α-Tocopherol succinate-modified chitosan as a micellar delivery system for paclitaxel: preparation, characterization and in vitro/in vivo evaluations

Glycol Chitosan-Poly(lactic acid) Conjugate Nanoparticles Encapsulating Ciprofloxacin: A Mucoadhesive, Antiquorum-Sensing, and Biofilm-Disrupting Treatment Modality for Bacterial Keratitis

Bacterial keratitis (BK) causes visual morbidity/blindness if not treated effectively. Here, ciprofloxacin (CIP)-loaded nanoparticles (NPs) using glycol chitosan (GC) and poly(lactic acid) (PLA) conjugate at three different ratios (CIP@GC(PLA) NPs (1:1,5,15)) were fabricated. CIP@GC(PLA) NPs (1:1) were more effective than other tested ratios, indicating the importance of optimal hydrophobic/hydrophilic balance for corneal penetration and preventing bacterial invasion. The CIP@GC(PLA) (NPs) (1:1) realized the highest association with human corneal epithelial cells, which were nonirritant to the hen's egg-chorioallantoic membrane test (HET-CAM test) and demonstrated significant antibacterial response in the in vitro minimum inhibitory, bactericidal, live-dead cells, zone of inhibition, and biofilm inhibition assays against the keratitis-inducing pathogen Pseudomonas aeruginosa. The antiquorum sensing activity of GC has been explored for the first time. The NPs disrupted the bacterial quorum sensing by inhibiting the production of virulence factors, including acyl homoserine lactones, pyocyanin, and motility, and caused significant downregulation of quorum sensing associated genes. In the in vivo studies, CIP@GC(PLA) NPs (1:1) displayed ocular retention in vivo (∼6 h) and decreased the opacity and the bacterial load effectively. Overall, the CIP@GC(PLA) NP (1:1) is a biofilm-disrupting antiquorum sensing treatment regimen with clinical translation potential in BK.

Optimizing Paclitaxel Oral Absorption and Bioavailability: TPGS Co-Coating via Supercritical Anti-Solvent Fluidized Bed Technology

Supercritical anti-solvent fluidized bed (SAS-FB) coating technology has the advantages of reducing particle size, preventing high surface energy particle aggregation, improving the dissolution performance and bioavailability of insoluble drugs. The poor solubility of Biopharmaceutics Classification System (BCS) class IV drugs poses challenges in achieving optimal bioavailability. Numerous anti-cancer drugs including paclitaxel (PTX) belong to the BCS class IV, hindering their therapeutic efficacy. To address this concern, our study explored SAS-FB technology to coat PTX with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) onto lactose. Under our optimized conditions, we achieved a PTX coating efficiency of 96.8%. Further characterization confirmed the crystalline state of PTX in the lactose surface coating by scanning electron microscopy and X-ray powder diffraction. Dissolution studies indicated that SAS-FB processed samples release over 95% of the drug within 1 min. Moreover, cell transmembrane transport assays demonstrated that SAS-FB processed PTX samples co-coated with TPGS had an enhanced PTX internalization into cells and a higher permeability coefficient compared to those without TPGS. Finally, compared to unprocessed PTX, SAS-FB (TPGS) and SAS-FB processed samples showed a 2.66- and 1.49-fold increase in oral bioavailability in vivo, respectively. Our study highlights the efficacy of SAS-FB co-coating for PTX and TPGS as a promising strategy to overcome bioavailability challenges inherent in BCS class IV drugs. Our approach holds broader implications for enhancing the performance of similarly classified medications.

Preparation of Seaweed Nanopowder Particles Using Planetary Ball Milling and Their Effects on Some Secondary Metabolites in Date Palm (Phoenix dactylifera L.) Seedlings

Due to their distinctive physicochemical characteristics, nanoparticles have recently emerged as pioneering materials in agricultural research. In this work, nanopowders (NP) of seaweed (Turbinaria triquetra) were prepared using the planetary ball milling procedure. The prepared nanopowders from marine seaweed were characterized by particle size, zeta potential, UV-vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). When the seaweed nanopowder of Turbinaria triquetra was subjected to FT-IR analysis, it revealed the presence of different functional groups, including alkane, carboxylic acids, alcohol, alkenes and aromatics. Moreover, the methanol extract was used to identify the polyphenolic components in seaweed (NP) using high performance liquid chromatography (HPLC) and the extract revealed the presence of a number of important compounds such as daidzein and quercetin. Moreover, the pot experiment was carried out in order to evaluate the effects of prepared seaweed (NP) as an enhancer for the growth of date palm (Phoenix dactylifera L.). The date palm seedlings received four NP doses, bi-distilled water was applied as the control and doses of 25, 50 or 100 mg L^-1 of seaweed liquid NP were used (referred to as T1, T2, T3 and T4, respectively). Foliar application of liquid NP was applied two times per week within a period of 30 days. Leaf area, number of branches, dry weight, chlorophylls, total soluble sugars and some other secondary metabolites were determined. Our results indicated that the foliar application of liquid NP at T3 enhanced the growth parameters of the date palm seedlings. Additionally, liquid NP at T3 and T4 significantly increased the photosynthetic pigments. The total phenolic, flavonoid and antioxidant activities were stimulated by NP foliar application. Moreover, the data showed that the T3 and T4 doses enhanced the activity of the antioxidant enzymes (CAT, POX or PPO) compared to other treatments. Therefore, the preparation of seaweed NP using the planetary ball milling method could produce an eco-friendly and cost- effective material for sustainable agriculture and could be an interesting way to create a nanofertilizer that mitigates plant growth.

Cervical cancer and novel therapeutic and diagnostic approaches using chitosan as a carrier: A review

In our knowledge, using appropriate carriers in delivery of chemotherapeutic drugs, would result in better targeting and therefore it would increase the effectiveness and decrease the side effects of drugs. Chitosan, a natural polymer derived from chitin, has attracted the attention of pharmaceutical industries recently. New research show that chitosan not only can be used in drug delivery but it can also have some usages in prevention and diagnosis of cancer. This means that using chitosan Nanoformulations can be a promising approach for prevention, diagnosis, and specially treatment of cervical cancer, fourth common cancer among the women of the world. We aim to investigate the related papers to find a novel method and preventing more women from suffering.

