Fabrication of a magnetic nanocarrier for doxorubicin delivery based on hyperbranched polyglycerol and carboxymethyl cellulose: An investigation on the effect of borax cross-linker on pH-sensitivity

A new core-shell pH-responsive nanocarrier was prepared based on magnetic nanoparticle (MNP) core. Magnetic nanoparticles were first modified with hyperbranched polyglycerol as the first shell. Then the magnetic core was decorated with doxorubicin anticancer drug (DOX) and covered with PEGylated carboxymethylcellulose as the second shell. Borax was used to partially cross-link organic shells in order to evaluate drug loading content and pH-sensitivity. The structure of nanocarrier, organic shell loadings, magnetic responsibility, morphology, size, dispersibility, and drug loading content were investigated by IR, NMR, TG, VSM, XRD, DLS, HR-TEM and UV-Vis analyses. In vitro release investigations demonstrated that the use of borax as cross-linker between organic shells make the nanocarrier highly sensitive to pH so that more that 70% of DOX is released in acidic pH. A reverse pH-sensitivity was observed for the nanocarrier without borax cross-linker. The MTT assay determined that the nanocarrier exhibited excellent biocompatibility toward normal cells (HEK-293) and high toxicity against cancerous cells (HeLa). The nanocarrier also showed high hemocompatibility. Cellular uptake revealed high ability of nanocarrier toward HeLa cells comparable with free DOX. The results also suggested that low concentration of nanocarrier has a great potential for use as contrast agent in magnetic resonance imaging (MRI).

Synthesis of nanomedicine hydrogel microcapsules by droplet microfluidic process and their pH and temperature dependent release

Chitosan and alginate hydrogels are attractive because they are highly biocompatible and suitable for developing nanomedicine microcapsules. Here we fabricated a polydimethylsiloxane-based droplet microfluidic reactor to synthesize nanomedicine hydrogel microcapsules using Au@CoFeB-Rg3 as a nanomedicine model and a mixture of sodium alginate and PEG-g-chitosan crosslinked by genipin as a hydrogel model. The release kinetics of nanomedicines from the hydrogel were evaluated by simulating the pH and temperature of the digestive tract during drug transport and those of the target pathological cell microenvironment. Their pH and temperature-dependent release kinetics were studied by measuring the mass loss of small pieces of thin films formed by the nanomedicine-encapsulating hydrogels in buffers of pH 1.2, 7.4, and 5.5, which replicate the pH of the stomach, gut and blood, and cancer microenvironment, respectively, at 20 °C and 37 °C, corresponding to the storage temperature of hydrogels before use and normal body temperature. Interestingly, nanomedicine-encapsulating hydrogels can undergo rapid decomposition at pH 5.5 and are relatively stable at pH 7.4 at 37 °C, which are desirable qualities for drug delivery, controlled release, and residue elimination after achieving target effects. These results indicate that the designed nanomedicine hydrogel microcapsule system is suitable for oral administration.

Topical Delivery of Rapamycin by Means of Microenvironment-Sensitive Core-Multi-Shell Nanocarriers: Assessment of Anti-Inflammatory Activity in an ex vivo Skin/T Cell Co-Culture Model

Introduction

Rapamycin (Rapa) is an immunosuppressive macrolide that inhibits the mechanistic target of rapamycin (mTOR) activity. Thanks to its anti-proliferative effects towards different cell types, including keratinocytes and T cells, Rapa shows promise in the treatment of skin diseases characterized by cell hyperproliferation. However, Rapa skin penetration is limited due to its lipophilic nature (log P = 4.3) and high molecular weight (MW = 914 g/mol). In previous studies, new microenvironment-sensitive core multishell (CMS) nanocarriers capable of sensing the redox state of inflamed skin were developed as more efficient and selective vehicles for macrolide delivery to inflamed skin.

Methods

In this study, we tested such redox-sensitive CMS nanocarriers using an inflammatory skin model based on human skin explants co-cultured with Jurkat T cells. Serine protease (SP) was applied on skin surface to induce skin barrier impairment and oxidative stress, whereas phytohaemagglutinin (PHA), IL-17A, and IL-22 were used to activate Jurkat cells. Activation markers, such as CD45 and CD69, phosphorylated ribosomal protein S6 (pRP-S6), and IL-2 release were monitored in activated T cells, whereas pro-inflammatory cytokines were measured in skin extracts and culture medium.

Results

We found that alteration of skin barrier proteins corneodesmosin (CDSN), occludin (Occl), and zonula occludens-1 (ZO-1) as well as oxidation-induced decrease of free thiol groups occurred upon SP-treatment. All Rapa formulations exerted inhibitory effects on T cells after penetration across ex vivo skin. No effects on skin inflammatory markers were detected. The superiority of the oxidative-sensitive CMS nanocarriers over the other formulations was observed with regard to drug delivery as well as downregulation of IL-2 release.

