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

Advancing tumor vaccines: Overcoming TME challenges, delivery strategies, and biomaterial-based vaccine for enhanced immunotherapy

Tumor vaccines, as an immunotherapeutic approach, harness the body's immune cells to provoke antitumor responses, which have shown promising efficacy in clinical settings. However, the immunosuppressive tumor microenvironment (TME) and the ineffective vaccine delivery systems hinder the progression of many vaccines beyond phase II trials. This article begins with a comprehensive review of the complex interactions between tumor vaccines and TME, summarizing the current state of vaccine clinical research. Subsequently, we review recent advancements in targeted vaccine delivery systems and explore biomaterial-based tumor vaccines as a strategy to improve the efficacy of both delivery systems and treatment. Finally, we have presented our perspectives on tumor vaccine development, aiming to advance the field towards the creation of more effective tumor vaccines.

Advances in active targeting of ligand-directed polymeric nanomicelles via exploiting overexpressed cellular receptors for precise nanomedicine

Many of the utilized drugs which already exist in the pharmaceutical sector are hydrophobic in nature. These drugs are characterized by being poorly absorbed and difficult to formulate in aqueous environments with low bioavailability, which could result in consuming high and frequent doses in order to fulfil the required therapeutic effect. As a result, there is a decisive demand to find modern alternatives to overcome all these drawbacks. Self-assembling polymeric nanomicelles (PMs) with their unique structure appear to be a fascinating choice as a pharmaceutical carrier system for improving the solubility & bioavailability of many drugs. PMs as drug carriers have many advantages including suitable size, high stability, prolonged circulation time, elevated cargo capacity and controlled therapeutic release. Otherwise, the pathological features of some diseased cells, like cancer, allow PMs with particle size <200 nm to be passively uptaken via enhanced permeability and retention phenomenon (EPR). However, the passive targeting approach was proven to be insufficient in many cases. Consequently, the therapeutic efficiency of these PMs can be further reinforced by enhancing their cellular internalization via incorporating targeting ligands. These targeting ligands can enhance the assemblage of loaded cargos in the intended tissues via receptor-mediated endocytosis through exploiting receptors robustly expressed on the exterior of the intended tissue while minimizing their toxic effects. In this review, the up-to-date approaches of harnessing active targeting ligands to exploit certain overexpressed receptors will be summarized concerning the functionalization of the exterior of PMs for ameliorating their targeting potential in the scope of nanomedicine.

Improved physicochemical stability of fish oil nanoemulsion via a dense interfacial layer formed by hyaluronic acid-poly(glyceryl)10-stearate

This study aimed to synthesize a novel emulsifier, hyaluronic acid-poly(glyceryl)10-stearate (HA-PG10-C18), and employ it for the fabrication of nanoemulsions incorporating deep-sea fish oil to improve their apparent solubility and physicochemical stability. 1H NMR and FT-IR analyses indicated successful synthesis of HA-PG10-C18. Nanoemulsions of deep-sea fish oil loaded with HA-PG10-C18 (HA-PG10-C18@NE) were successfully fabricated by ultrasonic emulsification. The fixed aqueous layer thickness (FALT) of PG10-C18@NE and HA-PG10-C18@NE was determined and the FALT of both nanoemulsions was similar, while the surface density of HA-PG10-C18@NE (4.92 × 10-12 ng/nm2) is 60 % higher than that of PG10-C18@NE (3.07 × 10-12 ng/nm2). Notably, HA-PG10-C18@NE demonstrated an exceptional physicochemical stability when exposed to various stressed environmental conditions, especially its freeze-thaw stability. Moreover, after simulated in vitro digestion, the HA-PG10-C18@NE exhibited a comparatively greater liberation of free fatty acids (94.0 ± 1.7 %) when compared to the release observed in PG10-C18@NE (85.5 ± 2.2 %).

Carbosilane Dendritic Amphiphiles from Cholesterol or Vitamin E for Micelle Formation

Cationic dendritic amphiphiles were prepared through the linkage of interesting hydrophobic molecules such as cholesterol or vitamin E to the focal point of carbosilane dendrons. These new dendritic systems self-assembled in saline, producing micellar aggregates with hydrodynamic diameters ranging from 6.5 to 9.2 nm, and critical micelle concentrations of approximately 5 and 10 μM for second- and third-generation systems, respectively. The assemblies were able to encapsulate drugs of different charges (anionic, neutral, and cationic). Surprisingly, a 92% encapsulation efficiency for diclofenac was achieved in micelles prepared from second-generation dendrons. Toxicity measurements on peripheral blood mononuclear cells indicated different behavior depending on the generation, corresponding to the micellar regime. In contrast to the third-generation system, the second-generation system was non-toxic up to 20 μM, opening a window for its use in a micellar regimen, thereby operating as a drug delivery system for different biomedical applications.

Potentials of ionic liquids to overcome physical and biological barriers

Over the last decades, ionic liquids (IL) have shown great potential in non-invasive delivery starting from synthetic small molecules to biological large molecules. ILs are emerging as a particular class of drug delivery systems due to their unique physiochemical properties, simple surface modification, and functionalization. These features of IL help achieve specific design principles that are essential for a non-invasive drug delivery system. In this review, we have discussed IL and their applications in non-invasive drug delivery systems. We evaluated state-of-the-art development and advances of IL aiming to mitigate the biological and physical barriers to improve transdermal and oral delivery, summarized in this review. We also provided an overview of the various factors determining the systemic transportation of IL-based formulation. Additionally, we have emphasized how the ILs facilitate the transportation of therapeutic molecules by overcoming biological barriers.