Development of α-Tocopherol Succinate-Based Nanostructured Lipid Carriers for Delivery of Paclitaxel

The management of retinoblastoma (RB) involves the use of invasive treatment regimens. Paclitaxel (PTX), an effective antineoplastic compound used in the treatment of a wide range of malignant tumors, poses treatment challenges due to systemic toxicity, rapid elimination, and development of resistance. The goal of this work was to develop PTX-loaded, α-tocopherol succinate (αTS)-based, nanostructured lipid carrier (NLCs; αTS-PTX-NLC) and PEGylated αTS-PTX-NLC (αTS-PTX-PEG-NLC) to improve ocular bioavailability. The hot homogenization method was used to prepare the NLCs, and repeated measures ANOVA analysis was used for formulation optimization. αTS-PTX-NLC and αTS-PTX-PEG-NLC had a mean particle size, polydispersity index and zeta potential of 186.2 ± 3.9 nm, 0.17 ± 0.03, −33.2 ± 1.3 mV and 96.2 ± 3.9 nm, 0.27 ± 0.03, −39.15 ± 3.2 mV, respectively. The assay and entrapment efficiency of both formulations was >95.0%. The NLC exhibited a spherical shape, as seen from TEM images. Sterilized (autoclaved) formulations were stable for up to 60 days (last time point checked) under refrigerated conditions. PTX-NLC formulations exhibited an initial burst release and 40% drug release, overall, in 48 h. The formulations exhibited desirable physicochemical properties and could lead to an effective therapeutic option in the management of RB.

Targeted drug delivery in cervical cancer: Current perspectives

Cervical cancer is preventable yet one of the most prevalent cancers among women around the globe. Though regular screening has resulted in the decline in incidence, the disease claims a high number of lives every year, especially in the developing countries. Owing to rather aggressive and non-specific nature of the conventional chemotherapeutics, there is a growing need for newer treatment modalities. The advent of nanotechnology has assisted in this through the use of nanocarriers for targeted drug delivery. A number of nanocarriers are continuously being developed and studied for their application in drug delivery. The present review summarises the different drug delivery approaches and nanocarriers that can be useful, their advantages and limitation.

Safety Evaluation of Nanotechnology Products

Nanomaterials are now being used in a wide variety of biomedical applications. Medical and health-related issues, however, have raised major concerns, in view of the potential risks of these materials against tissue, cells, and/or organs and these are still poorly understood. These particles are able to interact with the body in countless ways, and they can cause unexpected and hazardous toxicities, especially at cellular levels. Therefore, undertaking in vitro and in vivo experiments is vital to establish their toxicity with natural tissues. In this review, we discuss the underlying mechanisms of nanotoxicity and provide an overview on in vitro characterizations and cytotoxicity assays, as well as in vivo studies that emphasize blood circulation and the in vivo fate of nanomaterials. Our focus is on understanding the role that the physicochemical properties of nanomaterials play in determining their toxicity.

Biomimetic pH/lipase dual responsive vitamin-based solid lipid nanoparticles for on-demand delivery of vancomycin

In this study, ascorbyl tocopherol succinate (ATS) was designed, synthesized and characterized via FT-IR, HR-MS, H¹ NMR and C¹³ NMR, to simultaneously confer biomimetic and dual responsive properties of an antibiotic nanosystem to enhance their antibacterial efficacy and reduce antimicrobial resistance. Therefore, an in silico-aided design (to mimic the natural substrate of bacterial lipase) was employed to demonstrate the binding potential of ATS to lipase (-32.93 kcal/mol binding free energy (ΔG_bind) and bacterial efflux pumps blocking potential (NorA ΔG_bind: -37.10 kcal/mol, NorB ΔG_bind: -34.46 kcal/mol). ATS bound stronger to lipase than the natural substrate (35 times lower Kd value). The vancomycin loaded solid lipid nanoparticles (VM-ATS-SLN) had a hydrodynamic diameter, zeta potential, polydispersity index and entrapment efficiency of 106.9 ± 1.4 nm, -16.5 ± 0.93 mV, 0.11 ± 0.012 and 61.9 ± 1.31%, respectively. In vitro biocompatibility studies revealed VM-ATS-SLN biosafety and non-haemolytic activity. Significant enhancement in VM release was achieved in response to acidified pH and lipase enzyme, compared to controls. VM-ATS-SLN showed enhanced sustained in vitro antibacterial activity for 5 days, 2-fold greater MRSA biofilm growth inhibition and 3.44-fold reduction in bacterial burden in skin infected mice model compared to bare VM. Therefore, ATS shows potential as a novel multifunctional adjuvant for effective and targeted delivery of antibiotics.

Formation of Amphiphilic Molecules from the Most Common Marine Polysaccharides, toward a Sustainable Alternative?

Marine polysaccharides are part of the huge seaweeds resources and present many applications for several industries. In order to widen their potential as additives or bioactive compounds, some structural modifications have been studied. Among them, simple hydrophobization reactions have been developed in order to yield to grafted polysaccharides bearing acyl-, aryl-, alkyl-, and alkenyl-groups or fatty acid chains. The resulting polymers are able to present modified physicochemical and/or biological properties of interest in the current pharmaceutical, cosmetics, or food fields. This review covers the chemical structures of the main marine polysaccharides, and then focuses on their structural modifications, and especially on hydrophobization reactions mainly esterification, acylation, alkylation, amidation, or even cross-linking reaction on native hydroxyl-, amine, or carboxylic acid functions. Finally, the question of the necessary requirement for more sustainable processes around these structural modulations of marine polysaccharides is addressed, considering the development of greener technologies applied to traditional polysaccharides.

