-POSS, and the MIP microparticles showed a satisfactory affinity to PTX with high drug loading (17.1%) and encapsulation efficiency (85.5%). Moreover, these MIP microparticles were sensitive to pH, and consequently the release rates of PTX at pH 5 were much faster than those at pH 7 due to the acid cleavage of the hydrogen bonds. In addition, the results from release experiments of the MIP microparticles showed a very slow and controlled release of PTX, which heralded promising potential as a carrier for PTX delivery in cancer therapy.

Mechanisms and impact of altered tumour mechanics

The physical characteristics of tumours are intricately linked to the tumour phenotype and difficulties during treatment. Many factors contribute to the increased stiffness of tumours; from increased matrix deposition, matrix remodelling by forces from cancer cells and stromal fibroblasts, matrix crosslinking, increased cellularity, and the build-up of both solid and interstitial pressure. Increased stiffness then feeds back to increase tumour invasiveness and reduce therapy efficacy. Increased understanding of this interplay is offering new therapeutic avenues.

Paclitaxel delivered by CD44 receptor-targeting and endosomal pH sensitive dual functionalized hyaluronic acid micelles for multidrug resistance reversion

The drug efflux mediated by P-glycoprotein (P-gp) transporter is a major factor responsible for multidrug resistance (MDR) of paclitaxel (PTX). The efficient intracellular PTX delivery is a promising strategy for overcoming the MDR of tumor cells. A CD44 receptor targeting and endosome-pH sensitive dual functionalized hyaluronic acid-deoxycholic acid-histidine (HA-DOCA-His) micellar formulation was developed to overcome MDR, and a CD44 receptor targeting hyaluronic acid-deoxycholic acid (HA-DOCA) micelles was used as a comparison. Compared with Taxol solution and HA-DOCA micelles, the cytotoxicity of PTX loaded in HA-DOCA-His micelles against drug-resistant tumor cells was improved significantly and possessed superior MDR-overcoming performance; this phenomenon is due to the increased intracellular PTX delivery by CD44 receptor-mediated endocytosis pathway and endosome-pH sensitivity-mediated PTX triggering release. Upon pharmacokinetic study, PTX/HA-DOCA-His micelles demonstrated longer blood circulation time, larger AUC, decreased V_d and CL than the Taxol solution. More importantly, PTX/HA-DOCA-His micelles were more effective in tumor growth inhibition in MCF-7/Adr tumor-bearing mice compared with PTX/HA-DOCA micelles and Taxol solution. Dual targeting strategy-functionalized HA-DOCA-His micelles demonstrated excellent MDR-reversing ability for therapeutic efficacy and improvement on MDR tumors, thereby providing an effective targeting strategy for PTX delivery of nano-drug delivery system in MDR cancer chemotherapy.

Investigation of the intracellular oxidative stress amplification, safety and anti-tumor effect of a kind of novel redox-responsive micelle

Redox-responsive FSST micelles with good biocompatibility can increase ROS levels in tumor cells and amplify oxidative stress, ultimately inducing apoptosis.

Recent Advances in the Application of Vitamin E TPGS for Drug Delivery

D-ɑ-tocopheryl polyethylene glycol succinate (Vitamin E TPGS or TPGS) has been approved by FDA as a safe adjuvant and widely used in drug delivery systems. The biological and physicochemical properties of TPGS provide multiple advantages for its applications in drug delivery like high biocompatibility, enhancement of drug solubility, improvement of drug permeation and selective antitumor activity. Notably, TPGS can inhibit the activity of ATP dependent P-glycoprotein and act as a potent excipient for overcoming multi-drug resistance (MDR) in tumor. In this review, we aim to discuss the recent advances of TPGS in drug delivery including TPGS based prodrugs, nitric oxide donor and polymers, and unmodified TPGS based formulations. These potential applications are focused on enhancing delivery efficiency as well as the therapeutic effect of agents, especially on overcoming MDR of tumors. It also demonstrates that the clinical translation of TPGS based nanomedicines is still faced with many challenges, which requires more detailed study on TPGS properties and based delivery system in the future.

Recent developments in d-α-tocopheryl polyethylene glycol-succinate-based nanomedicine for cancer therapy

Cancer remains an obstacle to be surmounted by humans. As an FDA-approved biocompatible drug excipient, d-α-tocopheryl polyethylene glycol succinate (TPGS) has been widely applied in drug delivery system (DDS). Along with in-depth analyses of TPGS-based DDS, increasingly attractive results have revealed that TPGS is able to act not only as a simple drug carrier but also as an assistant molecule with various bio-functions to improve anticancer efficacy. In this review, recent advances in TPGS-based DDS are summarized. TPGS can inhibit P-glycoprotein, enhance drug absorption, induce mitochondrial-associated apoptosis or other apoptotic pathways, promote drug penetration and tumor accumulation, and even inhibit tumor metastasis. As a result, many formulations, by using original TPGS, TPGS-drug conjugates or TPGS copolymers, were prepared, and as expected, an enhanced therapeutic effect was achieved in different tumor models, especially in multidrug resistant and metastatic tumors. Although the mechanisms by which TPGS participates in such functions are not yet very clear, considering its effectiveness in tumor treatment, TPGS-based DDS appears to be one of the best candidates for future clinical applications.

Recent advances in TPGS-based nanoparticles of docetaxel for improved chemotherapy

Docetaxel (DTX) is one of the important antitumor drugs, being used in several common chemotherapies to control leading cancer types. Severe toxicities of the DTX are prominent due to sudden parenteral exposure of desired loading dose to maintain the therapeutic concentration. Field of nanotechnology is leading to resist sudden systemic exposure of DTX with more specific delivery to the site of cancer. Further nanometric size range of the formulation aid for prolonged circulation, thereby extensive exposure results better efficacy. In this article, we extensively reviewed the therapeutic benefit of incorporating d-α-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS, or simply TPGS) in the nanoparticle (NP) formulation of DTX for improved delivery, tumor control and tolerability. TPGS is well accepted nonionic-ampiphilic polymer which has been identified in the role of emulsifier, stabilizer, penetration enhancer, solubilizer and in protection in micelle. Simultaneously, P-glycoprotein inhibitory activity of TPGS in the multidrug resistant (MDR) cancer cells along with its apoptotic potential are the added advantage of TPGS to be incorporated in nano-chemotherapeutics. Thus, it could be concluded that TPGS based nanoparticulate application is an advanced approach to improve therapeutic efficacy of chemotherapeutic agents by better internalization and sustained retention of the NPs.