Sulfur dioxide-releasing polymeric micelles based on modified hyaluronic acid for combined cancer therapy

In this study, an amphiphilic polymer mPEG-HA(SA)-DNs was designed and synthesized to fabricate a multifunctional micellar system to enhance the therapeutic efficacy and reduce the toxic effect of paclitaxel (PTX). The polymer was prepared by introducing mPEG, stearic acid (SA) and 2,4-dinitrobenzenesulfonic acid (DNs) to the backbone of hyaluronic acid (HA). With above modifications, the fabricated micelles could encapsulate PTX in the core with high drug loading. The optimized PTX-loaded micelles had a mean size of 158.3 nm. Upon the effect of mPEG, the mPEG-HA(SA)-DNs micelles reduced the non-specific protein adsorption. In vitro drug release study revealed the excellent glutathione (GSH)-triggered PTX release behavior of the micelles. Moreover, GSH could trigger the detachment of DNs segment from mPEG-HA(SA)-DNs, and result in the release of SO2. In vitro and in vivo antitumor efficacy studies demonstrated that the PTX-loaded mPEG-HA(SA)-DNs micelles exhibited outstanding tumor suppression effect. The micelles would be potential carriers for combination cancer therapy by SO2 and PTX.

Hyaluronic Acid-Mediated Phenolic Compound Nanodelivery for Cancer Therapy

Phenolic compounds are bioactive phytochemicals showing a wide range of pharmacological activities, including anti-inflammatory, antioxidant, immunomodulatory, and anticancer effects. Moreover, they are associated with fewer side effects compared to most currently used antitumor drugs. Combinations of phenolic compounds with commonly used drugs have been largely studied as an approach aimed at enhancing the efficacy of anticancer drugs and reducing their deleterious systemic effects. In addition, some of these compounds are reported to reduce tumor cell drug resistance by modulating different signaling pathways. However, often, their application is limited due to their chemical instability, low water solubility, or scarce bioavailability. Nanoformulations, including polyphenols in combination or not with anticancer drugs, represent a suitable strategy to enhance their stability and bioavailability and, thus, improve their therapeutic activity. In recent years, the development of hyaluronic acid-based systems for specific drug delivery to cancer cells has represented a pursued therapeutic strategy. This is related to the fact that this natural polysaccharide binds to the CD44 receptor that is overexpressed in most solid cancers, thus allowing its efficient internalization in tumor cells. Moreover, it is characterized by high biodegradability, biocompatibility, and low toxicity. Here, we will focus on and critically analyze the results obtained in recent studies regarding the use of hyaluronic acid for the targeted delivery of bioactive phenolic compounds to cancer cells of different origins, alone or in combination with drugs.

Hyaluronic Acid-Based Nanocarriers for Anticancer Drug Delivery

Hyaluronic acid (HA), a main component of the extracellular matrix, is widely utilized to deliver anticancer drugs due to its biocompatibility, biodegradability, non-toxicity, non-immunogenicity and numerous modification sites, such as carboxyl and hydroxyl groups. Moreover, HA serves as a natural ligand for tumor-targeted drug delivery systems, as it contains the endocytic HA receptor, CD44, which is overexpressed in many cancer cells. Therefore, HA-based nanocarriers have been developed to improve drug delivery efficiency and distinguish between healthy and cancerous tissues, resulting in reduced residual toxicity and off-target accumulation. This article comprehensively reviews the fabrication of anticancer drug nanocarriers based on HA in the context of prodrugs, organic carrier materials (micelles, liposomes, nanoparticles, microbubbles and hydrogels) and inorganic composite nanocarriers (gold nanoparticles, quantum dots, carbon nanotubes and silicon dioxide). Additionally, the progress achieved in the design and optimization of these nanocarriers and their effects on cancer therapy are discussed. Finally, the review provides a summary of the perspectives, the lessons learned so far and the outlook towards further developments in this field.

Glucosamine-Modified Reduction-Responsive Polymeric Micelles for Liver Cancer Therapy

In this work, glucose transporter-1 (GLUT-1) and glutathione (GSH) over-expression in liver cancer was utilized to design a reduction-responsive and active targeting drug delivery system AG-PEG-SS-PCL (APSP) for the delivery of sorafenib (SF). The SF-APSP micelles were prepared using the thin film hydration method and characterized by various techniques. In vitro release experiments showed that the cumulative release of SF-APSP micelles in the simulated tumor microenvironment (pH 7.4 with GSH) reached 94.76 ± 1.78% at 48 h, while it was only 20.32 ± 1.67% in the normal physiological environment (pH 7.4 without GSH). The in vitro study revealed that glucosamine (AG) enhanced the antitumor effects of SF, and SF-APSP micelles inhibited proliferation by targeting HepG2 cells and suppressing cyclin D1 expression. The in vivo antitumor efficacy study further confirmed that the SF-APSP micelles had excellent antitumor effects and better tolerance against nude mouse with HepG2 cells than other treatment groups. All in all, these results indicated that SF-APSP micelles could be a promising drug delivery system for anti-hepatoma treatment.