Paclitaxel-loaded polymeric nanoparticles based on α-tocopheryl succinate for the treatment of head and neck squamous cell carcinoma: in vivo murine model

The prognosis of patients with recurrent or metastatic head and neck squamous cell cancer (HNSCC) is generally poor. New treatments are required to supplement the current standard of care. Paclitaxel (PTX), an effective chemotherapeutic for HNSCC, has serious side effects. A polymeric nanocarrier system was developed for the delivery of PTX to improve HNSCC treatment. This study aimed to evaluate the antitumor efficacy of PTX-loaded polymeric nanoparticles based on α-TOS (PTX-NPs) administered by direct intratumoral injection into a Hypopharynx carcinoma squamous cells (FaDu) tumor xenograft mouse model. The nanocarrier system based on block copolymers of polyethylene glycol (PEG) and a methacrylic derivative of α-TOS was synthesized and PTX was loaded into the delivery system. Tumor volume was measured to evaluate the antitumor effect of the PTX-NPs. The relative mechanisms of apoptosis, cell proliferation, growth, angiogenesis, and oxidative and nitrosative stress were detected by Western blotting, fluorescent probes, and immunohistochemical analysis. The antitumor activity results showed that compared to free PTX, PTX-NPs exhibited much higher antitumor efficacy and apoptosis-inducing in a FaDu mouse xenograft model and demonstrated an improved safety profile. Ki-67, EGFR, and angiogenesis markers (Factor VIII, CD31, and CD34) expression were significantly lower in the PTX-NPs group compared with other groups (p < .05). Also, PTX-NPs induced oxidative and nitrosative stress in tumor tissue. Direct administration of PTX-loaded polymeric nanoparticles based on α-Tocopheryl Succinate at the tumor sites, proved to be promising for HNSCC therapy.

Vitamin E succinate with multiple functions: A versatile agent in nanomedicine-based cancer therapy and its delivery strategies

Vitamin E succinate (VES), a succinic acid ester of vitamin E, is one of the most effective anticancer compounds of the vitamin E family. VES can inhibit tumor growth by multiple pathways mainly involve tumor proliferation inhibition, apoptosis induction, and metastasis prevention. More importantly, the mitochondrial targeting and damaging property of VES endows it with great potential in exhibiting synergetic effect with conventional chemotherapeutic drugs and overcoming multidrug resistance (MDR). Given the lipophilicity of VES that hinders its bioavailability and therapeutic activity, nanotechnology with multiple advantages has been widely explored to deliver VES and opened up new avenues for its in vivo application. This review aims to introduce the anticancer mechanisms of VES and summarize its delivery strategies using nano-drug delivery systems. Specifically, VES-based combination therapy for synergetic anticancer effect, MDR-reversal, and oral chemotherapy improvement are highlighted. Finally, the challenges and perspectives are discussed.

A Chitosan-Based Micellar System as Nanocarrier For the Delivery of Paclitaxel

In this study, a redox-sensitive chitosan derivative with modifications by cholesterol, sulfhydryl, and mPEG (mPEG-CS(SH)-CHO) was successfully synthesized and characterized. Due to its amphiphilicity, the conjugate could spontaneously form micelles in an aqueous environment. The optimized paclitaxel (PTX)-loaded mPEG-CS(SH)-CHO micelles, with a mean diameter of 158 nm, zeta potential of +26.9 mV, drug loading of 11.7%, and entrapment efficiency of 88.3%, were successfully prepared. The results of an XRD study demonstrated that PTX was loaded in the core of the micelles in a non-crystalline state. Inspiringly, the PTX-loaded micelles possessed excellent anticancer effect but low toxicity to the body. It can be concluded that the mPEG-CS(SH)-CHO micellar system is a promising drug delivery carrier for the controlled release of PTX.

Chitosan-based advanced materials for docetaxel and paclitaxel delivery: Recent advances and future directions in cancer theranostics

Paclitaxel (PTX) and docetaxel (DTX) are key members of taxanes with high anti-tumor activity against various cancer cells. These chemotherapeutic agents suffer from a number of drawbacks and it seems that low solubility in water is the most important one. Although much effort has been made in improving the bioavailability of PTX and DTX, the low bioavailability and minimal accumulation at tumor sites are still the challenges faced in PTX and DTX therapy. As a consequence, bio-based nanoparticles (NPs) have attracted much attention due to unique properties. Among them, chitosan (CS) is of interest due to its great biocompatibility. CS is a positively charged polysaccharide with the capability of interaction with negatively charged biomolecules. Besides, it can be processed into the sheet, micro/nano-particles, scaffold, and is dissolvable in mildly acidic pH similar to the pH of the tumor microenvironment. Keeping in mind the different applications of CS in the preparation of nanocarriers for delivery of PTX and DTX, in the present review, we demonstrate that how CS functionalized-nanocarriers and CS modification can be beneficial in enhancing the bioavailability of PTX and DTX, targeted delivery at tumor site, image-guided delivery and co-delivery with other anti-tumor drugs or genes.

Vitamin E succinate-grafted-chitosan/chitosan oligosaccharide mixed micelles loaded with C-DMSA for Hg2+ detection and detoxification in rat liver

AIM

To determine whether the use of a mixed polymeric micelle delivery system based on vitamin E succinate (VES)-grafted-chitosan oligosaccharide (CSO)/VES-grafted-chitosan (CS) mixed micelles (VES-g-CSO/VES-g-CS MM) enhances the delivery of C-DMSA, a theranostic fluorescent probe, for Hg2+ detection and detoxification in vitro and in vivo.