Conclusion

Overall, our results demonstrate that nanocarriers addressing features of diseased skin are promising approaches to improve the topical delivery of macrolide drugs.

Plausible role of chitosan in drug and gene delivery against resistant breast cancer cells

Breast cancer is the highest global spread of invasive cancer in women. While significant progress has been made in breast cancer, diagnostic and therapeutic effective prevention and treatment options remain scarce. Concerning chitosan-based chemotherapeutic therapies, the studies reported cell migration resistance, improved drug absorption, membrane interaction and permeability, immune stimulating behavior, and extended in-vitro drug release. However, chitosan has been practically restricted mostly to unmodified forms. Targeted distribution is ensured by chitosan-based ligand conjugated carrier systems in conjunction with active moieties such as DNA, RNA, proteins, and therapeutic agents. The purpose of this context is to emphasize the efficient drug delivery to breast cancer cell lines using chitosan. Chitosan also exhibited excellent capabilities in gene packaging. For the interaction of bioactive molecules and the regulation of the drug release profile, chemical modification of chitosan is beneficial. This article discusses the various chitosan-based ligand conjugated carrier systems. From the studies reviewed it can be concluded that chitosan derivatives are promising materials for targeted and non-viral gene delivery in treatment of breast cancer.

Development of Polymer-Assisted Nanoparticles and Nanogels for Cancer Therapy: An Update

With cancer remaining as one of the main causes of deaths worldwide, many studies are undergoing the effort to look for a novel and potent anticancer drug. Nanoparticles (NPs) are one of the rising fields in research for anticancer drug development. One of the key advantages of using NPs for cancer therapy is its high flexibility for modification, hence additional properties can be added to the NPs in order to improve its anticancer action. Polymer has attracted considerable attention to be used as a material to enhance the bioactivity of the NPs. Nanogels, which are NPs cross-linked with hydrophilic polymer network have also exhibited benefits in anticancer application. The characteristics of these nanomaterials include non-toxic, environment-friendly, and variable physiochemical properties. Some other unique properties of polymers are also attributed by diverse methods of polymer synthesis. This then contributes to the unique properties of the nanodrugs. This review article provides an in-depth update on the development of polymer-assisted NPs and nanogels for cancer therapy. Topics such as the synthesis, usage, and properties of the nanomaterials are discussed along with their mechanisms and functions in anticancer application. The advantages and limitations are also discussed in this article.

ATP/Hyals dually responsive core-shell hyaluronan/chitosan-based drug nanocarrier for potential application in breast cancer therapy

The stability of self-assembled drug nanocarriers during blood circulation and the controlled intracellular drug delivery are two challenges in cancer therapy. In this paper, we constructed an adenosine triphosphate (ATP)/hyaluronidase(Hyals) dually responsive core-shell hyaluronan/chitosan-based drug nanocarrier for breast cancer therapy, using SNX-loaded 3-fluoro-4-carboxyphenylboronic acid-conjugated quaternary ammonium chitosan nanoparticles (SNX@HTCC-FPBA NPs) as the core and crosslinked polyethylene glycol-/methacrylate-modified hyaluronic acid (mHA-PEG) as the shell. The formed SNX@HTCC-FPBA/mHA-PEG NPs were stable against salt ion strength, pH values and human plasma mimicking the bloodstream, but ATP/Hyals dually sensitive with a drug delivery of 85% within 48 h in the mimicking intracellular environment of breast cancer cells. These nanoparticles showed a low hemolysis of less than 3%, a high resistance to bovine serum albumin adsorption of 0.06 mg/mg, and an efficient internalization by two breast cancer cell lines (MCF-7 and MDA-MB-453). The cell culture indicated that they were friendly to human skin fibroblasts, but presented a close IC₅₀ value to SNX for MCF-7 (0.14 μg mL^-1) and MDA-MB-453 (0.05 μg mL^-1) at 48 h, respectively. Thus, SNX@HTCC-FPBA/mHA-PEG NPs were potential drug nanocarriers for breast tumor therapy.