Levan nanoparticles with intrinsic CD44-targeting ability for tumor-targeted drug delivery

Existing anticancer therapeutics exhibit short half-lives, non-specificity, and severe side effects. To address this, active-targeting nanoparticles have been developed; however, the complex fabrication procedures, scale-up, and low reproducibility delay FDA approval, particularly for functionalized nanoparticles. We developed levan nanoparticles via simple one-pot nanoprecipitation for specific anticancer drug delivery. Levan is a plant polysaccharide which has a binding affinity to CD44 receptors and amphiphilicity. The nanoparticles are self-assembled and enable active-targeting without chemical modifications. The paclitaxel-loaded levan nanoparticles (PTX@LevNP) demonstrated a sustained PTX release and long-term stability. The LevNP can bind CD44 receptors on cancer cells, and PTX@LevNP showed enhanced anticancer activity in CD44-positive cells (SCC7 cells). In SCC7 tumor-bearing mice, the accumulation of LevNP in tumor tissue was 3.7 times higher than that of the free-dye, resulting in improved anticancer efficacy of PTX@LevNP. This new strategy using levan can produce nanoparticles for effective cancer treatment without complex fabrication procedures.

Peptide-functionalized therapeutic nanoplatform for treatment orthotopic triple negative breast cancer and bone metastasis

Epidermal Growth Factor Receptor (EGFR) is a promising therapeutic target for triple-negative breast cancer (TNBC). Recently, specific EGFR-targeting peptide GE11-based delivery nano-system shows excellent potential because of its chemical versatility and good targeting ability. However, no further research focusing on the downstream of EGFR after binding with GE11 was explored. Hence, we tailor-designed a self-assembled nanoplatform named GENP using amphiphilic molecule of stearic acid-modified GE11. After loading doxorubicin (DOX), the resulted nanoplatform GENP@DOX demonstrated high loading efficiency and sustainable drug release. Importantly, our findings proved that GENP alone significantly suppressed the proliferation of MDA-MB-231 cells via EGFR-downstream PI3K/AKT signaling pathways, contributing to the synergistic treatment with its DOX release. Further work illustrated remarkable therapeutic efficacy both in orthotopic TNBC and its bone metastasis models with minimal biotoxicity. Together, the results highlight that our GENP-functionalized nanoplatform is a promising strategy for the synergistic therapeutic efficacy targeting EGFR-overexpressed cancer.

Tumor Targeting and pH-Sensitive Inclusion Complex Based on HP-β-CD as a Potential Carrier for Paclitaxel: Fabrication, Molecular Docking, and Characterization

In this study, a tumor-targeting and pH-sensitive inclusion complex based on the host-guest recognition between the chitosan and folic acid grafted HP-β-CD (FA-CS-CD) and stearic acid modified 2-benzimidazolemethanol (BM-SA) was designed and fabricated for the controlled delivery of paclitaxel (PTX). Through the combination of computational simulations and experiments, the interaction between FA-CS-CD, BM-SA, and PTX was investigated, and the optimized preparation method was obtained. For the optimized PTX-loaded FA-CS-CD/BM-SA inclusion complex, the particle size and zeta potential were 146 nm and +15.4 mV, respectively. In vitro drug release study revealed the pH-triggered drug release behavior of the inclusion complex. Both in vitro and in vivo evaluations demonstrated that the PTX-loaded FA-CS-CD/BM-SA inclusion complex exhibited enhanced antitumor efficiency and minimized systemic toxicity. This system might be a promising carrier for PTX.

Design and fabrication of chitosan-based AIE active micelles for bioimaging and intelligent delivery of paclitaxel

In this study, cetyl 4-formylbenzoate alkyl and 4-(2-hydroxyethoxy) benzophenonesalicylaldazide modified biotinylated chitosan (CS-BT-HBS-CB) featured with aggregation-induced emission (AIE) characteristic, active tumor-targeting ability and pH-responsive drug release property was designed and synthesized. The polymer was fabricated by introducing hydrophobic segment, tumor targeting ligand, acid-sensitive bond and AIE fluorophore to the backbone of chitosan. Due to its amphiphilicity, the polymer could self-assemble into micelles and encapsulate paclitaxel (PTX) to form PTX-loaded CS-BT-HBS-CB micelles. The mean size of the micelles was 167 nm, which was beneficial to the EPR effect. Moreover, with the help of above functional groups, the micelles exhibited excellent AIE effect, triggered drug release behavior by acidic condition, selective internalization by MCF-7 cells and excellent cellular imaging capability. In vivo studies revealed that the PTX-loaded CS-BT-HBS-CB micelles could enhance the antitumor efficacy with low systemic toxicity. This micellar system would be a potential candidate for cancer therapy and bioimaging.

Nanoscale bioconjugates: A review of the structural attributes of drug-loaded nanocarrier conjugates for selective cancer therapy

Nanobioconjugates are nanoscale drug delivery vehicles that have been conjugated to or decorated with biologically active targeting ligands. These targeting ligands can be antibodies, peptides, aptamers, or small molecules such as vitamins or hormones. Most research studies in this field have been devoted to targeting cancer. Moreover, the nanostructures can be designed with an additional level of targeting by being designed to be stimulus-responsive or "smart" by a judicious choice of materials to be incorporated into the hybrid nanostructures. This stimulus could be an acidic pH, raised temperature, enzyme, ultrasound, redox potential, an externally applied magnetic field, or laser irradiation. In this case, the smart capability can increase the accumulation at the tumor site or the on-demand drug release, while the ligand ensures selective binding to the tumor cells. The present review highlights some interesting studies classified according to the nanostructure material. These materials include natural substances (polysaccharides), multi-walled carbon nanotubes (and halloysite nanotubes), metal-organic frameworks and covalent-organic frameworks, metal nanoparticles (gold and silver), and polymeric micelles.