METHODS

Mixed micelles self-assembled from two polymers, VES-g-CSO and VES-g-CS, were used to load C-DMSA and afforded C-DMSA@VES-g-CSO/VES-g-CS MM for cell and in vivo applications. Fluorescence microscopy was used to assess C-DMSA cellular uptake and Hg2+ detection in L929 cells. C-DMSA@VES-g-CSO/VES-g-CS MM was then administered intravenously. Hg2+ detection was assessed by fluorescence microscopy in terms of bio-distribution while detoxification efficacy in Hg2+-poisoned rat models was evaluated in terms of mercury contents in blood and in liver.

RESULTS

The C-DMSA loaded mixed micelles, C-DMSA@VES-g-CSO/VES-g-CS MM, significantly enhanced cellular uptake and detoxification efficacy of C-DMSA in Hg2+ pretreated human L929 cells. Evidence from the reduction of liver coefficient, mercury contents in liver and blood, alanine transaminase and aspartate transaminase activities in Hg2+ poisoned SD rats treated with the mixed micelles strongly supported that the micelles were effective for Hg2+ detoxification in vivo. Furthermore, ex vivo fluorescence imaging experiments also supported enhanced Hg2+ detection in rat liver.

CONCLUSION

The mixed polymeric micelle delivery system could significantly enhance cell uptake and efficacy of a theranostic probe for Hg2+ detection and detoxification treatment in vitro and in vivo. Moreover, this nanoparticle drug delivery system could achieve targeted detection and detoxification in liver.

Loading paclitaxel into porous starch in the form of nanoparticles to improve its dissolution and bioavailability

In this work, paclitaxel was loaded into porous starch in the form of nanoparticles (PNPS), and the properties of PNPS were investigated by using raw paclitaxel and the system of paclitaxel directly loaded into porous starch (PPS) as control groups. According to the tested results, the drug loading (DL) and encapsulation efficiency (EE) of PNPS were 14.13%±0.27% and 73.92%±0.54%, higher than that of PPS (9.79%±0.31% and 71.17%±0.67%) respectively. Compared with raw paclitaxel and PPS, PNPS exhibited the more prominent dissolution rate and bioavailability, in which the bioavailability of PPS and PNPS were 2.94 and 5.42 times of that of raw paclitaxel respectively. In addition, the IC₅₀ values of raw paclitaxel, PPS and PNPS on Lewis Lung Carcinoma (LLC) cells were 17,703.41±15.76μM, 95.10±5.32μM and 85.68±7.38μM respectively. Furthermore, the residues of acetone in PPS and PNPS were less than the ICH limit for acetone in class III solvents. To summarize, the preparation of PNPS was a potential method to improve the dissolution and bioavailability of paclitaxel.

Co-Delivery of Paclitaxel by a Capsaicin Prodrug Micelle Facilitating for Combination Therapy on Breast Cancer

Poor anticancer ability, serious adverse reaction, and drug resistance against paclitaxel (PTX) have limited its clinical applications. When a mouse breast carcinoma cell line (4T1) was treated with both PTX and capsaicin (CAP), there was a synergistic anti-proliferative effect demonstrated with a combination index of 0.28. Therefore, a novel polyethylene glycol-derivatized CAP (PEG-Fmoc-CAP₂) polymeric prodrug micellar carrier was developed and further encapsulated with PTX for antitumor combination treatment. The PEG-Fmoc-CAP₂ polymeric micelles co-delivered with PTX achieved a 62.3% fraction of apoptotic cells in comparison to 45.4% fraction of apoptotic cells to that upon treatment with PTX alone. Comparable CAP amounts were found in the cell lysate treatment with PEG-Fmoc-CAP₂-conjugated micelles to that of free CAP-treated 4T1 cells after 12 h treatment. Pharmacokinetic and biodistribution studies showed that the micelles possessed much longer circulation time in blood and preferential tumor tissue accumulation compared to the Taxol solution. Importantly, PTX/CAP-loaded micelles exhibited superior in vivo antitumor activity on the inhibition rate of tumor growth than other treatments (70.5% tumor growth reduction in PTX/CAP micelle-treated mice vs 57.8, 43.3, and 23.8% of tumor growth inhibition rate in PTX/PEG-Fmoc-OA₂ micelles, Taxol, and PEG-Fmoc-CAP₂ micelle-treated mice, respectively). Thus, the dual-functional PEG-Fmoc-CAP₂ polymeric prodrug micelles are a promising co-delivery nanosystem for achieving synergistic antitumor efficacy of PTX and CAP.

Tumor-targeting micelles based on folic acid and α-tocopherol succinate conjugated hyaluronic acid for paclitaxel delivery

Tumor-targeting micelles for the delivery of paclitaxel (PTX) were developed based on folic acid and α-tocopherol succinate conjugated hyaluronic acid (FA-HA-TOS). The conjugate FA-HA-TOS was synthesized by an esterification reaction and was characterized by proton nuclear magnetic resonance (¹H NMR) and Fourier transform infrared (FT-IR) analysis. The conjugate self-assembles into nanosized micelles in aqueous medium with a critical micellar concentration (CMC) of 1.12 × 10^-2 mg/mL. The FA-HA-TOS micelles demonstrated high drug loading and entrapment efficiency for PTX, with respective values of 21.37% and 90.48%. The physicochemical properties of the micelles were measured by DLS, TEM and XRD. Moreover, in vitro and in vivo evaluations were performed to demonstrate the superior antitumor activity of the PTX-loaded micelles. It was suggested that the FA-HA-TOS micelle system represents a promising nanocarrier for targeted delivery of PTX.