Advances in Multiple Stimuli-Responsive Drug-Delivery Systems for Cancer Therapy

Nanomedicines afford unique advantages in therapeutic intervention against tumors. However, conventional nanomedicines have failed to achieve the desired effect against cancers because of the presence of complicated physiological fluids and the tumor microenvironment. Stimuli-responsive drug-delivery systems have emerged as potential tools for advanced treatment of cancers. Versatile nano-carriers co-triggered by multiple stimuli in different levels of organisms (eg, extracorporeal, tumor tissue, cell, subcellular organelles) have aroused widespread interest because they can overcome sequential physiological and pathological barriers to deliver diverse therapeutic “payloads” to the desired targets. Furthermore, multiple stimuli-responsive drug-delivery systems (MSR-DDSs) offer a good platform for co-delivery of agents and reversing multidrug resistance. This review affords a comprehensive overview on the “landscape” of MSR-DDSs against tumors, highlights the design strategies of MSR-DDSs in recent years, discusses the putative advantage of oncotherapy or the obstacles that so far have hindered the clinical translation of MSR-DDSs.

Core-shell nanostructures: perspectives towards drug delivery applications

Nanosystems have shown encouraging outcomes and substantial progress in the areas of drug delivery and biomedical applications. However, the controlled and targeted delivery of drugs or genes can be limited due to their physicochemical and functional properties. In this regard, core-shell type nanoparticles are promising nanocarrier systems for controlled and targeted drug delivery applications. These functional nanoparticles are emerging as a particular class of nanosystems because of their unique advantages, including high surface area, and easy surface modification and functionalization. Such unique advantages can facilitate the use of core-shell nanoparticles for the selective mingling of two or more different functional properties in a single nanosystem to achieve the desired physicochemical properties that are essential for effective targeted drug delivery. Several types of core-shell nanoparticles, such as metallic, magnetic, silica-based, upconversion, and carbon-based core-shell nanoparticles, have been designed and developed for drug delivery applications. Keeping the scope, demand, and challenges in view, the present review explores state-of-the-art developments and advances in core-shell nanoparticle systems, the desired structure-property relationships, newly generated properties, the effects of parameter control, surface modification, and functionalization, and, last but not least, their promising applications in the fields of drug delivery, biomedical applications, and tissue engineering. This review also supports significant future research for developing multi-core and shell-based functional nanosystems to investigate nano-therapies that are needed for advanced, precise, and personalized healthcare systems.

pH-responsive polymeric nanoparticles with tunable sizes for targeted drug delivery

Novel nanoparticles for efficient drug delivery were designed and constructed using polymeric 2,3-dialdehyde cellulose (DAC). The drug DOX was encapsulated into nanoparticles and underwent thoroughly controlled release in acidic tumor microenvironments.

Synergetic estrogen receptor-targeting liposome nanocarriers with anti-phagocytic properties for enhanced tumor theranostics

A synergetic targeted liposomal system which functionalized with both a tumor identification ligand and an immune targeting ligand was constructed. It could recognize and bind ER-positive breast cancer tissues in a specific way and reduce the macrophage phagocytosis of the nanoparticles.

Disassembly and tumor-targeting drug delivery of reduction-responsive degradable block copolymer nanoassemblies

Review on recent strategies to synthesize novel disulfide-containing reductively-degradable block copolymers and their nanoassemblies as being classified with the number, position, and location of the disulfide linkages toward effective tumor-targeting intracellular drug delivery exhibiting enhanced release of encapsulated drugs.

Multifunctional luminescent immuno-magnetic nanoparticles: toward fast, efficient, cell-friendly capture and recovery of circulating tumor cells

Highly efficient isolation and recovery of viable circulating tumor cells (CTCs) from the blood of patients is an important precondition to address the current dilemma of insufficient CTC studies, and can promote the development of individualized antitumor therapies. Herein, a cell-friendly CTC isolation and recovery nanoplatform with luminescent labelling was established using a layer-by-layer (LbL) assembly technique and a stimulated cellular-release strategy. In particular, the anti-epithelial cell adhesion molecule (anti-EpCAM) antibody was introduced with a disulfide bond-containing linker for further bio-friendly recovery of the CTCs. Quantum dots (QDs) were deposited onto fast magnet-responsive Fe₃O₄ nanoparticles through a facile LbL assembly method to monitor the capture and recovery process in real time. The obtained PEGlyated immuno-magnetic nanospheres (PIMNs) can all be magnetically collected within 2 min. Capture efficiencies above 90% can be achieved from blood samples with 5-200 CTCs per mL after only 1-2 min incubation. Nearly all PIMNs on the surface of the CTCs were detached after 15 min of glutathione (GSH) treatment with the disappearance of QD signals. Recovered CTCs could be directly used for culture (cell viability, ∼98%), and their invasiveness and migration characteristics remained unchanged. Furthermore, the PIMNs were successfully applied to isolate CTCs in cancer patients' peripheral blood samples, and an average of 8.6 ± 5.8 CTCs per mL was detected. The results above suggested that PIMNs may serve as a powerful nanoplatform for CTC screening, isolation and recovery.