Novel Tumor-Targeting Nanoparticles for Cancer Treatment-A Review

Being one of the leading causes of death and disability worldwide, cancer represents an ongoing interdisciplinary challenge for the scientific community. As currently used treatments may face limitations in terms of both efficiency and adverse effects, continuous research has been directed towards overcoming existing challenges and finding safer specific alternatives. In particular, increasing interest has been gathered around integrating nanotechnology in cancer management and subsequentially developing various tumor-targeting nanoparticles for cancer applications. In this respect, the present paper briefly describes the most used cancer treatments in clinical practice to set a reference framework for recent research findings, further focusing on the novel developments in the field. More specifically, this review elaborates on the top recent studies concerning various nanomaterials (i.e., carbon-based, metal-based, liposomes, cubosomes, lipid-based, polymer-based, micelles, virus-based, exosomes, and cell membrane-coated nanomaterials) that show promising potential in different cancer applications.

Novel ROS-responsive marine biomaterial fucoidan nanocarriers with AIE effect and chemodynamic therapy

Chemodynamic therapy (CDT) has been widely used in the treatment of many kinds of tumors, which can effectively induce tumor cell apoptosis by using produced reactive oxygen species (ROS). In this paper, ROS-sensitive multifunctional marine biomaterial natural polysaccharide nanoparticles were designed. Aggregation-induced emission (AIE) molecules tetraphenylethylene (TPE) labeled and caffeic acid (CA) modified fucoidan (FUC) amphiphilic carrier material (CA-FUC-TK-TPE, CFTT) was fabricated, in which the thioketal bond(TK) was used as the linkage arm between TPE and fucoidan chain, giving the CFTT material ROS sensitivity. In addition, amphiphilic carrier material (FUC-TK-VE, FTVE) composed of thioketal-linked vitamin E and fucoidan was synthesized. The mixed carrier material CFTT and FTVE self-assembled in water to form nanoparticles (CFTT - FTVE@PTX-Fe³⁺) loaded with PTX and Fe³⁺. The CDT effect was combined with the chemotherapeutic drug PTX to achieve tumor inhibition. In vitro cell studies have proved that CT/PTX nanoparticles have excellent cell permeability and tumor cytotoxicity. In vivo antitumor experiments confirmed effective antitumor activity and reduced side effects.

Progress and Principle of Drug Nanocrystals for Tumor Targeted Delivery

Drugs are referred to as drug nanocrystals when they exist as nanoscale crystal structures. This kind of nanocarrier has been widely utilized to increase the solubility and absorption for poorly aqueous soluble drugs after oral administration, or prolong the drug circulation when intravenous administration. The systemic cytotoxicity caused by antitumor drugs usually come from the nonspecific drug distribution. To solve the disadvantage of poor targetability, drug nanocrystals for tumor targeted delivery have been developed in recent years. In this review, the targeting mechanisms of various surface modified drug nanocrystals are introduced with the focus on passive targeting, active targeting and stimuli-responsive targeting in details. Function and application of common surface modified materials are also discussed.

Recent Advances in the Local Drug Delivery Systems for Improvement of Anticancer Therapy

The conventional anticancer chemotherapies not only cause serious toxic effects, but also produce resistance in tumor cells exposed to long-term therapy. Usually, the killing of metastasized cancer cells requires long-term therapy with higher drug doses, because the cancer cells develop resistance due to the induction of poly-glycoproteins (P-gps) that act as a transmembrane efflux pump to transport drugs out of the cells. During the last few decades, scientists have been exploring new anticancer drug delivery systems such as microencapsulation, hydrogels, and nanotubes to improve bioavailability, reduce drug-dose requirement, decrease multiple drug resistance, and to save normal cells as non-specific targets. Hopefully, the development of novel drug delivery vehicles (nanotubes, liposomes, supramolecules, hydrogels, and micelles) will assist to deliver drug molecules at the specific target site and reduce the undesirable side effects of anticancer therapies in humans. Nanoparticles and lipid formulations are also designed to deliver small drug payload at the desired tumor cell sites for their anticancer actions. This review will focus on the recent advances in the drug delivery systems, and their application in treating different cancer types in humans.

An updated review of folate-functionalized nanocarriers: A promising ligand in cancer

The uncontrolled release of drugs in conventional drug delivery systems has led to the introduction of new nanotechnology-based drug delivery systems and the use of targeted nanocarriers for cancer treatment. These targeted nanocarriers, which consist of intelligent nanoparticles modified with targeting ligands, can deliver drugs to specified locations at the right time and reduce drug doses to prevent side effects. Folate is a suitable targeting ligand for folate receptors overexpressed on cancer cells and has shown promising results in the diagnosis and treatment of cancer. In this review, we highlight the latest developments on the use of folate-conjugated nanoparticles in cancer diagnosis and treatment. Moreover, the toxicity, biocompatibility and efficacy of these nanocarriers are discussed.

Recent advances in polymeric core-shell nanocarriers for targeted delivery of chemotherapeutic drugs

The treatment effect of chemotherapeutics is often impeded by nonspecific biodistribution and limited biocompatibility. Polymeric core-shell nanocarriers (PCS NCs) composed of a polymer core and at least one shell have been widely applied for cancer therapy and have shown great potential in selectively delivering chemotherapeutic drugs to tumor sites. These PCS NCs can effectively ameliorate the delivery efficiency and therapeutic index of anticarcinogens by prolonging drug residence in the bloodstream, enhancing tumor tissue drug penetration, facilitating cellular drug uptake, controlling the spatiotemporal release of payloads, or codelivering two or more bioactive agents. This review summarizes recently published literature on using PCS NCs to transport chemotherapeutic drugs with poor aqueous solubility and discusses their design principles, structural features, functional properties, and potential limitations.