Incorporation of 3,3'-Diindolylmethane into Nanocapsules Improves Its Photostability, Radical Scavenging Capacity, and Cytotoxicity Against Glioma Cells

3,3'-Diindolylmethane (DIM) is a phytochemical that presents health benefits (antitumor, antioxidant, and anti-inflammatory effects). However, it is water insoluble and thermo- and photolabile, restraining its pharmaceutical applications. As a strategy to overcome such limitations, this study aimed the development and characterization of DIM-loaded nanocapsules (NCs) prepared with different compositions as well as the in vitro assessment of scavenging activity and cytotoxicity. The formulations were obtained using the interfacial deposition of preformed polymer method and were composed by Eudragit® RS100 or ethylcellulose as polymeric wall and primula or apricot oil as the core. All the formulations had adequate physicochemical characteristics: nanometric size (around 190 nm), low polydispersity index (< 0.2), pH value at acid range, high values of zeta potential, drug content, and encapsulation efficiency (~ 100%). Besides, nanoencapsulation protected DIM against UVC-induced degradation and increased the scavenging activity assessed by the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) and 1-1-diphenyl-2-picrylhydrazyl methods. The developed DIM-loaded nanocapsules were further evaluated regarding the in vitro release profile and cytotoxicity against a human glioblastoma cell line (U87 cells). The results demonstrated that the nanoencapsulation promoted a sustained release of the bioactive compound (in the range of 58-78% after 84 h) in comparison to its free form (86% after 12 h), as well as provided a superior cytotoxic effect against the U87 cells in the highest concentrations. Therefore, our results suggest that nanoencapsulation could be a promising approach to overcome the DIM physicochemical limitations and potentialize its biological properties.

Amphiphilic Polymeric Micelles Based on Deoxycholic Acid and Folic Acid Modified Chitosan for the Delivery of Paclitaxel

The present investigation aimed to develop a tumor-targeting drug delivery system for paclitaxel (PTX). The hydrophobic deoxycholic acid (DA) and active targeting ligand folic acid (FA) were used to modify water-soluble chitosan (CS). As an amphiphilic polymer, the conjugate FA-CS-DA was synthesized and characterized by Proton nuclear magnetic resonance (¹H-NMR) and Fourier-transform infrared spectroscopy (FTIR) analysis. The degree of substitutions of DA and FA were calculated as 15.8% and 8.0%, respectively. In aqueous medium, the conjugate could self-assemble into micelles with the critical micelle concentration of 6.6 × 10⁻³ mg/mL. Under a transmission electron microscope (TEM), the PTX-loaded micelles exhibited a spherical shape. The particle size determined by dynamic light scattering was 126 nm, and the zeta potential was +19.3 mV. The drug loading efficiency and entrapment efficiency were 9.1% and 81.2%, respectively. X-Ray Diffraction (XRD) analysis showed that the PTX was encapsulated in the micelles in a molecular or amorphous state. In vitro and in vivo antitumor evaluations demonstrated the excellent antitumor activity of PTX-loaded micelles. It was suggested that FA-CS-DA was a safe and effective carrier for the intravenous delivery of paclitaxel.

Polymeric Micelles Based on Modified Glycol Chitosan for Paclitaxel Delivery: Preparation, Characterization and Evaluation

Amphiphilic polymer of α-tocopherol succinate modified glycol chitosan (TS-GC) was successfully constructed by conjugating α-tocopherol succinate to the skeleton of glycol chitosan and characterized by Fourier-transform infrared (FT-IR) and proton nuclear magnetic resonance (¹H-NMR). In aqueous milieu, the conjugates self-assembled to micelles with the critical aggregation concentration of 7.2 × 10⁻³ mg/mL. Transmission electron microscope (TEM) observation and dynamic light scattering (DLS) measurements were carried out to determine the physicochemical properties of the micelles. The results revealed that paclitaxel (PTX)-loaded TS-GC micelles were spherical in shape. Moreover, the PTX-loaded micelles showed increased particle sizes (35 nm vs. 142 nm) and a little reduced zeta potential (+19 mV vs. +16 mV) compared with blank micelles. The X-ray diffraction (XRD) spectra demonstrated that PTX existed inside the micelles in amorphous or molecular state. In vitro and in vivo tests showed that the PTX-loaded TS-GC micelles had advantages over the Cremophor EL-based formulation in terms of low toxicity level and increased dose, which suggested the potential of the polymer as carriers for PTX to improve their delivery properties.

Transferrin-Modified Vitamin-E/Lipid Based Polymeric Micelles for Improved Tumor Targeting and Anticancer Effect of Curcumin

PURPOSE

Transferrin receptor (TfR) is up-regulated in various malignant tumors not only to meet the iron requirement, but also to increase the cell survival via participation in various cellular signaling pathways. Here we explored transferrin as ligand for Poly(ethylene Glycol) (PEG)-ylated vitamin-E/lipid (PE) core micelles (VPM).

METHODS

Transferrin modified polymer was synthesized and drug loaded micelles were evaluated in 2D Hela and HepG2 cancer cells for cellular uptake and cytotoxicity and in 3D Hela spheroids for growth inhibition, uptake and penetration studies.

RESULTS

Targeted (Tf-VPM) and non-targeted (VPM) micelles showed mean hydrodynamic diameter of 114.2 ± 0.64 nm and 117.4 ± 0.72 nm and zeta potential was -22.8 ± 0.62 and -14.8 ± 1.74 mV, respectively. Cellular uptake study indicated that the Tf-CVPM were taken up by cancer cells (Hela and HepG2) with higher efficiency. Enhanced cytotoxicity was demonstrated for Tf-VPM compared to CVPM. Marked spheroid growth inhibition following treatment with Tf-CVPM was observed compared to the treatment with non-targeted CVPM.

CONCLUSIONS

The developed transferrin-modified micelles have improved ability to solubilize the loaded drugs and could actively target solid tumors by its interaction with over-expressed transferrin receptors. Therefore, the nano-micelles could be further explored for its potential utilization in cancer therapy.