Augment the efficacy of eradicating metastatic lesions and tumor proliferation in breast cancer by honokiol-loaded pH-sensitive targeted lipid nanoparticles

Functionally-enabled delivery systems for aggressive lung metastases from breast cancer have been broadly examined, and the simultaneous inhibition of metastasis while fighting tumors persists as a provocative concern. We propose a valid strategy for delivering natural drugs-Honokiol (Hol) to achieve eradication of breast cancer cells and inhibition of pulmonary metastasis. A non-toxic degradable pH-sensitive polymer-PBAE for encapsulated Hol, and the outer layer was wrapped with Folate-DSPE-PEG₂₀₀₀ (FA/PBAE/Hol-NPs), which have strengthened stability, prolonged in vivo circulation time and efficiently targets tumor sites. FA/PBAE/Hol-NPs displayed dampening the capability of migration and invasion, elevated 4T1 uptake and boosted apoptosis. What's more, 4T1 breast cancer model mice exhibited marked anti-tumor (Inhibition rate of 62.8 %) and lung metastasis suppression (Inhibition rate of 84.3 %). In parallel, histological immunofluorescence and immunohistochemical assays demonstrate higher apoptosis levels and repression of matrix metalloproteinase expression in mice, all of which are instrumental in inhibiting lung metastasis. Taken together, FA/PBAE/Hol-NPs can as an efficacious intravenous drug delivery system for the curative treatment of metastatic breast cancer.

A pH-Sensitive Polymeric Micellar System Based on Chitosan Derivative for Efficient Delivery of Paclitaxel

In this study, an amphiphilic conjugate based on mPEG and cholesterol-modified chitosan with hydrazone bonds in the molecules (mPEG-CS-Hz-CH) was successfully synthesized. Using the polymer as the carrier, the paclitaxel (PTX)-loaded mPEG-CS-Hz-CH micelles were prepared by an ultrasonic probe method. The mean particle size and zeta potential of the optimized PTX-loaded micelles were 146 ± 4 nm and +21.7 ± 0.7 mV, respectively. An in vitro drug release study indicated that the PTX-loaded mPEG-CS-Hz-CH micelles were stable under normal physiological conditions (pH 7.4), whereas rapid drug release was observed in the simulated tumor intracellular microenvironment (pH 5.0). An in vitro cytotoxicity study demonstrated the non-toxicity of the polymer itself, and the PTX-loaded micelles exhibited superior cytotoxicity and significant selectivity on tumor cells. An in vivo antitumor efficacy study further confirmed that the PTX-loaded micelles could improve the therapeutic efficacy of PTX and reduce the side effects. All these results suggested that the mPEG-CS-Hz-CH micelles might be promising pH-sensitive nanocarriers for PTX delivery.

AIE-active polymeric micelles based on modified chitosan for bioimaging-guided targeted delivery and controlled release of paclitaxel

In this study, a novel polymer based on aggregation-induced emission (AIE) fluorogen, biotin and disulfide bonds modified chitosan (TPE-bi(SS-CS-Bio)) was designed and synthesized. The polymer could self-assemble into micelles in aqueous media and encapsulate paclitaxel (PTX) into the core with high drug loading. Fluorescence study indicated that the micelles exhibited excellent AIE feature with intense blue fluorescence emitted. In vitro drug release study indicated that the micelles could disassemble rapidly in the presence of high level of glutathione. The modification by biotin could enhance the cellular uptake of the micelles. The drug-loaded micelles possessed remarkable cytotoxicity against MCF-7 cells, and their distribution in the cells could be traced due to the excellent AIE feature. In vivo antitumor efficacy study demonstrated the superior antitumor activity of the PTX-loaded TPE-bi(SS-CS-Bio) micelles. These results indicated that TPE-bi(SS-CS-Bio) has the ability of biological imaging and can be used as a potential carrier for PTX.

Targeted antitumor comparison study between dopamine self-polymerization and traditional synthesis for nanoparticle surface modification in drug delivery

To improve the therapeutic efficacy of anticancer agents and extend their application, mussel-inspired chemical modifications have attracted considerable attention. Surface modification based on polydopamine (PDA) has been a facile and versatile method to immobilize biomolecules on substrates for targeted drug delivery. To better analyze pharmaceutical differences between PDA-based surface modification and traditional synthesis methods, we prepared two kinds of folate (FA)-targeted nanoparticles (NPs) loaded with paclitaxel (PTX). The resultant PTX-PDA-FA NPs and PTX-FA NPs represented PDA and synthesis strategies, respectively. PTX-PDA-FA NPs and PTX-FA NPs have been characterized. The particle size of PTX-PDA-FA NPs was smaller than that of PTX-FA NPs. The two kinds of NPs both exhibited long-rod morphology, good colloidal stability and sustained slow drug release. Cytotoxicityin vitrowas evaluated, and antitumor efficacy was investigated against 4T1 tumor-bearing mice. The tumor targeting therapeutic index of PTX-PDA-FA NPs and PTX-FA NPs showed equivalent superior specificity compared to nontargeted groups, which indicated that FA successfully attached to the surface of NPs by the PDA method and that the antitumor effect was equivalent to that of FA-modified NPs prepared by the chemical synthesis method. These results further indicated that PDA, as a simple and effective chemical surface modification platform, could be developed and applied in targeted delivery systems.