Novel amphiphilic folic acid-cholesterol-chitosan micelles for paclitaxel delivery

In order to decrease the toxicity of paclitaxel (PTX) and increase the efficiency, we developed an amphiphilic PTX injection system using a biodegradable and biocompatible polymer synthesized by folic acid, cholesterol, and chitosan (FACC). This FACC-based polymer had a low critical concentration (64.13μg/ml) and could self-assemble in aqueous condition to form nanoscale micelles. The particle sizes of FACC-PTX micelles were 253.2±0.56 nm, the encapsulation efficiency and loading capacity of these FACC-PTX micelles were 65.1±0.23% and 9.1±0.16%, respectively. The cumulative release rate was about 85% at pH 5.0 which was higher than that at pH 7.4 (76%). This pH-dependent release behavior was highly suggesting that PTX release from FACC-PTX micelles might be higher in a weak acidic tumor microenvironment and lower toxic for normal cells. The anti-cancer effectiveness of FACC-PTX micelles was investigated by in vitro cytotoxicity and targeting study. The results revealed that FACC micelles have non-toxic on cells as evidenced by high cell viability found (86% to 100%) in the cells cultured with various concentrations of FACC micelles (1 to 500 μg/ml). Targeting study indicated that the cytotoxic efficacy of FACC-PTX micelles was significantly higher than that with Taxol® in the Hela cells (folate receptor-positive cells). These findings indicated that the anticancer efficiency of PTX can be enhanced by adding some cancer cell positive receptor into drug carrier and the FACC micelle was a potential tumor targeting carrier for PXT delivery.

CD44-Targeted Facile Enzymatic Activatable Chitosan Nanoparticles for Efficient Antitumor Therapy and Reversal of Multidrug Resistance

Nanoparticles are attractive platforms for the delivery of various anticancer therapeutics. Nevertheless, their applications are still limited by the relatively low drug loading capacity and the occurrence of multidrug resistance (MDR) against chemotherapeutics. In this study, we report that the integration of d-α-tocopherol succinate (VES) residue with both chitosan and paclitaxel (PTX) led to significant improvement of drug loading capacity and drug loading efficiency through the enhancement of drug/carrier interaction. After the incorporation of hyaluronic acid containing PEG side chains (HA-PEG), higher serum stability and more efficient cellular uptake were obtained. Due to HA coating, VES residues and the enzymatic responsive drug release property, such facile nanoparticles actively targeted cancer cells that overexpress CD44 receptor and efficiently reversed the MDR of treated cells, but caused no significant toxicity to mouse fibroblast (NIH-3T3). More importantly, with HA-PEG coating, longer blood circulation and more effective tumor accumulation were achieved for prodrug nanoparticles. Finally, superior anticancer activity and excellent safety profile was demonstrated by HA-PEG coated enzymatically activatable prodrug nanoparticles compared to commercially available Taxol formulation.

Enhanced antitumor efficacy of arginine modified amphiphilic nanoparticles co-delivering doxorubicin and iSur-pDNA via the multiple synergistic effect

Arginine and α-tocopherol succinate (α-TOS) double grafted N-trimethyl chitosan chloride (TMC) nanoparticles (TAS NPs) were designed and developed for effective co-delivery of doxorubicin (DOX) and Survivin shRNA-expressing pDNA (iSur-pDNA). With DOX loading into the hydrophobic core and iSur-pDNA combining to the hydrophilic shell, TAS/DOX/pDNA NPs demonstrated favorable structural stability and sustained release properties in vitro. With the special non-clathrin-dependent endocytosis, TAS/DOX/pDNA NPs presented higher cellular uptake and mainly distributed in ER and Golgi rather than lysosomes following internalization. The in vitro nuclear localization, gene silencing efficiency, cell apoptosis, and growth inhibition of tumor cells were significantly promoted by arginine modification. In the tumor-bearing mice model, TAS/DOX/pDNA NPs possessed the maximum antitumor efficiency as compared with single delivery of DOX or iSur-pDNA. Particularly, blank TAS NPs were selectively be toxic to tumor cells as evidenced by their capabilities to inhibit proliferation and induce apoptosis of tumor cells. The promising tumor treatment of TAS/DOX/pDNA NPs via a multiple synergistic manner arising from DOX and pDNA as well as the vectors would provide a potential strategy for a dual-delivery system to improve their therapeutic efficacies.

Preclinical development of drug delivery systems for paclitaxel-based cancer chemotherapy

Paclitaxel (PTX) is one of the most successful drugs ever used in cancer chemotherapy, acting against a variety of cancer types. Formulating PTX with Cremophor EL and ethanol (Taxol®) realized its clinical potential, but the formulation falls short of expectations due to side effects such as peripheral neuropathy, hypotension, and hypersensitivity. Abraxane®, the albumin bound PTX, represents a superior replacement of Taxol® that mitigates the side effects associated with Cremophor EL. While Abraxane® is now considered a gold standard in chemotherapy, its 21% response rate leaves much room for further improvement. The quest for safer and more effective cancer treatments has led to the development of a plethora of innovative PTX formulations, many of which are currently undergoing clinical trials. In this context, we review recent development of PTX drug delivery systems and analyze the design principles underpinning each delivery strategy. We chose several representative examples to highlight the opportunities and challenges of polymeric systems, lipid-based formulations, as well as prodrug strategies.

Curcumin-loaded chitosan–cholesterol micelles: evaluation in monolayers and 3D cancer spheroid model

Aim: To improve the bioavailability and anticancer potential of curcumin by using a cholesterol-conjugated chitosan micelle. Methods & methods: Cholesterol was conjugated to chitosan (15 kDa) to form self-assembled micelles, which loaded curcumin. Physicochemical characterization and formulation optimization of the drug-loaded micelles (curcumin-loaded chitosan–cholesterol micelles [C-CCM]) were performed. In vitro cellular uptake and viability of C-CCM were investigated in melanoma and breast cancer cell lines. The antitumor efficacy was evaluated in 3D lung cancer spheroid model. Results & conclusion: The optimized C-CCM had size of approximately 162 nm with loading efficiency of approximately 36%. C-CCM was taken up efficiently by the cells, and it reduced cancer cell viability significantly compared with free curcumin. C-CCM enhanced the antitumor efficacy in spheroids, suggesting that C-CCM could be used as an effective chemotherapy in cancer.