Self-assembled and pH-responsive polymeric nanomicelles impart effective delivery of paclitaxel to cancer cells

Chemotherapy is an essential component of breast cancer therapy, but it is associated with serious side effects. Herein, a pluronic F68-based pH-responsive, and self-assembled nanomicelle system was designed to improve the delivery of paclitaxel (PTX) to breast cancer cells. Two pH-responsive pluronic F68-PTX conjugates i.e. succinoyl-linked conjugate (F68-SA-PTX) and cis-aconityl-linked conjugate (F68-CAA-PTX) were designed to respond the varying pH-environment in tumour tissue. Although both the linkers showed pH-sensitivity, the F68-CAA-PTX exhibited superior pH-sensitivity over the F68-SA-PTX and achieved a more selective release of PTX from the self-assembled nanomicelles. The prepared nanomicelles were characterized by dynamic light scattering, transmittance electron microscopy, differential scanning calorimetry and powder X-ray diffraction techniques. The anticancer activity of prepared nanomicelles and pure PTX were evaluated by 2D cytotoxicity assay against breast cancer cell line MDA-MB-231 and in the real tumour environments i.e. 3D tumor spheroids of MDA-MB-231 cells. The highest cytotoxicity effect of PTX was observed with F68-CAA-PTX nanomicelles followed by F68-SA-PTX and free PTX. Further, the F68-CAA-PTX nanomicelles also induced significant apoptosis with a combination of increase in ROS generation, decrease in the depolarisation of MMP and G2/M cell cycle arrest. These observed results provide a new insight for breast cancer treatment using pluronic nanomicelles.

Efficient drug delivery and anticancer effect of micelles based on vitamin E succinate and chitosan derivatives

Nanocarriers have emerged as a promising cancer drug delivery strategy. Multi-drug resistance caused by overexpression of multiple-drug excretion transporters in tumor cells is the major obstacle to successful chemotherapy. Vitamin E derivatives have many essential functions for drug delivery applications, such as biological components that are hydrophobic, stable, water-soluble enhancing compounds, and anticancer activity. In addition, vitamin E derivatives are also effective mitocan which can overcome multi-drug resistance by binding to P glycoproteins. Here, we developed a carboxymethyl chitosan/vitamin E succinate nano-micellar system (O-CMCTS-VES). The synthesized polymers were characterized by Fourier Transform IR, and ¹H NMR spectra. The mean sizes of O-CMCTS-VES and DOX-loaded nanoparticles were around 177 nm and 208 nm. The drug loading contents were 6.1%, 13.0% and 10.6% with the weight ratio of DOX to O-CMCTS-VES corresponding 1:10, 2:10 and 3:10, and the corresponding EEs were 64.3%, 74.5% and 39.7%. Cytotoxicity test, hemolysis test and histocompatibility test showed that it had good biocompatibility in vitro and in vivo. Drug release experiments implied good pH sensitivity and sustained-release effect. The DOX/O-CMCTS-VES nanoparticles can be efficiently taken up by HepG2 cancer cells and the tumor inhibition rate is up to 62.57%. In the in vivo study by using H22 cells implanted Balb/C mice, DOX/O-CMCTS-VES reduced the tumor volume and weight efficiently with a TIR of 35.58%. The newly developed polymeric micelles could successfully be utilized as a nanocarrier system for hydrophobic chemotherapeutic agents for the treatment of solid tumors.

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A nano-micellar system (O-CMCTS-VES) constituted by carboxymethyl chitosan and vitamin E succinate was fabricated.

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The micelles hold high cytocompatibility, hemocompatibility, tissue compatibility, and drug load contents.

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Drug release experiments implied good pH sensitivity and sustained-release effect of O-CMCTS-VES.

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O-CMCTS-VES loading DOX showed efficient anti-tumor effect in vitro and in vivo.

Novel nano-pomegranates based on astragalus polysaccharides for targeting ERα-positive breast cancer and multidrug resistance

Chemotherapy is an important method for treating breast cancer. However, multidrug resistance is one of the major challenges in breast cancer chemotherapy. There is an urgent need to develop novel, effective antitumor strategies that will perfect existing therapeutic regimens. In this study, the double-targeted nanocarrier, Quercetin-3'3-dithiodipropionic acid-Astragalus polysaccharides-Folic acid (QDAF), was successfully synthesized and self-assembled into a neoteric nano-targeted delivery strategy, named nano-pomegranates, and which were utilized to effectively inhibit multidrug resistance in estrogen receptor α (ERα)-positive breast tumor. The outstanding abilities of nano-pomegranates to release the drug in a reducing environment was determined by in vitro release assay. The cellular studies in MCF-7 cells were examined that nano-pomegranates have remarkable efficiencies of enhancing cellular uptake, inhibition and necrosis and apoptosis. In vivo antitumor experiments showed that nano-pomegranates have better anti-tumor effects and lower systemic toxicity than free Cur. In conclusion, nano-pomegranates have great potential in anti-breast cancer treatment.