Redox-sensitive self-assembled nanoparticles based on alpha-tocopherol succinate-modified heparin for intracellular delivery of paclitaxel

To remedy the problems riddled in cancer chemotherapy, such as poor solubility, low selectivity, and insufficient intra-cellular release of drugs, novel heparin-based redox-sensitive polymeric nanoparticles were developed. The amphiphilic polymer, heparin-alpha-tocopherol succinate (Hep-cys-TOS) was synthesized by grafting hydrophobic TOS to heparin using cystamine as the redox-sensitive linker, which could self-assemble into nanoparticles in phosphate buffer saline (PBS) with low critical aggregation concentration (CAC) values ranging from 0.026 to 0.093mg/mL. Paclitaxel (PTX)-loaded Hep-cys-TOS nanoparticles were prepared via a dialysis method, exhibiting a high drug-loading efficiency of 18.99%. Physicochemical properties of the optimized formulation were characterized by dynamic light scattering (DLS), transmission electron microscope (TEM) and differential scanning calorimetry (DSC). Subsequently, the redox-sensitivity of Hep-cys-TOS nanoparticles was confirmed by the changes in size distribution, morphology and appearance after dithiothreitol (DTT) treatment. Besides, the in vitro release of PTX from Hep-cys-TOS nanoparticles also exhibited a redox-triggered profile. Also, the uptake behavior and pathways of coumarin 6-loaded Hep-cys-TOS nanoparticles were investigated, suggesting the nanoparticles could be taken into MCF-7 cells in energy-dependent, caveolae-mediated and cholesterol-dependent endocytosis manners. Later, MTT assays of different PTX-free and PTX-loaded formulations revealed the desirable safety of PTX-free nanoparticles and the enhanced anti-cancer activity of PTX-loaded Hep-cys-TOS nanoparticles (IC₅₀=0.79μg/mL). Apoptosis study indicated the redox-sensitive formulation could induce more apoptosis of MCF-7 cells than insensitive one (55.2% vs. 41.7%), showing the importance of intracellular burst release of PTX. Subsequently, the hemolytic toxicity confirmed the safety of the nanoparticles for intravenous administration. The results indicated the developed redox-sensitive nanoparticles were promising as intracellular drug delivery vehicles for cancer treatment.

Microfluidic device for label-free quantitation and distinction of bladder cancer cells from the blood cells using micro machined silicon based electrical approach; suitable in urinalysis assays

This paper introduces an integrated microfluidic chip as a promising tool to measure the concentration of bladder cancer cells (BCC) in urine samples. Silicon microchannels were used as trapping gates for both floated BCC and leukocytes which are found in the urine of patients. By the assistance of the gold electrodes patterned at the bottom of the micro gates, the capacitance of captured cancerous and blood cells were measured. Different membrane capacitance between BCC and leukocyte was the indicative signal for diagnosing the nature of captured cells in a urine like solution. The concentration range of the target that could be detected was about 10 BCCs per one chip. Such response has been achieved without applying any biochemical or florescent markers. Thus, it could be a simple and cheap approach to support cytological and immune-fluorescent assays. The limit of detection was approximately 1 cancerous cell/11 leukocytes in 1ml of the urine like solution. The entire measurement time was less than an hour. Consequently, this electrical microfluidic device promises significant potential in urinalysis.

An injectable acellular matrix scaffold with absorbable permeable nanoparticles improves the therapeutic effects of docetaxel on glioblastoma

Intratumoral drug delivery (IT) is an inherently appealing approach for concentrating toxic chemotherapies at the site of action. However, for most chemotherapies, poor tumor penetration and short retention at the administration site limit their anti-tumor effects. In this work, we describe permeable nanoparticles (NPs) prepared with a novel amphiphilic polymer, RRR-α-tocopheryl succinate-grafted-ε-polylysine conjugate (VES-g-ε-PLL). The nanoparticles (NPs) of VES-g-ε-PLL exhibited an ultra-small hydrodynamic diameter (20.8 nm) and positive zeta potential (20.6 mV), which facilitate strong glioma spheroid penetration ability in vitro. Additionally, the hydrophobic model drug docetaxel (DTX) could be effectively encapsulated in the nanoparticles with 3.99% drug loading and 73.37% encapsulation efficiency. To prolong the retention time of DTX-loaded nanoparticles (DTX-NPs) in the tumor, intact decellularized brain extracellular matrix (dBECM) derived from healthy rats was used as a drug depot to adsorb the ultra-small DTX-NPs. The intact DTX-NPs-adsorbing dBECM scaffold was further homogenized into an injectable DTX-NPs-dBECM suspension for intratumoral administration. The DTX-NPs-dBECM suspension exhibited slower DTX release than naked DTX-NPs without compromising the tumor penetration ability of DTX-NPs. An antitumor study showed that the DTX-NPs-dBECM suspension exhibited more powerful in vitro inhibition of tumor spheroid growth than free DTX solution or DTX-NPs. Due to strong tumor penetration ability and prolonged retention, DTX-NPs-dBECM led to complete suppression of glioma growth in vivo at 28 days after treatment. The therapeutic mechanism was due to enhanced proliferation inhibition and apoptosis of tumor cells and angiogenesis inhibition of glioma after treatment with DTX-NPs-dBECM. Finally, the safety of DTX-NPs-dBECM at the therapeutic dose was demonstrated via pathological HE assay from heart, liver, spleen, lung and kidney tissues. In conclusion, permeable nanoparticle-absorbing dBECM is a potential carrier for intratumoral delivery of common chemotherapeutics.