An outlook on procedures of conjugating folate to (co)polymers and drugs for effective cancer targeting

Folate receptors (FRs) are expressed in vast majority of cancers. Selective targeting of the FRs is, therefore, one of the most popular and sought-after strategies for improving the efficacy of cancer therapeutics. Variety of approaches involving folate conjugation to several well-known and novel, nontoxic, biodegradable, and biocompatible (co)polymers have been attempted and successfully applied to a large number of nanoparticulate drug delivery systems (micelles, liposomes, nanoparticles, quantum dots, mesoporous silica-based materials, and others) in the last decade-and-a-half. Standard and novel synthetic approaches were utilized for the conjugation, followed by the formulation of the drug delivery modality. In most of the cases, the targeted system lived up to its reputation, validating its usefulness in targeted cancer therapeutics. The present review summarizes the progress and state-of-the-art synthetic methodologies for folate conjugation to (co)polymers, drugs, and nucleic acids. The limitations of the FR targeting are discussed in brief to give the reader the other side of the story. Finally, the information on marketed folic acid conjugates highlight their industrial applications.

Safety and efficacy concerns of modern strategies of local anesthetics delivery

In the last few decades, several formulations have evolved to realize better efficacy of administered anesthesia. These innovative formulations have facilitated surgeons to perform operations under purely local anesthesia, which provides extra protection and comfort to patients. Ease of delivery of local anesthesia is the need of the current generation, because some of the standard procedures are performed without the use of any sedative agent. Therefore, we are presenting here the various approaches of administration of local anesthetics by the surgeons. To construct a comprehensive report on various methods of anesthesia, we followed a systematic literature search of bibliographic databases of published articles recently in the international journals and publishers of repute. A comprehensive study of several reports of the field indicates that there are significant progresses towards developing novel formulations of anesthesia drugs as well as strategies of delivery. Among formulations, nanoparticle-based delivery approaches, including polymeric, liposomal, and micellar structures, have offered the much needed efficacy with low toxicity. Therefore, several of such techniques are at various stages of clinical trials. Nanotechnology-based delivery approaches have significantly emerged in recent past due to the low systemic toxicity and better efficacy of the nonconventional local anesthetics. The other methods of local anesthesia delivery such as transdermal, magnetophoresis, electrophoresis, and iontophoresis are frequently used due to them being minimally invasive and locally effective. Therefore, the combination of the nanotechnological methods with above mentioned techniques would significantly enhance the overall process of local anesthesia delivery and efficacy.

Improvement of the pharmacokinetic/pharmacodynamic relationship in the treatment of invasive aspergillosis with voriconazole. Reduced drug toxicity through novel rapid release formulations

Voriconazole (VCZ) is currently the first-line treatment for invasive aspergillosis, although the doses are limited by its poor solubility and high hepatic toxicity. The aim of this study was to develop a solid self-dispersing micellar system of VCZ to improve the pharmacokinetic/pharmacodynamic (PK/PD) relationship and reduce hepatotoxicity. In this work, solid micellar systems of VCZ are formulated with different polysorbate 80 ratios using mannitol as a hydrophilic carrier. The novel micellar systems were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and dissolution studies. Self-dispersing micellar systems reduced VCZ crystallinity, leading to an improvement in its dissolution rate. The in vitro susceptibility test also revealed that the most common microorganisms in invasive aspergillosis exhibited low minimum inhibitory concentration (MIC) values for micellar systems. Pharmacokinetic studies indicated an improvement in bioavailability for MS-1:3:0.05, and changes in its biodistribution to different organs. MS-1:3:0.05 showed an increased concentration in lungs and a significant decrease in VCZ accumulated in the liver.

Recent advantage of hyaluronic acid for anti-cancer application: a review of "3S" transition approach

In recent years, nano drug delivery system has been widely concerned because of its good therapeutic effect. However, the process from blood circulation to cancer cell release of nanodrugs will be eliminated by the human body's own defense trap, thus reducing the therapeutic effect. In recent years, a "3S" transition concept, including stability transition, surface transition and size transition, was proposed to overcome the barriers in delivery process. Hyaluronic (HA) acid has been widely used in delivery of anticancer drugs due to its excellent biocompatibility, biodegradability and specific targeting to cancer cells. In this paper, the strategies and methods of HA-based nanomaterials using "3S" theory are reviewed. The applications and effects of "3S" modified nanomaterials in various fields are also introduced.

Novel multifunctional triple folic acid, biotin and CD44 targeting pH-sensitive nano-actiniaes for breast cancer combinational therapy

In this study, novel multifunctional folic acid, biotin, and CD44 receptors targeted and pH-sensitive “nano-actiniaes” were fabricated with icariin (ICA) and curcumin (Cur) as loaded model drugs for breast cancer therapy. The newly synthesized polymer oligomeric hyaluronic acid-hydrazone bond-folic acid-biotin (Bio-oHA-Hyd-FA) was characterized by ¹H NMR spectrogram (proton nuclear magnetic resonance). The obtained drug carrier Bio-oHA-Hyd-FA self-assembled into nanomicelles, named as “nano-actiniaes”, in aqueous media with hydrodynamic diameter of 162.7 ± 5 nm. The size, surface zeta potential, and morphology of the “nano-actiniaes” were observed via TEM. The in vitro release experiment indicated that much more encapsulated icariin (ICA) and curcumin (Cur) were released from the Bio-oHA-Hyd-FA micelles (nano-actiniaes) in the acidic environment. Additionally, the cytotoxicity research demonstrated that the Bio-oHA-Hyd-FA carrier material was completely nontoxic, and the ICA&Cur “nano-actiniaes” had greater cytotoxicity compared with other control groups. In addition, the “nano-actiniaes” were found to significantly inhibit cancer cell invasion by Transwell assay. Moreover, in vivo evaluation of anti-tumor effect illustrated that the ICA and Cur “nano-actiniaes” possessed inhibitory effect on tumors. Consequently, the multi-targeted pH-sensitive “nano-actiniaes” can realize significant tumor targeting and effectively inhibit tumor growth.

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.

Preparation, characterization and preliminary pharmacokinetic study of pH-sensitive Hydroxyapatite/Zein nano-drug delivery system for doxorubicin hydrochloride

OBJECTIVES

Zein nanoparticles (Zein NPs) were used as a hydroxyapatite (HA) biomineralization template to generate HA/Zein NPs. Doxorubicin hydrochloride (DOX) was loaded on HA/Zein NPs (HA/Zein-DOX NPs) to improve its pH-sensitive release, bioavailability and decrease cardiotoxicity.

METHODS

HA/Zein-DOX NPs were prepared by phase separation and biomimetic mineralization method. Particle size, polydispersity index (PDI), Zeta potential, transmission electron microscope, X-ray diffraction and Fourier-transform infrared spectroscopy of HA/Zein-DOX NPs were characterized. The nanoparticles were then evaluated in vitro and in vivo.

KEY FINDINGS

The small PDI and high Zeta potential demonstrated that HA/Zein-DOX NPs were a stable and homogeneous dispersed system and that HA was mineralized on Zein-DOX NPs. HA/Zein-DOX NPs showed pH-sensitive release. Compared with free DOX, HA/Zein-DOX NPs increased cellular uptake which caused 7 times higher in-vitro cytotoxicity in 4T1 cells. Pharmacokinetic experiments indicated the t_1/2β and AUC_{0- t} of HA/Zein-DOX NPs were 2.73- and 3.12-fold higher than those of DOX solution, respectively. Tissue distribution exhibited HA/Zein-DOX NPs reduced heart toxicity with lower heart targeting efficiency (18.58%) than that of DOX solution (37.62%).

CONCLUSION

In this study, HA/Zein-DOX NPs represented an antitumour drug delivery system for DOX in clinical tumour therapy with improved bioavailability and decreased cardiotoxicity.

Synthesis and Physicochemical Characterization of Undecylenic Acid Grafted to Hyaluronan for Encapsulation of Antioxidants and Chemical Crosslinking

In this work, a new amphiphilic derivative made of 10-undecylenic acid grafted to hyaluronan was prepared by mixed anhydrides. The reaction conditions were optimized, and the effect of the molecular weight (Mw), reaction time, and the molar ratio of reagents was explored. Using this methodology, a degree of substitution up to 50% can be obtained. The viscosity of the conjugate can be controlled by varying the substitution degree. The physicochemical characterization of the modified hyaluronan was performed by infrared spectroscopy, Nuclear Magnetic Resonance, Size-Exclusion Chromatography combined with Multiangle Laser Light Scattering (SEC-MALLS), and rheology. The low proton motility and self-aggregation of the amphiphilic conjugate produced overestimation of the degree of substitution. Thus, a novel method using proton NMR was developed. Encapsulation of model hydrophobic guest molecules, coenzyme Q10, curcumin, and α-tocopherol into the micellar core was also investigated by solvent evaporation. HA-UDA amphiphiles were also shown to self-assemble into spherical nanostructures (about 300 nm) in water as established by dynamic light scattering. Furthermore, HA-UDA was crosslinked via radical polymerization mediated by ammonium persulphate (APS/TEMED). The cross-linking was also tested by photo-polymerization catalyzed by Irgacure 2959. The presence of the hydrophobic moiety decreases the swelling degree of the prepared hydrogels compared to methacrylated-HA. Here, we report a novel hybrid hyaluronan (HA) hydrogel system of physically encapsulated active compounds and chemical crosslinking for potential applications in drug delivery.

Synthesis, Formulation, and Characterization of Doxorubicin-Loaded Laponite/Oligomeric Hyaluronic Acid-Aminophenylboronic Acid Nanohybrids and Cytological Evaluation against MCF-7 Breast Cancer Cells

As a synthetic clay material, laponite RDS (LR) was investigated as an effective drug carrier as a result of the special nanodisk structure together with the negative-charged surface to achieve enhanced cellular uptake and targeted delivery. In this research work, the synthesized oligomeric hyaluronic acid-aminophenylboronic acid (oHA-APBA) was entangled onto LR nanodisks to fabricate a valid targeted platform for breast cancer therapy. Briefly, through the formation of amide bonds, 3-APBA was connected to the chain of oHA with a substituted ratio of 4.0 ± 0.2% to synthesize oHA-APBA copolymer. Thereafter, doxorubicin (DOX) was inserted into the interlayer space of LR by the way of the ion exchange process, followed by an assembly with oHA-APBA as a targeted protection layer. The satisfactory drug encapsulation efficiency (> 80%) and narrow size distribution were achieved. The in vitro drug release study demonstrated the release of DOX from DOX@LR/oHA-APBA was sustained and acid dependent. In addition, after fitting the drug cumulative release of DOX@LR/oHA-APBA under different pH conditions with several kinetic models, it was identified that drug release from DOX@LR/oHA-APBA nanohybrids at pH 5.0 was mainly dependent on both diffusion and ion exchange effects. However, under the condition of pH 7.4, the drug was most efficiently released by diffusion effect. Importantly, DOX@LR/oHA-APBA showed remarkable cellular uptake and intracellular drug distribution in MCF-7 cells, which were consistent with inhibitory ability against MCF-7 cells. Hence, the high DOX loading capacity and enhanced cellular tracking can enlighten LR/oHA-APBA as an effective drug delivery carrier for breast cancer therapy.