Polymeric lipid vesicles with pH-responsive turning on-off membrane for programed delivery of insulin in GI tract

A kind of polymeric lipid vesicles (PLVs) with pH-responsive turning on-off membrane for programed delivery of insulin in gastrointestinal (GI) tract was developed, which was self-assembled from the grafted amphipathic polymer of N-tocopheryl-N'-succinyl-ɛ-poly-l-lysine (TP/SC-g-PLL). By controlling the grafting ratio of hydrophobic alkane and ionizable carboxyl branches, the permeability of membrane was adjustable and thus allowing insulin release in a GI-pH dependent manner. The effects of grafting degree of substitution (DS) on the pH-responsive behavior of the formed vesicles were confirmed by critical aggregation concentration determination, morphology and size characterization. Their transepithelial permeability across the GI tract was proved by both confocal visualization in vitro model of Caco-2 cellular monolayer and in vivo hypoglycemic study in diabetic rats. Accordingly, the work described here indicated that the self-assembled PLVs could be a promising candidate for improving the GI delivery of hydrophilic biomacromolecule agents.

Vitamin E succinate-conjugated F68 micelles for mitoxantrone delivery in enhancing anticancer activity

Mitoxantrone (MIT) is a chemotherapeutic agent with promising anticancer efficacy. In this study, Pluronic F68-vitamine E succinate (F68-VES) amphiphilic polymer micelles were developed for delivering MIT and enhancing its anticancer activity. MIT-loaded F68–VES (F68–VES/MIT) micelles were prepared via the solvent evaporation method with self-assembly under aqueous conditions. F68–VES/MIT micelles were found to be of optimal particle size with the narrow size distribution. Transmission electron microscopy images of F68–VES/MIT micelles showed homogeneous spherical shapes and smooth surfaces. F68–VES micelles had a low critical micelle concentration value of 3.311 mg/L, as well as high encapsulation efficiency and drug loading. Moreover, F68–VES/MIT micelles were stable in the presence of fetal bovine serum for 24 hours and maintained sustained drug release in vitro. Remarkably, the half maximal inhibitory concentration (IC₅₀) value of F68–VES/MIT micelles was lower than that of free MIT in both MDA-MB-231 and MCF-7 cells (two human breast cancer cell lines). In addition, compared with free MIT, there was an increased trend of apoptosis and cellular uptake of F68–VES/MIT micelles in MDA-MB-231 cells. Taken together, these results indicated that F68–VES polymer micelles were able to effectively deliver MIT and largely improve its potency in cancer therapy.

Preparation, Characterization and Evaluation of α-Tocopherol Succinate-Modified Dextran Micelles as Potential Drug Carriers

In the present study, α-tocopherol succinate (TOS) conjugated dextran (Dex-TOS) was synthesized and characterized by fourier transform infrared (FT-IR) spectroscopy, ¹H nuclear magnetic resonance (¹H NMR), dynamic light scattering (DLS) and fluorescence spectroscopy. Dex-TOS could form nanoscaled micelles in aqueous medium. The critical micelle concentration (CMC) is 0.0034 mg/mL. Doxorubicin (Dox) was selected as a model drug. Dox-loaded Dex-TOS (Dex-TOS/Dox) micelles were prepared by a dialysis method. The size of Dex-TOS/Dox micelles increased from 295 to 325 nm with the Dox-loading content increasing from 4.21% to 8.12%. The Dex-TOS/Dox micelles were almost spherical in shape, as determined by transmission electron microscopy (TEM). In vitro release demonstrated that Dox release from the micelles was in a sustained manner for up to 96 h. The cellular uptake of Dex-TOS/Dox micelles in human nasopharyngeal epidermoid carcinoma (KB) cells is an endocytic process determined by confocal laser scanning microscopy (CLSM). Moreover, Dex-TOS/Dox micelles exhibited comparable cytotoxicity in contrast with doxorubicin hydrochloride. These results suggested that Dex-TOS micelles could be a promising carrier for drug delivery.

Polymeric Micelles: Recent Advancements in the Delivery of Anticancer Drugs

Nanotechnology, in health and medicine, extensively improves the safety and efficacy of different therapeutic agents, particularly the aspects related to drug delivery and targeting. Among various nano-carriers, polymer based macromolecular approaches have resulted in improved drug delivery for the diseases like cancers, diabetes, autoimmune disorders and many more. Polymeric micelles consisting of hydrophilic exterior and hydrophobic core have established a record of anticancer drug delivery from the laboratory to commercial reality. The nanometric size, tailor made functionality, multiple choices of polymeric micelle synthesis and stability are the unique properties, which have attracted scientists and researchers around the world to work upon in this opportunistic drug carrier. The capability of polymeric micelles as nano-carriers are nowhere less significant than nanoparticles, liposomes and other nanocarriers, as per as the commercial feasibility and presence is concerned. In fact polymeric micelles are among the most extensively studied delivery platforms for the effective treatment of different cancers as well as non-cancerous disorders. The present review highlights the sequential and recent developments in the design, synthesis, characterization and evaluation of polymeric micelles to achieve the effective anticancer drug delivery. The future possibilities and clinical outcome have also been discussed, briefly.

Polymeric Micelles: Recent Advancements in the Delivery of Anticancer Drugs

Nanotechnology, in health and medicine, extensively improves the safety and efficacy of different therapeutic agents, particularly the aspects related to drug delivery and targeting. Among various nano-carriers, polymer based macromolecular approaches have resulted in improved drug delivery for the diseases like cancers, diabetes, autoimmune disorders and many more. Polymeric micelles consisting of hydrophilic exterior and hydrophobic core have established a record of anticancer drug delivery from the laboratory to commercial reality. The nanometric size, tailor made functionality, multiple choices of polymeric micelle synthesis and stability are the unique properties, which have attracted scientists and researchers around the world to work upon in this opportunistic drug carrier. The capability of polymeric micelles as nano-carriers are nowhere less significant than nanoparticles, liposomes and other nanocarriers, as per as the commercial feasibility and presence is concerned. In fact polymeric micelles are among the most extensively studied delivery platforms for the effective treatment of different cancers as well as non-cancerous disorders. The present review highlights the sequential and recent developments in the design, synthesis, characterization and evaluation of polymeric micelles to achieve the effective anticancer drug delivery. The future possibilities and clinical outcome have also been discussed, briefly.